WorldWideScience

Sample records for burst host galaxies

  1. A Fast Radio Burst Host Galaxy

    CERN Document Server

    Keane, E F; Bhandari, S; Barr, E; Bhat, N D R; Burgay, M; Caleb, M; Flynn, C; Jameson, A; Kramer, M; Petroff, E; Possenti, A; van Straten, W; Bailes, M; Burke-Spolaor, S; Eatough, R P; Stappers, B W; Totani, T; Honma, M; Furusawa, H; Hattori, T; Morokuma, T; Niino, Y; Sugai, H; Terai, T; Tominaga, N; Yamasaki, S; Yasuda, N; Allen, R; Cooke, J; Jencson, J; Kasliwal, M M; Kaplan, D L; Tingay, S J; Williams, A; Wayth, R; Chandra, P; Perrodin, D; Berezina, M; Mickaliger, M; Bassa, C

    2016-01-01

    In recent years, millisecond duration radio signals originating from distant galaxies appear to have been discovered in the so-called Fast Radio Bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity which, in tandem with a redshift measurement, can be used for fundamental physical investigations. While every fast radio burst has a dispersion measurement, none before now have had a redshift measurement, due to the difficulty in pinpointing their celestial coordinates. Here we present the discovery of a fast radio burst and the identification of a fading radio transient lasting $\\sim 6$ days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be $z=0.492\\pm0.008$. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionised baryons in the intergalactic medium of $\\Omega_{\\mathrm{IGM}}=4.9 \\pm 1.3\\%$, in agreement with the expectation from WMAP, and i...

  2. Statistical Properties of Gamma-Ray Burst Host Galaxies

    Indian Academy of Sciences (India)

    Jie-Min Chen; Jin Zhang; Lan-Wei Jia; En-Wei Liang

    2014-09-01

    A statistical analysis of gamma-ray burst host galaxies is presented and a clear metallicity-stellar mass relation is found in our sample. A trend that a more massive host galaxy tends to have a higher star-formation rate is also found. No correlation is found between V and H. GRB host galaxies at a higher redshift also tend to have a higher star formation rate, however, even in the same redshift, the star formation rate may vary for three orders of magnitude.

  3. The host galaxy of a fast radio burst.

    Science.gov (United States)

    Keane, E F; Johnston, S; Bhandari, S; Barr, E; Bhat, N D R; Burgay, M; Caleb, M; Flynn, C; Jameson, A; Kramer, M; Petroff, E; Possenti, A; van Straten, W; Bailes, M; Burke-Spolaor, S; Eatough, R P; Stappers, B W; Totani, T; Honma, M; Furusawa, H; Hattori, T; Morokuma, T; Niino, Y; Sugai, H; Terai, T; Tominaga, N; Yamasaki, S; Yasuda, N; Allen, R; Cooke, J; Jencson, J; Kasliwal, M M; Kaplan, D L; Tingay, S J; Williams, A; Wayth, R; Chandra, P; Perrodin, D; Berezina, M; Mickaliger, M; Bassa, C

    2016-02-25

    In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts. PMID:26911781

  4. Keck Observations of 160 Gamma-Ray Burst Host Galaxies

    CERN Document Server

    Perley, Daniel A; Prochaska, Jason X

    2013-01-01

    We present a preliminary data release from our multi-year campaign at Keck Observatory to study the host galaxies of a large sample of Swift-era gamma-ray bursts via multi-color ground-based optical imaging and spectroscopy. With over 160 targets observed to date (and almost 100 host detections, most of which have not previously been reported in the literature) our effort represents the broadest GRB host survey to date. While targeting was heterogeneous, our observations span the known diversity of GRBs including short bursts, long bursts, spectrally soft GRBs (XRFs), ultra-energetic GRBs, X-ray faint GRBs, dark GRBs, SN-GRBs, and other sub-classes. We also present a preview of our database (currently available online via a convenient web interface) including a catalog of multi-color photometry, redshifts and line ID's. Final photometry and reduced imaging and spectra will be available in the near future.

  5. Radio Afterglows and Host Galaxies of Gamma-Ray Bursts

    CERN Document Server

    Li, Long-Biao; Huang, Yong-Feng; Wu, Xue-Feng; Kong, Si-Wei; Li, Di; Chang, Heon-Young; Choi, Chul-Sung

    2015-01-01

    Considering the contribution of the emission from the host galaxies of gamma-ray bursts (GRBs) to the radio afterglows, we investigate the effect of host galaxies on observations statistically. For the three types of events, e.g. low-luminosity, standard and high-luminosity GRBs, it is found that a tight correlation exists between the ratio of the radio flux (RRF) of host galaxy to the total radio peak emission and the observational frequency. Especially, toward lower frequencies, the contribution from the host increases significantly. The correlation can be used to get a useful estimate for the radio brightness of those host galaxies which only have very limited radio afterglow data. Using this prediction, we re-considered the theoretical radio afterglow light curves for four kinds of events, i.e. high-luminosity, low-luminosity, standard and failed GRBs, taking into account the contribution from the host galaxies and aiming at exploring the detectability of these events by the Five-hundred-meter Aperture Sp...

  6. A Morphological Study of Gamma-Ray Burst Host Galaxies

    CERN Document Server

    Wainwright, C; Penprase, B E

    2005-01-01

    We present a comprehensive study of the morphological properties of 42 gamma-ray burst (GRB) host galaxies imaged with the Hubble Space Telescope in the optical band. The purpose of this study is to understand the relation of GRBs to their macro-environments, and to compare the GRB-selected galaxies to other high redshift samples. We perform both qualitative and quantitative analyses by categorizing the galaxies according to their visual properties, and by examining their surface brightness profiles. We find that all of the galaxies have approximately exponential profiles, indicative of galactic disks, and have a median scale length of about 1.7 kpc. Inspection of the visual morphologies reveals a high fraction of merging and interacting systems, with \\~30% showing clear signs of interaction, and an additional ~30% exhibiting irregular and asymmetric structure which may be the result of recent mergers; these fractions are independent of redshift and galaxy luminosity. On the other hand, the three GRB host gal...

  7. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey - I. Sample Selection and Redshift Distribution

    OpenAIRE

    Perley, D. A.; Krühler, T.; Schulze, S.; De Ugarte Postigo, A.; Hjorth, J.; Berger, E.; Cenko, S. B.; Chary, R.; Cucchiara, A.; Ellis, R; Fong, W.; Fynbo, J. P. U.; J. Gorosabel; Greiner, J.; Jakobsson, P.

    2015-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey ("SHOALS"), a multi-observatory high-redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst (GRB) hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host galaxy obs...

  8. TOUGH: Observational aspects of gamma-ray burst host galaxies

    CERN Document Server

    Hjorth, Jens; Jaunsen, Andreas O; Levan, Andrew J; Milvang-Jensen, Bo; Watson, Darach; Gorosabel, Javier; Fynbo, Johan P U; Michałowski, Michał J; Tanvir, Nial R; Jakobsson, Páll; Møller, Palle; Schulze, Steve; Krühler, Thomas

    2012-01-01

    GRB-selected galaxies are broadly known to be faint, blue, young, star-forming dwarf galaxies. This insight, however, is based in part on heterogeneous samples of optically selected, lower-redshift galaxies. To study the statistical properties of GRB-selected galaxies we here introduce The Optically Unbiased GRB Host (TOUGH) complete sample of 69 X-ray selected Swift GRB host galaxies spanning the redshift range 0.03-6.30 and summarise the first results of a large observational survey of these galaxies.

  9. The Connection among Gamma-ray Burst Host-Galaxies, BL Lacs and Quasars

    OpenAIRE

    Rej, A.

    1999-01-01

    A possible connection among host-galaxies of gamma-ray bursts, BL Lacs and quasars is analysed. It is believed that the gamma-ray bursts, which do not show radio or infrared emission, occur in faint blue dwarf galaxies, that are seen around radio-quiet quasars, which lie in clusters. The GRB counterparts, which show radio emission, may be associated with more evolved starbursting environments, and arise from red galaxies, that are observed around some radio-loud quasars lying in richer cluste...

  10. Demographics of the Galaxies Hosting Short-duration Gamma-Ray Bursts

    CERN Document Server

    Fong, Wen-fai; Chornock, Ryan; Margutti, Raffaella; Levan, Andrew J; Tanvir, Nial R; Tunnicliffe, Rachel L; Czekala, Ian; Fox, Derek B; Perley, Daniel A; Cenko, S Bradley; Zauderer, B Ashley; Laskar, Tanmoy; Persson, S Eric; Monson, Andrew J; Kelson, Daniel D; Birk, Christoph; Murphy, David; Servillat, Mathieu; Anglada, Guillem

    2013-01-01

    We present observations of the afterglows and host galaxies of three short-duration gamma-ray bursts (GRBs): 100625A, 101219A and 110112A. We find that GRB 100625A occurred in a z=0.452 early-type galaxy with a stellar mass of 4.6e9 M_Sun and a stellar population age of 0.7 Gyr, and GRB 101219A originated in a star-forming galaxy at z=0.718 with a stellar mass of 1.4e9 M_Sun, a star formation rate of 16 M_Sun yr^-1, and a stellar population age of 50 Myr. We also report the discovery of the optical afterglow of GRB 110112A, which lacks a coincident host galaxy to i>26 mag and we cannot conclusively identify any field galaxy as a possible host. The bursts have inferred circumburst densities of ~1e-4-1 cm^-3, and isotropic-equivalent gamma-ray and kinetic energies of 1e50-1e51 erg. These events highlight the diversity of galaxies that host short GRBs. To quantify this diversity, we use the sample of 36 Swift short GRBs with robust associations to an environment (~1/2 of 68 short bursts detected by Swift to May ...

  11. Host Galaxies of Gamma-Ray Bursts and their Cosmological Evolution

    CERN Document Server

    Courty, S; Gudmundsson, E H

    2004-01-01

    We use numerical simulations of large scale structure formation to explore the cosmological properties of Gamma-Ray Burst (GRB) host galaxies. Among the different sub-populations found in the simulations, we identify the host galaxies as the most efficient star-forming objects, i.e. galaxies with high specific star formation rates. We find that the host candidates are low-mass, young galaxies with low to moderate star formation rate. These properties are consistent with those observed in GRB hosts, most of which are sub-luminous, blue galaxies. Assuming that host candidates are galaxies with high star formation rates would have given conclusions inconsistent with the observations. The specific star formation rate, given a galaxy mass, is shown to increase as the redshift increases. The low mass of the putative hosts makes them difficult to detect with present day telescopes and the probability density function of the specific star formation rate is predicted to change depending on whether or not these galaxie...

  12. The Galaxy Hosts And Large-Scale Environments of Short-Hard Gamma-Ray Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Prochaska, Jason X.; Bloom, J.S.; Chen, H.-W.; Foley, R.J.; Perley, D.A.; Ramirez-Ruiz, E.; Granot, J.; Lee, W.H.; Pooley, D.; Alatalo, K.; Hurley, K.; Cooper, M.C.; Dupree, A.K.; Gerke, B.F.; Hansen, B.M.S.; Kalirai, J.S.; Newman, J.A.; Rich, R.M.; Richer, H.; Stanford, S.A.; Stern, D.; /Lick Observ. /UC, Berkeley, Astron. Dept. /Chicago U.,

    2005-10-07

    The rapid succession of discovery of short-duration hard-spectrum GRBs has led to unprecedented insights into the energetics of the explosion and nature of the progenitors. Yet short of the detection of a smoking gun, like a burst of coincident gravitational radiation or a Li-Paczynski mini-supernova, it is unlikely that a definitive claim can be made for the progenitors. As was the case with long-duration soft-spectrum GRBs, however, the expectation is that a systematic study of the hosts and the locations of short GRBs could begin to yield fundamental clues about their nature. We present the first aggregate study of the host galaxies of short-duration hard-spectrum GRBs. In particular, we present the Gemini-North and Keck discovery spectra of the galaxies that hosted three short GRBs and a moderate-resolution (R {approx} 6000) spectrum of a fourth host. We find that these short-hard GRBs originate in a variety of low-redshift (z < 1) environments that differ substantially from those of long-soft GRBs, both on individual galaxy scales and on galaxy-cluster scales. Specifically, three of the bursts are found to be associated with old and massive galaxies with no current (< 0.1M{sub {circle_dot}} yr{sup -1}) or recent star formation. Two of these galaxies are located within a cluster environment. These observations support an origin from the merger of compact stellar remnants, such as double neutron stars of a neutron star-black hole binary. The fourth event, in contrast, occurred within a dwarf galaxy with a star formation rate exceeding 0.5 M{sub {circle_dot}} yr{sup -1}. Therefore, it appears that like supernovae of Type Ia, the progenitors of short-hard bursts are created in all galaxy types, suggesting a corresponding class with a wide distribution of delay times between formation and explosion.

  13. A Search for Host Galaxies of 24 Gamma-Ray Bursts

    CERN Document Server

    Ovaldsen, J E; Fynbo, J P U; Hjorth, J; Thoene, C C; Féron, C; Xu, D; Selj, J H; Teuber, J

    2007-01-01

    We report the results from observations of 24 gamma ray burst (GRB) fields from 2005 and 2006 undertaken at the Danish 1.54m telescope at ESO/La Silla. Photometry and positions for two previously unpublished host galaxy candidates (GRBs 050915 and 051021) are presented, as well as for eight other detected objects which are either known GRB hosts or candidate hosts. The candidates are suitable for spectroscopic follow-up in order to have their redshifts and other physical characteristics determined. In the cases where no likely host candidate is detected inside the refined Swift XRT error circle we are still able to put interesting and rather deep limits on the host magnitude. Based on our detections and upper limits we have performed simulations which suggest that the host galaxies are drawn from a fainter sample than previous (i.e. pre-Swift) studies.

  14. The Dust Extinction Curves of Gamma-Ray Burst Host Galaxies

    CERN Document Server

    Schady, P; Page, M J; Krühler, T; Greiner, J; Oates, S R; De Pasquale, M; Nardini, M; Roming, P W A; Rossi, A; Still, M

    2011-01-01

    The composition and amount of interstellar dust within gamma-ray burst (GRB) host galaxies is of key importance when addressing selection effects in the GRB redshift distribution, and when studying the properties of their host galaxies. As well as the implications for GRB research, probing the dust within the high-z hosts of GRBs also contributes to our understanding of the conditions of the interstellar medium and star-formation in the distant Universe. Nevertheless, the physical properties of dust within GRB host galaxies continues to be a highly contended issue. In this paper we explore the mean extinction properties of dust within the host galaxies of a sample of 17 GRBs with total host galaxy visual extinction Av=0.4), covering a redshift range z=0.7-3.1. We find the average host extinction curve to have an ultraviolet slope comparable to that of the LMC, but with little evidence of a 2175Angs dust extinction feature as observed along Milky Way and LMC sightlines. We cannot at present rule out the presen...

  15. The submillimetre properties of gamma-ray burst host galaxies

    NARCIS (Netherlands)

    N.R. Tanvir; V.E. Barnard; A.W. Blain; A.S. Fruchter; C. Kouveliotou; P. Natarajan; E. Ramirez-Ruiz; E. Rol; I.A. Smith; R.P.J. Tilanus; R.A.M.J. Wijers

    2004-01-01

    Long-duration gamma-ray bursts (GRBs) accompany the deaths of some massive stars and hence, because massive stars are short-lived, are a tracer of star formation activity. Given that GRBs are bright enough to be seen to very high redshifts and detected even in dusty environments, they should therefo

  16. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey. I. Sample Selection and Redshift Distribution

    Science.gov (United States)

    Perley, D. A.; Krühler, T.; Schulze, S.; de Ugarte Postigo, A.; Hjorth, J.; Berger, E.; Cenko, S. B.; Chary, R.; Cucchiara, A.; Ellis, R.; Fong, W.; Fynbo, J. P. U.; Gorosabel, J.; Greiner, J.; Jakobsson, P.; Kim, S.; Laskar, T.; Levan, A. J.; Michałowski, M. J.; Milvang-Jensen, B.; Tanvir, N. R.; Thöne, C. C.; Wiersema, K.

    2016-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey (“SHOALS”), a multi-observatory high-redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst (GRB) hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host galaxy observational program, consisting of deep Spitzer/IRAC imaging of every field supplemented by similarly deep, multicolor optical/near-IR photometry, plus spectroscopy of events without preexisting redshifts. Our optimized selection cuts combined with host galaxy follow-up have so far enabled redshift measurements for 110 targets (92%) and placed upper limits on all but one of the remainder. About 20% of GRBs in the sample are heavily dust obscured, and at most 2% originate from z\\gt 5.5. Using this sample, we estimate the redshift-dependent GRB rate density, showing it to peak at z∼ 2.5 and fall by at least an order of magnitude toward low (z = 0) redshift, while declining more gradually toward high (z∼ 7) redshift. This behavior is consistent with a progenitor whose formation efficiency varies modestly over cosmic history. Our survey will permit the most detailed examination to date of the connection between the GRB host population and general star-forming galaxies, directly measure evolution in the host population over cosmic time and discern its causes, and provide new constraints on the fraction of cosmic star formation occurring in undetectable galaxies at all redshifts.

  17. The Swift Gamma-Ray Burst Host Galaxy Legacy Survey - I. Sample Selection and Redshift Distribution

    CERN Document Server

    Perley, D A; Schulze, S; Postigo, A de Ugarte; Hjorth, J; Berger, E; Cenko, S B; Chary, R; Cucchiara, A; Ellis, R; Fong, W; Fynbo, J P U; Gorosabel, J; Greiner, J; Jakobsson, P; Laskar, T; Levan, A J; Michałowski, M J; Milvang-Jensen, B; Tanvir, N R; Thöne, C C; Wiersema, K

    2016-01-01

    We introduce the Swift Gamma-Ray Burst Host Galaxy Legacy Survey ("SHOALS"), a multi-observatory high-redshift galaxy survey targeting the largest unbiased sample of long-duration gamma-ray burst hosts yet assembled (119 in total). We describe the motivations of the survey and the development of our selection criteria, including an assessment of the impact of various observability metrics on the success rate of afterglow-based redshift measurement. We briefly outline our host-galaxy observational program, consisting of deep Spitzer/IRAC imaging of every field supplemented by similarly-deep, multi-color optical/NIR photometry, plus spectroscopy of events without pre-existing redshifts. Our optimized selection cuts combined with host-galaxy follow-up have so far enabled redshift measurements for 110 targets (92%) and placed upper limits on all but one of the remainder. About 20% of GRBs in the sample are heavily dust-obscured, and at most 2% originate from z>5.5. Using this sample we estimate the redshift-depen...

  18. Probing dust-obscured star formation in the most massive Gamma-Ray Burst host galaxies

    CERN Document Server

    Greiner, Jochen; Klose, Sylvio; Hunt, Leslie K; Gentile, Gianfranco; Kamphuis, Peter; Herrero-Illana, Ruben; Wieringa, Mark; Krühler, Thomas; Schady, Patricia; Elliott, Jonathan; Graham, John F; Ibar, Eduardo; Knust, Fabian; Guelbenzu, Ana Nicuesa; Palazzi, Eliana; Rossi, Andrea; Savaglio, Sandra

    2016-01-01

    Due to their relation to massive stars, long-duration gamma-ray bursts (GRBs) allow pinpointing star formation in galaxies independently of redshift, dust obscuration, or galaxy mass/size, thus providing a unique tool to investigate the star-formation history over cosmic time. About half of the optical afterglows of long-duration GRBs are missed due to dust extinction, and are primarily located in the most massive GRB hosts. In order to understand this bias it is important to investigate the amount of obscured star-formation in these GRB host galaxies. Radio emission of galaxies correlates with star-formation, but does not suffer extinction as do the optical star-formation estimators. We selected 11 GRB host galaxies with either large stellar mass or large UV-/optical-based star-formation rates (SFRs) and obtained radio observations of these with the Australia Telescope Compact Array and the Karl Jansky Very Large Array. Despite intentionally selecting GRB hosts with expected high SFRs, we do not find any sta...

  19. Detection of three Gamma-Ray Burst host galaxies at $z\\sim6$

    CERN Document Server

    McGuire, J T W; Levan, A J; Trenti, M; Stanway, E R; Shull, J M; Wiersema, K; Perley, D A; Starling, R L C; Bremer, M; Stocke, J T; Hjorth, J; Rhoads, J E; Levesque, E M; Robertson, B; Fynbo, J P U; Ellis, R S; Fruchter, A S; Perna, R

    2015-01-01

    Gamma-ray bursts allow us to pinpoint and study star-forming galaxies in the early universe, thanks to their immense luminosities and association with deaths of massive stars. We present {\\em Hubble Space Telescope} Wide Field Camera 3 detections of three {\\em Swift} GRBs lying at redshifts $z = 5.913$ (GRB 130606A), $z = 6.295$ (GRB 050904), and $z = 6.327$ (GRB 140515A) in the F140W (wide-$JH$ band, $\\lambda_{\\rm{obs}}\\sim1.4\\,\\mu m$) filter. The hosts have magnitudes (corrected for Galactic extinction) of $m_{\\rm{\\lambda_{obs},AB}}= 26.26^{+0.12}_{-0.14}, 27.63^{+0.16}_{-0.18},$ and $28.23^{+0.24}_{-0.30}$ respectively. In all three cases the probability of chance coincidence of lower redshift galaxies is $\\lesssim1.5\\%$, indicating that the detected galaxies are most likely the GRB hosts. These are the first detections of high redshift ($z > 5$) GRB host galaxies in emission. The galaxies have luminosities in the range $0.1-0.7\\,L^{*}_{z=6}$ (with $M_{1600}^{*}=-20.95\\pm0.12$), along with half-light radii...

  20. Another short-burst host galaxy with an optically obscured high star formation rate: The case of GRB 071227

    International Nuclear Information System (INIS)

    We report on radio continuum observations of the host galaxy of the short gamma-ray burst 071227 (z = 0.381) with the Australia Telescope Compact Array. We detect the galaxy in the 5.5 GHz band with an integrated flux density of F ν = 43 ± 11 μJy, corresponding to an unobscured star-formation rate of about 24 M ☉ yr–1, 40 times higher than what was found from optical emission lines. Among the ∼30 well-identified and studied host galaxies of short bursts this is the third case where the host is found to undergo an episode of intense star formation. This suggests that a fraction of all short-burst progenitors hosted in star-forming galaxies could be physically related to recent star formation activity, implying a relatively short merger timescale.

  1. DEMOGRAPHICS OF THE GALAXIES HOSTING SHORT-DURATION GAMMA-RAY BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Fong, W.; Berger, E.; Chornock, R.; Margutti, R.; Czekala, I.; Zauderer, B. A.; Laskar, T.; Servillat, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Levan, A. J.; Tunnicliffe, R. L. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Fox, D. B. [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Perley, D. A. [Cahill Center for Astronomy and Astrophysics, Room 232, California Institute of Technology, Pasadena, CA 91125 (United States); Cenko, S. B. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Persson, S. E.; Monson, A. J.; Kelson, D. D.; Birk, C.; Murphy, D. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Anglada, G. [Institut fuer Astrophysik, Friedrich-Hund-Platz 1, Universitaet Goettingen, D-37077 Goettingen (Germany)

    2013-05-20

    We present observations of the afterglows and host galaxies of three short-duration gamma-ray bursts (GRBs): 100625A, 101219A, and 110112A. We find that GRB 100625A occurred in a z = 0.452 early-type galaxy with a stellar mass of Almost-Equal-To 4.6 Multiplication-Sign 10{sup 9} M{sub Sun} and a stellar population age of Almost-Equal-To 0.7 Gyr, and GRB 101219A originated in a star-forming galaxy at z = 0.718 with a stellar mass of Almost-Equal-To 1.4 Multiplication-Sign 10{sup 9} M{sub Sun }, a star formation rate of Almost-Equal-To 16 M{sub Sun} yr{sup -1}, and a stellar population age of Almost-Equal-To 50 Myr. We also report the discovery of the optical afterglow of GRB 110112A, which lacks a coincident host galaxy to i {approx}> 26 mag, and we cannot conclusively identify any field galaxy as a possible host. From afterglow modeling, the bursts have inferred circumburst densities of Almost-Equal-To 10{sup -4}-1 cm{sup -3} and isotropic-equivalent gamma-ray and kinetic energies of Almost-Equal-To 10{sup 50}-10{sup 51} erg. These three events highlight the diversity of galactic environments that host short GRBs. To quantify this diversity, we use the sample of 36 Swift short GRBs with robust associations to an environment ({approx}1/2 of 68 short bursts detected by Swift to 2012 May) and classify bursts originating from four types of environments: late-type ( Almost-Equal-To 50%), early-type ( Almost-Equal-To 15%), inconclusive ( Almost-Equal-To 20%), and ''host-less'' (lacking a coincident host galaxy to limits of {approx}> 26 mag; Almost-Equal-To 15%). To find likely ranges for the true late- and early-type fractions, we assign each of the host-less bursts to either the late- or early-type category using probabilistic arguments and consider the scenario that all hosts in the inconclusive category are early-type galaxies to set an upper bound on the early-type fraction. We calculate most likely ranges for the late- and early-type fractions of

  2. The metallicity and dust content of a redshift 5 gamma-ray burst host galaxy

    International Nuclear Information System (INIS)

    Observations of the afterglows of long gamma-ray bursts (GRBs) allow the study of star-forming galaxies across most of cosmic history. Here we present observations of GRB 111008A, from which we can measure metallicity, chemical abundance patterns, dust-to-metals ratio (DTM), and extinction of the GRB host galaxy at z = 5.0. The host absorption system is a damped Lyα absorber with a very large neutral hydrogen column density of log N(H I)/cm−2=22.30±0.06 and a metallicity of [S/H] = –1.70 ± 0.10. It is the highest-redshift GRB with such a precise metallicity measurement. The presence of fine-structure lines confirms the z = 5.0 system as the GRB host galaxy and makes this the highest redshift where Fe II fine-structure lines have been detected. The afterglow is mildly reddened with AV = 0.11 ± 0.04 mag, and the host galaxy has a DTM that is consistent with being equal to or lower than typical values in the Local Group.

  3. The metallicity and dust content of a redshift 5 gamma-ray burst host galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Sparre, M.; Krühler, T.; Fynbo, J. P. U.; Watson, D. J.; De Ugarte Postigo, A.; Hjorth, J.; Malesani, D. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Hartoog, O. E.; Kaper, L. [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam (Netherlands); Wiersema, K. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); D' Elia, V. [INAF/Rome Astronomical Observatory, via Frascati 33, I-00040 Monteporzio Catone (Roma) (Italy); Zafar, T. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Afonso, P. M. J. [Physics and Astronomy Department, American River College, 4700 College Oak Drive, Sacramento, CA 95841 (United States); Covino, S. [INAF, Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate (Italy); Flores, H. [Laboratoire GEPI, Observatoire de Paris, CNRS-UMR8111, Universite Paris Diderot 5 place Jules Janssen, F-92195 Meudon (France); Goldoni, P. [APC, Astroparticule et Cosmologie, Universite Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, 10, Rue Alice Domon et Léonie Duquet, F-75205 Paris, Cedex 13 (France); Greiner, J. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, D-85748 Garching (Germany); Jakobsson, P. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, IS-107 Reykjavik (Iceland); Klose, S. [Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg (Germany); Levan, A. J., E-mail: sparre@dark-cosmology.dk [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); and others

    2014-04-20

    Observations of the afterglows of long gamma-ray bursts (GRBs) allow the study of star-forming galaxies across most of cosmic history. Here we present observations of GRB 111008A, from which we can measure metallicity, chemical abundance patterns, dust-to-metals ratio (DTM), and extinction of the GRB host galaxy at z = 5.0. The host absorption system is a damped Lyα absorber with a very large neutral hydrogen column density of log N(H I)/cm{sup −2}=22.30±0.06 and a metallicity of [S/H] = –1.70 ± 0.10. It is the highest-redshift GRB with such a precise metallicity measurement. The presence of fine-structure lines confirms the z = 5.0 system as the GRB host galaxy and makes this the highest redshift where Fe II fine-structure lines have been detected. The afterglow is mildly reddened with A{sub V} = 0.11 ± 0.04 mag, and the host galaxy has a DTM that is consistent with being equal to or lower than typical values in the Local Group.

  4. The metallicity and dust content of a redshift 5 gamma-ray burst host galaxy

    DEFF Research Database (Denmark)

    Sparre, M.; Hartoog, O. E.; Krühler, T.;

    2014-01-01

    Observations of the afterglows of long gamma-ray bursts (GRBs) allow the study of star-forming galaxies across most of cosmic history. Here we present observations of GRB 111008A from which we can measure metallicity, chemical abundance patterns, dust-to-metals ratio and extinction of the GRB host...... galaxy at z=5.0. The host absorption system is a damped Lyman-alpha absorber (DLA) with a very large neutral hydrogen column density of log N(HI)/cm^(-2) = 22.30 +/- 0.06, and a metallicity of [S/H]= -1.70 +/- 0.10. It is the highest redshift GRB with such a precise metallicity measurement. The presence...... of fine-structure lines confirms the z=5.0 system as the GRB host galaxy, and makes this the highest redshift where Fe II fine-structure lines have been detected. The afterglow is mildly reddened with A_V = 0.11 +/- 0.04 mag, and the host galaxy has a dust-to-metals ratio which is consistent with being...

  5. The Spitzer/Swift Gamma-Ray Burst Host Galaxy Legacy Survey

    Science.gov (United States)

    Perley, Daniel; Berger, Edo; Butler, Nathaniel; Cenko, S. Bradley; Chary, Ranga-Ram; Cucchiara, Antonino; Ellis, Richard; Fong, Wen-fai; Fruchter, Andrew; Fynbo, Johan; Gehrels, Neil; Graham, John; Greiner, Jochen; Hjorth, Jens; Hunt, Leslie; Jakobsson, Pall; Kruehler, Thomas; Laskar, Tanmoy; Le Floc'h, Emerich; Levan, Andrew; Levesque, Emily; Littlejohns, Owen; Malesani, Daniele; Michalowski, Michal; Milvang-Jensen, Bo; Prochaska, J. Xavier; Salvaterra, Ruben; Schulze, Steve; Schady, Patricia; Tanvir, Nial; de Ugarte Postigo, Antonio; Vergani, Susanna; Watson, Darach

    2016-08-01

    Long-duration gamma-ray bursts act as beacons to the sites of star-formation in the distant universe. GRBs reveal galaxies too faint and star-forming regions too dusty to characterize in detail using any other method, and provide a powerful independent constraint on the evolution of the cosmic star-formation rate density at high-redshift. However, a full understanding of the GRB phenomenon and its relation to cosmic star-formation requires connecting the observations obtained from GRBs to the properties of the galaxies hosting them. The large majority of GRBs originate at moderate to high redshift (z>1) and Spitzer has proven crucial for understanding the host population, given its unique ability to observe the rest-frame NIR and its unrivaled sensitivity and efficiency. We propose to complete a comprehensive public legacy survey of the Swift GRB host population to build on our earlier successes and push beyond the statistical limits of previous, smaller efforts. Our survey will enable a diverse range of GRB and galaxy science including: (1) to quantitatively and robustly map the connection between GRBs and cosmic star-formation to constrain the GRB progenitor and calibrate GRB rate-based measurements of the high-z cosmic star-formation rate; (2) to constrain the luminosity function of star-forming galaxies at the faint end and at high redshift; (3) to understand how the ISM properties seen in absorption in high-redshift galaxies unveiled by GRBs - metallicity, dust column, dust properties - connect to global properties of the host galaxies such as mass and age. Building on a decade of experience at both observatories, our observations will create an enduring joint Swift-Spitzer legacy sample - providing the definitive resource with which to examine all aspects of the GRB/galaxy connection for years to come and setting the stage for intensive JWST follow-up of the most interesting sources from our sample.

  6. Physical conditions and element abundances in supernova and γ-ray burst host galaxies at different redshifts

    Science.gov (United States)

    Contini, M.

    2016-08-01

    We compare the physical parameters and the relative abundances calculated throughout supernova (SN) and γ-ray burst (GRB) host galaxies using a detailed modelling of the spectra. The coupled effect of shocks and radiation from the starburst within the host galaxy is considered. We have found the following. (i) Shock velocities are lower in long-period GRBs (LGRBs) than in SN host galaxies. (ii) O/H relative abundances in SN hosts are scattered within a range 8.0 105 K). The values of T* in LGRB hosts are ˜3-8 × 104 K. (iv) The Hα absolute flux calculated from the emitting clouds of a few SN hosts at 0.1 analysis suggests that the SN-host symbiosis is stronger than for GRBs in terms of activity. The physical and chemical conditions in the GRB host galaxies are similar to those in starburst galaxies within a large redshift range.

  7. Probing dust-obscured star formation in the most massive gamma-ray burst host galaxies

    Science.gov (United States)

    Greiner, Jochen; Michałowski, Michał J.; Klose, Sylvio; Hunt, Leslie K.; Gentile, Gianfranco; Kamphuis, Peter; Herrero-Illana, Rubén; Wieringa, Mark; Krühler, Thomas; Schady, Patricia; Elliott, Jonathan; Graham, John F.; Ibar, Eduardo; Knust, Fabian; Nicuesa Guelbenzu, Ana; Palazzi, Eliana; Rossi, Andrea; Savaglio, Sandra

    2016-08-01

    Context. As a result of their relation to massive stars, long-duration gamma-ray bursts (GRBs) allow the pinpointing of star formation in galaxies independent of redshift, dust obscuration, or galaxy mass/size, thus providing a unique tool to investigate star formation history over cosmic time. Aims: About half of the optical afterglows of long-duration GRBs are missed owing to dust extinction and are primarily located in the most massive GRB hosts. It is important to investigate the amount of obscured star formation in these GRB host galaxies to understand this bias. Methods: Radio emission of galaxies correlates with star formation, but does not suffer extinction as do the optical star formation estimators. We selected 11 GRB host galaxies with either large stellar mass or large UV-based and optical-based star formation rates (SFRs) and obtained radio observations of these with the Australia Telescope Compact Array and the Karl Jansky Very Large Array. Results: Despite intentionally selecting GRB hosts with expected high SFRs, we do not find any radio emission related to star formation in any of our targets. Our upper limit for GRB 100621A implies that the earlier reported radio detection was due to afterglow emission. We detect radio emission from the position of GRB 020819B, but argue that it is in large part, if not completely, due to afterglow contamination. Conclusions: Half of our sample has radio-derived SFR limits, which are only a factor 2-3 above the optically measured SFRs. This supports other recent studies that the majority of star formation in GRB hosts is not obscured by dust. Based on observations collected with ATCA under ID C2718, and at VLA under ID 13B-017.

  8. Origins of short gamma-ray bursts deduced from offsets in their host galaxies revisited

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hong Cui; Shigehiro Nagataki; Junichi Aoi; Ren-Xin Xu

    2012-01-01

    The spatial distribution of short Gamma-ray bursts (GRBs) in their host galaxies provides us with an opportunity to investigate their origins.Based on the currently observed distribution of short GRBs relative to their host galaxies,we obtain the fraction of the component that traces the mergers of binary compact objects and the one that traces star formation rate (such as massive stars) in early- and late-type host galaxies.From the analysis of projected offset distribution and only based on population synthesis and massive star models,we find that the fraction of massive stars is 0.37+0.42-0.37 with an error at the lσ level for a sample with 22 short GRBs in the literature.From these results,it is hard to accept that the origin of short GRBs with observed statistics is well described by current models using only the offset distribution.The uncertainties in observational localizations of short GRBs also strongly affect the resulting fraction.

  9. Constraining the Molecular Gas in the Environs of a z~8 Gamma Ray Burst Host Galaxy

    CERN Document Server

    Stanway, Elizabeth R; Tanvir, Nial R; Levan, Andrew J; Davies, Luke J M

    2010-01-01

    GRB 090423 is the most distant spectroscopically-confirmed source observed in the universe. Using observations at 37.5 GHz, we place constraints on molecular gas emission in the CO(3-2) line from its host galaxy and immediate environs. The source was not detected either in line emission or in the rest-frame 850 micron continuum, yielding an upper limit of S_{8mm}=9.3 milli-Jy and M(H_2)<4.3x10^9 M_sun (3 sigma), applying standard conversions. This implies that the host galaxy of GRB 090423 did not possess a large reservoir of warm molecular gas but was rather modest either in star formation rate or in mass. It suggests that this was not an extreme starburst, and hence that gamma ray bursts at high redshift trace relatively modest star formation rates, in keeping with the behaviour seen at lower redshifts. We do, however, identify a millimetre emission line source in the field of GRB 090423. Plausible interpretations include a CO(1-0) emitting galaxy at z=2.1, CO(2-1) at z=5.2 and CO(3-2) at z=8.3. Efforts ...

  10. Implications for the origin of short gamma-ray bursts from their observed positions around their host galaxies

    CERN Document Server

    Church, Ross P; Davies, Melvyn B; Tanvir, Nial

    2011-01-01

    We present the observed offsets of short-duration gamma-ray bursts (SGRBs) from their putative host galaxies and compare them to the expected distributions of merging compact object binaries, given the observed properties of the hosts. We find that for all but one burst in our sample the offsets are consistent with this model. For the case of bursts with massive elliptical host galaxies, the circular velocities of the hosts' haloes exceed the natal velocities of almost all our compact object binaries. Hence the extents of the predicted offset distributions for elliptical galaxies are determined largely by their spatial extents. In contrast, for spiral hosts the galactic rotation velocities are smaller than typical binary natal velocities and the predicted burst offset distributions are more extended than the galaxies. One SGRB, 060502B, apparently has a large radial offset that is inconsistent with an origin in a merging galactic compact binary. Although it is plausible that the host of GRB 060502B is mis-ide...

  11. Far-infrared observations of an unbiased sample of gamma-ray burst host galaxies

    CERN Document Server

    Kohn, Saul A; Bourne, Nathan; Baes, Maarten; Fritz, Jacopo; Cooray, Asantha; De Looze, Ilse; De Zotti, Gianfranco; Dannerbauer, Helmut; Dunne, Loretta; Dye, Simon; Eales, Stephen; Furlanetto, Cristina; Gonzalez-Nuevo, Joaquin; Ibar, Edo; Ivison, Rob J; Maddox, Steve J; Scott, Douglas; Smith, Daniel J B; Smith, Matthew W L; Symeonidis, Myrto; Valiante, Elisabetta

    2015-01-01

    Gamma-ray bursts (GRBs) are the most energetic phenomena in the Universe; believed to result from the collapse and subsequent explosion of massive stars. Even though it has profound consequences for our understanding of their nature and selection biases, little is known about the dust properties of the galaxies hosting GRBs. We present analysis of the far-infrared properties of an unbiased sample of 21 GRB host galaxies (at an average redshift of $z\\,=\\,3.1$) located in the {\\it Herschel} Astrophysical Terahertz Large Area Survey (H-ATLAS), the {\\it Herschel} Virgo Cluster Survey (HeViCS), the {\\it Herschel} Fornax Cluster Survey (HeFoCS), the {\\it Herschel} Stripe 82 Survey (HerS) and the {\\it Herschel} Multi-tiered Extragalactic Survey (HerMES), totalling $880$ deg$^2$, or $\\sim 3$\\% of the sky in total. Our sample selection is serendipitous, based only on whether the X-ray position of a GRB lies within a large-scale {\\it Herschel} survey -- therefore our sample can be considered completely unbiased. Using ...

  12. Massive stars formed in atomic hydrogen reservoirs: HI observations of gamma-ray burst host galaxies

    CERN Document Server

    Michałowski, Michał J; Hjorth, J; Krumholz, M R; Tanvir, N R; Kamphuis, P; Burlon, D; Baes, M; Basa, S; Berta, S; Ceron, J M Castro; Crosby, D; D'Elia, V; Elliott, J; Greiner, J; Hunt, L K; Klose, S; Koprowski, M P; Floc'h, E Le; Malesani, D; Murphy, T; Guelbenzu, A Nicuesa; Palazzi, E; Rasmussen, J; Rossi, A; Savaglio, S; Schady, P; Sollerman, J; Postigo, A de Ugarte; Watson, D; van der Werf, P; Vergani, S D; Xu, D

    2015-01-01

    Long gamma-ray bursts (GRBs), among the most energetic events in the Universe, are explosions of massive and short-lived stars, so they pinpoint locations of recent star formation. However, several GRB host galaxies have recently been found to be deficient in molecular gas (H2), believed to be the fuel of star formation. Moreover, optical spectroscopy of GRB afterglows implies that the molecular phase constitutes only a small fraction of the gas along the GRB line-of-sight. Here we report the first ever 21 cm line observations of GRB host galaxies, using the Australia Telescope Compact Array, implying high levels of atomic hydrogen (HI), which suggests that the connection between atomic gas and star formation is stronger than previously thought, with star formation being potentially directly fuelled by atomic gas (or with very efficient HI-to-H2 conversion and rapid exhaustion of molecular gas), as has been theoretically shown to be possible. This can happen in low metallicity gas near the onset of star forma...

  13. Extracting host galaxy dispersion measure and constraining cosmological parameters using fast radio burst data

    CERN Document Server

    Yang, Yuan-Pei

    2016-01-01

    The excessive dispersion measures (DMs) and high Galactic latitudes of fast radio bursts (FRBs) hint toward a cosmological origin of these mysterious transients. Methods of using measured DM and redshift $z$ to study cosmology have been proposed, but one needs to assume a certain amount of DM contribution from the host galaxy (DM$_{\\rm HG}$) in order to apply those methods. We introduce a slope parameter $\\beta(z) \\equiv d \\ln \\left / d \\ln z$ (where DM$_{\\rm E}$ is the observed DM subtracting the Galactic contribution), which can be directly measured when a sample of FRBs have $z$ measured. We show that $\\left$ can be roughly inferred from $\\beta$ and the mean values, $\\overline{\\rm \\left}$ and $\\bar z$, of the sample. Through Monte Carlo simulations, we show that the mean value of local host galaxy DM, $\\left$, along with other cosmological parameters (mass density $\\Omega_m$ in the $\\Lambda$CDM model, and the IGM portion of the baryon energy density $\\Omega_b f_{\\rm IGM}$) can be independently measured thr...

  14. The host galaxies of core-collapse supernovae and gamma ray bursts

    CERN Document Server

    Svensson, K M; Tanvir, N R; Fruchter, A S; Strolger, L -G

    2010-01-01

    We present a comparative study of the galactic and small scale environments of gamma-ray bursts (GRB) and core collapse supernovae (CCSN). We use a sample of 34 GRB hosts at z<1.2, and a comparison sample of 58 supernova hosts located within the Great Observatories Origins Deep Survey footprint. We fit template spectra to the available photometric data, which span the range 0.45-24 micron, and extract absolute magnitudes, stellar masses and star formation rates from the resulting fits. Our results broadly corroborate previous findings, but offer significant enhancements in spectral coverage and a factor 2-3 increase in sample size. Specifically, we find that CCSN occur frequently in massive spirals (spiral fraction ~50%). In contrast GRBs occur in small, relatively low mass galaxies with high specific and surface star formation rates, and have a spiral fraction of only ~10%. A comparison of the rest frame absolute magnitudes of the GRB and CCSN sample is less conclusive than found in previous work, suggest...

  15. The host galaxy and optical light curve of the gamma-ray burst GRB 980703

    DEFF Research Database (Denmark)

    Holland, S.; Fynbo, J.P.U.; Hjorth, J.;

    2001-01-01

    that is approximate to0.2 mag bluer than the outer regions of the galaxy. The galaxy has a star-formation rate of 8-13 M-circle dot yr(-1), assuming no extinction in the host. We find that the galaxy is best fit by a Sersic R-1/n profile with n approximate to 1.0 and a half-light radius of 0." 13 (= 0:72h(100...

  16. Hydrogen-Poor Superluminous Supernovae and Long-Duration Gamma-Ray Bursts Have Similar Host Galaxies

    CERN Document Server

    Lunnan, R; Berger, E; Laskar, T; Fong, W; Sanders, N E; Challis, P M; Drout, M R; Huber, M E; Kirshner, R P; Leibler, C; Marion, G H; McCrum, M; Milisavljevic, D; Narayan, G; Rest, A; Scolnic, D; Smartt, S J; Smith, K W; Soderberg, A M; Stubbs, C W; Tonry, J L; Burgett, W S; Chambers, K C; Flewelling, H; Hodapp, K W; Kaiser, N; Magnier, E A; Price, P A; Wainscoat, R J

    2013-01-01

    We present optical spectroscopy and optical/near-IR photometry of 31 host galaxies of hydrogen-poor superluminous supernovae (SLSNe), including 15 events from the Pan-STARRS1 Medium Deep Survey. Our sample spans the redshift range 0.1 ~ -17.3 mag), low stellar mass ( ~ 2 x 10^8 Msun) population, with a high median specific star formation rate ( ~ 2 Gyr^{-1}). The median metallicity of our spectroscopic sample is low, 12 + log(O/H) ~ 8.35 ~ 0.45 Z_sun, although at least one host galaxy has solar metallicity. The host galaxies of H-poor SLSNe are statistically distinct from the hosts of GOODS core-collapse SNe (which cover a similar redshift range), but resemble the host galaxies of long-duration gamma-ray bursts (LGRBs) in terms of stellar mass, SFR, sSFR and metallicity. This result indicates that the environmental causes leading to massive stars forming either SLSNe or LGRBs are similar, and in particular that SLSNe are more effectively formed in low metallicity environments. We speculate that the key ingre...

  17. GRB 090417B and its Host Galaxy: A Step Towards an Understanding of Optically-Dark Gamma-Ray Bursts

    Science.gov (United States)

    Holland, Stephen T.; Sbarufatti, Boris; Shen, Rongfeng; Schady, Patricia; Cummings, Jay R.; Fonseca, Emmanuel; Fynbo, Johan P. U.; Jakobsson, Pall; Leitet, Elisabet; Linne, Staffan; Roming, Peter W.A.; Still, Martin; Zhang, Bing

    2009-01-01

    GRB 090417B was an unusually long burst with a T(sub 90) duration of at least 2130 s and a multi-peaked light curve at energies of 15-150 keV. It was optically dark and has been convincingly associated with a bright star-forming galaxy at a redshift of 0.345 that is broadly similar to the Milky Way. This is one of the few cases where a host galaxy has been clearly identified for a dark gamma-ray burst and thus an ideal candidate for studying the origin of dark bursts. We find that the dark nature of GRB 090417B can not be explained by high redshift, incomplete observations, or unusual physics in the production of the afterglow. The Swift/XRT X-ray data are consistent with the afterglow being obscured by a dense, localized sheet of dust approximately 30-80 pc from the burst along the line of sight. Assuming the standard relativistic fireball model for the afterglow we find that the optical flux is at least 2.5 mag fainter than predicted by the X -ray flux. We are able to explain the lack of an optical afterglow, and the evolution of the X -ray spectrum, by assuming that there is a sheet of dust along the line of sight approximately 30-80 pc from the progenitor. Our results suggest that this dust sheet imparts an extinction of A(sub v)> or = 12 mag, which is sufficient to explain the missing optical flux. GRB 090417B is an example of a gamma-ray burst that is dark due to the localized dust structure in its host galaxy.

  18. Taking stock of superluminous supernovae and long gamma-ray burst host galaxy comparison using a complete sample of LGRBs

    Science.gov (United States)

    Japelj, J.; Vergani, S. D.; Salvaterra, R.; Hunt, L. K.; Mannucci, F.

    2016-10-01

    Long gamma-ray bursts (LGRBs) and superluminous supernovae (SLSNe) are both explosive transients with very massive progenitor stars. Clues about the nature of the progenitors can be found by investigating environments in which such transients occur. While studies of LGRB host galaxies have a long history, dedicated observational campaigns have only recently resulted in a high enough number of photometrically and spectroscopically observed SLSN hosts to allow statistically significant analysis of their properties. In this paper we make a comparison of the host galaxies of hydrogen-poor (H-poor) SLSNe and the Swift/BAT6 sample of LGRBs. In contrast to previous studies, we use a complete sample of LGRBs and we pay special attention to the comparison methodology and the selection of SLSN sample whose data have been compiled from the available literature. At intermediate redshifts (0.3 < z < 0.7) the two classes of transients select galaxies whose properties (stellar mass, luminosity, star formation rate, specific star formation rate and metallicity) do not differ significantly. Moreover, the host galaxies of both classes of objects follow the fundamental metallicity relation and the fundamental plane of metallicity. In contrast to previous studies we show that at intermediate redshifts the emission line equivalent widths of the two populations are essentially the same and that the previous claims regarding the higher fraction of SLSN hosts among the extreme emission line galaxies with respect to LGRBs are mostly due to a larger fraction of strong-line emitters among SLSN hosts at z < 0.3, where samples of LGRB hosts are small and poorly defined.

  19. Hydrogen-poor superluminous supernovae and long-duration gamma-ray bursts have similar host galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Lunnan, R.; Chornock, R.; Berger, E.; Laskar, T.; Fong, W.; Sanders, N. E.; Challis, P. M.; Drout, M. R.; Foley, R. J.; Kirshner, R. P.; Leibler, C.; Marion, G. H.; Milisavljevic, D.; Narayan, G. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rest, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Huber, M. E. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); McCrum, M.; Smartt, S. J.; Smith, K. W. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Scolnic, D., E-mail: rlunnan@cfa.harvard.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); and others

    2014-06-01

    We present optical spectroscopy and optical/near-IR photometry of 31 host galaxies of hydrogen-poor superluminous supernovae (SLSNe), including 15 events from the Pan-STARRS1 Medium Deep Survey. Our sample spans the redshift range 0.1 ≲ z ≲ 1.6, and is the first comprehensive host galaxy study of this specific subclass of cosmic explosions. Combining the multi-band photometry and emission-line measurements, we determine the luminosities, stellar masses, star formation rates, and metallicities. We find that, as a whole, the hosts of SLSNe are a low-luminosity ((M{sub B} ) ≈ –17.3 mag), low stellar mass ((M {sub *}) ≈ 2 × 10{sup 8} M {sub ☉}) population, with a high median specific star formation rate ((sSFR) ≈ 2 Gyr{sup –1}). The median metallicity of our spectroscopic sample is low, 12 + log (O/H) ≈ 8.35 ≈ 0.45 Z {sub ☉}, although at least one host galaxy has solar metallicity. The host galaxies of H-poor SLSNe are statistically distinct from the hosts of GOODS core-collapse SNe (which cover a similar redshift range), but resemble the host galaxies of long-duration gamma-ray bursts (LGRBs) in terms of stellar mass, SFR, sSFR, and metallicity. This result indicates that the environmental causes leading to massive stars forming either SLSNe or LGRBs are similar, and in particular that SLSNe are more effectively formed in low metallicity environments. We speculate that the key ingredient is large core angular momentum, leading to a rapidly spinning magnetar in SLSNe and an accreting black hole in LGRBs.

  20. A Merger Origin for Short Gamma-Ray Bursts Inferred from the Afterglow and Host Galaxy of GRB 050724

    CERN Document Server

    Berger, E; Cenko, S B; Gal-Yam, A; Soderberg, A M; Kasliwal, M; Leonard, D C; Cameron, P B; Frail, D A; Kulkarni, S R; Murphy, D C; Krzeminski, W; Piran, T; Lee, B L; Roth, K C; Moon, D S; Fox, D B; Harrison, F A; Persson, S E; Schmidt, B P; Penprase, B E; Rich, J; Peterson, B A; Cowie, L L

    2005-01-01

    Despite a rich phenomenology, gamma-ray bursts (GRBs) are divided into two classes based on their duration and spectral hardness -- the long-soft and the short-hard bursts. The discovery of afterglow emission from long GRBs was a watershed event, pinpointing their origin to star forming galaxies, and hence the death of massive stars, and indicating an energy release of about 10^51 erg. While theoretical arguments suggest that short GRBs are produced in the merger of compact object binaries (neutron stars or black holes), the progenitors, energetics, and environments of these events remain elusive despite recent localizations. Here we report the discovery of radio, optical, and infrared afterglow emission from the short-hard GRB 050724, which unambiguously associate it with an elliptical galaxy at a redshift, z=0.257. We show that the energy release is 1-3 orders of magnitude smaller than that of long GRBs, and that the burst ejecta may be collimated in jets. More importantly, the nature of the host galaxy for...

  1. The Optically Unbiased Gamma-Ray Burst Host (TOUGH) Survey. VII. The Host Galaxy Luminosity Function: Probing the Relationship Between GRBs and Star Formation to Redshift $\\sim6$

    CERN Document Server

    Schulze, S; Hjorth, J; Levan, A J; Jakobsson, P; Björnsson, G; Perley, D A; Krühler, T; Gorosabel, J; Tanvir, N R; Postigo, A de Ugarte; Fynbo, J P U; Milvang-Jensen, B; Møller, P; Watson, D J

    2015-01-01

    Gamma-ray bursts (GRBs) offer a route to characterizing star-forming galaxies and quantifying high-$z$ star-formation that is distinct from the approach of traditional galaxy surveys: GRB selection is independent of dust and probes even the faintest galaxies that can evade detection in flux-limited surveys. However, the exact relation between GRB rate and Star Formation Rate (SFR) throughout all redshifts is controversial. The TOUGH survey includes observations of all GRB hosts (69) in an optically unbiased sample and we utilize these to constrain the evolution of the UV GRB-host-galaxy Luminosity Function (LF) between $z=0$ and $z=4.5$, and compare this with LFs derived from both Lyman-break galaxy (LBG) surveys and simulation modeling. At all redshifts we find the GRB hosts to be most consistent with a Luminosity Function derived from SFR weighted models incorporating GRB production via both metallicity-dependent and independent channels with a relatively high level of bias towards low metallicity hosts. In...

  2. DETECTION OF THREE GAMMA-RAY BURST HOST GALAXIES AT z ~ 6

    DEFF Research Database (Denmark)

    McGuire, J.T.W.; Tanvir, N.R.; Levan, A.J.;

    2016-01-01

    host galaxies in emission. The galaxies have luminosities in the range 0.1–0.6 {L}z=6* (with {M}1600* =-20.95+/- 0.12) and half-light radii in the range 0.6–0.9 {{kpc}}. Both their half-light radii and luminosities are consistent with existing samples of Lyman-break galaxies at z∼ 6. Spectroscopic...... analysis of the GRB afterglows indicate low metallicities ([{{M/H}}]≲ -1) and low dust extinction ({A}{{V}}≲ 0.1) along the line of sight. Using stellar population synthesis models, we explore the implications of each galaxy’s luminosity for its possible star-formation history and consider the potential...... for emission line metallicity determination with the upcoming James Webb Space Telescope....

  3. GEMINI SPECTROSCOPY OF THE SHORT-HARD GAMMA-RAY BURST GRB 130603B AFTERGLOW AND HOST GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Cucchiara, A.; Prochaska, J. X.; Werk, J. [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Perley, D.; Cao, Y. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd, Pasadena, CA 91125 (United States); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD (United States); Cardwell, A.; Turner, J. [Gemini South Observatory, AURA, Casilla 603, La Serena (Chile); Bloom, J. S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Cobb, B. E., E-mail: acucchia@ucolick.org [The George Washington University, Washington, DC (United States)

    2013-11-10

    We present early optical photometry and spectroscopy of the afterglow and host galaxy of the bright short-duration gamma-ray burst GRB 130603B discovered by the Swift satellite. Using our Target of Opportunity program on the Gemini South telescope, our prompt optical spectra reveal a strong trace from the afterglow superimposed on continuum and emission lines from the z = 0.3568 ± 0.0005 host galaxy. The combination of a relatively bright optical afterglow (r' = 21.52 at Δt = 8.4 hr), together with an observed offset of 0.''9 from the host nucleus (4.8 kpc projected distance at z = 0.3568), allow us to extract a relatively clean spectrum dominated by afterglow light. Furthermore, the spatially resolved spectrum allows us to constrain the properties of the explosion site directly, and compare these with the host galaxy nucleus, as well as other short-duration GRB host galaxies. We find that while the host is a relatively luminous (L∼0.8 L{sup *}{sub B}), star-forming (SFR = 1.84 M{sub ☉} yr{sup –1}) galaxy with almost solar metallicity, the spectrum of the afterglow exhibits weak Ca II absorption features but negligible emission features. The explosion site therefore lacks evidence of recent star formation, consistent with the relatively long delay time distribution expected in a compact binary merger scenario. The star formation rate (SFR; both in an absolute sense and normalized to the luminosity) and metallicity of the host are both consistent with the known sample of short-duration GRB hosts and with recent results which suggest GRB 130603B emission to be the product of the decay of radioactive species produced during the merging process of a neutron-star-neutron-star binary ({sup k}ilonova{sup )}. Ultimately, the discovery of more events similar to GRB 130603B and their rapid follow-up from 8 m class telescopes will open new opportunities for our understanding of the final stages of compact-objects binary systems and provide crucial

  4. X-ray absorption evolution in Gamma-Ray Bursts: intergalactic medium or evolutionary signature of their host galaxies?

    CERN Document Server

    Starling, R L C; Tanvir, N R; Scott, A E; Wiersema, K; O'Brien, P T; Levan, A J; Stewart, G C

    2013-01-01

    The intrinsic X-ray emission of Gamma-Ray Bursts (GRBs) is often found to be absorbed over and above the column density through our own galaxy. The extra component is usually assumed to be due to absorbing gas lying within the host galaxy of the GRB itself. There is an apparent correlation between the equivalent column density of hydrogen, N(H,intrinsic) (assuming it to be at the GRB redshift), and redshift, z, with the few z>6 GRBs showing the greatest intrinsic column densities. We investigate the N(H,intrinsic) - z relation using a large sample of Swift GRBs, as well as active galactic nuclei (AGN) and quasar samples, paying particular attention to the spectral energy distributions of the two highest redshift GRBs. Various possible sample biases and systematics that might produce such a correlation are considered, and we conclude that the correlation is very likely to be real. This may indicate either an evolutionary effect in the host galaxy properties, or a contribution from gas along the line-of-sight, ...

  5. Exploring Gamma-Ray Bursts, Their Immediate Environment and Host Galaxies

    CERN Document Server

    Friis, Mette

    2015-01-01

    Lasting anywhere from a few milliseconds to several minutes, GRBs shine hundreds of times brighter than a typical supernova, making them briefly the brightest source of cosmic gamma-ray photons in the observable Universe. This thesis focuses on 3 different aspects of GRBs: (1) The radiative mechanism of GRBs and their afterglows, i.e. the occurrence of thermal emission and the physical parameters we can determine through this emission. (2) Their host galaxies, using results from observations of GRB 121024A as a case study. (3) How they can be used to answer some of the larger astrophysical questions, more specifically in this case, to study interstellar dust and grey extinction.

  6. Massive stars formed in atomic hydrogen reservoirs: H i observations of gamma-ray burst host galaxies

    DEFF Research Database (Denmark)

    Michałowski, M. J.; Gentile, G.; Hjorth, J.;

    2015-01-01

    Long gamma-ray bursts (GRBs), among the most energetic events in the Universe, are explosions of massive and short-lived stars, so they pinpoint locations of recent star formation. However, several GRB host galaxies have recently been found to be deficient in molecular gas (H2), believed......, implying high levels of atomic hydrogen (HI), which suggests that the connection between atomic gas and star formation is stronger than previously thought. In this case, it is possible that star formation is directly fuelled by atomic gas (or that the H1-to-H2 conversion is very efficient, which rapidly...... exhaust molecular gas), as has been theoretically shown to be possible. This can happen in low-metallicity gas near the onset of star formation because cooling of gas (necessary for star formation) is faster than the H1-to-H2 conversion. Indeed, large atomic gas reservoirs, together with low molecular gas...

  7. The low-extinction afterglow in the solar-metallicity host galaxy of gamma-ray burst 110918A

    CERN Document Server

    Elliott, J; Greiner, J; Savaglio, S; E., F Olivares; Rau, A; Postigo, A de Ugarte; Sánchez-Ramírez, R; Wiersema, K; Schady, P; Kann, D A; Filgas, R; Nardini, M; Berger, E; Fox, D; Gorosabel, J; Klose, S; Levan, A; Guelbenzu, A Nicuesa; Rossi, A; Schmidl, S; Sudilovsky, V; Tanvir, N R; Thöne, C C

    2013-01-01

    Metallicity is theoretically thought to be a fundamental driver in gamma-ray burst (GRB) explosions and energetics, but is still, even after more than a decade of extensive studies, not fully understood. This is largely related to two phenomena: a dust-extinction bias, that prevented high-mass and thus likely high-metallicity GRB hosts to be detected in the first place, and a lack of efficient instrumentation, that limited spectroscopic studies including metallicity measurements to the low-redshift end of the GRB host population. The subject of this work is the very energetic GRB 110918A, for which we measure a redshift of z=0.984. GRB 110918A gave rise to a luminous afterglow with an intrinsic spectral slope of b=0.70, which probed a sight-line with little extinction (A_V=0.16 mag) typical of the established distributions of afterglow properties. Photometric and spectroscopic follow-up observations of the galaxy hosting GRB 110918A, including optical/NIR photometry with GROND and spectroscopy with VLT/X-shoo...

  8. A population of massive, luminous galaxies hosting heavily dust-obscured gamma-ray bursts: Implications for the use of GRBs as tracers of cosmic star formation

    Energy Technology Data Exchange (ETDEWEB)

    Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd., Pasadena, CA 91125 (United States); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Cenko, S. B.; Bloom, J. S.; Filippenko, A. V.; Morgan, A. N. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Hjorth, J.; Krühler, T.; Fynbo, J. P. U.; Milvang-Jensen, B. [Dark Cosmology Centre, Niels Bohr Institute, Copenhagen (Denmark); Fruchter, A.; Kalirai, J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Jakobsson, P. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavík (Iceland); Prochaska, J. X. [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Silverman, J. M., E-mail: dperley@astro.caltech.edu [Department of Astronomy, University of Texas, Austin, TX 78712 (United States)

    2013-12-01

    We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite during the years 2005-2009, representing all GRBs with an unambiguous host-frame extinction of A{sub V} > 1 mag from this period. Deep observations with Keck, Gemini, Very Large Telescope, Hubble Space Telescope, and Spitzer successfully detect the host galaxies and establish spectroscopic or photometric redshifts for all 23 events, enabling us to provide measurements of the intrinsic host star formation rates, stellar masses, and mean extinctions. Compared to the hosts of unobscured GRBs at similar redshifts, we find that the hosts of dust-obscured GRBs are (on average) more massive by about an order of magnitude and also more rapidly star forming and dust obscured. While this demonstrates that GRBs populate all types of star-forming galaxies, including the most massive, luminous systems at z ≈ 2, at redshifts below 1.5 the overall GRB population continues to show a highly significant aversion to massive galaxies and a preference for low-mass systems relative to what would be expected given a purely star-formation-rate-selected galaxy sample. This supports the notion that the GRB rate is strongly dependent on metallicity, and may suggest that the most massive galaxies in the universe underwent a transition in their chemical properties ∼9 Gyr ago. We also conclude that, based on the absence of unobscured GRBs in massive galaxies and the absence of obscured GRBs in low-mass galaxies, the dust distributions of the lowest-mass and the highest-mass galaxies are relatively homogeneous, while intermediate-mass galaxies (∼10{sup 9} M {sub ☉}) have diverse internal properties.

  9. CONNECTING GRBs AND ULIRGs: A SENSITIVE, UNBIASED SURVEY FOR RADIO EMISSION FROM GAMMA-RAY BURST HOST GALAXIES AT 0 < z < 2.5

    Energy Technology Data Exchange (ETDEWEB)

    Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Perley, R. A. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); Hjorth, J.; Malesani, D. [Dark Cosmology Centre, Niels Bohr Institute, DK-2100 Copenhagen (Denmark); Michałowski, M. J. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ (United Kingdom); Cenko, S. B. [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Jakobsson, P. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavík (Iceland); Krühler, T. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Tanvir, N. R., E-mail: dperley@astro.caltech.edu [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2015-03-10

    Luminous infrared galaxies and submillimeter galaxies contribute significantly to stellar mass assembly and provide an important test of the connection between the gamma-ray burst (GRB) rate and that of overall cosmic star formation. We present sensitive 3 GHz radio observations using the Karl G. Jansky Very Large Array of 32 uniformly selected GRB host galaxies spanning a redshift range from 0 < z < 2.5, providing the first fully dust- and sample-unbiased measurement of the fraction of GRBs originating from the universe's most bolometrically luminous galaxies. Four galaxies are detected, with inferred radio star formation rates (SFRs) ranging between 50 and 300 M {sub ☉} yr{sup –1}. Three of the four detections correspond to events consistent with being optically obscured 'dark' bursts. Our overall detection fraction implies that between 9% and 23% of GRBs between 0.5 < z < 2.5 occur in galaxies with S {sub 3GHz} > 10 μJy, corresponding to SFR > 50 M {sub ☉} yr{sup –1} at z ∼ 1 or >250 M {sub ☉} yr{sup –1} at z ∼ 2. Similar galaxies contribute approximately 10%-30% of all cosmic star formation, so our results are consistent with a GRB rate that is not strongly biased with respect to the total SFR of a galaxy. However, all four radio-detected hosts have stellar masses significantly lower than IR/submillimeter-selected field galaxies of similar luminosities. We suggest that the GRB rate may be suppressed in metal-rich environments but independently enhanced in intense starbursts, producing a strong efficiency dependence on mass but little net dependence on bulk galaxy SFR.

  10. GRB hosts through cosmic time. VLT/X-Shooter emission-line spectroscopy of 96 γ-ray-burst-selected galaxies at 0.1

    NARCIS (Netherlands)

    T. Krühler; D. Malesani; J.P.U. Fynbo; O.E. Hartoog; J. Hjorth; P. Jakobsson; D.A. Perley; A.. Rossi; P. Schady; S. Schulze; N.R. Tanvir; S.D. Vergani; K. Wiersema; P.M.J. Afonso; J. Bolmer; Z. Cano; S. Covino; V. D’Elia; A. de Ugarte Postigo; R. Filgas; M. Friis; J.F. Graham; J. Greiner; P. Goldoni; A. Gomboc; F. Hammer; J. Japelj; D.A. Kann; L. Kaper; S. Klose; A.J. Levan; G. Leloudas; B. Milvang-Jensen; A. Nicuesa Guelbenzu; E. Palazzi; E. Pian; S. Piranomonte; R. Sánchez-Ramírez; S. Savaglio; J. Selsing; G. Tagliaferri; P.M. Vreeswijk; D.J. Watson; D. Xu

    2015-01-01

    We present data and initial results from VLT/X-Shooter emission-line spectroscopy of 96 galaxies selected by long γ-ray bursts (GRBs) at 0.1 host spectra available to date. Most of our GRBs were detected by Swift and 76% are at 0.5

  11. Late-Time VLA Reobservations Rule Out ULIRG-Like Host Galaxies For Most Pre-Swift Long-Duration Gamma-Ray Bursts

    CERN Document Server

    Perley, Daniel A; Tanvir, Nial R; Perley, Richard A

    2016-01-01

    We present new Jansky Very Large Array observations of five pre-Swift gamma-ray bursts for which an ultraluminous (SFR > 100 M_sun/yr) dusty host galaxy had previously been inferred from late-time radio or submillimetre observations taken 1-3 years after the burst. In four of the five cases we no longer detect any source at the host location to limits much fainter than the original observations, ruling out the existence of an ultraluminous galaxy hosting any of these GRBs. We continue to detect a source at the position of GRB 980703, but it is much fainter than it was a decade ago and the inferred radio star-formation rate (~80 M_sun) is relatively modest. The radio flattening at 200-1000 days observed in the light curve of this GRB may have been caused by a decelerating counterjet oriented 180 degrees away from the viewer, although an unjetted wind model can also explain the data. Our results eliminate all well-established pre-Swift ULIRG hosts, and all cases for which an unobscured GRB was found in a galaxy...

  12. A Population of Massive, Luminous Galaxies Hosting Heavily Dust-Obscured Gamma-Ray Bursts: Implications for the Use of GRBs as Tracers of Cosmic Star Formation

    CERN Document Server

    Perley, D A; Tanvir, N R; Cenko, S B; Bloom, J S; Hjorth, J; Kruehler, T; Filippenko, A V; Fruchter, A; Fynbo, J P U; Jakobsson, P; Kalirai, J; Milvang-Jensen, B; Morgan, A N; Prochaska, J X; Silverman, J M

    2013-01-01

    We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite between the years 2005-2009, a sample representing all GRBs during this period with an unambiguous host-frame extinction of at least A_V>1 mag. Deep observations with Keck, Gemini, VLT, HST, and Spitzer successfully detect the host galaxies and establish redshifts for all 23 events, enabling us to provide measurements of the host stellar masses, star-formation rates (SFRs), and mean extinctions. Compared to the hosts of unobscured GRBs at similar redshifts, we find that the hosts of dust-obscured GRBs are (on average) more massive by about an order of magnitude and are also significantly more rapidly star-forming and more dust-obscured. However, while the inclusion of this population of dust-obscured hosts shows that GRBs populate all types of star-forming galaxies including the most massive, luminous systems at z~2, at redshifts below z<1.5 the overall GRB populatio...

  13. Connecting GRBs and ULIRGs: A Sensitive, Unbiased Survey for Radio Emission from Gamma-Ray Burst Host Galaxies at 0

    CERN Document Server

    Perley, D A; Hjorth, J; Michałowski, M J; Cenko, S B; Jakobsson, P; Krühler, T; Levan, A J; Malesani, D; Tanvir, N R

    2014-01-01

    Luminous infrared galaxies and submillimeter galaxies contribute significantly to stellar mass assembly and the frequency of GRBs in these systems provides an important test of the connection between the gamma-ray burst rate and that of overall cosmic star-formation. We present sensitive 3 GHz radio observations using the Karl G. Jansky Very Large Array of 31 uniformly-selected GRB host galaxies spanning a redshift range from 0 10 uJy, corresponding to SFR > 50 Msun/yr at z~1 or > 250 Msun/yr at z~2. Similar galaxies contribute approximately 10-30% of all cosmic star-formation, so our results are consistent with a GRB rate which is not strongly biased with respect to the total star-formation rate of a galaxy. However, all four radio-detected hosts have modest stellar masses (~few x 10^10 Msun), significantly lower than IR/submillimeter-selected field galaxies of similar luminosities. We suggest that GRBs may be suppressed in metal-rich environments but independently are enhanced in intense starbursts, produc...

  14. The very red afterglow of GRB 000418: Further evidence for dust extinction in a gamma-ray burst host galaxy

    DEFF Research Database (Denmark)

    Klose, S.; Stecklum, B.; Masetti, N.;

    2000-01-01

    -infrared. During the first 10 days its R-band afterglow was well characterized by a single power-law decay with a slope of 0.86. However, at later times the temporal evolution of the afterglow flattens with respect to a simple power-law decay. Attributing this to an underlying host galaxy, we find its magnitude...

  15. Photometry and spectroscopy of GRB 060526: a detailed study of the afterglow and host galaxy of a z = 3.2 gamma-ray burst

    Science.gov (United States)

    Thöne, C. C.; Kann, D. A.; Jóhannesson, G.; Selj, J. H.; Jaunsen, A. O.; Fynbo, J. P. U.; Akerlof, C. W.; Baliyan, K. S.; Bartolini, C.; Bikmaev, I. F.; Bloom, J. S.; Burenin, R. A.; Cobb, B. E.; Covino, S.; Curran, P. A.; Dahle, H.; Ferrero, A.; Foley, S.; French, J.; Fruchter, A. S.; Ganesh, S.; Graham, J. F.; Greco, G.; Guarnieri, A.; Hanlon, L.; Hjorth, J.; Ibrahimov, M.; Israel, G. L.; Jakobsson, P.; Jelínek, M.; Jensen, B. L.; Jørgensen, U. G.; Khamitov, I. M.; Koch, T. S.; Levan, A. J.; Malesani, D.; Masetti, N.; Meehan, S.; Melady, G.; Nanni, D.; Näränen, J.; Pakstiene, E.; Pavlinsky, M. N.; Perley, D. A.; Piccioni, A.; Pizzichini, G.; Pozanenko, A.; Roming, P. W. A.; Rujopakarn, W.; Rumyantsev, V.; Rykoff, E. S.; Sharapov, D.; Starr, D.; Sunyaev, R. A.; Swan, H.; Tanvir, N. R.; Terra, F.; de Ugarte Postigo, A.; Vreeswijk, P. M.; Wilson, A. C.; Yost, S. A.; Yuan, F.

    2010-11-01

    Aims: With this paper we want to investigate the highly variable afterglow light curve and environment of gamma-ray burst (GRB) 060526 at z = 3.221. Methods: We present one of the largest photometric datasets ever obtained for a GRB afterglow, consisting of multi-color photometric data from the ultraviolet to the near infrared. The data set contains 412 data points in total to which we add additional data from the literature. Furthermore, we present low-resolution high signal-to-noise spectra of the afterglow. The afterglow light curve is modeled with both an analytical model using broken power law fits and with a broad-band numerical model which includes energy injections. The absorption lines detected in the spectra are used to derive column densities using a multi-ion single-component curve-of-growth analysis from which we derive the metallicity of the host of GRB 060526. Results: The temporal behaviour of the afterglow follows a double broken power law with breaks at t = 0.090 ± 0.005 and t = 2.401 ± 0.061 days. It shows deviations from the smooth set of power laws that can be modeled by additional energy injections from the central engine, although some significant microvariability remains. The broadband spectral-energy distribution of the afterglow shows no significant extinction along the line of sight. The metallicity derived from S ii and Fe ii of [S/H] = -0.57 ± 0.25 and [Fe/H] = -1.09 ± 0.24 is relatively high for a galaxy at that redshift but comparable to the metallicity of other GRB hosts at similar redshifts. At the position of the afterglow, no host is detected to F775W(AB) = 28.5 mag with the HST, implying an absolute magnitude of the host M(1500 Å) > -18.3 mag which is fainter than most long-duration hosts, although the GRB may be associated with a faint galaxy at a distance of 11 kpc. Based in part on observations obtained with the European Southern Observatory's Very Large Telescope under proposals 077.D-0661 (PI: Vreeswijk) and 177.A-0591

  16. Detection of Wolf-Rayet stars in host galaxies of Gamma-Ray Bursts (GRBs): are GRBs produced by runaway massive stars ejected from high stellar density regions ?

    CERN Document Server

    Hammer, F; Schärer, D; Dessauges-Zavadsky, M; Le Floc'h, E; Puech, M

    2006-01-01

    We have obtained deep spectroscopic observations of several nearby gamma-ray burst (GRB) host galaxies revealing for the first time the presence of Wolf-Rayet (WR) stars and numerous O stars located in rich and compact clusters or star forming regions. Surprisingly, high spatial resolution imaging shows that the GRBs and the associated supernovae did not occur in these regions, but several hundreds of parsec away. Considering various scenarios for GRB progenitors, we do not find any simple explanation of why they should be preferentially born in regions with low stellar densities. All the examined GRBs and associated SNe have occurred 400 to 800 pc from very high density stellar environments including large numbers of WR stars. Such distances can be travelled through at velocities of 100 km/s or larger, assuming the travel time to be the typical life time of WR stars. It leads us to suggest that GRB progenitors may be runaway massive stars ejected from compact massive star clusters. The ejection from such sup...

  17. Closing in on a Short-Hard Burst Progenitor: Constraints from Early-Time Optical Imaging and Spectroscopy of a Possible Host Galaxy of GRB 050509b

    CERN Document Server

    Bloom, J S; Pooley, D; Blake, C W; Foley, R J; Jha, S; Ramirez-Ruiz, E; Granot, J; Filippenko, A V; Sigurdsson, S; Barth, A J; Chen, H W; Cooper, M C; Falco, E E; Gal, R R; Gerke, B F; Gladders, M D; Greene, J E; Hennanwi, J; Ho, L C; Hurley, K; Koester, B P; Li, W; Lubin, L; Newman, J; Perley, D A; Squires, G K; Wood-Vasey, W M

    2006-01-01

    The localization of the short-duration, hard-spectrum gamma-ray burst GRB 050509b by the Swift satellite was a watershed event. Thanks to the nearly immediate relay of the GRB position, we began imaging the field ~8 minutes after the burst and have continued during the 8 days since. Though the X-ray Telescope (XRT) discovered an X-ray afterglow, the first ever of a short-hard burst, thus far no convincing optical/infrared candidate afterglow or supernova has been found for the object. We present a re-analysis of the XRT afterglow and find an absolute position that is ~4'' to the west of the XRT position reported previously. Near to this position is a bright elliptical galaxy with redshift z=0.2248 +- 0.0002, about 1' from the center of a rich cluster of galaxies. We find several fainter galaxies consistent with the XRT position from deep Keck imaging and have obtained Gemini spectra of two of these sources. Based on positional coincidences, we argue that the GRB and the bright elliptical are likely to be phys...

  18. An HST study of three very faint GRB host galaxies

    DEFF Research Database (Denmark)

    Jaunsen, A.O.; Andersen, M.I.; Hjorth, J.;

    2003-01-01

    As part of the HST/STIS GRB host survey program we present the detection of three faint gamma-ray burst (GRB) host galaxies based on an accurate localisation using ground-based data of the optical afterglows (OAs). A common property of these three hosts is their extreme faintness. The location...... at which GRBs occur with respect to their host galaxies and surrounding environments are robust indicators of the nature of GRB progenitors. The bursts studied here are among the four most extreme outliers, in terms of relative distance from the host center, in the recent comprehensive study of Bloom et al...

  19. Closing in on a Short-Hard Burst Progenitor: Constraints From Early-Time Optical Imaging and Spectroscopy of a Possible Host Galaxy of GRB 050509b

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Joshua S.; Prochaska, J.X.; Pooley, D.; Blake, C.W.; Foley, R.J.; Jha, S.; Ramirez-Ruiz, E.; Granot, J.; Filippenko, A.V.; Sigurdsson, S.; Barth, A.J.; Chen,; Cooper, M.C.; Falco, E.E.; Gal, R.R.; Gerke, B.F.; Gladders, M.D.; Greene, J.E.; Hennanwi, J.; Ho, L.C.; Hurley, K.; /UC, Berkeley, Astron. Dept. /Lick Observ.

    2005-06-07

    The localization of the short-duration, hard-spectrum gamma-ray burst GRB050509b by the Swift satellite was a watershed event. Never before had a member of this mysterious subclass of classic GRBs been rapidly and precisely positioned in a sky accessible to the bevy of ground-based follow-up facilities. Thanks to the nearly immediate relay of the GRB position by Swift, we began imaging the GRB field 8 minutes after the burst and have continued during the 8 days since. Though the Swift X-ray Telescope (XRT) discovered an X-ray afterglow of GRB050509b, the first ever of a short-hard burst, thus far no convincing optical/infrared candidate afterglow or supernova has been found for the object. We present a re-analysis of the XRT afterglow and find an absolute position of R.A. = 12h36m13.59s, Decl. = +28{sup o}59'04.9'' (J2000), with a 1{sigma} uncertainty of 3.68'' in R.A., 3.52'' in Decl.; this is about 4'' to the west of the XRT position reported previously. Close to this position is a bright elliptical galaxy with redshift z = 0.2248 {+-} 0.0002, about 1' from the center of a rich cluster of galaxies. This cluster has detectable diffuse emission, with a temperature of kT = 5.25{sub -1.68}{sup +3.36} keV. We also find several ({approx}11) much fainter galaxies consistent with the XRT position from deep Keck imaging and have obtained Gemini spectra of several of these sources. Nevertheless we argue, based on positional coincidences, that the GRB and the bright elliptical are likely to be physically related. We thus have discovered reasonable evidence that at least some short-duration, hard-spectra GRBs are at cosmological distances. We also explore the connection of the properties of the burst and the afterglow, finding that GRB050509b was underluminous in both of these relative to long-duration GRBs. However, we also demonstrate that the ratio of the blast-wave energy to the {gamma}-ray energy is consistent with that

  20. Star formation rates and stellar masses in z ~ 1 gamma-ray burst hosts

    DEFF Research Database (Denmark)

    Castro Cerón, José María; Michalowski, Michal; Hjorth, J.;

    2006-01-01

    Cosmology: Observations, ISM: Dust, Extinction, Galaxies: High-Redshift, Galaxies: ISM, Gamma Rays: Bursts, Infrared: Galaxies Udgivelsesdato: Dec. 4......Cosmology: Observations, ISM: Dust, Extinction, Galaxies: High-Redshift, Galaxies: ISM, Gamma Rays: Bursts, Infrared: Galaxies Udgivelsesdato: Dec. 4...

  1. Are long gamma-ray bursts biased tracers of star formation? Clues from the host galaxies of the Swift/BAT6 complete sample of bright LGRBs. II. Star formation rates and metallicities at z < 1

    Science.gov (United States)

    Japelj, J.; Vergani, S. D.; Salvaterra, R.; D'Avanzo, P.; Mannucci, F.; Fernandez-Soto, A.; Boissier, S.; Hunt, L. K.; Atek, H.; Rodríguez-Muñoz, L.; Scodeggio, M.; Cristiani, S.; Le Floc'h, E.; Flores, H.; Gallego, J.; Ghirlanda, G.; Gomboc, A.; Hammer, F.; Perley, D. A.; Pescalli, A.; Petitjean, P.; Puech, M.; Rafelski, M.; Tagliaferri, G.

    2016-05-01

    Aims: Long gamma-ray bursts (LGRBs) are associated with the deaths of massive stars and might therefore be a potentially powerful tool for tracing cosmic star formation. However, especially at low redshifts (zextinction, star formation rate (SFR), and nebular metallicity (Z) of the hosts and supplemented the data set with previously measured stellar masses M⋆. The distributions of the obtained properties and their interrelations (e.g. mass-metallicity and SFR-M⋆ relations) are compared to samples of field star-forming galaxies. Results: We find that LGRB hosts at z< 1 have on average lower SFRs than if they were direct star formation tracers. By directly comparing metallicity distributions of LGRB hosts and star-forming galaxies, we find a good match between the two populations up to 12 +log ≤ft( frac{OHright)} 8.4-8.5, after which the paucity of metal-rich LGRB hosts becomes apparent. The LGRB host galaxies of our complete sample are consistent with the mass-metallicity relation at similar mean redshift and stellar masses. The cutoff against high metallicities (and high masses) can explain the low SFR values of LGRB hosts. We find a hint of an increased incidence of starburst galaxies in the Swift/BAT6 z< 1 sample with respect to that of a field star-forming population. Given that the SFRs are low on average, the latter is ascribed to low stellar masses. Nevertheless, the limits on the completeness and metallicity availability of current surveys, coupled with the limited number of LGRB host galaxies, prevents us from investigating more quantitatively whether the starburst incidence is such as expected after taking into account the high-metallicity aversion of LGRB host galaxies. Based on observations at ESO, Program IDs: 077.D-0425, 177.A-0591, 080.D-0526, 081.A-0856, 082.D-0276, 083.D-0069, 084.A-0303, 084.A-0260, 086.A-0644, 086.B-0954, 089.A-0868, 090.A-0760, 095.D-0560.The reduced spectra are available in the ESO archive as Phase 3 data products and in

  2. Radio Observations of GRB Host Galaxies

    CERN Document Server

    Stanway, E R; Davies, Luke J M

    2014-01-01

    We present 5.5 and 9.0 GHz observations of a sample of seventeen GRB host galaxies at 0.5galaxies with similar observations. Four sources are detected, one of those (GRB 100418A) likely due to lingering afterglow emission. We suggest that the previously-reported radio afterglow of GRB 100621A may instead be due to host galaxy flux. We see no strong evidence for redshift evolution in the typical star formation rate of GRB hosts, but note that the fraction of `dark' bursts with detections is higher than would be expected given constraints on the more typical long GRB population. We also determine the average radio-derived star formation rates of core collapse supernovae at comparable redshift, and show that these are still well below the limits obtained for GRB hosts, and show evidence for a rise in typical star formation rate with redshift in supernova hosts.

  3. GRB hosts through cosmic time. VLT/X-Shooter emission-line spectroscopy of 96 γ-ray-burst-selected galaxies at 0.1

    Science.gov (United States)

    Krühler, T.; Malesani, D.; Fynbo, J. P. U.; Hartoog, O. E.; Hjorth, J.; Jakobsson, P.; Perley, D. A.; Rossi, A.; Schady, P.; Schulze, S.; Tanvir, N. R.; Vergani, S. D.; Wiersema, K.; Afonso, P. M. J.; Bolmer, J.; Cano, Z.; Covino, S.; D'Elia, V.; de Ugarte Postigo, A.; Filgas, R.; Friis, M.; Graham, J. F.; Greiner, J.; Goldoni, P.; Gomboc, A.; Hammer, F.; Japelj, J.; Kann, D. A.; Kaper, L.; Klose, S.; Levan, A. J.; Leloudas, G.; Milvang-Jensen, B.; Nicuesa Guelbenzu, A.; Palazzi, E.; Pian, E.; Piranomonte, S.; Sánchez-Ramírez, R.; Savaglio, S.; Selsing, J.; Tagliaferri, G.; Vreeswijk, P. M.; Watson, D. J.; Xu, D.

    2015-09-01

    We present data and initial results from VLT/X-Shooter emission-line spectroscopy of 96 galaxies selected by long γ-ray bursts (GRBs) at 0.1 Swift and 76% are at 0.5 2 by ~0.4 dex. These properties of GRB hosts and their evolution with redshift can be understood in a cosmological context of star-forming galaxies and a picture in which the hosts' properties at low redshift are influenced by the tendency of GRBs to avoid the most metal-rich environments. Based on observations at ESO, Program IDs: 084.A-0260, 084.A-0303, 085.A-0009, 086.B-0954, 086.A-0533, 086.A-0874, 087.A-0055, 087.A-0451, 087.B-0737, 088.A-0051, 088.A-0644, 089.A-0067, 089.A-0120, 089.D-0256, 089.A-0868, 090.A-0088, 090.A-0760, 090.A-0825, 091.A-0342, 091.A-0703, 091.A-0877, 091.C-0934, 092.A-0076, 092.A-0124, 092.A-0231, 093.A-0069, 094.A-0593.Tables 1-4 and appendices are available in electronic form at http://www.aanda.orgThe reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A125

  4. The blue host galaxy of the red GRB 000418

    DEFF Research Database (Denmark)

    Gorosabel, J.; Klose, S.; Christensen, L.;

    2003-01-01

    We report on multi-band (UBVRIZJ(s)K(s)) observations of the host galaxy of the April 18, 2000 gamma-ray burst. The Spectral Energy Distribution (SED) is analysed by fitting empirical and synthetic spectral templates. We find that: (i) the best SED fit is obtained with a starburst template, (ii) ...

  5. AGN and their host galaxies

    Science.gov (United States)

    Steinborn, L. K.; Dolag, K.; Hirschmann, M.; Remus, R.-S.; Teklu, A. F.

    2016-06-01

    Large scale cosmological hydrodynamic simulations are an important tool to study the co-evolution between black holes (BHs) and their host galaxies. However, in order to model the accretion onto BHs and AGN feedback we need sub-grid models which contain several free parameters. The choice of these parameters has a significant impact on the properties of the BHs and their host galaxies. Therefore, we improve the accretion model and the AGN feedback model based on both theory and observations to eliminate most free parameters. In that way, the slope of the observed relation between BH mass and stellar mass is reproduced self-consistently. We performed a few extremely large simulation runs as part of the Magneticum Pathfinder simulation set, combining a high resolution with very large cosmological volumes, enabling us to study for example dual AGN, the role of galaxy mergers and AGN clustering properties.

  6. A multi-colour study of the dark GRB 000210 host galaxy and its environment

    DEFF Research Database (Denmark)

    Gorosabel, J.; Christensen, Lise; Hjorth, J.;

    2003-01-01

    We present UBVRIZJsHKs broad band photometry of the host galaxy of the dark gamma-ray burst (GRB) of February 10, 2000. These observations represent the most exhaustive photometry given to date of any GRB host galaxy. A grid of spectral templates have been fitted to the Spectral Energy Distributi...

  7. Identifying the host galaxy of the short GRB 100628A

    Science.gov (United States)

    Nicuesa Guelbenzu, A.; Klose, S.; Palazzi, E.; Greiner, J.; Michałowski, M. J.; Kann, D. A.; Hunt, L. K.; Malesani, D.; Rossi, A.; Savaglio, S.; Schulze, S.; Xu, D.; Afonso, P. M. J.; Elliott, J.; Ferrero, P.; Filgas, R.; Hartmann, D. H.; Krühler, T.; Knust, F.; Masetti, N.; Olivares E., F.; Rau, A.; Schady, P.; Schmidl, S.; Tanga, M.; Updike, A. C.; Varela, K.

    2015-11-01

    We report on the results of a comprehensive observing campaign to reveal the host galaxy of the short GRB 100628A. This burst was followed by a faint X-ray afterglow but no optical counterpart was discovered. However, inside the X-ray error circle a potential host galaxy at a redshift of z = 0.102 was soon reported in the literature. If this system is the host, then GRB 100628A was the cosmologically most nearby unambiguous short burst with a measured redshift so far. We used the multi-colour imager GROND at the ESO/La Silla MPG 2.2 m telescope, ESO/VLT spectroscopy, and deep Australia Telescope Compact Array (ATCA) radio-continuum observations together with publicly available Gemini imaging data to study the putative host and the galaxies in the field of GRB 100628A. We confirm that inside the X-ray error circle the most probable host-galaxy candidate is the morphologically disturbed, interacting galaxy system at z = 0.102. The interacting galaxies are connected by a several kpc long tidal stream, which our VLT/FORS2 spectroscopy reveals strong emission lines of [O ii], [O iii], Hα and Hβ, characteristic for the class of extreme emission-line galaxies and indicative of ongoing star formation. The latter leaves open the possibility that the GRB progenitor was a member of a young stellar population. However, we indentify a second host-galaxy candidate slightly outside the X-ray error circle. It is a radio-bright, luminous elliptical galaxy at a redshift z = 0.311. With a K-band luminosity of 2 × 1011L⊙ this galaxy resembles the probable giant elliptical host of the first well-localized short burst, GRB 050509B. If this is the host, then the progenitor of GRB 100628A was a member of an old stellar population. Based on observations collected at the Very Large Telescope of the European Southern Observatory, Paranal, Chile (ESO programme 087.D-0503 and 290.D-5194; PI: A. Nicuesa Guelbenzu; 090.A-0825; PI: D. Malesani), GROND (PI: J. Greiner), and ATCA (Program C

  8. A novel approach for identifying host galaxies of nearby FRBs

    CERN Document Server

    Rane, Akshaya

    2016-01-01

    We report on a search for host galaxies of a subset of Rotating Radio Transients (RRATs) that possess a dispersion measure (DM) near or above the maximum Galactic value in their direction. These RRATs could have an extragalactic origin and therefore be Fast Radio Bursts (FRBs). The sizes of related galaxies on the sky at such short distances are comparable to the beam size of a single-dish telescope (for example, the $7.0'$ radius of the Parkes beam). Hence the association, if found, could be more definitive as compared to finding host galaxies for more distant FRBs. We did not find any host galaxy associated with six RRATs near the maximum Galactic DM. This result is consistent with the fact that the probability of finding an FRB host galaxy within this volume is also very small. We propose that future follow-up observations of such RRATs be carried out in searching for local host galaxies as well as the sources of FRBs.

  9. The host of GRB 060206: kinematics of a distant galaxy

    CERN Document Server

    Thoene, Christina C; Ledoux, Cedric; Starling, Rhaana L C; Fynbo, Johan P U; Curran, Peter A; Gorosabel, Javier; van der Horst, Alexander J; Kewley, Lisa J; Levan, Andrew J; LLorente, Alvaro; Rol, Evert; Tanvir, Nial R; Postigo, Antonio de Ugarte; Vreeswijk, Paul M; Wijers, Ralph A M J

    2007-01-01

    Context. The spectra of afterglows can provide us with detailed information on the line-of-sight towards high redshift gamma-ray bursts (GRBs). This allows us to use GRB afterglows as sensitive probes of interstellar matter in their host galaxies, and the circumstellar material around the progenitor star. Aims. In this paper we present early WHT/ISIS optical spectroscopy of the afterglow of the gamma-ray burst GRB 060206 at z = 4.048, detecting a range of metal absorption lines and their fine-structure transitions. Additional information is provided by properties derived from the afterglow lightcurve and from deep imaging of the host galaxy. Methods. The resolution and wavelength range of the spectra and the bright afterglow facilitate a detailed study of the circumburst and host galaxy environment through fitting of the absorption line systems. Their column densities allow us to derive properties for the different detected velocity components. We also use the deep imaging to detect the host galaxy and probe ...

  10. Host Galaxy Identification for Supernova Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ravi R.; et al.

    2016-04-20

    Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), which will discover SNe by the thousands. Spectroscopic resources are limited, so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Therefore, reliable identification of host galaxies is essential for cosmology and SN science. We simulate SN events and their locations within their host galaxies to develop and test methods for matching SNe to their hosts. We use both real and simulated galaxy catalog data from the Advanced Camera for Surveys General Catalog and MICECATv2.0, respectively. We also incorporate "hostless" SNe residing in undetected faint hosts into our analysis, with an assumed hostless rate of 5%. Our fully automated algorithm is run on catalog data and matches SNe to their hosts with 91% accuracy. We find that including a machine learning component, run after the initial matching algorithm, improves the accuracy (purity) of the matching to 97% with a 2% cost in efficiency (true positive rate). Although the exact results are dependent on the details of the survey and the galaxy catalogs used, the method of identifying host galaxies we outline here can be applied to any transient survey.

  11. The SEDs and Host Galaxies of the dustiest GRB afterglows

    CERN Document Server

    Krühler, T; Schady, P; Savaglio, S; Afonso, P M J; Clemens, C; Elliott, J; Filgas, R; Gruber, D; Kann, D A; Klose, S; Küpcü-Yoldas, A; McBreen, S; E., F Olivares; Pierini, D; Rau, A; Rossi, A; Nardini, M; Guelbenzu, A Nicuesa; Sudilovsky, V; Updike, A C

    2011-01-01

    (Abridged) Until recently the information inferred from gamma-ray burst follow-up observations was mostly limited to optically bright afterglows, biasing all demographic studies against sight-lines that contain large amounts of dust. Here, we present GRB afterglow and host observations for a sample of bursts that are exemplary of previously missed ones because of high visual extinction along the sight-line. This facilitates an investigation of the properties, geometry and location of the absorbing dust of these poorly-explored host galaxies, and a comparison to hosts from optically-selected samples. The hosts of the dustiest afterglows are diverse in their properties, but on average redder, more luminous and massive than the hosts of optically-bright events. We hence probe a different galaxy population, suggesting that previous host samples miss most of the massive, chemically-evolved and metal-rich members. This also indicates that the dust along the sight-line is often related to host properties, and thus p...

  12. Spatially-resolved dust properties of the GRB 980425 host galaxy

    DEFF Research Database (Denmark)

    Michałowski, Michał J.; Hunt, L. K.; Palazzi, E.;

    2014-01-01

    Gamma-ray bursts (GRBs) have been proposed as a tool to study star formation in the Universe, so it is crucial to investigate whether their host galaxies and immediate environments are in any way special compared with other star-forming galaxies. Here we present spatially resolved maps of dust em...

  13. The host galaxy and environment of a neutron star merger

    CERN Document Server

    Postigo, A de Ugarte; Rowlinson, A; Garcia-Benito, R; Levan, A J; Gorosabel, J; Goldoni, P; Schulze, S; Zafar, T; Wiersema, K; Sanchez-Ramirez, R; Melandri, A; D'Avanzo, P; Oates, S; D'Elia, V; De Pasquale, M; Kruehler, T; van der Horst, A J; Xu, D; Watson, D; Piranomonte, S; Vergani, S; Milvang-Jensen, B; Kaper, L; Malesani, D; Fynbo, J P U; Cano, Z; Covino, S; Flores, H; Greiss, S; Hammer, F; Hartoog, O E; Hellmich, S; Heuser, C; Hjorth, J; Jakobsson, P; Mottola, S; Sparre, M; Sollerman, J; Tagliaferri, G; Tanvir, N R; Vestergaard, M; Wijers, R A M J

    2013-01-01

    The mergers of neutron stars have been predicted to cause an r-process supernova - a luminous near-infrared transient powered by the radioactive decay of freshly formed heavy metals. An r-process supernova, or kilonova, has recently been discovered coincident with the short-duration gamma-ray burst GRB 130603B, simultaneously confirming the widely-held theory of the origin of most short-durations GRBs in neutron star mergers. We report here the absorption spectrum of the afterglow of this GRB. From it we determine the redshift of the burst and the properties of the host galaxy and the environment in which the merger occurred. The merger is not associated with the most star-forming region of the galaxy; however, it did occur in a dense region, implying a rapid merger or a low natal kick velocity for the neutron star binary.

  14. The metallicity properties of simulated long-GRB galaxy hosts and the Fundamental Metallicity Relation

    CERN Document Server

    Campisi, M A; Salvaterra, R; Mannucci, F; Colpi, M

    2011-01-01

    We study the implication of the collapsar model for Long Gamma-Ray Bursts (LGRBs) on the metallicity properties of the host galaxies, by combining high-resolution N-body simulations with semi-analytic models of galaxy formation. The cosmological model that we use reproduces the Fundamental Metallicity Relation recently discovered for the SDSS galaxies, whereby the metallicity decreases with increasing Star Formation Rate for galaxies of a given stellar mass. We select host galaxies housing pockets of gas-particles, young and with different thresholds in metallicities, that can be sites of LRGB events, according to the collapsar model. The simulated samples are compared with 18 observed LGRB hosts in the aim at discriminating whether the metallicity is a primary parameter. We find that a threshold in metallicity for the LGRB progenitors, within the model galaxies, is not necessary in order to reproduce the observed distribution of host metallicities. The low metallicities of observed LGRB hosts is a consequenc...

  15. GRB 080517: a local, low-luminosity gamma-ray burst in a dusty galaxy at z = 0.09

    Science.gov (United States)

    Stanway, Elizabeth R.; Levan, Andrew J.; Tanvir, Nial; Wiersema, Klaas; van der Horst, Alexander; Mundell, Carole G.; Guidorzi, Cristiano

    2015-02-01

    We present an analysis of the photometry and spectroscopy of the host galaxy of Swift-detected GRB 080517. From our optical spectroscopy, we identify a redshift of z = 0.089 ± 0.003, based on strong emission lines, making this a rare example of a very local, low-luminosity, long gamma-ray burst. The galaxy is detected in the radio with a flux density of S4.5 GHz = 0.22 ± 0.04 mJy - one of relatively few known gamma-ray bursts hosts with a securely measured radio flux. Both optical emission lines and a strong detection at 22 μm suggest that the host galaxy is forming stars rapidly, with an inferred star formation rate ˜16 M⊙ yr-1 and a high dust obscuration (E(B - V) > 1, based on sightlines to the nebular emission regions). The presence of a companion galaxy within a projected distance of 25 kpc, and almost identical in redshift, suggests that star formation may have been triggered by galaxy-galaxy interaction. However, fitting of the remarkably flat spectral energy distribution from the ultraviolet through to the infrared suggests that an older, 500 Myr post-starburst stellar population is present along with the ongoing star formation. We conclude that the host galaxy of GRB 080517 is a valuable addition to the still very small sample of well-studied local gamma-ray burst hosts.

  16. The extremely red host galaxy of GRB 080207

    CERN Document Server

    Hunt, Leslie; Rossi, Andrea; Savaglio, Sandra; Cresci, Giovanni; Klose, Sylvio; Michalowski, Michal; Pian, Elena

    2011-01-01

    We present optical, near-infrared, and Spitzer IRAC and MIPS observations of the host galaxy of the dark gamma-ray burst GRB 080207. The host is faint, with extremely red optical-infrared colors ($R-K\\,=\\,6.3$, 24\\micron/$R-$band flux $\\sim1000$) making it an extremely red object (ERO) and a dust-obscured galaxy (DOG). The spectral energy distribution (SED) shows the clear signature of the 1.6 micron photometric "bump", typical of evolved stellar populations. We use this bump to establish the photometric redshift $z_{\\rm phot}$ as 2.2$^{+0.2}_{-0.3}$, using a vast library of SED templates, including M 82. The star-formation rate (SFR) inferred from the SED fitting is $\\sim$119\\msun\\,yr$^{-1}$, the stellar mass $3\\times10^{11}$\\,\\msun, and \\av\\ extinction from 1-2\\,mag. The ERO and DOG nature of the host galaxy of the dark GRB 080207 may be emblematic of a distinct class of dark GRB hosts, with high SFRs, evolved and metal-rich stellar populations, and significant dust extinction within the host galaxy.

  17. THE OPTICALLY UNBIASED GAMMA-RAY BURST HOST (TOUGH) SURVEY. I. SURVEY DESIGN AND CATALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Hjorth, Jens; Malesani, Daniele; Fynbo, Johan P. U.; Kruehler, Thomas; Milvang-Jensen, Bo; Watson, Darach [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Jakobsson, Pall; Schulze, Steve [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavik (Iceland); Jaunsen, Andreas O. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Gorosabel, Javier [Instituto de Astrofisica de Andalucia (IAA-CSIC), P.O. Box 03004, E-18080 Granada (Spain); Levan, Andrew J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Michalowski, Michal J. [SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Moller, Palle [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching by Muenchen (Germany); Tanvir, Nial R., E-mail: jens@dark-cosmology.dk [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2012-09-10

    Long-duration gamma-ray bursts (GRBs) are powerful tracers of star-forming galaxies. We have defined a homogeneous subsample of 69 Swift GRB-selected galaxies spanning a very wide redshift range. Special attention has been devoted to making the sample optically unbiased through simple and well-defined selection criteria based on the high-energy properties of the bursts and their positions on the sky. Thanks to our extensive follow-up observations, this sample has now achieved a comparatively high degree of redshift completeness, and thus provides a legacy sample, useful for statistical studies of GRBs and their host galaxies. In this paper, we present the survey design and summarize the results of our observing program conducted at the ESO Very Large Telescope (VLT) aimed at obtaining the most basic properties of galaxies in this sample, including a catalog of R and K{sub s} magnitudes and redshifts. We detect the host galaxies for 80% of the GRBs in the sample, although only 42% have K{sub s} -band detections, which confirms that GRB-selected host galaxies are generally blue. The sample is not uniformly blue, however, with two extremely red objects detected. Moreover, galaxies hosting GRBs with no optical/NIR afterglows, whose identification therefore relies on X-ray localizations, are significantly brighter and redder than those with an optical/NIR afterglow. This supports a scenario where GRBs occurring in more massive and dusty galaxies frequently suffer high optical obscuration. Our spectroscopic campaign has resulted in 77% now having redshift measurements, with a median redshift of 2.14 {+-} 0.18. TOUGH alone includes 17 detected z > 2 Swift GRB host galaxies suitable for individual and statistical studies-a substantial increase over previous samples. Seven hosts have detections of the Ly{alpha} emission line and we can exclude an early indication that Ly{alpha} emission is ubiquitous among GRB hosts, but confirm that Ly{alpha} is stronger in GRB

  18. Host Galaxy Identification for Supernova Surveys

    CERN Document Server

    Gupta, Ravi R; Kovacs, Eve; Spinka, Harold; Kessler, Richard; Goldstein, Daniel A; Liotine, Camille; Pomian, Katarzyna; D'Andrea, Chris B; Sullivan, Mark; Carretero, Jorge; Castander, Francisco J; Nichol, Robert C; Finley, David A; Fischer, John A; Foley, Ryan J; Kim, Alex G; Papadopoulos, Andreas; Sako, Masao; Scolnic, Daniel M; Smith, Mathew; Tucker, Brad E; Uddin, Syed; Wolf, Rachel C; Yuan, Fang; Abbott, Tim M C; Abdalla, Filipe B; Benoit-Levy, Aurelien; Bertin, Emmanuel; Brooks, David; Rosell, Aurelio Carnero; Kind, Matias Carrasco; Cunha, Carlos E; da Costa, Luiz N; Desai, Shantanu; Doel, Peter; Eifler, Tim F; Evrard, August E; Flaugher, Brenna; Fosalba, Pablo; Gaztanaga, Enrique; Gruen, Daniel; Gruendl, Robert; James, David J; Kuehn, Kyler; Kuropatkin, Nikolay; Maia, Marcio A G; Marshall, Jennifer L; Miquel, Ramon; Plazas, Andres A; Romer, A Kathy; Sanchez, Eusebio; Schubnell, Michael; Sevilla-Noarbe, Ignacio; Sobreira, Flavia; Suchyta, Eric; Swanson, Molly E C; Tarle, Gregory; Walker, Alistair R; Wester, William

    2016-01-01

    Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), which will discover SNe by the thousands. Spectroscopic resources are limited, so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Therefore, reliable identification of host galaxies is essential for cosmology and SN science. We simulate SN events and their locations within their host galaxies to develop and test methods for matching SNe to their hosts. We use both real and simulated galaxy catalog data from the Advanced Camera for Surveys General Catalog and MICECATv2.0, respectively. We also incorporate "hostless" SNe residing in undetected faint hosts into our analysis, with an assumed hostless rate of 5%. Our fully automated alg...

  19. The afterglow and the host galaxy of GRB 011211

    CERN Document Server

    Jakobsson, P; Fynbo, J P U; Gorosabel, J; Pedersen, K; Burud, I; Levan, A J; Kouveliotou, C; Tanvir, N R; Fruchter, A S; Rhoads, J; Grav, T; Hansen, M W; Michelsen, R; Andersen, M I; Jensen, B L; Pedersen, H; Thomsen, B; Weidinger, M; Bhargavi, S G; Cowsik, R; Pandey, S B

    2003-01-01

    We present optical, near-infrared, and X-ray observations of the optical afterglow (OA) of the X-ray rich, long-duration gamma-ray burst GRB 011211. Hubble Space Telescope (HST) data obtained 14, 26, 32, and 59 days after the burst, show the host galaxy to have a morphology that is fairly typical of blue galaxies at high redshift. We measure its magnitude to be R = 24.95 +/- 0.11. We detect a break in the OA R-band light curve which is naturally accounted for by a collimated outflow geometry. By fitting a broken power-law to the data we find a best fit with a break 1.56 +/- 0.02 days after the burst, a pre-break slope of alpha_1 = -0.95 +/- 0.02, and a post-break slope of alpha_2 = -2.11 +/- 0.07. The UV-optical spectral energy distribution (SED) around 14 hours after the burst is best fit with a power-law with index beta = -0.56 +/- 0.19 reddened by an SMC-like extinction law with a modest A_V = 0.08 +/- 0.08 mag. By comparison, from the XMM-Newton X-ray data at around the same time, we find a decay index of...

  20. What are the galaxies that host MIR-selected AGN?

    Science.gov (United States)

    Rosario, David

    2016-08-01

    Infra-red selection techniques, sensitive to dust strongly heated by an AGN, offer a way to identify some of the most obscured accretion events in the Universe. I will describe the results of a comprehensive multi-wavelength study of AGN to z>2 selected using Spitzer/IRAC based methods in the COSMOS field. Armed with AGN-optimised redshifts and stellar masses, we explore the dust emission from the active nucleus and the host galaxy. We demonstrate that IR-selected AGN tend to be found in low mass host galaxies, when compared to other AGN identification methods. The star-formation rates of obscured and unobscured IR-selected AGN are very similar, implying that large-scale obscuration with co-eval star-bursts are not found in a major proportion of heavily obscured AGN.

  1. The host galaxy of GRB 990712

    DEFF Research Database (Denmark)

    Christensen, L.; Hjorth, J.; Gorosabel, J.;

    2004-01-01

    galaxy types shows that the host is similar to a moderately kreddened starburst galaxy with a young stellar population. The estimated internal extinction in the host is A(V) = 0.15 +/- 0.1 and the star-formation rate (SFR) from the UV continuum is 1.3 +/- 0.3 M-circle dot yr(-1) (not corrected...... for the effects of extinction). Other galaxy template spectra than starbursts failed to reproduce the observed SED. We also present VLT spectra leading to the detection of Halpha from the GRB host galaxy. A SFR of 2.8 +/- 0.7 M-circle dot yr(-1) is inferred from the Halpha line flux, and the presence of a young...

  2. Supernovae without host galaxy? - Hypervelocity stars in foreign galaxies

    CERN Document Server

    Zinn, Peter-Christian; Bomans, Dominik J

    2011-01-01

    Harvesting the SAI supernova catalog, we search for SNe that apparently do not occur within a distinct host galaxy but lie a great distance apart from their assigned host galaxy. Assuming two possible explanations for this host-lessness of a fraction of reported SNe, namely (i) a host galaxy which is too faint to be detected within the limits of currently available surveys or (ii) a hypervelocity star (HVS) as progenitor of the SN,we want to distinguish between these two cases. To do so, we use deep imaging to test explanation (i). If within our detection limit of 27 mag/arcsec^2, the central surface brightness of the faintest known LSB galaxy so far, no galaxy could be identified, we discard this explanation and regard the SN, after several other checks, to have had a hypervelocity star progenitor. Analyzing a selected subsample of five host-less SNe we find one, SN 2006bx in UGC5434, to be put in the hypervelocity progenitor category with a high probability, exhibiting a projected velocity of > 800 km/s. SN...

  3. Tidal Disruption Events Prefer Unusual Host Galaxies

    CERN Document Server

    French, K Decker; Zabludoff, Ann

    2016-01-01

    Tidal Disruption Events (TDEs) are transient events observed when a star passes close enough to a supermassive black hole to be tidally destroyed. Many TDE candidates have been discovered in host galaxies whose spectra have weak or no line emission yet strong Balmer line absorption, indicating a period of intense star formation that has recently ended. As such, TDE host galaxies fall into the rare class of quiescent Balmer-strong galaxies. Here, we quantify the fraction of galaxies in the Sloan Digital Sky Survey (SDSS) with spectral properties like those of TDE hosts, determining the extent to which TDEs are over-represented in such galaxies. Galaxies whose spectra have Balmer absorption H$\\delta_{\\rm A}$ $-$ $\\sigma$(H$\\delta_{\\rm A}$) $>$ 4 \\AA\\ (where $\\sigma$(H$\\delta_{\\rm A}$) is the error in the Lick H$\\delta_{\\rm A}$ index) and H$\\alpha$ emission EW $$ 1.31 \\AA\\ and H$\\alpha$ EW $80\\times$ enhancement in such hosts and providing an observational link between the $\\gamma$/X-ray-bright and optical/UV-br...

  4. The Offset and Host Light Distributions of Long Gamma-Ray Bursts: A New View from HST Observations of Swift Bursts

    CERN Document Server

    Blanchard, Peter K; Fong, Wen-fai

    2015-01-01

    [Abridged] We present the results of an extensive Hubble Space Telescope (HST) imaging study of ~100 Swift long-duration gamma-ray bursts (LGRBs) spanning 0.03 0.6 while bursts at R/R_h > 0.5 uniformly trace the light of their hosts. This indicates that the spatial correlation of LGRB locations with bright star forming regions seen in the full sample is dominated by the contribution from bursts at small offset and that LGRBs in the outer parts of galaxies show no preference for unusually bright star forming regions. We conclude that LGRBs strongly prefer the bright, inner regions of their hosts indicating that the star formation taking place there is more favorable for LGRB progenitor production. This indicates that another environmental factor beyond metallicity, such as binary interactions or IMF differences, may be operating in the central regions of LGRB hosts.

  5. Bursts of star formation in computer simulations of dwarf galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Comins, N.F.

    1984-09-01

    A three-dimensional Stochastic Self-Propagating Star Formation (SSPSF) model of compact galacies is presented. Two phases of gas, active and inactive, are present, and permanent depletion of gas in the form of long lived, low mass stars and remnants occurs. Similarly, global infall of gas from a galactic halo or through galactic cannibalism is permitted. We base our parameters on the observed properties of the compact blue galaxy I Zw 36. Our results are that bursts of star formation occur much more frequently in these runs than continuous nonbursting star formation, suggesting that the blue compact galaxies are probably undergoing bursts rather than continuous, nonbursting low-level star formation activity.

  6. On the Host Galaxy of GRB 150101B and the Associated Active Galactic Nucleus

    CERN Document Server

    Xie, Chen; Wang, Junfeng; Liu, Tong; Jiang, Xiaochuan

    2016-01-01

    We present a multi-wavelength analysis of the host galaxy of short-duration gamma-ray burst (GRB) 150101B. Follow-up optical and X-ray observations suggested that the host galaxy, 2MASX J12320498-1056010, likely harbors a low-luminosity active galactic nuclei (AGN). Our modeling of the spectral energy distribution (SED) has confirmed the nature of the AGN, making it the first reported GRB host that contains an AGN. We have also found the host galaxy is a massive elliptical galaxy with stellar population of $\\sim 5.7\\ Gyr$, one of the oldest among the short-duration GRB hosts. Our analysis suggests that the host galaxy can be classified as an X-ray bright, optically normal galaxy (XBONG), and the central AGN is likely dominated by a radiatively inefficient accretion flow (RIAF). Our work explores interesting connection that may exist between GRB and AGN activities of the host galaxy, which can help understand the host environment of the GRB events and the roles of AGN feedback.

  7. Spectral Decomposition of Broad-Line AGNs and Host Galaxies

    CERN Document Server

    Vanden Berk, Daniel E; Yip, C W; Schneider, D P; Connolly, A J; Burton, R E; Jester, S; Hall, P B; Szalay, A S; Brinkmann, J; Berk, Daniel E. Vanden; Shen, Jiajian; Yip, Ching-Wa; Schneider, Donald P.; Connolly, Andrew J.; Burton, Ross E.; Jester, Sebastian; Hall, Patrick B.; Szalay, Alex S.; Brinkmann, John

    2005-01-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasing...

  8. AGN Absorption Linked to Host Galaxies

    CERN Document Server

    Juneau, Stéphanie

    2013-01-01

    Multiwavelength identification of AGN is crucial not only to obtain a more complete census, but also to learn about the physical state of the nuclear activity (obscuration, efficiency, etc.). A panchromatic strategy plays an especially important role when the host galaxies are star-forming. Selecting far-Infrared galaxies at 0.3host galaxies, indicating a physical link between X-ray absorption and either the gas fraction or the gas geometry in the hosts. These findings have implications for our current understanding of both the AGN unification model and the nature of the black hole-galaxy connection. These proceedi...

  9. Hα Imaging of Nearby Seyfert Host Galaxies

    Science.gov (United States)

    Theios, Rachel L.; Malkan, Matthew A.; Ross, Nathaniel R.

    2016-05-01

    We used narrowband (Δλ = 70 Å) interference filters with the CCD imaging camera on the Nickel 1.0 m telescope at Lick Observatory to observe 31 nearby (z extinction. We separated the Hα emission line of the “nucleus” (central 100-1000 pc) from that of the host galaxy. The extended Hα emission is expected to be powered by newly formed hot stars, and indeed correlates well with other indicators of current star formation rates (SFRs) in these galaxies: extended 7.7 μm polycyclic aromatic hydrocarbon, total far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The Hα luminosity we measured in the centers of our galaxies is dominated by the active galactic nucleus (AGN), and is linearly correlated with the hard X-ray luminosity. There is, however, an upward offset of 1 dex in this correlation for the Seyfert 1s, because their nuclear Hα emission includes a strong additional contribution from the broad-line region. We found a correlation between SFR and AGN luminosity. In spite of selection effects, we concluded that the absence of bright Seyfert nuclei in galaxies with low SFRs is real, albeit only weakly significant. Finally, we used our measured spatial distributions of Hα emission to determine what these Seyfert galaxies would look like when observed through fixed apertures (e.g., a spectroscopic fiber) at high redshifts. We found that although all of these Seyfert galaxies would be detectable emission-line galaxies at any redshift, most of them would appear to be dominated by (>67%) their H ii region emission. Only the most luminous AGNs (log(L Hα /erg s-1) > 41.5) would still be identified as such at z ˜ 0.3.

  10. MODELING THE GRB HOST GALAXY MASS DISTRIBUTION: ARE GRBs UNBIASED TRACERS OF STAR FORMATION?

    International Nuclear Information System (INIS)

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low-metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity relationship for galaxies, along with a sharp host metallicity cutoff suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that subsolar metallicity cutoffs effectively limit GRBs to low-stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low-metallicity cutoffs of 0.1 to 0.5 Zsun are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H)KK04 = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z ∼ 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity-biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  11. Modeling The GRB Host Galaxy Mass Distribution: Are GRBs Unbiased Tracers of Star Formation?

    Energy Technology Data Exchange (ETDEWEB)

    Kocevski, Daniel; /KIPAC, Menlo Park; West, Andrew A.; /UC, Berkeley, Astron. Dept. /MIT, MKI; Modjaz, Maryam; /UC, Berkeley, Astron. Dept.

    2009-08-03

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity (M-Z) relationship for galaxies, along with a sharp host metallicity cut-off suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that sub-solar metallicity cut-offs effectively limit GRBs to low stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low metallicity cut-offs of 0.1 to 0.5 Z{sub {circle_dot}} are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H){sub KK04} = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z {approx} 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  12. Spectral decomposition of broad-line agns and host galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Vanden Berk, Daniel E.; Shen, Jiajian; /Penn State U., Astron. Astrophys.; Yip, Ching-Wa; /Pittsburgh U.; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Connolly,; /Pittsburgh U.; Burton, Ross E.; /Pittsburgh U. /Case Western Reserve U.; Jester, Sebastian; /Fermilab; Hall, Patrick B.; /York U., Canada; Szalay, Alex S.; /Johns Hopkins; Brinkmann, John; /Apache Point Observ.

    2005-09-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  13. Preliminary Results on VLT K-band Imaging Observations of GRB Host Galaxies

    Indian Academy of Sciences (India)

    E. Le Floc’h; I. F. Mirabel; P.-A. Duc

    2002-03-01

    We have obtained -band imaging observations of Gamma-Ray Burst (GRB) host galaxies with the near-infrared spectro-imager ISAAC installed on the Very Large Telescope at Paranal (Chile). The derived magnitudes, combined with other photometric data taken from the literature, are used to investigate the – colors of GRB hosts. We do not find any extremely reddened starbursts in our sample, despite the capability of GRBs to trace star formation even in dusty regions. The observed – colors are on the contrary typical of irregular and spiral blue galaxies at high redshift.

  14. The Post-Starburst Evolution of Tidal Disruption Event Host Galaxies

    CERN Document Server

    French, K Decker; Zabludoff, Ann

    2016-01-01

    Tidal Disruption Events (TDEs) favor quiescent host galaxies with strong Balmer absorption lines. Here we study eight hosts of optical/UV-detected TDEs to determine the duration of the recent star formation episode, the time elapsed since it ended, and the fraction of stellar mass produced. Most hosts (6/8) have had short recent starbursts of <200 Myr as opposed to a slower decline in star formation. TDE host galaxies span a wide range of post-starburst ages (60-600 Myr for 6/8 galaxies), indicating that TDEs are not limited to a specific time in their hosts' post-starburst evolution. If the disrupted star was a main sequence star that formed in the burst or before, the post-burst ages provide an independent constraint on its likely mass, excluding O, B and the most massive A stars. If the starburst arose from a galaxy merger, the time elapsed since the starburst began constrains the coalescence timescale and thus limits the merger mass ratio to more equal than 12:1 in most (7/8) TDE hosts. This uncommon r...

  15. The optical afterglow and host galaxy of GRB 000926

    DEFF Research Database (Denmark)

    Fynbo, J.U.; Gorosabel, J.; Dall, T.H.;

    2002-01-01

    In this paper we illustrate with the case of GRB 000926 how Gamma Ray Bursts (GRBs) can be used as cosmological lighthouses to identify and study star forming galaxies at high redshifts. The optical afterglow of the burst was located with optical imaging at the Nordic Optical Telescope 20.7 hours...

  16. Host Galaxy Properties of the Swift BAT Ultra Hard X-Ray Selected AGN

    Science.gov (United States)

    Koss, Michael; Mushotzky, Richard; Veilleux, Sylvain; Winter, Lisa M.; Baumgartner, Wayne; Tueller, Jack; Gehrels, Neil; Valencic, Lynne

    2011-01-01

    We have assembled the largest sample of ultra hard X-ray selected (14-195 keV) AGN with host galaxy optical data to date, with 185 nearby (zAGN from the Swift Burst Alert Telescope (BAT) sample. The BAT AGN host galaxies have intermediate optical colors (u -- r and g -- r) that are bluer than a comparison sample of inactive galaxies and optically selected AGN from the Sloan Digital Sky Survey (SDSS) which are chosen to have the same stellar mass. Based on morphological classifications from the RC3 and the Galaxy Zoo, the bluer colors of BAT AGN are mainly due to a higher fraction of mergers and massive spirals than in the comparison samples. BAT AGN in massive galaxies (log Stellar Mass >10.5) have a 5 to 10 times higher rate of spiral morphologies than in SDSS AGN or inactive galaxies. We also see enhanced far-IR emission in BAT AGN suggestive of higher levels of star formation compared to the comparison samples. BAT AGN are preferentially found in the most massive host galaxies with high concentration indexes indicative of large bulge-to-disk ratios and large supermassive black holes. The narrow-line (NL) BAT AGN have similar intrinsic luminosities as the SDSS NL Seyferts based on measurements of [O III] Lambda 5007. There is also a correlation between the stellar mass and X-ray emission. The BAT AGN in mergers have bluer colors and greater ultra hard X-ray emission compared to the BAT sample as whole. In agreement with the Unified Model of AGN, and the relatively unbiased nature of the BAT sources, the host galaxy colors and morphologies are independent of measures of obscuration such as X-ray column density or Seyfert type. The high fraction of massive spiral galaxies and galaxy mergers in BAT AGN suggest that host galaxy morphology is related to the activation and fueling of local AGN.

  17. On the Origin of the Mass-Metallicity Relation for GRB Host Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Kocevski, Daniel; /KIPAC, Menlo Park; West, Andrew A.; /Boston U., Dept. Astron.

    2011-06-02

    We investigate the nature of the mass-metallicity (M-Z) relation for long gamma-ray burst (LGRB) host galaxies. Recent studies suggest that the M-Z relation for local LGRB host galaxies may be systematically offset towards lower metallicities relative to the M-Z relation defined by the general star forming galaxy (SDSS) population. The nature of this offset is consistent with suggestions that low metallicity environments may be required to produce high mass progenitors, although the detection of several GRBs in high-mass, high-metallicity galaxies challenges the notion of a strict metallicity cut-off for host galaxies that are capable of producing GRBs. We show that the nature of this reported offset may be explained by a recently proposed anti-correlation between the star formation rate (SFR) and the metallicity of star forming galaxies. If low metallicity galaxies produce more stars than their equally massive, high-metallicity counterparts, then transient events that closely trace the SFR in a galaxy would be more likely to be found in these low metallicity, low mass galaxies. Therefore, the offset between the GRB and SDSS defined M-Z relations may be the result of the different methods used to select their respective galaxy populations, with GRBs being biased towards low metallicity, high SFR, galaxies. We predict that such an offset should not be expected of transient events that do not closely follow the star formation history of their host galaxies, such as short duration GRBs and SN Ia, but should be evident in core collapse SNe found through upcoming untargeted surveys.

  18. A Hubble Space Telescope Survey of the Host Galaxies of Superluminous Supernovae

    CERN Document Server

    Angus, C R; Perley, D A; Tanvir, N R; Lyman, J D; Stanway, E R; Fruchter, A S

    2016-01-01

    We present Hubble Space Telescope (HST) WFC3 UV and near-IR (nIR) imaging of 21 Superluminous Supernovae (SLSNe) host galaxies, providing a sensitive probe of star formation and stellar mass with the hosts. Comparing the photometric and morphological properties of these host galaxies with those of core collapse supernovae (CCSNe) and long-duration gamma-ray bursts (LGRBs), we find SLSN hosts are fainter and more compact at both UV and nIR wavelengths, in some cases we barely recover hosts with absolute magnitude around MV ~ -14. With the addition of ground based optical observations and archival results, we produce spectral energy distribution (SED) fits to these hosts, and show that SLSN hosts possess lower stellar mass and star formation rates. This is most pronounced for the hydrogen deficient Type-I SLSN hosts, although Type-II H-rich SLSN host galaxies remain distinct from the bulk of CCSNe, spanning a remarkably broad range of absolute magnitudes, with ~30% of SLSNe-II arising from galaxies fainter than...

  19. The Contribution from Scattered Light to Quasar Galaxy Hosts

    CERN Document Server

    Young, S; Robinson, A; Capetti, A

    2009-01-01

    We present models representing the scattering of quasar radiation off free electrons and dust grains in geometries that approximate the structure of quasar host galaxies. We show that, for reasonable assumptions, scattering alone can easily produce ratios of nuclear (point source) to extended fluxes comparable to those determined in studies of quasar hosts. This result suggests that scattered quasar light, as well as stellar emission from the host galaxy, contributes significantly to the detected extended flux, leading to uncertainty in the inferred properties of quasar host. A significant contribution from scattered quasar light will lead to overestimates of the luminosity and hence mass of the host galaxy, and may also distort its morphology. Scattering of quasar light within the host galaxy may provide alternative explanations for the apparent peak in host luminosity at z = 2-3; possibly the overall average higher luminosity of radio-loud host galaxies relative to those of radio-quiet quasars (RQQs), and t...

  20. Survival analysis of the optical brightness of GRB host galaxies

    CERN Document Server

    Racz, I I; Bagoly, Z; Toth, L V

    2015-01-01

    We studied the unbiased optical brightness distribution which was calculated from the survival analysis of host galaxies and its relationship with the Swift GRB data of the host galaxies observed by the Keck telescopes. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we also studied the dependence of this distribution on the data of the GRBs. Finally, we compared the HGs distribution with standard galaxies distribution which is in the DEEP2 galaxies catalog.

  1. The structure of host galaxies of radio-loud quasars and possible triggering mechanisms for quasar activity

    Energy Technology Data Exchange (ETDEWEB)

    Romanishin, W.; Hintzen, P. (Arizona State Univ., Tempe (USA); NASA, Goddard Space Flight Center, Greenbelt, MD (USA))

    1989-06-01

    An image modeling program is used to analyze optical imaging data for a sample of radio-loud quasars with redshifts between 0.2 and 0.7. It is found that the host galaxies of these quasars tend to be more compact than normal ellipticals. The cooling flow cluster elliptical galaxies near these host galaxies are studied. It is suggested that these cooling flow galaxies are also compact due to star formation in their central regions. Two populations of quasars are identified. One, in which activity is triggered by galaxy mergers of interactions has predominately spiral galaxies and are radio quiet. The other, in which activity is triggered by star formation bursts induced by cooling flows, has predominately elliptical hosts and may be radio loud. 28 refs.

  2. The structure of host galaxies of radio-loud quasars and possible triggering mechanisms for quasar activity

    International Nuclear Information System (INIS)

    An image modeling program is used to analyze optical imaging data for a sample of radio-loud quasars with redshifts between 0.2 and 0.7. It is found that the host galaxies of these quasars tend to be more compact than normal ellipticals. The cooling flow cluster elliptical galaxies near these host galaxies are studied. It is suggested that these cooling flow galaxies are also compact due to star formation in their central regions. Two populations of quasars are identified. One, in which activity is triggered by galaxy mergers of interactions has predominately spiral galaxies and are radio quiet. The other, in which activity is triggered by star formation bursts induced by cooling flows, has predominately elliptical hosts and may be radio loud. 28 refs

  3. The structure of host galaxies of radio-loud quasars and possible triggering mechanisms for quasar activity

    Science.gov (United States)

    Romanishin, W.; Hintzen, Paul

    1989-01-01

    An image modeling program is used to analyze optical imaging data for a sample of radio-loud quasars with redshifts between 0.2 and 0.7. It is found that the host galaxies of these quasars tend to be more compact than normal ellipticals. The cooling flow cluster elliptical galaxies near these host galaxies are studied. It is suggested that these cooling flow galaxies are also compact due to star formation in their central regions. Two populations of quasars are identified. One, in which activity is triggered by galaxy mergers of interactions has predominately spiral galaxies and are radio quiet. The other, in which activity is triggered by star formation bursts induced by cooling flows, has predominately elliptical hosts and may be radio loud.

  4. A Detection of Molecular Gas Emission in the Host Galaxy of GRB 080517

    CERN Document Server

    Stanway, E R; Tanvir, N R; Wiersema, K; van der Laan, T P R

    2014-01-01

    We have observed the host galaxy of the low redshift, low luminosity GRB 080517 at 105.8 GHz using the IRAM Plateau de Bure interferometer. We detect an emission line with integrated flux S.delta{nu} = 0.39 +/- 0.05 Jy km/s - consistent both spatially and in velocity with identification as the J=1-0 rotational transition of carbon monoxide (CO) at the host galaxy redshift. This represents only the third long GRB host galaxy with molecular gas detected in emission. The inferred molecular gas mass, M_H2 ~ 6.3 x 10^8 M_sun, implies a gas consumption timescale of ~40 Myr if star formation continues at its current rate. Similar short timescales appear characteristic of the long GRB population with CO observations to date, suggesting that the gamma-ray burst in these sources occurs towards the end of their star formation episode.

  5. The Afterglows and Host Galaxies of Short GRBs: An Overview

    CERN Document Server

    Berger, E

    2006-01-01

    Despite a rich diversity in observational properties, gamma-ray bursts (GRBs) can be divided into two broad categories based on their duration and spectral hardness -- the long-soft and the short-hard GRBs. The discovery of afterglows from long GRBs in 1997, and their localization to arcsecond accuracy, was a watershed event. The ensuing decade of intense study led to the realization that long-soft GRBs are located in star forming galaxies, produce about 10^51 erg in collimated relativistic ejecta, are accompanied by supernovae, and result from the death of massive stars. While theoretical arguments suggest that short GRBs have a different physical origin, the lack of detectable afterglows prevented definitive conclusions. The situation changed dramatically starting in May 2005 with the discovery of the first afterglows from short GRBs localized by Swift and HETE-2. Here I summarize the discovery of these afterglows and the underlying host galaxies, and draw initial conclusions about the nature of the progeni...

  6. STAR CLUSTER COMPLEXES AND THE HOST GALAXY IN THREE H II GALAXIES: Mrk 36, UM 408, AND UM 461

    Energy Technology Data Exchange (ETDEWEB)

    Lagos, P. [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Telles, E. [Observatorio Nacional, Rua Jose Cristino, 77, Rio de Janeiro 20921-400 (Brazil); Nigoche-Netro, A. [Instituto de Astrofisica de Andalucia (IAA), Glorieta de la Astronomia s/n, 18008 Granada (Spain); Carrasco, E. R., E-mail: plagos@astro.up.pt, E-mail: etelles@on.br, E-mail: nigoche@iaa.es, E-mail: rcarrasco@gemini.edu [Gemini Observatory/AURA, Southern Operations Center, Casilla 603, La Serena (Chile)

    2011-11-15

    We present a stellar population study of three H II galaxies (Mrk 36, UM 408, and UM 461) based on the analysis of new ground-based high-resolution near-infrared J, H, and K{sub p} broadband and Br{gamma} narrowband images obtained with Gemini/NIRI. We identify and determine the relative ages and masses of the elementary star clusters and/or star cluster complexes of the starburst regions in each of these galaxies by comparing the colors with evolutionary synthesis models that include the contribution of stellar continuum, nebular continuum, and emission lines. We found that the current star cluster formation efficiency in our sample of low-luminosity H II galaxies is {approx}10%. Therefore, most of the recent star formation is not in massive clusters. Our findings seem to indicate that the star formation mode in our sample of galaxies is clumpy, and that these complexes are formed by a few massive star clusters with masses {approx}>10{sup 4} M{sub Sun }. The age distribution of these star cluster complexes shows that the current burst started recently and likely simultaneously over short timescales in their host galaxies, triggered by some internal mechanism. Finally, the fraction of the total cluster mass with respect to the low surface brightness (or host galaxy) mass, considering our complete range in ages, is less than 1%.

  7. Energy input from quasars regulates the growth and activity of black holes and their host galaxies.

    Science.gov (United States)

    Di Matteo, Tiziana; Springel, Volker; Hernquist, Lars

    2005-02-10

    In the early Universe, while galaxies were still forming, black holes as massive as a billion solar masses powered quasars. Supermassive black holes are found at the centres of most galaxies today, where their masses are related to the velocity dispersions of stars in their host galaxies and hence to the mass of the central bulge of the galaxy. This suggests a link between the growth of the black holes and their host galaxies, which has indeed been assumed for a number of years. But the origin of the observed relation between black hole mass and stellar velocity dispersion, and its connection with the evolution of galaxies, have remained unclear. Here we report simulations that simultaneously follow star formation and the growth of black holes during galaxy-galaxy collisions. We find that, in addition to generating a burst of star formation, a merger leads to strong inflows that feed gas to the supermassive black hole and thereby power the quasar. The energy released by the quasar expels enough gas to quench both star formation and further black hole growth. This determines the lifetime of the quasar phase (approaching 100 million years) and explains the relationship between the black hole mass and the stellar velocity dispersion. PMID:15703739

  8. Spatially-resolved dust properties of the GRB 980425 host galaxy

    CERN Document Server

    Michałowski, Michał J; Palazzi, E; Savaglio, S; Gentile, G; Rasmussen, J; Baes, M; Basa, S; Bianchi, S; Berta, S; Burlon, D; Ceron, J M Castro; Covino, S; Cuby, J -G; D'Elia, V; Ferrero, P; Gotz, D; Hjorth, J; Koprowski, M P; Borgne, D Le; Floc'h, E Le; Malesani, D; Murphy, T; Pian, E; Piranomonte, S; Rossi, A; Sollerman, J; Tanvir, N R; Postigo, A de Ugarte; Watson, D; van der Werf, P; Vergani, S D; Xu, D

    2013-01-01

    Gamma-ray bursts (GRBs) have been proposed as a tool to study star formation in the Universe, so it is crucial to investigate whether their host galaxies and immediate environments are in any way special compared with other star-forming galaxies. Here we present spatially resolved maps of dust emission of the host galaxy of the closest known GRB 980425 at z=0.0085 using our new high-resolution observations from Herschel, APEX, ALMA and ATCA. We modeled the spectral energy distributions of the host and of the star-forming region displaying the Wolf-Rayet signatures in the spectrum (WR region), located 800 pc away from the GRB position. The host is characterised by low dust content and high fraction of UV-visible star-formation, similar to other dwarf galaxies. Such galaxies are abundant in the local universe, so it is not surprising to find a GRB in one of them, assuming the correspondence between the GRB rate and star-formation. The WR region contributes substantially to the host emission at the far-infrared,...

  9. Radio Galaxy Zoo: host galaxies and radio morphologies derived from visual inspection

    Science.gov (United States)

    Banfield, J. K.; Wong, O. I.; Willett, K. W.; Norris, R. P.; Rudnick, L.; Shabala, S. S.; Simmons, B. D.; Snyder, C.; Garon, A.; Seymour, N.; Middelberg, E.; Andernach, H.; Lintott, C. J.; Jacob, K.; Kapińska, A. D.; Mao, M. Y.; Masters, K. L.; Jarvis, M. J.; Schawinski, K.; Paget, E.; Simpson, R.; Klöckner, H.-R.; Bamford, S.; Burchell, T.; Chow, K. E.; Cotter, G.; Fortson, L.; Heywood, I.; Jones, T. W.; Kaviraj, S.; López-Sánchez, Á. R.; Maksym, W. P.; Polsterer, K.; Borden, K.; Hollow, R. P.; Whyte, L.

    2015-11-01

    We present results from the first 12 months of operation of Radio Galaxy Zoo, which upon completion will enable visual inspection of over 170 000 radio sources to determine the host galaxy of the radio emission and the radio morphology. Radio Galaxy Zoo uses 1.4 GHz radio images from both the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) and the Australia Telescope Large Area Survey (ATLAS) in combination with mid-infrared images at 3.4 μm from the Wide-field Infrared Survey Explorer (WISE) and at 3.6 μm from the Spitzer Space Telescope. We present the early analysis of the WISE mid-infrared colours of the host galaxies. For images in which there is >75 per cent consensus among the Radio Galaxy Zoo cross-identifications, the project participants are as effective as the science experts at identifying the host galaxies. The majority of the identified host galaxies reside in the mid-infrared colour space dominated by elliptical galaxies, quasi-stellar objects and luminous infrared radio galaxies. We also find a distinct population of Radio Galaxy Zoo host galaxies residing in a redder mid-infrared colour space consisting of star-forming galaxies and/or dust-enhanced non-star-forming galaxies consistent with a scenario of merger-driven active galactic nuclei (AGN) formation. The completion of the full Radio Galaxy Zoo project will measure the relative populations of these hosts as a function of radio morphology and power while providing an avenue for the identification of rare and extreme radio structures. Currently, we are investigating candidates for radio galaxies with extreme morphologies, such as giant radio galaxies, late-type host galaxies with extended radio emission and hybrid morphology radio sources.

  10. Comparing the host galaxies of different type supernovae

    Science.gov (United States)

    Liang, Yanchun; Shao, Xu; Dennefeld, Michel; Chen, Xiaoyan; Zhou, Li; Hammer, Francois

    2015-08-01

    We examine and compare the properties of host galaxies of 902 supernovae, including both SNe Ia and Core-collapse supernovae (SNe II and SNe Ibc), selected by cross-matching the Asiago Supernova Catalog with the SDSS DR7 main-galaxy sample. Then, a main working sample consisting 213 galaxies are further selected by requiring the light fraction > 15% covered by the fiber spectral observations. This criterion of light fraction minimizes the aperture effect on the analysis of properties of SN host galaxies. Since 135 among the 213 galaxies appear on the Baldwin-Phillips-Terlevich (BPT) diagram, we then could compare the host properties of different types of SNe on the basis of their BPT diagnosis, i.e. star-forming (SF) galaxies, AGNs, and then the rest 78 “Absorption” galaxies. A comparative sample composed by the remaining 689 galaxies are analyzed simultaneously for comparisons, then the obvious aperture effect on the properties of SN host galaxies are shown. The parameters Dn(4000), HδA, stellar masses, SFRs, specific SFRs and relations of stellar mass with metallicity of SN host galaxies are analyzed in the work.

  11. The apparently normal galaxy hosts for two luminous quasars

    CERN Document Server

    Bahcall, J N; Bahcall, John N; Schneider, Donald P

    1995-01-01

    HST images (with WFPC2) of PHL~909\\ (z = 0.171) and PG~0052+251\\ (z = 0.155) show that these luminous radio-quiet quasars each occur in an apparently normal host galaxy. The host galaxy of PHL~909 is an elliptical galaxy (\\sim E4) and the host of PG~0052+251 is a spiral (\\sim~Sb). Both host galaxies are several tenths of a magnitude brighter than L^*, the characteristic Schechter luminosity of field galaxies. The images of PHL~909 and PG~0052+251, when compared with HST images of other objects in our sample of 20 luminous, small-redshift (z \\leq 0.30) quasars, show that luminous quasars occur in a variety of environments. The local environments of the luminous quasars range from luminous ellipticals, to apparently normal host galaxies, to complex systems of interacting components, to faint (and as yet undetected) hosts. The bright HII regions of the host galaxy of PG~0052+251 provide an opportunity to measure directly the metallicity of the host of a luminous quasar, to establish an upper limit to the mass of...

  12. LONG GRBs ARE METALLICITY-BIASED TRACERS OF STAR FORMATION: EVIDENCE FROM HOST GALAXIES AND REDSHIFT DISTRIBUTION

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F. Y.; Dai, Z. G., E-mail: fayinwang@nju.edu.cn, E-mail: dzg@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2014-07-01

    We investigate the mass distribution of long gamma-ray burst (GRB) host galaxies and the redshift distribution of long GRBs by considering that long GRBs occur in low-metallicity environments. We calculate the upper limit on the stellar mass of a galaxy which can produce long GRBs by utilizing the mass-metallicity (M-Z) relation of galaxies. After comparing with the observed GRB host galaxies masses, we find that the observed GRB host galaxy masses can fit the predicted masses well if GRBs occur in low-metallicity 12 + log (O/H){sub KK04} < 8.7. GRB host galaxies have low metallicity, low mass, and high star formation rate compared with galaxies of seventh data release of the Sloan Digital Sky Survey. We also study the cumulative redshift distribution of the latest Swift long GRBs by adding dark GRBs and 10 new GRBs redshifts from the TOUGH survey. The observed discrepancy between the GRB rate and the star formation history can be reconciled by considering that GRBs tend to occur in low-metallicity galaxies with 12 + log (O/H){sub KK04} < 8.7. We conclude that the metallicity cutoff that can produce long GRBs is about 12 + log (O/H){sub KK04} < 8.7 from the host mass distribution and redshift distribution.

  13. LATE-TIME OBSERVATIONS OF GRB 080319B: JET BREAK, HOST GALAXY, AND ACCOMPANYING SUPERNOVA

    International Nuclear Information System (INIS)

    The Swift-discovered GRB 080319B was by far the most distant source ever observed at naked-eye brightness, reaching a peak apparent magnitude of 5.3 at a redshift of z = 0.937. We present our late-time optical (Hubble Space Telescope, Gemini, and Very Large Telescope) and X-ray (Chandra) observations, which confirm that an achromatic break occurred in the power-law afterglow light curve at ∼11 days post-burst. This most likely indicates that the gamma-ray burst (GRB) outflow was collimated, which for a uniform jet would imply a total energy in the jet Ejet ∼> 1052 erg. Our observations also show a late-time excess of red light, which is well explained if the GRB was accompanied by a supernova (SN), similar to those seen in some other long-duration GRBs. The latest observations are dominated by light from the host and show that the GRB took place in a faint dwarf galaxy (r(AB) ∼ 27.0, rest frame MB ∼ -17.2). This galaxy is small even by the standards of other GRB hosts, which is suggestive of a low-metallicity environment. Intriguingly, the properties of this extreme event-a small host and bright SN-are entirely typical of the very low luminosity bursts such as GRB 980425 and GRB 060218.

  14. Galaxy Zoo: Evidence for rapid, recent quenching within a population of AGN host galaxies

    Science.gov (United States)

    Smethurst, R. J.; Lintott, C. J.; Simmons, B. D.; Schawinski, K.; Bamford, S. P.; Cardamone, C. N.; Kruk, S. J.; Masters, K. L.; Urry, C. M.; Willett, K. W.; Wong, O. I.

    2016-09-01

    We present a population study of the star formation history of 1244 Type 2 AGN host galaxies, compared to 6107 inactive galaxies. A Bayesian method is used to determine individual galaxy star formation histories, which are then collated to visualise the distribution for quenching and quenched galaxies within each population. We find evidence for some of the Type 2 AGN host galaxies having undergone a rapid drop in their star formation rate within the last 2 Gyr. AGN feedback is therefore important at least for this population of galaxies. This result is not seen for the quenching and quenched inactive galaxies whose star formation histories are dominated by the effects of downsizing at earlier epochs, a secondary effect for the AGN host galaxies. We show that histories of rapid quenching cannot account fully for the quenching of all the star formation in a galaxy's lifetime across the population of quenched AGN host galaxies, and that histories of slower quenching, attributed to secular (non-violent) evolution, are also key in their evolution. This is in agreement with recent results showing both merger-driven and non-merger processes are contributing to the co-evolution of galaxies and supermassive black holes. The availability of gas in the reservoirs of a galaxy, and its ability to be replenished, appear to be the key drivers behind this co-evolution.

  15. Herschel/PACS Observations of the Host Galaxy of GRB 031203

    CERN Document Server

    Symeonidis, M; de Pasquale, M; Page, M J; Wiersema, K; Starling, R; Schady, P; Seymour, N; O'Halloran, B

    2014-01-01

    We present Herschel/PACS observations of the nearby (z=0.1055) dwarf galaxy that has hosted the long gamma ray burst (LGRB) 031203. Using the PACS data we have been able to place constraints on the dust temperature, dust mass, total infrared luminosity and infrared-derived star-formation rate (SFR) for this object. We find that the GRB host galaxy (GRBH) 031203 has a total infrared luminosity of 3x10^10 L_sun placing it in the regime of the IR-luminous galaxy population. Its dust temperature and specific SFR are comparable to that of many high-redshift (z=0.3-2.5) infrared (IR)-detected GRB hosts (T_dust>40K ; sSFR>10 Gyr^-1), however its dust-to-stellar mass ratio is lower than what is commonly seen in IR-luminous galaxies. Our results suggest that GRBH 031203 is undergoing a strong starburst episode and its dust properties are different to those of local dwarf galaxies within the same metallicity and stellar mass range. Furthermore, our measurements place it in a distinct class to the well studied nearby ho...

  16. Galaxies of all Shapes Host Black Holes

    Science.gov (United States)

    2008-01-01

    This artist's concept illustrates the two types of spiral galaxies that populate our universe: those with plump middles, or central bulges (upper left), and those lacking the bulge (foreground). New observations from NASA's Spitzer Space Telescope provide strong evidence that the slender, bulgeless galaxies can, like their chubbier counterparts, harbor supermassive black holes at their cores. Previously, astronomers thought that a galaxy without a bulge could not have a supermassive black hole. In this illustration, jets shooting away from the black holes are depicted as thin streams. The findings are reshaping theories of galaxy formation, suggesting that a galaxy's 'waistline' does not determine whether it will be home to a big black hole.

  17. UV Emission in Type Ia Supernova Elliptical Host Galaxies

    Science.gov (United States)

    Tucker, Brad E.

    2015-03-01

    The current use of Type Ia supernova (SN Ia) as standard candles is to measure the dark energy equation-of-state to better than 10%. However, we still lack a clear understanding of their progenitor systems. We analyze the host galaxies of type Ia Supernova (SN Ia) discovered by the ESSENCE survey using UV and optical data, as studying the environments of SN Ia is a great way to understand the progenitors. We developed a new method for determining the SED and rest-frame magnitudes of the host galaxies and we use empirical relations to derive stellar mass and star-formation rate (SFR) measurements of the host galaxies. We find a high rate of UV emission in our passive galaxies, suggesting current star-formation in these galaxies.

  18. Detailed afterglow modelling and host galaxy properties of the dark GRB 111215A

    Science.gov (United States)

    van der Horst, A. J.; Levan, A. J.; Pooley, G. G.; Wiersema, K.; Krühler, T.; Perley, D. A.; Starling, R. L. C.; Curran, P. A.; Tanvir, N. R.; Wijers, R. A. M. J.; Strom, R. G.; Kouveliotou, C.; Hartoog, O. E.; Xu, D.; Fynbo, J. P. U.; Jakobsson, P.

    2015-02-01

    Gamma-ray burst (GRB) 111215A was bright at X-ray and radio frequencies, but not detected in the optical or near-infrared (nIR) down to deep limits. We have observed the GRB afterglow with the Westerbork Synthesis Radio Telescope and Arcminute Microkelvin Imager at radio frequencies, with the William Herschel Telescope and Nordic Optical Telescope in the nIR/optical, and with the Chandra X-ray Observatory. We have combined our data with the Swift X-Ray Telescope monitoring, and radio and millimetre observations from the literature to perform broad-band modelling, and determined the macro- and microphysical parameters of the GRB blast wave. By combining the broad-band modelling results with our nIR upper limits we have put constraints on the extinction in the host galaxy. This is consistent with the optical extinction we have derived from the excess X-ray absorption, and higher than in other dark bursts for which similar modelling work has been performed. We also present deep imaging of the host galaxy with the Keck I telescope, Spitzer Space Telescope, and Hubble Space Telescope (HST), which resulted in a well-constrained photometric redshift, giving credence to the tentative spectroscopic redshift we obtained with the Keck II telescope, and estimates for the stellar mass and star formation rate of the host. Finally, our high-resolution HST images of the host galaxy show that the GRB afterglow position is offset from the brightest regions of the host galaxy, in contrast to studies of optically bright GRBs.

  19. Stripped-envelope supernova rates and host-galaxy properties

    CERN Document Server

    Graur, Or; Modjaz, Maryam; Maoz, Dan; Shivvers, Isaac; Filippenko, Alexei V; Li, Weidong

    2015-01-01

    The progenitors of stripped-envelope supernovae (SNe Ibc) remain to be conclsuively identified, but correlations between SN rates and host-galaxy properties can constrain progenitor models. Here, we present one result from a re-analysis of the rates from the Lick Observatory Supernova Search. Galaxies with stellar masses less than $\\sim 10^{10}~{\\rm M_\\odot}$ are less efficient at producing SNe Ibc than more massive galaxies. Any progenitor scenario must seek to explain this new observation.

  20. The host galaxies of AGN with powerful relativistic jets

    Science.gov (United States)

    Olguín-Iglesias, A.; León-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Añorve, C.; Valdés, J.; Carrasco, L.

    2016-08-01

    We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift (0.310^27 WHz^-1), previously classified as flat-spectrum radio quasars. We also compile host galaxy and nuclear magnitudes for blazars from literature. The combined sample (this work and compilation) contains 100 radio-loud AGN with host galaxy detections and a broad range of radio luminosities L1.4GHz = 10^23.7 - 10^28.3WHz^-1, allowing us to divide our sample into high-excitation (quasar-mode; HERGs) and low-excitation (radio-mode; LERGs) radio galaxies. The host galaxies of our sample are bright and seem to follow the Kormendy relation. Nuclear emission (dominated by non-thermal mechanisms) and host-galaxy magnitudes show a slightly negative weak trend for LERGs. On the other hand, the m_bulge -m_nuc relation is statistically significant for HERGs. Although it may be affected by selection effects, this correlation suggests a close coupling between the relativistic jets and their host galaxy. Our findings are consistent with the excitation state (LERG/HERG) scenario. In this view, LERGs emit the bulk of their energy in the form of radio jets, producing a strong feedback mechanism, and HERGs are affected by galaxy mergers and interactions, which provide a common supply of cold gas to feed both nuclear activity and star formation episodes.

  1. Galaxy Zoo: Evidence for rapid, recent quenching within a population of AGN host galaxies

    CERN Document Server

    Smethurst, R J; Simmons, B D; Schawinski, K; Bamford, S P; Cardamone, C N; Kruk, S J; Masters, K L; Urry, C M; Willett, K W; Wong, O I

    2016-01-01

    We present a population study of the star formation history of 1244 Type 2 AGN host galaxies, compared to 6107 inactive galaxies. A Bayesian method is used to determine individual galaxy star formation histories, which are then collated to visualise the distribution for quenching and quenched galaxies within each population. We find evidence for some of the Type 2 AGN host galaxies having undergone a rapid drop in their star formation rate within the last 2 Gyr. AGN feedback is therefore important at least for this population of galaxies. This result is not seen for the quenching and quenched inactive galaxies whose star formation histories are dominated by the effects of downsizing at earlier epochs, a secondary effect for the AGN host galaxies. We show that histories of rapid quenching cannot account fully for the quenching of all the star formation in a galaxy's lifetime across the population of quenched AGN host galaxies, and that histories of slower quenching, attributed to secular (non-violent) evolutio...

  2. Constraining the star formation histories of GRB Host Galaxies from their observed abundance patterns

    CERN Document Server

    Calura, F; Prochaska, J X; Matteucci, F

    2008-01-01

    Long-duration Gamma Ray Bursts (GRBs) are linked to the collapse of massive stars and their hosts are exclusively identified as active, star forming galaxies. Four long GRBs observed at high spectral resolution at redshift 1.5 host galaxies of these GRBs from the study of the chemical abundances measured in their ISM. We are also able to provide constraints on the age and on the dust content of GRB hosts. Our results support the hypothesis that long duration GRBs occur preferentially in low metallicity, star forming galaxies. We compare the specific star formation rate, namely the star formation rate per unit stellar mass, predicted for the hosts of these GRBs with observational values for GRB hosts distributed across a lar...

  3. On the multiplicity of supernovae within host galaxies

    CERN Document Server

    Anderson, J P

    2012-01-01

    We investigate the nature of multiple supernova hosting galaxies, and the types of events which they produce. Using all known historical supernovae, we split host galaxies into samples containing single or multiple events. These samples are then characterised in terms of their relative supernova fractions, and host properties. In multiple supernova hosts the ratio of type Ia to core-collapse events is lower than in single supernova hosts. For core-collapse events there is a suggestion that the ratio of types Ibc to type II events is higher in multiples than within single supernova hosts. This second increase is dominated by an increase in the number of SNIb. Within multiple supernova hosts, supernovae of any given type appear to 'prefer' to explode in galaxies that are host to the same type of SN. We also find that multiple SN hosts have higher T-type morphologies. While our results suffer from low number statistics, we speculate that their simplest interpretation is that star formation within galaxies is gen...

  4. The host of GRB/XRF 030528 - an actively star forming galaxy at z=0.782

    CERN Document Server

    Rau, A

    2005-01-01

    An important parameter for the distinction of X-ray flashes, X-ray rich bursts and Gamma-ray bursts in the rest frame is the distance to the explosion site. Here we report on the spectroscopic redshift determination of the host galaxy of XRF/GRB 030528 using the ESO VLT FORS2 instrument. From the strong oxygen and hydrogen emission lines the redshift was measured to be z=0.782+-0.001. Obtaining the line luminosities and ratios we find that the host is consistent with being an actively star forming galaxy with sub-solar metallicity. With a stellar mass of ~10E10 Msun the host is placed among the most massive GRB host galaxies at a similar redshift. Estimating the redshifted properties of the prompt emission, we find that XRF/GRB 030528 would be classified as an X-ray rich bursts in the rest frame rather than an X-ray flash in the typically used observer frame.

  5. A Mature Dusty Star-forming Galaxy Hosting GRB080607 at z=3.036

    CERN Document Server

    Chen, Hsiao-Wen; Wilson, Christine D; Cenko, S Bradley; Levan, Andrew J; Bloom, Joshua S; Prochaska, Jason X; Tanvir, Nial R; Dessauges-Zavadsky, Miroslava; Pettini, Max

    2010-01-01

    We report the discovery of the host galaxy of dark burst GRB080607 at z_GRB=3.036. GRB080607 is a unique case of a highly extinguished (A_V~3 mag) afterglow that was yet sufficiently bright for high-quality absorption-line spectroscopy. The host galaxy is clearly resolved in deep HST WF3/IR F160W images and well detected in the Spitzer IRAC 3.5 micron and 4.5 micron channels, while displaying little/no fluxes in deep optical images from Keck and Magellan. The extremely red optical-infrared colors are consistent with the large extinction seen in the afterglow light, suggesting that the large amount of dust and gas surface mass density seen along the afterglow sightline is not merely local but likely reflects the global dust content across the entire host galaxy. Adopting the dust properties and metallicity of the host ISM derived from studies of early-time afterglow light and absorption-line spectroscopy, we perform a stellar population synthesis analysis of the observed spectral energy distribution to constra...

  6. How SN Ia host-galaxy properties affect cosmological parameters

    CERN Document Server

    Campbell, H; Gilmore, G

    2016-01-01

    We present a systematic study of the relationship between Type Ia Supernova (SN Ia) properties, and the characteristics of their host galaxies, using a sample of 581 SNe Ia from the full Sloan Digital Sky Survey II (SDSS-II) SN Survey. We also investigate the effects of this on the cosmological constraints derived from SNe~Ia. Compared to previous studies, our sample is larger by a factor of $>4$, and covers a substantially larger redshift range (up to z~0.5), which is directly applicable to the volume of cosmological interest. We measure a significant correlation (>5\\sigma) between the host-galaxy stellar-mass and the SN~Ia Hubble Residuals (HR). We find a weak correlation (1.4\\sigma) between the host-galaxy metallicity as measured from emission lines in the spectra, and the SN~Ia HR. We also find evidence that the slope of the correlation between host-galaxy mass and HR is -0.11 $\\mathrm{mag}/\\mathrm{log}(\\mathrm{M}_{\\mathrm{host}}/\\mathrm{M}_{\\odot})$ steeper in lower metallicity galaxies. We test the effe...

  7. Radio Galaxy Zoo: host galaxies and radio morphologies derived from visual inspection

    CERN Document Server

    Banfield, J K; Willett, K W; Norris, R P; Rudnick, L; Shabala, S S; Simmons, B D; Snyder, C; Garon, A; Seymour, N; Middelberg, E; Andernach, H; Lintott, C J; Jacob, K; Kapinska, A D; Mao, M Y; Masters, K L; Jarvis, M J; Schawinski, K; Paget, E; Simpson, R; Klockner, H R; Bamford, S; Burchell, T; Chow, K E; Cotter, G; Fortson, L; Heywood, I; Jones, T W; Kaviraj, S; Lopez-Sanchez, A R; Maksym, W P; Polsterer, K; Borden, K; Hollow, R P; Whyte, L

    2015-01-01

    We present results from the first twelve months of operation of Radio Galaxy Zoo, which upon completion will enable visual inspection of over 170,000 radio sources to determine the host galaxy of the radio emission and the radio morphology. Radio Galaxy Zoo uses $1.4\\,$GHz radio images from both the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) and the Australia Telescope Large Area Survey (ATLAS) in combination with mid-infrared images at $3.4\\,\\mu$m from the {\\it Wide-field Infrared Survey Explorer} (WISE) and at $3.6\\,\\mu$m from the {\\it Spitzer Space Telescope}. We present the early analysis of the WISE mid-infrared colours of the host galaxies. For images in which there is $>\\,75\\%$ consensus among the Radio Galaxy Zoo cross-identifications, the project participants are as effective as the science experts at identifying the host galaxies. The majority of the identified host galaxies reside in the mid-infrared colour space dominated by elliptical galaxies, quasi-stellar objects (QSOs), and l...

  8. Supernovae without host galaxies? The low surface brightness host of SN 2009Z

    CERN Document Server

    Zinn, P -C; Braithwaite, J; Gallazzi, A; Grunden, P; Bomans, D J; Morrell, N I; Bach, U

    2011-01-01

    A remarkable fraction of supernovae (SNe) have no obvious host galaxy. Two possible explanations are that (i) the host galaxy is simply not detected within the sensitivity of the available data or that (ii) the progenitor is a hypervelocity star that has escaped its parent galaxy. We use the Type IIb SN 2009Z as a prototype of case (i), an example of how a very faint (here Low Surface Brightness; LSB) galaxy can be discovered via the observation of a seemingly host-less SN. By identifying and studying LSB galaxies that host SNe related to the death of massive stars, we can place constraints on the stellar population and environment of LSB galaxies, which at present are poorly understood. From an HI spectrum, a redshift of z = 0.02513+-0.00001 and an HI mass of (2.96+-0.12) 10^9 M_sun are computed. This redshift is consistent with that obtained from optical emission lines of SN 2009Z. Furthermore, a gas mass fraction of f_g = 0.87+-0.04 is obtained, one of the highest fractions ever measured. The host galaxy s...

  9. How SN Ia host-galaxy properties affect cosmological parameters

    Science.gov (United States)

    Campbell, H.; Fraser, M.; Gilmore, G.

    2016-04-01

    We present a systematic study of the relationship between Type Ia Supernova (SN Ia) properties, and the characteristics of their host galaxies, using a sample of 581 SNe Ia from the full Sloan Digital Sky Survey II (SDSS-II) SN Survey. We also investigate the effects of this on the cosmological constraints derived from SNe Ia. Compared to previous studies, our sample is larger by a factor of >4, and covers a substantially larger redshift range (up to z ˜ 0.5), which is directly applicable to the volume of cosmological interest. We measure a significant correlation (>5σ) between the host-galaxy stellar-mass and the SN Ia Hubble Residuals (HR). We find a weak correlation (1.4σ) between the host-galaxy metallicity as measured from emission lines in the spectra, and the SN Ia HR. We also find evidence that the slope of the correlation between host-galaxy mass and HR is -0.11 mag/log(Mhost/M⊙) steeper in lower metallicity galaxies. We test the effects on a cosmological analysis using both the derived best-fitting correlations between host parameters and HR, and by allowing an additional free parameter in the fit to account for host properties which we then marginalize over when determining cosmological parameters. We see a shift towards more negative values of the equation-of-state parameter w, along with a shift to lower values of Ωm after applying mass or metallicity corrections. The shift in cosmological parameters with host-galaxy stellar-mass correction is consistent with previous studies. We find a best-fitting cosmology of Ω m =0.266_{-0.016}^{+0.016}, Ω _{Λ }=0.740_{-0.018}^{+0.018} and w=-1.151_{-0.121}^{+0.123} (statistical errors only).

  10. Herschel Dust Measurements of SDSS Supernovae Host Galaxies

    Science.gov (United States)

    Trinh, Donald; Cooray, Asantha R.; Nayyeri, Hooshang; Herschel Hermes and h-atlas Collaboration

    2016-01-01

    We use Herschel Spectral and Photometric Imaging Receiver (SPIRE) far-infrared observations of Supernova host galaxies to study the cosmological distant measurement from Hubble diagrams. We investigate the dust content of SN host galaxy from the Sloan Digital Sky Survery (SDSS) using the far-infrared stacks of Herschel in the Equatorial Stripe using , Herschel Multi-Tiered Extragalactic Survey (HELMS), and the Herschel Stripe 82 Survey (HERS). Cosmic dust may contribute to much more obscuring of standard candles than previously thought. Measuring the average flux values of stacks from dim Type-Ia supernovae provides a measure of the dust content of galaxies as a function of deviation of those sources from the Hubble diagram given a standard cosmology. Using the optical to far infrared stacked data of the galaxies we also measure the physical properties of the standard candles as a function of dust content.

  11. Decreased specific star formation rates in AGN host galaxies

    Science.gov (United States)

    Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio; Koss, Michael; Rosario, David J.

    2015-09-01

    We investigate the location of an ultra-hard X-ray selected sample of active galactic nuclei (AGN) from the Swift Burst Alert Telescope (BAT) catalogue with respect to the main sequence (MS) of star-forming galaxies using Herschel-based measurements of the star formation rate (SFR) and M*'s from Sloan Digital Sky Survey photometry where the AGN contribution has been carefully removed. We construct the MS with galaxies from the Herschel Reference Survey and Herschel Stripe 82 Survey using the exact same methods to measure the SFR and M* as the Swift/BAT AGN. We find that a large fraction of the Swift/BAT AGN lie below the MS indicating decreased specific SFR (sSFR) compared to non-AGN galaxies. The Swift/BAT AGN are then compared to a high-mass galaxy sample (CO Legacy Database for GALEX Arecibo SDSS Survey, COLD GASS), where we find a similarity between the AGN in COLD GASS and the Swift/BAT AGN. Both samples of AGN lie firmly between star-forming galaxies on the MS and quiescent galaxies far below the MS. However, we find no relationship between the X-ray luminosity and distance from the MS. While the morphological distribution of the BAT AGN is more similar to star-forming galaxies, the sSFR of each morphology is more similar to the COLD GASS AGN. The merger fraction in the BAT AGN is much higher than the COLD GASS AGN and star-forming galaxies and is related to distance from the MS. These results support a model in which bright AGN tend to be in high-mass star-forming galaxies in the process of quenching which eventually starves the supermassive black hole itself.

  12. Spectroscopy of superluminous supernova host galaxies

    DEFF Research Database (Denmark)

    Leloudas, G.; Kruehler, T.; Schulze, S;

    2015-01-01

    -poor SLSNe. We propose that H-poor SLSNe result from the very first stars exploding in a starburst, even earlier than GRBs. This might indicate a bottom-light initial mass function in these systems. SLSNe present a novel method of selecting candidate EELGs independent of their luminosity.......-poor) often (~50% in our sample) occur in a class of galaxies that is known as Extreme Emission Line Galaxies (EELGs). The probability of this happening by chance is negligible and we therefore conclude that the extreme environmental conditions and the SLSN phenomenon are related. In contrast, SLSNe...

  13. Decreased Specific Star Formation Rates in AGN Host Galaxies

    CERN Document Server

    Shimizu, T Taro; Melendez, Marcio; Koss, Michael; Rosario, David

    2015-01-01

    We investigate the location of an ultra-hard X-ray selected sample of AGN from the Swift Burst Alert Telescope (BAT) catalog with respect to the main sequence (MS) of star-forming galaxies using Herschel-based measurements of the star formation rate (SFR) and stellar mass (\\mstar) from Sloan Digital Sky Survey (SDSS) photometry where the AGN contribution has been carefully removed. We construct the MS with galaxies from the Herschel Reference Survey and Herschel Stripe 82 Survey using the exact same methods to measure the SFR and \\mstar{} as the Swift/BAT AGN. We find a large fraction of the Swift/BAT AGN lie below the MS indicating decreased specific SFR (sSFR) compared to non-AGN galaxies. The Swift/BAT AGN are then compared to a high-mass galaxy sample (COLD GASS), where we find a similarity between the AGN in COLD GASS and the Swift/BAT AGN. Both samples of AGN lie firmly between star-forming galaxies on the MS and quiescent galaxies far below the MS. However, we find no relationship between the X-ray lum...

  14. The Black Hole - Bulge Mass Relation in Megamaser Host Galaxies

    CERN Document Server

    Läsker, Ronald; Seth, Anil; van de Ven, Glenn; Braatz, James A; Henkel, Christian; Lo, K Y

    2016-01-01

    We present HST images for nine megamaser disk galaxies with the primary goal of studying photometric BH-galaxy scaling relations. The megamaser disks provide the highest-precision extragalactic BH mass measurements, while our high-resolution HST imaging affords us the opportunity to decompose the complex nuclei of their late-type hosts in detail. Based on the morphologies and shapes of the galaxy nuclei, we argue that most of these galaxies' central regions contain secularly evolving components (pseudo-bulges), and in many cases we photometrically identify co-existing "classical" bulge components as well. Using these decompositions, we draw the following conclusions: (1) The megamaser BH masses span two orders of magnitude ($10^6$ -- $10^8 M_\\odot$) while the stellar mass of their spiral host galaxies are all $\\sim 10^{11} M_\\odot$ within a factor of three; (2) the BH masses at a given bulge mass or total stellar mass in the megamaser host spiral galaxies tend to be lower than expected, when compared to an ex...

  15. The Dependence of Galaxy Type on Host Halo Mass

    CERN Document Server

    Weinmann, S M; Yang, X; Mo, H J; Weinmann, Simone M.; Bosch, Frank C. van den; Yang, Xiaohu

    2006-01-01

    We examine the relation between galaxy properties and environment in the SDSS DR2, quantifying environment in terms of the mass of the host halo, which is obtained with a new iterative group finder. We find that galaxy type fractions scale strongly and smoothly with halo mass, but, at fixed mass, not with luminosity. We compare these findings with the semi-analytical galaxy formation model of Croton et al. (2006). The discrepancies we find can be explained with an oversimplified implementation of strangulation, the neglect of tidal stripping, and shortcomings in the treatments of dust extinction and/or AGN feedback.

  16. A DETECTION OF MOLECULAR GAS EMISSION IN THE HOST GALAXY OF GRB 080517

    International Nuclear Information System (INIS)

    We have observed the host galaxy of the low-redshift, low-luminosity Swift GRB 080517 at 105.8 GHz using the IRAM Plateau de Bure interferometer. We detect an emission line with integrated flux SΔν = 0.39 ± 0.05 Jy km s–1—consistent both spatially and in velocity with identification as the J = 1-0 rotational transition of carbon monoxide (CO) at the host galaxy redshift. This represents only the third long gamma-ray burst (GRB) host galaxy with molecular gas detected in emission. The inferred molecular gas mass, MH2∼6.3×108 M ☉, implies a gas consumption timescale of ∼40 Myr if star formation continues at its current rate. Similar short timescales appear characteristic of the long GRB population with CO observations to date, suggesting that the GRB in these sources occurs toward the end of their star formation episode

  17. A DETECTION OF MOLECULAR GAS EMISSION IN THE HOST GALAXY OF GRB 080517

    Energy Technology Data Exchange (ETDEWEB)

    Stanway, E. R.; Levan, A. J. [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL (United Kingdom); Tanvir, N. R.; Wiersema, K. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Van der Laan, T. P. R., E-mail: e.r.stanway@warwick.ac.uk [Institute de Radioastronomie Millimetrique (IRAM), 300 Rue de la Piscine, 38406 St. Martin d' Heres, Grenoble (France)

    2015-01-01

    We have observed the host galaxy of the low-redshift, low-luminosity Swift GRB 080517 at 105.8 GHz using the IRAM Plateau de Bure interferometer. We detect an emission line with integrated flux SΔν = 0.39 ± 0.05 Jy km s{sup –1}—consistent both spatially and in velocity with identification as the J = 1-0 rotational transition of carbon monoxide (CO) at the host galaxy redshift. This represents only the third long gamma-ray burst (GRB) host galaxy with molecular gas detected in emission. The inferred molecular gas mass, M{sub H{sub 2}}∼6.3×10{sup 8} M {sub ☉}, implies a gas consumption timescale of ∼40 Myr if star formation continues at its current rate. Similar short timescales appear characteristic of the long GRB population with CO observations to date, suggesting that the GRB in these sources occurs toward the end of their star formation episode.

  18. Taking stock of SLSN and LGRB host galaxy comparison using a complete sample of LGRBs

    CERN Document Server

    Japelj, J; Salvaterra, R; Hunt, L K; Mannucci, F

    2016-01-01

    Long gamma-ray bursts (LGRBs) and superluminous supernovae (SLSNe) are both explosive transients with very massive progenitor stars. Clues about the nature of the progenitors can be found by investigating environments in which such transients occur. While studies of LGRB host galaxies have a long history, dedicated observational campaigns have only recently resulted in a high enough number of photometrically and spectroscopically observed SLSN hosts to allow statistically significant analysis of their properties. In this paper we make a comparison of the host galaxies of hydrogen-poor (H-poor) SLSNe and the Swift/BAT6 sample of LGRBs. In contrast to previous studies we use a complete sample of LGRBs and we address a special attention to the comparison methodology and the selection of SLSN sample whose data have been compiled from the available literature. At intermediate redshifts (0.3 < z < 0.7) the two classes of transients select galaxies whose properties (stellar mass, luminosity, star-formation rat...

  19. Late time observations of GRB080319B: jet break, host galaxy and accompanying supernova

    CERN Document Server

    Tanvir, Nial R; Levan, Andrew; Fruchter, Andrew; Granot, Jonathan; Svensson, Karl M; O'Brien, Paul T; Wiersema, Klaas; Starling, Rhaana L C; Jakobsson, Pall; Fynbo, Johan; Hjorth, Jens; Curran, Peter; van der Horst, Alexander J; Kouveliotou, Chryssa; Racusin, Judith L; Burrows, David N; Genet, Frank

    2008-01-01

    The Swift-discovered GRB080319B was by far the most distant source ever observed at naked eye brightness, reaching a peak magnitude of 5.3 at a redshift of z=0.937. We present our late time optical and X-ray observations, which confirm that an achromatic break occurred in the power-law afterglow light curve at ~10^6 s post-burst. This most likely indicates that the gamma-ray burst (GRB) outflow was collimated, which for a uniform jet would imply a total energy in the jet E_{jet} \\gsim 10^{52.5} erg. Our observations also show a late-time excess of red light, which is well explained if the GRB was accompanied by a supernova, similar to those seen in some other long-duration GRBs. The latest observations are dominated by light from the host and show that the GRB took place in a faint dwarf galaxy (r(AB) = 27.2, rest-frame M_B = -17.3). This galaxy is small even by the standards of other GRB hosts, which is suggestive of a low metallicity environment.

  20. Detailed Afterglow Modeling and Host Galaxy Properties of the Dark GRB 111215A

    CERN Document Server

    van der Horst, A J; Pooley, G G; Wiersema, K; Kruhler, T; Perley, D A; Starling, R L C; Curran, P A; Tanvir, N R; Wijers, R A M J; Strom, R G; Kouveliotou, C; Hartoog, O E; Xu, D; Fynbo, J P U; Jakobsson, P

    2014-01-01

    Gamma-ray burst (GRB) 111215A was bright at X-ray and radio frequencies, but not detected in the optical or near-infrared (nIR) down to deep limits. We have observed the GRB afterglow with the Westerbork Synthesis Radio Telescope and Arcminute Microkelvin Imager at radio frequencies, with the William Herschel Telescope and Nordic Optical Telescope in the nIR/optical, and with the Chandra X-ray Observatory. We have combined our data with the Swift X-Ray Telescope monitoring, and radio and millimeter observations from the literature to perform broadband modeling, and determined the macro- and microphysical parameters of the GRB blast wave. By combining the broadband modeling results with our nIR upper limits we have put constraints on the extinction in the host galaxy. This is consistent with the optical extinction we have derived from the excess X-ray absorption, and higher than in other dark bursts for which similar modeling work has been performed. We also present deep imaging of the host galaxy with the Kec...

  1. The First Two Host Galaxies of X-ray Flashes: XRF 011030 and XRF 020427

    CERN Document Server

    Bloom, J S; Van Dokkum, P G; Kulkarni, S R; Berger, E; Djorgovski, S G; Frail, D A

    2003-01-01

    Given the paucity of empirical constraints, the nature of the newly-recognized phenomena called X-Ray Flashes (XRFs) has been an open question. However, with the recent detections of radio and X-ray afterglow it is finally possible to study the large- and small-scale environments of XRFs. We present Chandra, Hubble Space Telescope (HST), and Keck observations of the fields of XRFs 011030 and 020427. Astrometric comparisons of the X-ray transient positions and the HST images reveal the XRFs to be associated with faint blue galaxies. Photometric evidence of these putative hosts suggests that these two XRFs originated from redshifts less than z ~ 3.5, and thus cannot be due to GRBs at very high redshifts. In both host-burst offsets and host properties, these XRFs could have been drawn from distributions similar to those measured of gamma-ray bursts (GRBs). We conclude with a discussion of the implications of this XRF-GRB host connection for the possible progenitors of XRFs.

  2. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A

    Energy Technology Data Exchange (ETDEWEB)

    Levan, A. J. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Tanvir, N. R.; Wiersema, K. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); Fruchter, A. S.; Hounsell, R. A.; Graham, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Hjorth, J.; Fynbo, J. P. U. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Pian, E. [INAF, Trieste Astronomical Observatory, via G.B. Tiepolo 11, I-34143 Trieste (Italy); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, IC2 Liverpool Science Park 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd., Pasadena, CA 91125 (United States); Cano, Z. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Kouveliotou, C. [Science and Technology Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Pe' er, A. [Department of Physics, University College Cork, Cork (Ireland); Misra, K., E-mail: a.j.levan@warwick.ac.uk [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263 002 (India)

    2014-09-10

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E {sub iso} > 10{sup 54} erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ∼17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v {sub ph} ∼ 15, 000 km s{sup –1}). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v {sub ph} ∼ 30, 000 km s{sup –1}), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ∼4 kpc from the nucleus of a moderately star forming (1 M {sub ☉} yr{sup –1}), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  3. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A

    International Nuclear Information System (INIS)

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E iso > 1054 erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ∼17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v ph ∼ 15, 000 km s–1). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v ph ∼ 30, 000 km s–1), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ∼4 kpc from the nucleus of a moderately star forming (1 M ☉ yr–1), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  4. Hubble Space Telescope Observations of the Afterglow, Supernova and Host Galaxy Associated with the Extremely Bright GRB 130427A

    Science.gov (United States)

    Levan, A.J.; Tanvir, N. R.; Fruchter, A. S.; Hjorth, J.; Pian, E.; Mazzali, P.; Hounsell, R. A.; Perley, D. A.; Cano, Z.; Graham, J.; Cenko, S. B.; Fynbo, J. P. U.; Kouveliotou, C.; Pe'er, A.; Misra, K.; Wiersema, K.

    2014-01-01

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst, GRB 130427A. At z=0.34 this burst affords an excellent opportunity to study the supernova and host galaxy associated with an intrinsically extremely luminous burst (E(sub iso) greater than 10(exp 54) erg): more luminous than any previous GRB with a spectroscopically associated supernova. We use the combination of the image quality, UV capability and and invariant PSF of HST to provide the best possible separation of the afterglow, host and supernova contributions to the observed light approximately 17 rest-frame days after the burst utilising a host subtraction spectrum obtained 1 year later. Advanced Camera for Surveys (ACS) grism observations show that the associated supernova, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, vph approximately 15,000 kilometers per second). The positions of the bluer features are better matched by the higher velocity SN 2010bh (vph approximately 30,000 kilometers per second), but SN 2010bh (vph approximately 30,000 kilometers per second but this SN is significantly fainter, and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated approximately 4 kpc from the nucleus of a moderately star forming (1 Solar Mass yr(exp-1)), possibly interacting disc galaxy. The absolute magnitude, physical size and morphology of this galaxy, as well as the location of the GRB within it are also strikingly similar to those of GRB980425SN 1998bw. The similarity of supernovae and environment from both the most luminous and least luminous GRBs suggests broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  5. A Revised Host Galaxy Association for GRB 020819B: A High-Redshift Dusty Starburst, Not a Low-Redshift Gas-Poor Spiral

    CERN Document Server

    Perley, Daniel A; Schady, Patricia; Michałowski, Michał J; Thöne, Christina C; Petry, Dirk; Graham, John F; Greiner, Jochen; Schulze, Steve; Kim, Sam

    2016-01-01

    The purported spiral host galaxy of GRB 020819B at z=0.41 has been seminal in establishing our view of the diversity of long-duration gamma-ray burst environments: optical spectroscopy of this host provided evidence that GRBs can form even at high metallicities, while millimetric observations suggested that GRBs may preferentially form in regions with minimal molecular gas. We report new observations from VLT (MUSE and X-shooter) which demonstrate that the purported host is an unrelated foreground galaxy. The probable radio afterglow is coincident with a compact, highly star-forming, dusty galaxy at z=1.9621. The revised redshift naturally explains the apparent nondetection of CO(3-2) line emission at the afterglow site from ALMA. There is no evidence that molecular gas properties in GRB host galaxies are unusual, and limited evidence that GRBs can form readily at super-Solar metallicity.

  6. Probability for chance coincidence of a gamma-ray burst with a galaxy on the sky

    OpenAIRE

    Campisi, Maria Angela; Li, Li-Xin

    2008-01-01

    The nearby long GRB 060614 was not accompanied by a supernova, challenging the collapsar model for long-duration GRBs and the traditional classification scheme for GRBs. However, Cobb et al. have argued that the association of GRB 060614 and its host galaxy could be chance coincidence. In this work we calculate the probability for a GRB to be randomly coincident with a galaxy on the sky, using a galaxy luminosity function obtained from current galaxy surveys. We find that, with a magnitude li...

  7. Distributions of Quasar Hosts on the Galaxy Main Sequence Plane

    Science.gov (United States)

    Zhang, Zhoujian; Shi, Yong; Rieke, George H.; Xia, Xiaoyang; Wang, Yikang; Sun, Bingqing; Wan, Linfeng

    2016-03-01

    The relation between star formation rates (SFRs) and stellar masses, i.e., the galaxy main sequence, is a useful diagnostic of galaxy evolution. We present the distributions relative to the main sequence of 55 optically selected PG and 12 near-IR-selected Two Micron All Sky Survey (2MASS) quasars at z ≤ 0.5. We estimate the quasar host stellar masses from Hubble Space Telescope or ground-based AO photometry, and the SFRs through the mid-infrared aromatic features and far-IR photometry. We find that PG quasar hosts more or less follow the main sequence defined by normal star-forming galaxies while 2MASS quasar hosts lie systematically above the main sequence. PG and 2MASS quasars with higher nuclear luminosities seem to have higher specific SFRs (sSFRs), although there is a large scatter. No trends are seen between sSFRs and SMBH masses, Eddington ratios, or even morphology types (ellipticals, spirals, and mergers). Our results could be placed in an evolutionary scenario with quasars emerging during the transition from ULIRGs/mergers to ellipticals. However, combined with results at higher redshift, they suggest that quasars can be widely triggered in normal galaxies as long as they contain abundant gas and have ongoing star formation.

  8. Massive relic galaxies challenge the co-evolution of SMBHs and their host galaxies

    CERN Document Server

    Ferré-Mateu, Anna; Trujillo, Ignacio; Balcells, Marc; Bosch, Remco C E van den

    2015-01-01

    We study a sample of eight massive galaxies that are extreme outliers (3-5$\\sigma$) in the M$_{\\bullet}$-M$_\\mathrm{bulge}$ local scaling relation. Two of these galaxies are confirmed to host extremely large super massive black holes (SMBHs), whereas the virial mass estimates for the other six are also consistent with having abnormally large SMBHs. From the analysis of their star formation histories and their structural properties we find that all these extreme outliers can be considered as relic galaxies from the early (z$\\sim$2) Universe: i.e. they are compact (R$_{\\mathrm{e}}$$<$2 kpc) and have purely old stellar populations (t$\\gtrsim$10 Gyr). In order to explain the nature of such deviations from the local relations, we propose a scenario in which the hosts of these \\"uber-massive SMBHs are galaxies that have followed a different evolutionary path than the two-phase growth channel assumed for massive galaxies. Once the SMBH and the core of the galaxy are formed at z$\\sim$2, the galaxy skips the second...

  9. Clustering of galaxies around gamma-ray burst sight-lines

    DEFF Research Database (Denmark)

    Sudilovsky, V.; Greiner, J.; Rau, A.;

    2013-01-01

    -lines, as strong MgII tends to trace these sources. In this work, we test this expectation by calculating the two point angular correlation function of galaxies within 120'' (~470 h Kpc470h71-1Kpc at z ~ 0.4) of GRB afterglows. We compare the gamma-ray burst optical and near-infrared detector (GROND) GRB afterglow......There is evidence of an overdensity of strong intervening MgII absorption line systems distributed along the lines of sight toward gamma-ray burst (GRB) afterglows relative to quasar sight-lines. If this excess is real, one should also expect an overdensity of field galaxies around GRB sight...

  10. Simple Stellar Population Modeling of Low S/N Galaxy Spectra and Quasar Host Galaxy Applications

    CERN Document Server

    Mosby, Gregory; Hooper, Eric; Wolf, Marsha; Sheinis, Andrew; Richards, Joseph

    2014-01-01

    To study the effect of supermassive black holes (SMBHs) on their host galaxies it is important to study the hosts when the SMBH is near its peak activity. A method to investigate the host galaxies of high luminosity quasars is to obtain optical spectra at positions offset from the nucleus where the relative contribution of the quasar and host are comparable. However, at these extended radii the galaxy surface brightness is often low (20-22 mag per arcsec$^{2}$) and the resulting spectrum might have such low S/N that it hinders analysis with standard stellar population modeling techniques. To address this problem we have developed a method that can recover galaxy star formation histories (SFHs) from rest frame optical spectra with S/N $\\sim$ 5~\\AA$^{-1}$. This method uses the statistical technique diffusion k-means to tailor the stellar population modeling basis set. Our diffusion k-means minimal basis set, composed of 4 broad age bins, is successful in recovering a range of galaxy SFHs. Additionally, using an...

  11. Radio Galaxy Zoo: host galaxies and radio morphologies for large surveys from visual inspection

    CERN Document Server

    Willett, Kyle W

    2016-01-01

    We present early results from Radio Galaxy Zoo, a web-based citizen science project for visual inspection and classification of images from all-sky radio surveys. The goals of the project are to classify individual radio sources (particularly galaxies with multiple lobes and/or complex morphologies) as well as matching the continuum radio emission to the host galaxy. Radio images come from the FIRST and ATLAS surveys, while matches to potential hosts are performed with infrared imaging from WISE and SWIRE. The first twelve months of classification yielded more than 1 million classifications of more than 60,000 sources. For images with at least 75% consensus by the volunteer classifiers, the accuracy is comparable to visual inspection by the expert science team. Based on mid-infrared colors, the hosts associated with radio emission are primarily a mixture of elliptical galaxies, QSOs, and LIRGs, which are in good agreement with previous studies. The full catalog of radio lobes and their host galaxies will meas...

  12. Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies

    CERN Document Server

    Kormendy, John

    2013-01-01

    We review the observed demographics and inferred evolution of supermassive black holes (BHs) found by dynamical modeling of spatially resolved kinematics. Most influential was the discovery of a tight correlation between BH mass and the velocity dispersion of the host-galaxy bulge. It and other correlations led to the belief that BHs and bulges coevolve by regulating each other's growth. New results are now replacing this simple story with a richer and more plausible picture in which BHs correlate differently with different galaxy components. BHs are found in pure-disk galaxies, so classical (elliptical-galaxy-like) bulges are not necessary to grow BHs. But BHs do not correlate with galaxy disks. And any correlations with disk-grown pseudobulges or halo dark matter are so weak as to imply no close coevolution. We suggest that there are four regimes of BH feedback. 1- Local, stochastic feeding of small BHs in mainly bulgeless galaxies involves too little energy to result in coevolution. 2- Global feeding in ma...

  13. H{\\alpha} Imaging of Nearby Seyfert Host Galaxies

    CERN Document Server

    Theios, R L; Ross, N R

    2016-01-01

    We used narrowband interference filters with the CCD imaging camera on the Nickel 1.0 meter telescope at Lick Observatory to observe 31 nearby (z < 0.03) Seyfert galaxies in the 12 {\\mu}m Active Galaxy Sample. We obtained pure emission line images of each galaxy in order to separate H{\\alpha} emission from the nucleus from that of the host galaxy. The extended H{\\alpha} emission is expected to be powered by newly formed hot stars, and correlates well with other indicators of current star formation in these galaxies: 7.7 {\\mu}m PAH, far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The nuclear H{\\alpha} luminosity is dominated by the AGN, and is correlated with the hard X-ray luminosity. There is an upward offset of 1 dex in this correlation for the Seyfert 1s due to a strong contribution from the Broad Line Region. We found a correlation between star formation rate and AGN luminosity. In sp...

  14. A nearby GRB host galaxy: VLT/X-shooter observations of HG 031203

    CERN Document Server

    Guseva, N G; Fricke, K J; Henkel, C; 10.1051/0004-6361/201116765

    2011-01-01

    (abridged) Long-duration gamma-ray bursts (LGRBs) occur in galaxies of generally low metallicity. We aim at a spectroscopic analysis of HG 031203, the host galaxy of a LRGB burst, to obtain its properties. Based on VLT/X-shooter spectroscopic observations in the wavelength range 3200-24000A, we use standard direct methods to evaluate physical conditions and element abundances. The resolving power of the instrument also allowed us to trace the kinematics of the ionised gas. We derive an interstellar oxygen abundance of 12+logO/H=8.20+/-0.03. The observed fluxes of hydrogen lines correspond to the theoretical recombination values after correction for extinction with a single value C(Hbeta)=1.67. We produce the CLOUDY photoionisation HII region model that reproduces observed emission-line fluxes of different ions in the optical range. This model also predicts emission-line fluxes in the near-infrared (NIR) and mid-infrared (MIR) ranges that agree well with the observed ones. This implies that the star-forming re...

  15. The Role of Host Galaxy for the Environmental Dependence of Active Nuclei in Local Galaxies

    CERN Document Server

    Davies, R I; Erwin, P; Burtscher, L; Contursi, A; Genzel, R; Janssen, A; Koss, M; Lin, M -Y; Lutz, D; Maciejewski, W; Mueller-Sanchez, F; de Xivry, G Orban; Ricci, C; Riffel, R; Riffel, R A; Rosario, D; Schartmann, M; Schnorr-Mueller, A; Shimizu, T; Sternberg, A; Sturm, E; Storchi-Bergmann, T; Tacconi, L; Veilleux, S

    2016-01-01

    We discuss the environment of local hard X-ray selected active galaxies, with reference to two independent group catalogues. We find that the fraction of these AGN in S0 host galaxies decreases strongly as a function of galaxy group size (halo mass) - which contrasts with the increasing fraction of galaxies of S0 type in denser environments. However, there is no evidence for an environmental dependence of AGN in spiral galaxies. Because most AGN are found in spiral galaxies, this dilutes the signature of environmental dependence for the population as a whole. We argue that the differing results for AGN in disk-dominated and bulge-dominated galaxies is related to the source of the gas fuelling the AGN, and so may also impact the luminosity function, duty cycle, and obscuration. We find that there is a significant difference in the luminosity function for AGN in spiral and S0 galaxies, and tentative evidence for some difference in the fraction of obscured AGN.

  16. A FAST RADIO BURST IN THE DIRECTION OF THE CARINA DWARF SPHEROIDAL GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, V. [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Shannon, R. M. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Jameson, A., E-mail: v.vikram.ravi@gmail.com [Swinburne University of Technology, Centre for Astrophysics and Supercomputing, Mail H39, P.O. Box 218, VIC 3122 (Australia)

    2015-01-20

    We report the real-time discovery of a fast radio burst (FRB 131104) with the Parkes radio telescope in a targeted observation of the Carina dwarf spheroidal galaxy. The dispersion measure of the burst is 779 cm{sup –3} pc, exceeding predictions for the maximum line-of-sight Galactic contribution by a factor of 11. The temporal structure of the burst is characterized by an exponential scattering tail with a timescale of 2.0{sub −0.5}{sup +0.8} ms at 1582 MHz that scales as frequency to the power –4.4{sub −1.8}{sup +1.6} (all uncertainties represent 95% confidence intervals). We bound the intrinsic pulse width to be <0.64 ms due to dispersion smearing across a single spectrometer channel. Searches in 78 hr of follow-up observations with the Parkes telescope reveal no additional sporadic emission and no evidence for associated periodic radio emission. We hypothesize that the burst is associated with the Carina dwarf galaxy. Follow-up observations at other wavelengths are necessary to test this hypothesis.

  17. The obscured hyper-energetic GRB 120624B hosted by a luminous compact galaxy at z = 2.20

    CERN Document Server

    Postigo, A de Ugarte; Thoene, C C; D'Avanzo, P; Sanchez-Ramirez, R; Melandri, A; Gorosabel, J; Ghirlanda, G; Veres, P; Martin, S; Petitpas, G; Covino, S; Fynbo, J P U; Levan, A J

    2013-01-01

    Gamma-ray bursts are the most luminous explosions that we can witness in the Universe. Studying the most extreme cases of these phenomena allows us to constrain the limits for the progenitor models. In this Letter, we study the prompt emission, afterglow, and host galaxy of GRB 120624B, one of the brightest GRBs detected by Fermi, to derive the energetics of the event and characterise the host galaxy in which it was produced. Following the high-energy detection we conducted a multi-wavelength follow-up campaign, including near-infrared imaging from HAWKI/VLT, optical from OSIRIS/GTC, X-ray observations from the Chandra X-ray Observatory and at sub-millimetre/millimetre wavelengths from SMA. Optical/nIR spectroscopy was performed with X-shooter/VLT. We detect the X-ray and nIR afterglow of the burst and determine a redshift of z = 2.1974 +/- 0.0002 through the identification of emission lines of [OII], [OIII] and H-alpha from the host galaxy of the GRB. This implies an energy release of Eiso = (3.0+/-0.2)x10^5...

  18. Morphology of QSO host galaxies --- a look at the SED

    Science.gov (United States)

    Andrei, A.; Coelho, B.; Anton, S.

    2015-08-01

    The Gaia Initial QSO Catalogue presents several characteristics of its 1,248,372 listed objects, among which the optical morphological type. From this a program studies the host galaxies of QSOs present in the SDSS up to its 8th release, based on retrieving a data bank of images in the five ugriz colors for the 105,783 objects spectroscopically found as QSOs. The first scope of this program is to study QSOs for which the isophotes of the host galaxy are not pronounced, so that the centroid determination is not affected for those fundamental grid-points of the Gaia Celestial Reference Frame. Since the target images come from relatively short exposures, we developed an approach to access disturbances of the target PSF relatively to the nearby stars. Here we focus on the first results for absolute magnitude of QSOs combining the SDSS colors and the SED library from Gaia.

  19. Infrared Characters of Host Galaxies with H2O Megamaser

    Institute of Scientific and Technical Information of China (English)

    俞志尧

    2001-01-01

    Infrared characters of all the host galaxies with the H2O megamaser have been studied. The most striking featureis the anticorrelation of S(60)/S(100) versus S(12)/S(25), and S(25)/S(60) versus S(12)/S(25). The anticorrelationin the tlux density ratio can been explained by coexistence of large and very small dust particles. The latter, whichare heated by absorption of single photon, are believed to be responsible for the bulk of 12μm radiation. If thephoton energy of the host galaxy is small, this implies large S(12)/S(25) and small S(60)/S(100). However, whenphoton energy density becomes larger, the infrared spectrum will peak at wavelengths ≤ 100 μm and enhanceemission at 25 μm. As a consequence small S(12)/S(25) and large S(60)/S(100) are observed.

  20. SNLS: Constraints on SN Ia progenitors from host galaxies

    Science.gov (United States)

    Howell, D. A.; Sullivan, M.; Le Borgne, D.; Hodsman, A.; Astier, P.; Aubourg, E.; Balam, D.; Basa, S.; Carlberg, R. G.; Conley, A.; Fabbro, S.; Fouchez, D.; Guy, J.; Hook, I. M.; Lafoux, H.; Neill, J. D.; Pain, R.; Palanque-Delabrouille, N.; Perrett, K.; Pritchet, C. J.; Regnault, N.; Rich, J.; Taillet, R.; Baumont, S.; Bronder, T. J.; Filliol, M.; Perlmutter, S.; Tao, C.; SNLS Collaboration

    2005-12-01

    We investigate the single degenerate and double degenerate progenitor scenarios for SNe Ia using Pegase galaxy population synthesis models fit to the SN Ia host galaxy ugriz data from the SNLS. For the single degenerate scenario, we present the results of a Monte Carlo sumulation combining limits on the star formation history of the model hosts and analytic contraints on the allowable primary and secondary mass distributions. Under the assuption that all SNe are from the single degenerate channel, we find that SNe in star forming galaxies have a wide range of secondary masses, with a median of about 5 solar masses. Supernovae from the older galaxy population must come from a narrower distribution of secondary masses, with a median less than two solar masses. When combined with the differing stretch distributions for the two populations, this argues that there is a light curve shape-secondary mass correlation if the single degenerate model is the only route to an SN Ia. However, the single degenerate scenario has difficulty producing the observed SN Ia rate in old populations so the double degenerate scenario may be preferred.

  1. The star formation rates of active galactic nuclei host galaxies

    CERN Document Server

    Ellison, Sara L; Rosario, David J; Mendel, J Trevor

    2016-01-01

    Using artificial neural network (ANN) predictions of total infra-red luminosities (LIR), we compare the host galaxy star formation rates (SFRs) of ~21,000 optically selected active galactic nuclei (AGN), 466 low excitation radio galaxies (LERGs) and 721 mid-IR selected AGN. SFR offsets (Delta SFR) relative to a sample of star-forming `main sequence' galaxies (matched in M*, z and local environment) are computed for the AGN hosts. Optically selected AGN exhibit a wide range of Delta SFR, with a distribution skewed to low SFRs and a median Delta SFR = -0.06 dex. The LERGs have SFRs that are shifted to even lower values with a median Delta SFR = -0.5 dex. In contrast, mid-IR selected AGN have, on average, SFRs enhanced by a factor ~1.5. We interpret the different distributions of Delta SFR amongst the different AGN classes in the context of the relative contribution of triggering by galaxy mergers. Whereas the LERGs are predominantly fuelled through low accretion rate secular processes which are not accompanied ...

  2. Are Some Milky Way Globular Clusters Hosted by Undiscovered Galaxies?

    CERN Document Server

    Zaritsky, Dennis; Sand, David J

    2016-01-01

    The confirmation of a globular cluster (GC) in the recently discovered ultrafaint galaxy Eridanus II (Eri II) motivated us to examine the question posed in the title. After estimating the halo mass of Eri II using a published stellar mass - halo mass relation, the one GC in this galaxy supports extending the relationship between the number of GCs hosted by a galaxy and the galaxy's total mass about two orders of magnitude in stellar mass below the previous limit. For this empirically determined specific frequency of between 0.06 and 0.39 globular clusters per 10$^9$ $M_\\odot$ of total mass, the surviving Milky Way (MW) subhalos with masses smaller than $10^{10} M_\\odot$ could host as many as 5 to 31 GCs, broadly consistent with the actual population of outer halo MW GCs, although matching the radial distribution in detail remains a challenge. Using a subhalo mass function from published high resolution numerical simulations and a Poissonian model for populating those halos with the aforementioned empirically ...

  3. Star formation in hosts of young radio galaxies

    OpenAIRE

    Labiano, A.; O'Dea, C. P.; Barthel, P. D.; W. H. De Vries; Baum, S. A.

    2005-01-01

    We present near ultraviolet imaging with the Hubble Space Telescope Advanced Camera for Surveys, targeting young radio galaxies (Gigahertz Peaked Spectrum and Compact Steep Spectrum sources), in search of star formation regions in their hosts. We find near UV light which could be the product of recent star formation in eight of the nine observed sources. However, observations at other wavelengths and colors are needed to definitively establish the nature of the observed UV light. In the CSS s...

  4. Locating star-forming regions in quasar host galaxies

    Science.gov (United States)

    Young, J. E.; Eracleous, M.; Shemmer, O.; Netzer, H.; Gronwall, C.; Lutz, Dieter; Ciardullo, R.; Sturm, Eckhard

    2014-02-01

    We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are motivated by recent evidence for a close relationship between black hole growth and the stellar mass evolution in its host galaxy. We use narrow-band [O II]λ3727, Hβ, [O III]λ5007 and Paα images, taken with the Wide Field Planetary Camera 2 and NICMOS instruments, to map the morphology of line-emitting regions, and, after extinction corrections, diagnose the excitation mechanism and infer star-formation rates. Significant challenges in this type of work are the separation of the quasar light from the stellar continuum and the quasar-excited gas from the star-forming regions. To this end, we present a novel technique for image decomposition and subtraction of quasar light. Our primary result is the detection of extended line-emitting regions with sizes ranging from 0.5 to 5 kpc and distributed symmetrically around the nucleus, powered primarily by star formation. We determine star-formation rates of the order of a few tens of M⊙ yr-1. The host galaxies of our target quasars have stellar masses of the order of 1011 M⊙ and specific star-formation rates on a par with those of M82 and luminous infrared galaxies. As such they fall at the upper envelope or just above the star-formation mass sequence in the specific star formation versus stellar mass diagram. We see a clear trend of increasing star-formation rate with quasar luminosity, reinforcing the link between the growth of the stellar mass of the host and the black hole mass found by other authors.

  5. Supermassive black holes and their host spheroids I. Galaxy vivisection

    CERN Document Server

    Savorgnan, Giulia A D

    2015-01-01

    Several recent studies have performed galaxy decompositions to investigate correlations between the black hole mass and various properties of the host spheroid, but they have not converged on the same conclusions. This is because their models for the same galaxy were often significantly different and not consistent with each other in terms of fitted components. Using $3.6 \\rm ~\\mu m$ $Spitzer$ imagery, which is a superb tracer of the stellar mass (superior to the $K$-band), we have performed state-of-the-art multicomponent decompositions for 66 galaxies with directly measured black hole masses. Our sample is the largest to date and, unlike previous studies, contains a large number (17) of spiral galaxies with low black hole masses. We paid careful attention to the image mosaicking, sky subtraction and masking of contaminating sources. After a scrupulous inspection of the galaxy photometry (through isophotal analysis and unsharp masking) and - for the first time - 2D kinematics, we were able to account for sph...

  6. SUPERMASSIVE BLACK HOLES AND THEIR HOST SPHEROIDS. I. DISASSEMBLING GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Savorgnan, G. A. D.; Graham, A. W., E-mail: gsavorgn@astro.swin.edu.au [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)

    2016-01-15

    Several recent studies have performed galaxy decompositions to investigate correlations between the black hole mass and various properties of the host spheroid, but they have not converged on the same conclusions. This is because their models for the same galaxy were often significantly different and not consistent with each other in terms of fitted components. Using 3.6 μm Spitzer imagery, which is a superb tracer of the stellar mass (superior to the K band), we have performed state-of-the-art multicomponent decompositions for 66 galaxies with directly measured black hole masses. Our sample is the largest to date and, unlike previous studies, contains a large number (17) of spiral galaxies with low black hole masses. We paid careful attention to the image mosaicking, sky subtraction, and masking of contaminating sources. After a scrupulous inspection of the galaxy photometry (through isophotal analysis and unsharp masking) and—for the first time—2D kinematics, we were able to account for spheroids; large-scale, intermediate-scale, and nuclear disks; bars; rings; spiral arms; halos; extended or unresolved nuclear sources; and partially depleted cores. For each individual galaxy, we compared our best-fit model with previous studies, explained the discrepancies, and identified the optimal decomposition. Moreover, we have independently performed one-dimensional (1D) and two-dimensional (2D) decompositions and concluded that, at least when modeling large, nearby galaxies, 1D techniques have more advantages than 2D techniques. Finally, we developed a prescription to estimate the uncertainties on the 1D best-fit parameters for the 66 spheroids that takes into account systematic errors, unlike popular 2D codes that only consider statistical errors.

  7. GRB host galaxies with VLT/X-Shooter: properties at 0.8 < z < 1.3

    CERN Document Server

    Piranomonte, S; Vergani, S D; Savaglio, S; Palazzi, E; Covino, S; Flores, H; Goldoni, P; Cupani, G; Kruhler, T; Mannucci, F; Onori, F; Rossi, A; D'Elia, V; Pian, E; D'Avanzo, P; Gomboc, A; Hammer, F; Randich, S; Fiore, F; Stella, L; Tagliaferri, G

    2015-01-01

    Long gamma-ray bursts (LGRBs) are associated with the death of massive stars. Their host galaxies therefore represent a unique class of objects tracing star formation across the observable Universe. Indeed, recently accumulated evidence shows that GRB hosts do not differ substantially from general population of galaxies at high (z > 2) redshifts. However, it has been long recognised that the properties of z < 1.5 hosts, compared to general star-forming population, are unusual. To better understand the reasons for the supposed difference in LGRB hosts properties at z < 1.5, we obtained VLT/X- Shooter spectra of six hosts lying in the redshift range of 0.8 < z < 1.3. Some of these hosts have been observed before, yet we still lack well constrained information on their characteristics such as metallicity, dust extinction and star formation rate. We search for emission lines in the VLT/X-Shooter spectra of the hosts and measure their fluxes. We perform a detailed analysis, estimating host average exti...

  8. Fast outflows and star formation quenching in quasar host galaxies

    Science.gov (United States)

    Carniani, S.; Marconi, A.; Maiolino, R.; Balmaverde, B.; Brusa, M.; Cano-Díaz, M.; Cicone, C.; Comastri, A.; Cresci, G.; Fiore, F.; Feruglio, C.; La Franca, F.; Mainieri, V.; Mannucci, F.; Nagao, T.; Netzer, H.; Piconcelli, E.; Risaliti, G.; Schneider, R.; Shemmer, O.

    2016-06-01

    Negative feedback from active galactic nuclei (AGN) is considered a key mechanism in shaping galaxy evolution. Fast, extended outflows are frequently detected in the AGN host galaxies at all redshifts and luminosities, both in ionised and molecular gas. However, these outflows are only potentially able to quench star formation, and we are still lacking decisive evidence of negative feedback in action. Here we present observations obtained with the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) H- and K-band integral-field of two quasars at z ~ 2.4 that are characterised by fast, extended outflows detected through the [Oiii]λ5007 line. The high signal-to-noise ratio of our observations allows us to identify faint narrow (FWHManti-correlated with the fast outflows. The ionised outflows therefore appear to be able to suppress star formation in the region where the outflow is expanding. However, the detection of narrow spatially extended Hα emission indicates star formation rates of at least ~50-90 M⊙ yr-1, suggesting either that AGN feedback does not affect the whole galaxy or that many feedback episodes are required before star formation is completely quenched. On the other hand, the narrow Hα emission extending along the edges of the outflow cone may also lead also to a positive feedback interpretation. Our results highlight the possible double role of galaxy-wide outflows in host galaxy evolution. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, P.ID: 086.B-0579(A) and 091.A-0261(A).The reduced data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A28

  9. Revisiting The First Galaxies: The effects of Population III stars on their host galaxies

    CERN Document Server

    Muratov, Alexander L; Gnedin, Nickolay Y; Zemp, Marcel

    2012-01-01

    We revisit the formation and evolution of the first galaxies using new hydrodynamic cosmological simulations with the ART code. Our simulations feature a recently developed model for H2 formation and dissociation, and a star formation recipe that is based on molecular rather than atomic gas. Here, we develop and implement a new recipe for the formation of metal-free Population III stars. We find the epoch during which Pop III stars dominated the energy and metal budget of the first galaxies to be short-lived. Galaxies which host Pop III stars do not retain dynamical signatures of their thermal and radiative feedback for more than 10^8 yr after the lives of the stars end in pair-instability supernovae, even when we consider the maximum reasonable efficiency of the feedback. Though metals ejected by the supernovae can travel well beyond the virial radius of the host galaxy, they will typically begin to fall back quickly, and do not enrich a large fraction of the intergalactic medium. Galaxies more massive than ...

  10. Early-type host galaxies of Type II and Ib Supernovae

    CERN Document Server

    Suh, Hyewon; Jeong, Hyunjin; Yi, Sukyoung K

    2011-01-01

    Recent studies find that some early-type galaxies host Type II or Ibc supernovae (SNe II, Ibc). This may imply recent star-formation activities in these SNe host galaxies, but a massive star origin of the SNe Ib so far observed in early-type galaxies has been questioned because of their intrinsic faintness and unusually strong Ca lines shown in the nebular phase. To address the issue, we investigate the properties of early-type SNe host galaxies using the data with Galaxy Evolution Explore(GALEX) ultraviolet photometry, and the Sloan Digital Sky Survey (SDSS) optical data. Our sample includes eight SNe II and one peculiar SN Ib (SN 2000ds) host galaxies as well as 32 SN Ia host galaxies. The host galaxy of SN 2005cz, another peculiar SN Ib, is also analysed using the GALEX data and the NASA/IPAC Extragalactic Database (NED) optical data. We find that the NUV-optical colors of SN II/Ib host galaxies are systematically bluer than those of SN Ia host galaxies, and some SN II/Ib host galaxies with NUV-r colors ma...

  11. The Massive Hosts of Radio Galaxies Across Cosmic Time

    Science.gov (United States)

    Seymour, Nick; SHzRG Collaboration

    2007-05-01

    We present the results of a comprehensive Spitzer survey of 69 radio galaxies across 160% for 75% the high redshift radio galaxies. As expected from unified models of AGN, the stellar fraction of the rest-frame H-band luminosity has no correlation with redshift, radio luminosity, or rest-frame mid-IR (5um) luminosity. Additionally, while the stellar H-band luminosity does not vary with stellar fraction, the total H-band luminosity anti-correlates with the stellar fraction as would be expected if the underlying hosts of these radio galaxies comprise a homogeneous population. The resultant stellar luminosities imply stellar masses of 10^{11-11.5}Msun even at the highest redshifts. Powerful radio galaxies tend to lie in a similar region of mid-IR color-color space as unobscured AGN, despite the stellar contribution to their mid-IR SEDs at shorter-wavelengths. The mid-IR luminosities alone classify most HzRGs as LIRGs or ULIRGs with even higher total-IR luminosities. As expected, these exceptionally high mid-IR luminosities are consistent with an obscured, highly-accreting AGN. Sub-mm observed starformation rates imply very high specific starformation rates, higher than other massive galaxies at these redshift ranges, suggesting we are watching the final formation of massive galaxies and black holes. We also present new evidence that the blackhole accretion rate (from mid-IR luminosity) correlates with radio lobe size and anti-correlates with specific starformation rate, begging the question which came first?

  12. The host galaxy/AGN connection in nearby early-type galaxies. Is there a miniature radio-galaxy in every "core" galaxy?

    OpenAIRE

    Balmaverde, B.; Capetti, A.

    2005-01-01

    This is the second of a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. In Capetti et al. (2005) we presented a study of the surface brightness profiles for the 65 objects with available archival HST images out of the 116 radio-detected galaxies. We classified early-type galaxies into ``core'' and ``power-law'' galaxies, discriminating on the basis of the slope of their nuclear ...

  13. Fast outflows and star formation quenching in quasar host galaxies

    CERN Document Server

    Carniani, S; Maiolino, R; Balmaverde, B; Brusa, M; Cano-Díaz, M; Cicone, C; Comastri, A; Cresci, G; Fiore, F; Feruglio, C; La Franca, F; Mainieri, V; Mannucci, F; Nagao, T; Netzer, H; Piconcelli, E; Risaliti, G; Schneider, R; Shemmer, O

    2016-01-01

    Negative feedback from active galactic nuclei (AGN) is considered a key mechanism in shaping galaxy evolution. Fast, extended outflows are frequently detected in the AGN host galaxies at all redshifts and luminosities, both in ionised and molecular gas. However, these outflows are only "potentially" able to quench star formation and we are still missing a decisive evidence of negative feedback in action. Here we present Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) H- and K-band integral-field spectroscopic observations of two quasars at $z\\sim$2.4 characterised by fast, extended outflows detected through the [OIII]$\\lambda$5007 line (Carniani et al. 2015). The high signal-to-noise ratio of our observations allows us to identify faint narrow (FWHM $< 500$ km/s), and spatially extended components in [OIII]$\\lambda$5007 and H$\\alpha$ emission associated with star formation in the host galaxy. Such star-formation powered emission is spatially anti-correlated with the fast outflow...

  14. The Contribution of Host Galaxies to the Infrared Energy Output of $z\\gtrsim5.0$ QUASARS

    CERN Document Server

    Lyu, Jianwei; Alberts, Stacey

    2015-01-01

    The infrared spectral energy distributions (SEDs) of $z\\gtrsim 5$ quasars can be reproduced by combining a low-metallicity galaxy template with a standard AGN template. The host galaxy is represented by Haro 11, a compact, moderately low metallicity, star-bursting galaxy that shares typical features of high-$z$ galaxies. For the vast majority of $z\\gtrsim 5$ quasars, the AGN contribution is well modeled by a standard empirical template with the contamination of star formation in the infrared subtracted. Together, these two templates can separate the contributions from the host galaxy and the AGN even in the case of limited data points, given that this model has only two free parameters. Using this method, we re-analyze 69 $z\\gtrsim 5$ quasars with extensive Herschel observations, and derive their AGN luminosities $L_{\\rm AGN}$ in a range $\\sim (0.78-27.4) \\times10^{13}\\, L_{\\odot}$, the infrared luminosities from star formation $L_{\\rm SF,IR} \\sim (<1.5-25.7)\\times10^{12}\\, L_{\\odot}$, and the correspondin...

  15. OPTICAL PROPERTIES OF HOST GALAXIES OF EXTRAGALACTIC NUCLEAR WATER MASERS

    International Nuclear Information System (INIS)

    We study the optical properties of the host galaxies of nuclear 22 GHz (λ = 1.35 cm) water masers. To do so, we cross-match the galaxy sample surveyed for water maser emission (123 detections and 3806 non-detections) with the Sloan Digital Sky Survey (SDSS) low-redshift galaxy sample (z B ), larger velocity dispersion (σ), and higher [O III] λ5007 luminosity, with [O III] λ5007 being the dominant factor. These detection rates are essentially the result of the correlations of isotropic maser luminosity with all three of these variables. These correlations are natural if maser strength increases with central black hole mass and the level of active galactic nucleus (AGN) activity. We also find that the detection rate is higher in galaxies with higher extinction. Based on these results, we propose that maser surveys seeking to efficiently find masers should rank AGN targets by extinction-corrected [O III] λ5007 flux when available. This prioritization would improve maser detection efficiency, from an overall ∼3% without pre-selection to ∼16% for the strongest intrinsic [O III] λ5007 emitters, by a factor of ∼5.

  16. Atomic hydrogen properties of active galactic nuclei host galaxies: H I in 16 nuclei of galaxies (NUGA) sources

    International Nuclear Information System (INIS)

    We present a comprehensive spectroscopic imaging survey of the distribution and kinematics of atomic hydrogen (H I) in 16 nearby spiral galaxies hosting low luminosity active galactic nuclei (AGN), observed with high spectral and spatial resolution (resolution: ∼20'', ∼5 km s–1) using the NRAO Very Large Array (VLA). The sample contains a range of nuclear types ranging from Seyfert to star-forming nuclei, and was originally selected for the NUclei of GAlaxies project (NUGA)—a spectrally and spatially resolved interferometric survey of gas dynamics in nearby galaxies designed to identify the fueling mechanisms of AGN and the relation to host galaxy evolution. Here we investigate the relationship between the H I properties of these galaxies, their environment, their stellar distribution, and their AGN type. The large-scale H I morphology of each galaxy is classified as ringed, spiral, or centrally concentrated; comparison of the resulting morphological classification with the AGN type reveals that ring structures are significantly more common in low-ionization narrow emission-line regions (LINER) than in Seyfert host galaxies, suggesting a time evolution of the AGN activity together with the redistribution of the neutral gas. Dynamically disturbed H I disks are also more prevalent in LINER host galaxies than in Seyfert host galaxies. While several galaxies are surrounded by companions (some with associated H I emission), there is no correlation between the presence of companions and the AGN type (Seyfert/LINER).

  17. MOLECULAR GAS IN z ∼ 6 QUASAR HOST GALAXIES

    International Nuclear Information System (INIS)

    We report our new observations of redshifted carbon monoxide emission from six z ∼ 6 quasars, using the IRAM Plateau de Bure Interferometer. CO (6-5) or (5-4) line emission was detected in all six sources. Together with two other previous CO detections, these observations provide unique constraints on the molecular gas emission properties in these quasar systems close to the end of the cosmic re-ionization. Complementary results are also presented for low-J CO lines observed at the Green Bank Telescope and the Very Large Array, and dust continuum from five of these sources with the SHARC-II bolometer camera at the Caltech Submillimeter Observatory. We then present a study of the molecular gas properties in our combined sample of eight CO-detected quasars at z ∼ 6. The detections of high-order CO line emission in these objects indicates the presence of highly excited molecular gas, with estimated masses on the order of 1010 Msun within the quasar host galaxies. No significant difference is found in the gas mass and CO line width distributions between our z ∼ 6 quasars and samples of CO-detected 1.4 ≤ z ≤ 5 quasars and submillimeter galaxies. Most of the CO-detected quasars at z ∼ 6 follow the far-infrared-CO luminosity relationship defined by actively star-forming galaxies at low and high redshifts. This suggests that ongoing star formation in their hosts contributes significantly to the dust heating at FIR wavelengths. The result is consistent with the picture of galaxy formation co-eval with supermassive black hole (SMBH) accretion in the earliest quasar-host systems. We investigate the black hole-bulge relationships of our quasar sample, using the CO dynamics as a tracer for the dynamical mass of the quasar host. The median estimated black hole-bulge mass ratio is about 15 times higher than the present-day value of ∼0.0014. This places important constraints on the formation and evolution of the most massive SMBH-spheroidal host systems at the

  18. Hubble Space Telescope observations of the afterglow, supernova and host galaxy associated with the extremely bright GRB 130427A

    CERN Document Server

    Levan, A J; Fruchter, A S; Hjorth, J; Pian, E; Mazzali, P; Perley, D A; Cano, Z; Graham, J; Hounsell, R A; Cenko, S B; Fynbo, J P U; Kouveliotou, C; Pe'er, A; Misra, K; Wiersema, K

    2013-01-01

    We present Hubble Space Telescope observations of the exceptionally bright and luminous Swift gamma-ray burst, GRB 130427A. At z=0.34 this burst affords an excellent opportunity to study the supernova associated with an intrinsically extremely luminous burst (E_iso >10^54 erg), much more luminous than almost all previous GRBs with spectroscopically associated supernovae. We use the combination of the image quality and UV capability of HST to provide the best possible separation of the afterglow, host and supernova contributions to the observed light ~17 rest-frame days after the burst. We find that the burst originated ~4 kpc from the nucleus of a moderately star forming (1 Msol/yr), possibly interacting disc galaxy. ACS grism observations show that the associated supernova, SN 2013cq, is well fit in the red by an SN 1998bw-like supernovae of similar luminosity and velocity (v~15,000 km/s). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v~30,000 km/s), but this SN fai...

  19. Dust extinction in high-z galaxies with gamma-ray burst afterglow spectroscopy

    DEFF Research Database (Denmark)

    Elíasdóttir, Á.; Fynbo, J. P. U.; Hjorth, J.;

    2009-01-01

    in a GRB host galaxy, while several tens of optical afterglow spectra without the bump have been recorded in the past decade. The derived extinction curve gives AV = 0.8-1.5 depending on the assumed intrinsic slope. Of the three local extinction laws, a Large Magellanic Cloud (LMC) type extinction gives...

  20. The Optical Afterglow and z=0.92 Early-type Host Galaxy of the Short GRB 100117A

    CERN Document Server

    Fong, Wen-fai; Chornock, Ryan; Tanvir, Nial R; Levan, Andrew J; Graham, John F; Fruchter, Andrew S; Cucchiara, Antonino; Fox, Derek B

    2010-01-01

    We present the discovery of the optical afterglow and early-type host galaxy of the short-duration GRB 100117A. The faint afterglow is detected 8.3 hr after the burst with r_AB = 25.46 +/- 0.20 mag. Follow-up optical and near-IR observations uncover a coincident compact red galaxy, identified as an early-type galaxy at a photometric redshift of z~0.6-0.9 (2-sigma) with a mass of 3x10^10 M_Sun, an age of ~1 Gyr, and a luminosity of L_B~0.5L_star. Spectroscopic observations of the host reveal a notable break corresponding to the Balmer 4000-Angstrom break at z~0.9, and stellar population spectral evolution template fits indicate z~0.915, which we adopt as the redshift of the host, with stellar population ages of ~1-3 Gyr. From a possible weak detection of [OII]-3727 emission at z=0.915 we infer an upper bound on the star formation rate of ~0.1 M_Sun per yr, leading to a specific star formation rate of 1 early-type hosts.

  1. The bursting nature of star formation in compact star-forming galaxies from the Sloan Digital Sky Survey

    Science.gov (United States)

    Izotov, Y. I.; Guseva, N. G.; Fricke, K. J.; Henkel, C.

    2016-08-01

    We study integrated characteristics of ˜ 14000 low-redshift (0 integrated characteristics of these galaxies to zero burst age would result in a considerably tighter and almost linear relation between stellar mass and star formation rate (SFR). The same correction implies that the specific star formation rate (the ratio of SFR and stellar mass) is not dependent on the galaxy stellar mass. We conclude that the correction for rapid luminosity evolution must be taken into account in a similar way when comparing different samples of low- and high-redshift SFGs. If the bursting nature of star formation and young burst ages are characteristics of the galaxies selected at high redshifts, the age correction of observed SFRs derived from the Hβ emission line or UV continua would modify the derived SFR densities in the early universe.

  2. Herschel Observed Stripe 82 Quasars and Their Host Galaxies: Connections between AGN Activity and host Galaxy Star Formation

    Science.gov (United States)

    Dong, X. Y.; Wu, Xue-Bing

    2016-06-01

    In this work, we present a study of 207 quasars selected from the Sloan Digital Sky Survey quasar catalogs and the Herschel Stripe 82 survey. Quasars within this sample are high-luminosity quasars with a mean bolometric luminosity of 1046.4 erg s-1. The redshift range of this sample is within z luminosity, far-IR (FIR) luminosity, stellar mass, as well as many other AGN and galaxy properties are deduced from the SED fitting results. The mean star formation rate (SFR) of the sample is 419 M ⊙ yr-1 and the mean gas mass is ˜1011.3 M ⊙. All of these results point to an IR luminous quasar system. Compared with star formation main sequence (MS) galaxies, at least 80 out of 207 quasars are hosted by starburst galaxies. This supports the statement that luminous AGNs are more likely to be associated with major mergers. The SFR increases with the redshift up to z = 2. It is correlated with the AGN bolometric luminosity, where {L}{{FIR}}\\propto {L}{{Bol}}0.46+/- 0.03. The AGN bolometric luminosity is also correlated with the host galaxy mass and gas mass. Yet the correlation between L FIR and L Bol has higher significant level, implies that the link between AGN accretion and the SFR is more primal. The M BH/M * ratio of our sample is 0.02, higher than the value 0.005 in the local universe. It might indicate an evolutionary trend of the M BH-M * scaling relation.

  3. The low-extinction afterglow in the solar-metallicity host galaxy of GRB 110918A

    CERN Document Server

    Elliott, J; Greiner, J; Savaglio, S; E., F Olivares; Rau, A; Postigo, A de Ugarte; Sánchez-Ramírez, R; Wiersema, K; Schady, P; Kann, D A; Filgas, R; Nardini, M; Berger, E; Fox, D; Gorosabel, J; Klose, S; Levan, A; Guelbenzu, A Nicuesa; Rossi, A; Schmidl, S; Sudilovsky, V; Tanvir, N R; Thöne, C C

    2013-01-01

    Galaxies selected through long gamma-ray bursts (GRBs) could be of fundamental importance when mapping the star formation history out to the highest redshifts. Before using them as efficient tools in the early Universe, however, the environmental factors that govern the formation of GRBs need to be understood. Metallicity is theoretically thought to be a fundamental driver in GRB explosions and energetics, but is still, even after more than a decade of extensive studies, not fully understood. This is largely related to two phenomena: a dust-extinction bias, that prevented high-mass and thus likely high-metallicity GRB hosts to be detected in the first place, and a lack of efficient instrumentation, that limited spectroscopic studies including metallicity measurements to the low-redshift end of the GRB host population. The subject of this work is the very energetic GRB 110918A, for which we measure one of the largest host-integrated metallicities, ever, and the highest stellar mass for z<1.9. This presents ...

  4. Erratum: The Late Afterglow and Host Galaxy of GRB 990712

    Science.gov (United States)

    Hjorth, J.; Holland, S.; Courbin, F.; Dar, A.; Olsen, L. F.; Scodeggio, M.

    2000-08-01

    In the Letter ``The Late Afterglow and Host Galaxy of GRB 990712'' by J. Hjorth, S. Holland, F. Courbin, A. Dar, L. F. Olsen, & M. Scodeggio (ApJ, 534, L147 [2000]), there was an error in the flux calibration of the spectrum. The y-axis scale of Figure 2 and the fluxes in the last column of Table 1 should be multiplied by a factor of 3.47 to read 2.25, 0.86, 1.61, and 3.79×10-16 ergs s-1 cm-2. The error affects the luminosities and star formation rates (SFRs) presented in the third and fourth paragraphs of § 5 as follows. In the third paragraph, the total SFR based on the continuum flux should be 0.91-1.41 Msolar yr-1 instead of 0.29-0.45 the [O II] luminosity should be L3727=1.5×1041 ergs s-1 instead of 6.3×1040 and the implied [O II] SFR should be 2.12+/-0.60 Msolar yr-1 instead of 0.88+/-0.25. Consequently, the last two sentences of this paragraph are revised to read ``The derived SFR (from the [O II] flux) is about half of the SFR found by Bloom et al. (1999b) for the host of GRB 990123 and 2-3 times that of the host of GRB 970508 (Bloom et al. 1998). The specific SFR per unit luminosity of the GRB 990712 host galaxy is comparable to that of the host galaxies of GRB 990123 and GRB 970508.'' In the fourth paragraph, the total V-band flux in the feature should be 0.405+/-0.004 μJy instead of 0.323+/-0.003 the power-law spectral index should be β=-2.57 instead of -2.93 and the SFR in the feature should be 0.11-0.17 Msolar instead of 0.03-0.05. The main results and conclusions of the original Letter are unaffected by the error. The authors thank P. M. Vreeswijk for bringing this error to their attention.

  5. Host Galaxies of Type Ia Supernovae from the Nearby Supernova Factory

    Science.gov (United States)

    Childress, M.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Gangler, E.; Guy, J.; Hsiao, E. Y.; Kerschhaggl, M.; Kim, A. G.; Kowalski, M.; Loken, S.; Nugent, P.; Paech, K.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Scalzo, R.; Smadja, G.; Tao, C.; Thomas, R. C.; Weaver, B. A.; Wu, C.

    2013-06-01

    We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory. Combining Galaxy Evolution Explorer (GALEX) UV data with optical and near-infrared photometry, we employ stellar population synthesis techniques to measure SN Ia host galaxy stellar masses, star formation rates (SFRs), and reddening due to dust. We reinforce the key role of GALEX UV data in deriving accurate estimates of galaxy SFRs and dust extinction. Optical spectra of SN Ia host galaxies are fitted simultaneously for their stellar continua and emission lines fluxes, from which we derive high-precision redshifts, gas-phase metallicities, and Hα-based SFRs. With these data we show that SN Ia host galaxies present tight agreement with the fiducial galaxy mass-metallicity relation from Sloan Digital Sky Survey (SDSS) for stellar masses log(M */M ⊙) > 8.5 where the relation is well defined. The star formation activity of SN Ia host galaxies is consistent with a sample of comparable SDSS field galaxies, though this comparison is limited by systematic uncertainties in SFR measurements. Our analysis indicates that SN Ia host galaxies are, on average, typical representatives of normal field galaxies.

  6. Locating Star-Forming Regions in Quasar Host Galaxies

    CERN Document Server

    Young, J E; Shemmer, O; Netzer, H; Gronwall, C; Lutz, Dieter; Ciardullo, R; Sturm, Eckhard

    2013-01-01

    We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are motivated by recent evidence for a close relationship between black hole growth and the stellar mass evolution in its host galaxy. We use narrow-band [O II] $\\lambda$3727, H$\\beta$, [O III] $\\lambda$5007 and Pa$\\alpha$ images, taken with the WFPC2 and NICMOS instruments, to map the morphology of line-emitting regions, and, after extinction corrections, diagnose the excitation mechanism and infer star-formation rates. Significant challenges in this type of work are the separation of the quasar light from the stellar continuum and the quasar-excited gas from the star-forming regions. To this end, we present a novel technique for image decomposition and subtraction of quasar light. Our primary result is the detection of extended line-emitting regions with sizes ranging from 0.5 to 5 kpc and distributed symmetrically aroun...

  7. The bursting nature of star formation in compact star-forming galaxies from the Sloan Digital Sky Survey

    CERN Document Server

    Izotov, Y I; Fricke, K J; Henkel, C

    2016-01-01

    We study integrated characteristics of ~14000 low-redshift (0galaxies (SFGs) selected from the Data Release 12 of the Sloan Digital Sky Survey. It is found that emission of these galaxies is dominated by strong young bursts of star formation, implying that their luminosities experience rapid variations on a time scale of a few Myr. Reducing integrated characteristics of these galaxies to zero burst age would result in a considerably tighter and almost linear relation between stellar mass and star formation rate (SFR). The same correction implies that the specific star formation rate (the ratio of SFR and stellar mass) is not dependent on the galaxy stellar mass. We conclude that the correction for rapid luminosity evolution must be taken into account in a similar way when comparing different samples of low- and high-redshift SFGs. If the bursting nature of star formation and young burst ages are characteristics of the galaxies selected at high redshifts, the age correction of ...

  8. The bursting nature of star formation in compact star-forming galaxies from the Sloan Digital Sky Survey

    Science.gov (United States)

    Izotov, Y. I.; Guseva, N. G.; Fricke, K. J.; Henkel, C.

    2016-11-01

    We study integrated characteristics of ˜14 000 low-redshift (0 < z < 1) compact star-forming galaxies (SFGs) selected from the Data Release 12 of the Sloan Digital Sky Survey. It is found that emission of these galaxies is dominated by strong young bursts of star formation, implying that their luminosities experience rapid variations on a time-scale of a few Myr. Reducing integrated characteristics of these galaxies to zero burst age would result in a considerably tighter and almost linear relation between stellar mass and star formation rate (SFR). The same correction implies that the specific star formation rate (the ratio of SFR and stellar mass) is not dependent on the galaxy stellar mass. We conclude that the correction for rapid luminosity evolution must be taken into account in a similar way when comparing different samples of low- and high-redshift SFGs. If the bursting nature of star formation and young burst ages are characteristics of the galaxies selected at high redshifts, the age correction of observed SFRs derived from the Hβ emission line or UV continua would modify the derived SFR densities in the early universe.

  9. Spectroscopy of the short-hard GRB 130603B. The host galaxy and environment of a compact object merger

    Science.gov (United States)

    de Ugarte Postigo, A.; Thöne, C. C.; Rowlinson, A.; García-Benito, R.; Levan, A. J.; Gorosabel, J.; Goldoni, P.; Schulze, S.; Zafar, T.; Wiersema, K.; Sánchez-Ramírez, R.; Melandri, A.; D'Avanzo, P.; Oates, S.; D'Elia, V.; De Pasquale, M.; Krühler, T.; van der Horst, A. J.; Xu, D.; Watson, D.; Piranomonte, S.; Vergani, S. D.; Milvang-Jensen, B.; Kaper, L.; Malesani, D.; Fynbo, J. P. U.; Cano, Z.; Covino, S.; Flores, H.; Greiss, S.; Hammer, F.; Hartoog, O. E.; Hellmich, S.; Heuser, C.; Hjorth, J.; Jakobsson, P.; Mottola, S.; Sparre, M.; Sollerman, J.; Tagliaferri, G.; Tanvir, N. R.; Vestergaard, M.; Wijers, R. A. M. J.

    2014-03-01

    Context. Short duration gamma-ray bursts (SGRBs) are thought to be related to the violent merger of compact objects, such as neutron stars or black holes, which makes them promising sources of gravitational waves. The detection of a "kilonova"-likesignature associated to the Swift-detected GRB 130603B has suggested that this event is the result of a compact object merger. Aims: Our knowledge on SGRB has been, until now, mostly based on the absence of supernova signatures and the analysis of the host galaxies to which they cannot always be securely associated. Further progress has been significantly hampered by the faintness and rapid fading of their optical counterparts (afterglows), which has so far precluded spectroscopy of such events. Afterglow spectroscopy is the key tool to firmly determine the distance at which the burst was produced, crucial to understand its physics, and study its local environment. Methods: Here we present the first spectra of a prototypical SGRB afterglow in which both absorption and emission features are clearly detected. Together with multi-wavelength photometry we study the host and environment of GRB 130603B. Results: From these spectra we determine the redshift of the burst to be z = 0.3565 ± 0.0002, measure rich dynamics both in absorption and emission, and a substantial line of sight extinction of AV = 0.86 ± 0.15 mag. The GRB was located at the edge of a disrupted arm of a moderately star forming galaxy with near-solar metallicity. Unlike for most long GRBs (LGRBs), NHX/AV is consistent with the Galactic ratio, indicating that the explosion site differs from those found in LGRBs. Conclusions: The merger is not associated with the most star-forming region of the galaxy; however, it did occur in a dense region, implying a rapid merger or a low natal kick velocity for the compact object binary. Appendices are available in electronic form at http://www.aanda.org

  10. Star formation in the hosts of GHz peaked spectrum and compact steep spectrum radio galaxies

    CERN Document Server

    Labiano, A; Barthel, P D; De Vries, W H; Baum, S A

    2007-01-01

    AIMS: Search for star formation regions in the hosts of potentially young radio galaxies (Gigahertz Peaked Spectrum and Compact Steep Spectrum sources). METHODS: Near-UV imaging with the Hubble Space Telescope Advanced Camera for Surveys.} RESULTS: We find near-UV light which could be the product of recent star formation in eight of the nine observed sources, though other explanations are not currently ruled out. The UV luminosities of the GPS and CSS sources are similar to those of a sample of nearby large scale radio galaxies. Stellar population synthesis models are consistent with a burst of recent star formation occuring before the formation of the radio source. However, observations at other wavelengths and colors are needed to definitively establish the nature of the observed UV light. In the CSS sources 1443+77 and 1814-637 the near-UV light is aligned with and is co-spatial with the radio source. We suggest that in these sources the UV light is produced by star formation triggered and/or enhanced by t...

  11. Strong bimodality in the host halo mass of central galaxies from galaxy-galaxy lensing

    CERN Document Server

    Mandelbaum, Rachel; Zu, Ying; White, Simon; Henriques, Bruno; More, Surhud

    2015-01-01

    We use galaxy-galaxy lensing to study the dark matter halos surrounding a sample of Locally Brightest Galaxies (LBGs) selected from the Sloan Digital Sky Survey. We measure mean halo mass as a function of the stellar mass and colour of the central galaxy. Mock catalogues constructed from semi-analytic galaxy formation simulations demonstrate that most LBGs are the central objects of their halos, greatly reducing interpretation uncertainties due to satellite contributions to the lensing signal. Over the full stellar mass range, $10.3 10.7$. Tests using the mock catalogues and on the data themselves clarify the effects of LBG selection and show that it cannot artificially induce a systematic dependence of halo mass on LBG colour. The bimodality in halo mass at fixed stellar mass is reproduced by the astrophysical model underlying our mock catalogue, but the sign of the effect is inconsistent with recent, nearly parameter-free age-matching models. The sign and magnitude of the effect can, however, be reproduced...

  12. Strong bimodality in the host halo mass of central galaxies from galaxy-galaxy lensing

    Science.gov (United States)

    Mandelbaum, Rachel; Wang, Wenting; Zu, Ying; White, Simon; Henriques, Bruno; More, Surhud

    2016-04-01

    We use galaxy-galaxy lensing to study the dark matter haloes surrounding a sample of locally brightest galaxies (LBGs) selected from the Sloan Digital Sky Survey. We measure mean halo mass as a function of the stellar mass and colour of the central galaxy. Mock catalogues constructed from semi-analytic galaxy formation simulations demonstrate that most LBGs are the central objects of their haloes, greatly reducing interpretation uncertainties due to satellite contributions to the lensing signal. Over the full stellar mass range, 10.3 10.7. Tests using the mock catalogues and on the data themselves clarify the effects of LBG selection and show that it cannot artificially induce a systematic dependence of halo mass on LBG colour. The bimodality in halo mass at fixed stellar mass is reproduced by the astrophysical model underlying our mock catalogue, but the sign of the effect is inconsistent with recent, nearly parameter-free age-matching models. The sign and magnitude of the effect can, however, be reproduced by halo occupation distribution models with a simple (few-parameter) prescription for type dependence.

  13. Fast Radio Bursts as Probes of Magnetic Fields in Filaments of Galaxies

    CERN Document Server

    Akahori, Takuya; Gaensler, B M

    2016-01-01

    We examine the proposal that the dispersion measures (DMs) and Faraday rotation measures (RMs) of extragalactic linearly-polarized fast radio bursts (FRBs) can be used to probe the intergalactic magnetic field (IGMF) in filaments of galaxies. The DM through the cosmic web is dominated by contributions from the warm-hot intergalactic medium (WHIM) in filaments and from the gas in voids. On the other hand, RM is induced mostly by the hot medium in galaxy clusters, and only a fraction of it is produced in the WHIM. We show that if one excludes FRBs whose sightlines pass through galaxy clusters, the line-of-sight strength of the IGMF in filaments, $B_{||}$, is approximately $C(\\langle 1+z \\rangle/f_{DM})(RM/DM)$, where $C$ is a known constant. Here, {the redshift of the FRB is not required to be known;} $f_{DM}$ is the fraction of total DM due the WHIM, while $\\langle 1+z \\rangle$ is the redshift of interevening gas weighted by the WHIM gas density, both of which can be evaluated for a given cosmology model solel...

  14. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties

    CERN Document Server

    Kim, A G; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Cellier-Holzem, F; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Feindt, U; Fleury, M; Gangler, E; Greskovic, P; Guy, J; Kowalski, M; Lombardo, S; Nordin, J; Nugent, P; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Runge, K; Saunders, C; Scalzo, R; Smadja, G; Tao, C; Thomas, R C; Weaver, B A

    2014-01-01

    Kim et al. (2013) [K13] introduced a new methodology for determining peak-brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spectrophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is $0.013\\pm 0.031$ mag for a supernova subsample with data coverage corresponding to the K13 training; at $\\ll 1\\sigma$, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement the Hubble residual step with host mass is $0.045\\pm 0.026$ mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch para...

  15. The host galaxy/AGN connection in nearby early-type galaxies. Is there a miniature radio-galaxy in every "core" galaxy?

    CERN Document Server

    Balmaverde, B

    2005-01-01

    This is the second of a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. In Capetti et al. (2005) we presented a study of the surface brightness profiles for the 65 objects with available archival HST images out of the 116 radio-detected galaxies. We classified early-type galaxies into ``core'' and ``power-law'' galaxies, discriminating on the basis of the slope of their nuclear brightness profiles. Here we focus on the 29 core galaxies (hereafter CoreG). We used HST and Chandra data to isolate their nuclear emission. The CoreG invariably host radio-loud nuclei, with an average radio-loudness parameter of Log R = 3.6. The optical and X-ray nuclear luminosities correlate with the radio-core power, smoothly extending the analogous correlations already found for low luminosity radio-galaxies. This supports the interpretation of a common non-thermal origin of the nuclear emission also for CoreG. The ...

  16. High-redshift quasar host galaxies with adaptive optics

    CERN Document Server

    Kuhlbrodt, B; Wisotzki, L; Jahnke, K

    2005-01-01

    We present K band adaptive optics observations of three high-redshift (z ~ 2.2) high-luminosity quasars, all of which were studied for the first time. We also bserved several point spread function (PSF) calibrators, non-simultaneously because of the small field of view. The significant temporal PSF variations on timescales of minutes inhibited a straightforward scaled PSF removal from the quasar images. Characterising the degree of PSF concentration by the radii encircling 20% and 80% of the total flux, respectively, we found that even under very different observing conditions the r20 vs. r80 relation varied coherently between individual short exposure images, delineating a well-defined relation for point sources. Placing the quasar images on this relation, we see indications that all three objects were resolved. We designed a procedure to estimate the significance of this result, and to estimate host galaxy parameters, by reproducing the statistical distribution of the individual short exposure images. We fi...

  17. A Multi-wavelength Survey of AGN in Massive Clusters: AGN Distribution and Host Galaxy Properties

    CERN Document Server

    Klesman, Alison J

    2014-01-01

    We investigate the effect of environment on the presence and fuelling of Active Galactic Nuclei (AGN) by identifying galaxies hosting AGN in massive galaxy clusters and the fields around them. We have identified AGN candidates via optical variability (178), X-ray emission (74), and mid-IR SEDs (64) in multi- wavelength surveys covering regions centered on 12 galaxy clusters at redshifts 0.5 < z < 0.9. In this paper, we present the radial distribution of AGN in clusters to examine how local environment affects the presence of an AGN and its host galaxy. While distributions vary from cluster to cluster, we find that the radial distribution of AGN generally differs from that of normal galaxies. AGN host galaxies also show a different colour distribution than normal galaxies, with many AGN hosts displaying galaxy colours in the "green valley" between the red sequence and blue star-forming normal galaxies. This result is similar to those found in field galaxy studies. The colour distribution of AGN hosts is ...

  18. The optically unbiased GRB host (TOUGH) survey. VI. Radio observations at z<1 and consistency with typical star-forming galaxies

    CERN Document Server

    Michałowski, Michał J; Hjorth, J; Malesani, D; Reinfrank, R F; Bonavera, L; Cerón, J M Castro; Ibar, E; Dunlop, J S; Fynbo, J P U; Garrett, M A; Jakobsson, P; Kaplan, D L; Krühler, T; Levan, A J; Massardi, M; Pal, S; Sollerman, J; Tanvir, N R; van der Horst, A J; Watson, D; Wiersema, K

    2012-01-01

    The objective of this paper is to determine the level of obscured star formation activity and dust attenuation in a sample of gamma-ray burst (GRB) hosts; and to test the hypothesis that GRB hosts have properties consistent with those of the general star-forming galaxy populations. We present a radio continuum survey of all z 500 Mo yr^-1. For the undetected hosts the mean radio flux (<35 uJy 3sigma) corresponds to an average SFR < 15 Mo yr^-1. Moreover, ~92% of the z<1 GRB hosts have ultraviolet dust attenuation A_UV < 6.7 mag (visual attenuation A_V < 3 mag). Hence we did not find evidence for large dust obscuration in a majority of GRB hosts. Finally, we found that the distributions of SFRs and A_UV of GRB hosts are consistent with those of Lyman break galaxies, Halpha emitters at similar redshifts and of galaxies from cosmological simulations. The similarity of the GRB population with other star-forming galaxies is consistent with the hypothesis that GRBs, a least at z<1, trace a large f...

  19. IDENTIFYING THE LOCATION IN THE HOST GALAXY OF THE SHORT GRB 111117A WITH THE CHANDRA SUBARCSECOND POSITION

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, T.; Troja, E. [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Aoki, K. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Guiriec, S.; Barthelmy, S. D. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Im, M.; Jeon, Y. [Center for the Exploration of the Origin of the Universe (CEOU), Department of Physics and Astronomy, Seoul National University, Seoul, 151-747 (Korea, Republic of); Leloudas, G.; Malesani, D.; De Ugarte Postigo, A.; Andersen, M. I. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Melandri, A.; D' Avanzo, P. [INAF-Osservatorio Astronomico di Brera, via Bianchi 46, I-23807 Merate (Italy); Urata, Y. [Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China); Xu, D. [Department of Particle Physics and Astronomy, The Weizmann Institute of Science, Rehovot 76100 (Israel); Gorosabel, J.; Sanchez-Ramirez, R. [Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia s/n, E-18008 Granada (Spain); Bai, J. [Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan Province, 650011 (China); Briggs, M. S. [Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Foley, S. [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); and others

    2013-03-20

    We present our successful Chandra program designed to identify, with subarcsecond accuracy, the X-ray afterglow of the short GRB 111117A, which was discovered by Swift and Fermi. Thanks to our rapid target of opportunity request, Chandra clearly detected the X-ray afterglow, though no optical afterglow was found in deep optical observations. The host galaxy was clearly detected in the optical and near-infrared band, with the best photometric redshift of z=1.31{sub -0.23}{sup +0.46} (90% confidence), making it one of the highest known short gamma-ray burst (GRB) redshifts. Furthermore, we see an offset of 1.0 {+-} 0.2 arcsec, which corresponds to 8.4 {+-} 1.7 kpc, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining subarcsecond X-ray localizations of short GRB afterglows to study GRB environments.

  20. IDENTIFYING THE LOCATION IN THE HOST GALAXY OF THE SHORT GRB 111117A WITH THE CHANDRA SUBARCSECOND POSITION

    International Nuclear Information System (INIS)

    We present our successful Chandra program designed to identify, with subarcsecond accuracy, the X-ray afterglow of the short GRB 111117A, which was discovered by Swift and Fermi. Thanks to our rapid target of opportunity request, Chandra clearly detected the X-ray afterglow, though no optical afterglow was found in deep optical observations. The host galaxy was clearly detected in the optical and near-infrared band, with the best photometric redshift of z=1.31-0.23+0.46 (90% confidence), making it one of the highest known short gamma-ray burst (GRB) redshifts. Furthermore, we see an offset of 1.0 ± 0.2 arcsec, which corresponds to 8.4 ± 1.7 kpc, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining subarcsecond X-ray localizations of short GRB afterglows to study GRB environments.

  1. Host Galaxies of Luminous Quasars: Structural Properties and the Fundamental Plane

    Science.gov (United States)

    Wolf, Marsha J.; Sheinis, Andrew I.

    2008-10-01

    We present stellar velocity dispersion measurements in the host galaxies of ten luminous quasars (MV < -23) using the Ca H&K lines in off-nuclear spectra. We combine these data with effective radii and magnitudes from the literature to place the host galaxies on the fundamental plane (FP) where their properties are compared with other types of galaxies. We find that the radio-loud (RL) QSO hosts have similar properties to massive elliptical galaxies, while the radio-quiet (RQ) hosts are more similar to intermediate-mass galaxies. The RL hosts lie at the upper extreme of the FP due to their large velocity dispersions (langσ*rang = 321 km s-1), low surface brightness (langμ e (r)rang = 20.8 mag arcsec-2), and large effective radii (langRe rang = 11.4 kpc), and have langM *rang = 1.5 × 1012 M sun and langM/Lrang = 12.4. In contrast, properties of the RQ hosts are langσ*rang = 241 km s-1, langM *rang = 4.4 × 1011 M sun, and M/L ~ 5.3. The distinction between these galaxies occurs at σ*~ 300 km s-1, Re ~ 6 kpc, and corresponding M * ~ 5.9 ± 3.5 × 1011 M sun. Our data support previous results that Palomar-Green QSOs are related to gas-rich galaxy mergers that form intermediate-mass galaxies, while RL QSOs reside in massive early-type galaxies, most of which also show signs of recent mergers or interactions. Previous authors have drawn these conclusions by using estimates of the black hole mass and inferring host galaxy properties from that, while here we have relied purely on directly measured host galaxy properties.

  2. EARLY-TYPE HOST GALAXIES OF TYPE Ia SUPERNOVAE. I. EVIDENCE FOR DOWNSIZING

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yijung; Kim, Young-Lo; Lim, Dongwook; Chung, Chul; Lee, Young-Wook, E-mail: ywlee2@yonsei.ac.kr [Center for Galaxy Evolution Research and Department of Astronomy, Yonsei University, Seoul 03722 (Korea, Republic of)

    2016-03-15

    Type Ia supernova (SN Ia) cosmology provides the most direct evidence for the presence of dark energy. This result is based on the assumption that the lookback time evolution of SN Ia luminosity, after light curve corrections, would be negligible. Recent studies show, however, that the Hubble residual (HR) of SN Ia is correlated with the mass and morphology of host galaxies, implying the possible dependence of SN Ia luminosity on host galaxy properties. In order to investigate this more directly, we have initiated a spectroscopic survey for early-type host galaxies, for which population age and metallicity can be more reliably determined from the absorption lines. In this first paper of the series, we present here the results from high signal-to-noise ratio (≳100 per pixel) spectra for 27 nearby host galaxies in the southern hemisphere. For the first time in host galaxy studies, we find a significant (∼3.9σ) correlation between host galaxy mass (velocity dispersion) and population age, which is consistent with the “downsizing” trend among non-host early-type galaxies. This result is rather insensitive to the choice of population synthesis models. Since we find no correlation with metallicity, our result suggests that stellar population age is mainly responsible for the relation between host mass and HR. If confirmed, this would imply that the luminosity evolution plays a major role in the systematic uncertainties of SN Ia cosmology.

  3. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties

    Energy Technology Data Exchange (ETDEWEB)

    Nearby Supernova Factory; Kim, A. G.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Childress, M.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Feindt, U.; Fleury, M.; Gangler, E.; Greskovic, P.; Guy, J.; Kowalski, M.; Lombardo, S.; Nordin, J.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Saunders, C.; Scalzo, R.; Smadja, G.; Tao, C.; Thomas, R. C.; Weaver, B. A.

    2014-01-17

    Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spec- trophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is 0.013 ? 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at ? 1?, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement the Hubble residual step with host mass is 0.045 ? 0.026 mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch param- eters: Steps at> 2? significance are found in SALT2 Hubble residuals in samples split by the values of their K13 x(1) and x(2) light-curve parameters. x(1) affects the light- curve width and color around peak (similar to the∆m15 and stretch parameters), and x(2) affects colors, the near-UV light-curve width, and the light-curve decline 20 to 30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN Ia diversity arising from progenitor stellar evolution.

  4. The Host Galaxies of High-Luminosity Obscured Quasars at 2.5

    Science.gov (United States)

    Ross, Nicholas; Strauss, M. A.; Greene, J. E.; Zakamska, N. L.; Brandt, W. N.; Alexandroff, R.; Liu, G.; Smith, P. S.; The SDSS-III BOSS Quasar Working Group

    2014-01-01

    Active Galactic Nuclei play a key role in the evolution of galaxies. However, very little is known about the host galaxies of the most luminous quasars at redshift 2.5, the epoch when massive black hole growth peaked. The brightness of the quasar itself, which can easily outshine a galaxy by a large factor, makes it very difficult to study emission from extended gas or stars in the host galaxy. However, we have imaged the extended emission from the host galaxies of a unique sample of six optically extinguished (Type II) luminous quasars with 2.5, with the Hubble Space Telescope (Cycle 20, GO 13014) using ACS/F814W to access the rest-frame near-ultraviolet, and WFC3/F160W for the rest-frame optical longward of 4000A. These objects are selected from the spectroscopic database of the SDSS/Baryon Oscillation Spectroscopic Survey to have strong, narrow emission lines and weak continua. With these images, we have quantified the luminosity, morphology, and dynamical state of the host galaxies, and searched for extended scattered light from the obscured central engine. These observations are the first comprehensive study of both host galaxy light and scattered light in high-luminosity quasars at the epoch of maximum black hole growth, and give insights into the relationship between host galaxies and black holes during this important, and yet largely unexplored period.

  5. Comparing the Host Galaxies of Type Ia, Type II, and Type Ibc Supernovae

    Science.gov (United States)

    Shao, X.; Liang, Y. C.; Dennefeld, M.; Chen, X. Y.; Zhong, G. H.; Hammer, F.; Deng, L. C.; Flores, H.; Zhang, B.; Shi, W. B.; Zhou, L.

    2014-08-01

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D n (4000), Hδ A , stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D n (4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D n (4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (~0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  6. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

    International Nuclear Information System (INIS)

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters Dn(4000), HδA, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low Dn(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high Dn(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (∼0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  7. The Effect of Host Galaxies on Type Ia Supernovae in the SDSS-II Supernova Survey

    Energy Technology Data Exchange (ETDEWEB)

    Lampeitl, Hubert; /Portsmouth U., ICG; Smith, Mathew; /Cape Town U. /Portsmouth U., ICG; Nichol, Robert C.; /Portsmouth U., ICG; Bassett, Bruce; /South African Astron. Observ. /Cape Town U.; Cinabro, David; /Wayne State U.; Dilday, Benjamin; /Rutgers U., Piscataway; Foley, Ryan J.; /Harvard-Smithsonian Ctr. Astrophys.; Frieman, Joshua A.; /Chicago U. /Fermilab; Garnavich, Peter M.; /Notre Dame U.; Goobar, Ariel; /Stockholm U., OKC; Im, Myungshin; /Seoul Natl. U. /Rutgers U., Piscataway

    2010-05-01

    We present an analysis of the host galaxy dependencies of Type Ia Supernovae (SNe Ia) from the full three year sample of the SDSS-II Supernova Survey. We re-discover, to high significance, the strong correlation between host galaxy type and the width of the observed SN light curve, i.e., fainter, quickly declining SNe Ia favor passive host galaxies, while brighter, slowly declining Ia's favor star-forming galaxies. We also find evidence (at between 2 to 3{sigma}) that SNe Ia are {approx_equal} 0.1 magnitudes brighter in passive host galaxies, than in star-forming hosts, after the SN Ia light curves have been standardized using the light curve shape and color variations: This difference in brightness is present in both the SALT2 and MCLS2k2 light curve fitting methodologies. We see evidence for differences in the SN Ia color relationship between passive and star-forming host galaxies, e.g., for the MLCS2k2 technique, we see that SNe Ia in passive hosts favor a dust law of R{sub V} {approx_equal} 1, while SNe Ia in star-forming hosts require R{sub V} {approx} 2. The significance of these trends depends on the range of SN colors considered. We demonstrate that these effects can be parameterized using the stellar mass of the host galaxy (with a confidence of > 4{sigma}) and including this extra parameter provides a better statistical fit to our data. Our results suggest that future cosmological analyses of SN Ia samples should include host galaxy information.

  8. Host Galaxies of Type Ia Supernovae from the Nearby Supernova Factory

    CERN Document Server

    Childress, M J; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Cellier-Holzem, F; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Guy, J; Hsiao, E Y; Kerschhaggl, M; Kim, A G; Kowalski, M; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Runge, K; Scalzo, R; Smadja, G; Tao, C; Thomas, R C; Weaver, B A; Wu, C

    2013-01-01

    We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory (SNfactory). Combining GALEX UV data with optical and near infrared photometry, we employ stellar population synthesis techniques to measure SN Ia host galaxy stellar masses, star-formation rates (SFRs), and reddening due to dust. We reinforce the key role of GALEX UV data in deriving accurate estimates of galaxy SFRs and dust extinction. Optical spectra of SN Ia host galaxies are fitted simultaneously for their stellar continua and emission lines fluxes, from which we derive high precision redshifts, gas-phase metallicities, and Halpha-based SFRs. With these data we show that SN Ia host galaxies present tight agreement with the fiducial galaxy mass-metallicity relation from SDSS for stellar masses log(M_*/M_Sun)>8.5 where the relation is well-defined. The star-formation activity of SN Ia host galaxies is consistent with a sample of comparable SDSS field galaxies, thou...

  9. High-redshift quasars host galaxies: is there a stellar mass crisis?

    CERN Document Server

    Valiante, Rosa; Salvadori, Stefania; Gallerani, Simona

    2014-01-01

    We investigate the evolutionary properties of a sample of quasars at 5bursts, while the central BH grows via gas accretion and BH-BH mergers. Eventually, a strong AGN driven wind starts to clear up the ISM of dust and gas, damping the star formation and un-obscuring the line of sight toward the QSO. In this scenario, all the QSOs hosts have final stellar masses in the range $(4-6)\\times 10^{11} M_{sun}$, a factor 3-30 larger than the upper limits allowed by the observations. We discuss alternative scenarios to alleviate this apparent tension: the most likely explanation resides in the large uncertainties that still affect dynamical mass measurements in these high-z galaxies. In addition, during the transition between the starburs...

  10. Comparative Studies of Clustering Properties Between Active Galactic Nucleus (AGN) Host Galaxies and Star-Forming Ones

    International Nuclear Information System (INIS)

    Using the volume-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6), we have explored the difference of clustering properties between Active Galactic Nucleus (AGN) host galaxies and star-forming galaxies. Our results preferentially show that AGN host galaxies have a lower fraction in isolated, close double and multiple systems than star-forming galaxies. (authors)

  11. The properties of the host galaxy and the immediate environment of GRB 980425 / SN 1998bw from the multi-wavelength spectral energy distribution

    CERN Document Server

    Michałowski, Michał J; Malesani, Daniele; Michałowski, Tadeusz; Cerón, José María Castro; Reinfrank, Robert F; Garrett, Michael A; Fynbo, Johan P U; Watson, Darach J; Jørgensen, Uffe G

    2008-01-01

    We present an analysis of the spectral energy distribution (SED) of the galaxy ESO 184-G82, the host of the closest known long gamma-ray burst (GRB) 980425 and its associated supernova SN 1998bw. We use our observations obtained at the Australia Telescope Compact Array (the third >3 sigma radio detection of a GRB host) as well as archival infrared (IR) and ultraviolet (UV) observations to estimate its star formation state. We find that ESO 184-G82 has a UV star formation rate (SFR) and stellar mass consistent with the population of cosmological GRB hosts and of local dwarf galaxies. It has however a higher specific SFR (per unit stellar mass) and lower molecular gas-to-dust ratio than luminous spiral galaxies. The mass of ESO 184-G82 is dominated by an older stellar population in contrast to the majority of GRB hosts. The Wolf-Rayet region ~800 pc from the supernova site experienced a starburst episode during which the majority of its stellar population was built up. Unlike that of the entire galaxy, its SED ...

  12. The host galaxy/AGN connection in nearby early-type galaxies. Is there a miniature radio-galaxy in every "core" galaxy?

    Science.gov (United States)

    Balmaverde, B.; Capetti, A.

    2006-02-01

    This is the second of a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. We selected two samples with 5 GHz VLA radio flux measurements down to 1 mJy, reaching levels of radio luminosity as low as 1036 erg s-1. In Paper I we presented a study of the surface brightness profiles for the 65 objects with available archival HST images out of the 116 radio-detected galaxies. We classified early-type galaxies into "core" and "power-law" galaxies, discriminating on the basis of the slope of their nuclear brightness profiles, following the Nukers scheme. Here we focus on the 29 core galaxies (hereafter CoreG). We used HST and Chandra data to isolate their optical and X-ray nuclear emission. The CoreG invariably host radio-loud nuclei, with an average radio-loudness parameter of Log R = L5 {GHz} / LB ˜ 3.6. The optical and X-ray nuclear luminosities correlate with the radio-core power, smoothly extending the analogous correlations already found for low luminosity radio-galaxies (LLRG) toward even lower power, by a factor of ˜ 1000, covering a combined range of 6 orders of magnitude. This supports the interpretation of a common non-thermal origin of the nuclear emission also for CoreG. The luminosities of the nuclear sources, most likely dominated by jet emission, set firm upper limits, as low as L/L_Edd ˜ 10-9 in both the optical and X-ray band, on any emission from the accretion process. The similarity of CoreG and LLRG when considering the distributions host galaxies luminosities and black hole masses, as well as of the surface brightness profiles, indicates that they are drawn from the same population of early-type galaxies. LLRG represent only the tip of the iceberg associated with (relatively) high activity levels, with CoreG forming the bulk of the population. We do not find any relationship between radio-power and black hole mass. A minimum black hole

  13. The Host Galaxies of Type Ia Supernovae Discovered by the Palomar Transient Factory

    Science.gov (United States)

    Pan, Y.-C.; Sullivan, M.; McGuire, K.; Hook, I. M.; Nugent, P. E.; Howell, D. A.; Arcavi, I.; Botyanszki, J.; Cenko, Stephen Bradley; DeRose, J.

    2013-01-01

    We present spectroscopic observations of the host galaxies of 82 low-redshift type Ia supernovae (SNe Ia) discovered by the Palomar Transient Factory (PTF). We determine star-formation rates, gas-phase stellar metallicities, and stellar masses and ages of these objects. As expected, strong correlations between the SN Ia light-curve width (stretch) and the host age mass metallicity are found: fainter, faster-declining events tend to be hosted by older massive metal-rich galaxies. There is some evidence that redder SNe Ia explode in higher metallicity galaxies, but we found no relation between the SN colour and host galaxy extinction based on the Balmer decrement, suggesting that the colour variation of these SNe does not primarily arise from this source. SNe Ia in higher-mass metallicity galaxies also appear brighter after stretch colour corrections than their counterparts in lower mass hosts, and the stronger correlation is with gas-phase metallicity suggesting this may be the more important variable. We also compared the host stellar mass distribution to that in galaxy targeted SN surveys and the high-redshift untargeted Supernova Legacy Survey (SNLS). SNLS has many more low mass galaxies, while the targeted searches have fewer. This can be explained by an evolution in the galaxy stellar mass function, coupled with a SN delay-time distribution proportional to t1. Finally, we found no significant difference in the mass--metallicity relation of our SN Ia hosts compared to field galaxies, suggesting any metallicity effect on the SN Ia rate is small.

  14. Host galaxies of luminous quasars: population synthesis of optical off-axis spectra

    CERN Document Server

    Wold, I; Wolf, M J; Hooper, E J

    2010-01-01

    There is increasing evidence of a connection between AGN activity and galaxy evolution. To obtain further insight into this potentially important evolutionary phase, we analyse the properties of quasar host galaxies. In this paper, we present a population synthesis modeling technique for off-axis spectra, the results of which constrain host colour and the stellar ages of luminous quasars (M_V(nuc) 10^40 erg s^-1) quasars to be located in redder host galaxies in comparison to th eir less luminous radio counterparts. While the host colour and age of our radio luminous sample is in close proximity to the green valley, our radio faint sample is consistent with quiescent star-forming galaxies. However, further observations are needed to confirm these results. Finally, we discuss future applications for our technique on a larger sample of objects being obtained via SALT and WIYN telescope observing campaigns.

  15. Comparing the Host Galaxies of Type Ia, Type II and Type Ibc Supernovae

    CERN Document Server

    Shao, X; Dennefeld, M; Chen, X Y; Zhong, G H; Hammer, F; Deng, L C; Flores, H; Zhang, B; Shi, W B; Zhou, L

    2014-01-01

    We compare the host galaxies of 902 supernovae, including SNe Ia, SNe II and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the SDSS Data Release 7. We further selected 213 galaxies by requiring the light fraction of spectral observations $>$15%, which could represent well the global properties of the galaxies. Among them, 135 galaxies appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of star-forming, AGNs (including composites, LINERs and Seyfert 2s) and "Absorp" (their related emission-lines are weak or non-existence) galaxies. The diagrams related to parameters D$_n$(4000), H$\\delta_A$, stellar masses, SFRs and specific SFRs for the SNe hosts show that almost all SNe II and most of SNe Ibc occur in SF galaxies, which have a wide range of stellar mass and low D$_n$(4000). The SNe Ia hosts as SF galaxies follow similar trends. A significant fraction of SNe Ia occurs in AGNs and Absorp galaxies, which are massive and have high D$_n...

  16. The MOSDEF survey: AGN multi-wavelength identification, selection biases and host galaxy properties

    CERN Document Server

    Azadi, Mojegan; Aird, James; Reddy, Naveen; Shapley, Alice; Freeman, William R; Kriek, Mariska; Leung, Gene C K; Mobasher, Bahram; Price, Sedona H; Sanders, Ryan L; Shivaei, Irene; Siana, Brian

    2016-01-01

    We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey on the identification, selection biases and host galaxy properties of 55 X-ray, IR and optically-selected active galactic nuclei (AGN) at $1.4 < z < 3.8$. We obtain rest-frame optical spectra of galaxies and AGN and use the BPT diagram to identify optical AGN. We examine the uniqueness and overlap of the AGN identified at different wavelengths. There is a strong bias against identifying AGN at any wavelength in low mass galaxies, and an additional bias against identifying IR AGN in the most massive galaxies. AGN host galaxies span a wide range of star formation rate (SFR), similar to inactive galaxies once stellar mass selection effects are accounted for. However, we generally identify IR AGN in less dusty galaxies with relatively higher SFR and optical AGN in dusty galaxies with relatively lower SFR. X-ray AGN selection does not display a bias with host galaxy SFR. These results are consistent with those from larger studies at low...

  17. Star-formation in the host galaxies of radio-AGN

    OpenAIRE

    Karouzos, Marios; Trichas, Markos; Im, Myungshin; Malkan, Matthew; team, the AKARI-NEP

    2013-01-01

    There exist strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies. It is however still unclear what the exact role of nuclear activity, in the form of accretion onto these supermassive black holes, in this co-evolution is. We use a rich multi-wavelength dataset available for the North Ecliptic Pole field, most notably surveyed by the AKARI satellite infrared telescope to study the host galaxy properties of AGN. In particular we are interested ...

  18. Supernovae and their host galaxies - IV. The distribution of supernovae relative to spiral arms

    CERN Document Server

    Aramyan, L S; Petrosian, A R; de Lapparent, V; Bertin, E; Mamon, G A; Kunth, D; Nazaryan, T A; Adibekyan, V; Turatto, M

    2016-01-01

    Using a sample of 215 supernovae (SNe), we analyze their positions relative to the spiral arms of their host galaxies, distinguishing grand-design (GD) spirals from non-GD (NGD) galaxies. We find that: (1) in GD galaxies, an offset exists between the positions of Ia and core-collapse (CC) SNe relative to the peaks of arms, while in NGD galaxies the positions show no such shifts; (2) in GD galaxies, the positions of CC SNe relative to the peaks of arms are correlated with the radial distance from the galaxy nucleus. Inside (outside) the corotation radius, CC SNe are found closer to the inner (outer) edge. No such correlation is observed for SNe in NGD galaxies nor for SNe Ia in either galaxy class; (3) in GD galaxies, SNe Ibc occur closer to the leading edges of the arms than do SNe II, while in NGD galaxies they are more concentrated towards the peaks of arms. In both samples of hosts, the distributions of SNe Ia relative to the arms have broader wings. These observations suggest that shocks in spiral arms of...

  19. H0LiCOW VI. Testing the fidelity of lensed quasar host galaxy reconstruction

    CERN Document Server

    Ding, Xuheng; Treu, Tommaso; Suyu, Sherry H; Chen, Geoff C -F; Auger, Matthew W; Marshall, Philip J; Agnello, Adriano; Courbin, Frederic; Nierenberg, Anna M; Rusu, Cristian E; Sluse, Dominique; Sonnenfeld, Alessandro; Wong, Kenneth C

    2016-01-01

    The empirical correlation between the mass of a super-massive black hole (MBH) and its host galaxy properties is widely considered to be evidence of their co-evolution. A powerful way to test the co-evolution scenario and learn about the feedback processes linking galaxies and nuclear activity is to measure these correlations as a function of redshift. Unfortunately, currently MBH can only be estimated in active galaxies at cosmological distances. At these distances, bright active galactic nuclei (AGN) can outshine the host galaxy, making it extremely difficult to measure the host's luminosity. Strongly lensed AGNs provide in principle a great opportunity to improve the sensitivity and accuracy of the host galaxy luminosity measurements as the host galaxy is magnified and more easily separated from the point source, provided the lens model is sufficiently accurate. In order to measure the MBH-L correlation with strong lensing, it is necessary to ensure that the lens modelling is accurate, and that the host ga...

  20. The Swift Burst Alert Telescope Detected Seyfert 1 Galaxies: X-Ray Broadband Properties and Warm Absorbers

    Science.gov (United States)

    Winter, Lisa M.; Veilleux, Sylvain; McKernan, Barry; Kallman, T.

    2012-01-01

    We present results from an analysis of the broadband, 0.3-195 keV, X-ray spectra of 48 Seyfert 1-1.5 sources detected in the very hard X-rays with the Swift Burst Alert Telescope (BAT). This sample is selected in an all-sky survey conducted in the 14-195 keV band. Therefore, our sources are largely unbiased toward both obscuration and host galaxy properties. Our detailed and uniform model fits to Suzaku/BAT and XMM-Newton/BAT spectra include the neutral absorption, direct power-law, reflected emission, soft excess, warm absorption, and narrow Fe I K[alpha] emission properties for the entire sample. We significantly detect O VII and O VIII edges in 52% of our sample. The strength of these detections is strongly correlated with the neutral column density measured in the spectrum. Among the strongest detections, X-ray grating and UV observations, where available, indicate outflowing material. The ionized column densities of sources with O VII and O VIII detections are clustered in a narrow range with Nwarm [approx] 1021 cm-2, while sources without strong detections have column densities of ionized gas an order of magnitude lower. Therefore, we note that sources without strong detections likely have warm ionized outflows present but at low column densities that are not easily probed with current X-ray observations. Sources with strong complex absorption have a strong soft excess, which may or may not be due to difficulties in modeling the complex spectra of these sources. Still, the detection of a flat [Gamma] [approx] 1 and a strong soft excess may allow us to infer the presence of strong absorption in low signal-to-noise active galactic nucleus spectra. Additionally, we include a useful correction from the Swift BAT luminosity to bolometric luminosity, based on a comparison of our spectral fitting results with published spectral energy distribution fits from 33 of our sources.

  1. Astrobiological Effects of Gamma-Ray Bursts in the Milky Way Galaxy

    CERN Document Server

    Gowanlock, Michael G

    2016-01-01

    A planet having protective ozone within the collimated beam of a Gamma Ray Burst (GRB) may suffer ozone depletion, potentially causing a mass extinction event to existing life on a planet's surface and oceans. We model the dangers of long GRBs to planets in the Milky Way and utilize a static statistical model of the Galaxy that matches major observable properties, such as the inside-out star formation history, metallicity evolution, and 3-dimensional stellar number density distribution. The GRB formation rate is a function of both the star formation history and metallicity; however, the extent to which chemical evolution reduces the GRB rate over time in the Milky Way is still an open question. Therefore, we compare the damaging effects of GRBs to biospheres in the Milky Way using two models. One model generates GRBs as a function of the inside-out star formation history. The other model follows the star formation history, but generates GRB progenitors as a function of metallicity, thereby favoring metal-poor...

  2. A gamma-ray burst remnant in our Galaxy : HESS J1303-631

    CERN Document Server

    Atoyan, A; Krawczynski, H

    2005-01-01

    The H.E.S.S. (High Energy Stereoscopic System) collaboration recently reported the discovery of a bright and extended TeV gamma-ray source HESS J1303-631, which remains notably silent in all other wavebands, and is the second of an emerging class of unidentified TeV sources serendipitously discovered in the Galactic plane. Here we present the results of our investigation of the multiwavelength data on HESS J1303-631 which strongly suggest its identification as the remnant of a Gamma-Ray Burst (GRB) in our own Galaxy. Long GRBs are thought to originate from the collapse of the cores of evolved very massive stars into black holes producing narrow relativistic outflows pointed to the Earth. We show that the unique power of GRBs and the specific characteristics of relativistic shock acceleration produce GRB remnants (GRBRs), large nebulae that brightly glow in TeV gamma-rays while hardly emitting at longer wavelengths. We predict spectral and spatial signatures that unambiguously distinguish GRBRs from ordinary s...

  3. Probing WHIM around Galaxy Clusters with Fast Radio Bursts and the Sunyaev-Zel'dovich effect

    CERN Document Server

    Fujita, Yutaka; Umetsu, Keiichi; Sarazin, Craig L; Wong, Ka-Wah

    2016-01-01

    We propose a new method to probe the Warm Hot Intergalactic Medium (WHIM) beyond the virial radius (R_200) of a cluster of galaxies, where X-ray observations are not easily achievable. In this method, we use dispersion measures (DMs) of Fast Radio Bursts (FRBs) that appear behind the cluster and the Sunyaev-Zel'dovich (SZ) effect towards the cluster. The DMs reflect the density of the intracluster medium (ICM) including the WHIM. If we observe a sufficient number of FRBs in the direction of the cluster, we can derive the density profile from the DMs. Similarly, we can derive the pressure profile from the SZ effect. By combining the density and the pressure profiles, the temperature profile can be obtained. Based on mock observations of nearby clusters, we find that the density of the WHIM can be determined even at > 2 R_200} from the cluster center when FRB observations with the Square Kilometre Array (SKA) become available. The temperature can be derived out to r~ 1.5 R_200, and the radius is limited by the ...

  4. Host Galaxies of Luminous Quasars: Structural Properties and the Fundamental Plane

    CERN Document Server

    Wolf, Marsha J

    2008-01-01

    We present stellar velocity dispersion measurements in the host galaxies of 10 luminous quasars (M_V = 321 km s^-1), low surface brightness ( = 20.8 mag arcsec^-2), and large effective radii ( = 11.4 kpc), and have = 1.5 x 10^12 M_sun and = 12.4. In contrast, properties of the RQ hosts are = 241 km s^-1, ~ 4.4 x 10^11 M_sun, and ~ 5.3. The distinction between these galaxies occurs at sigma_* ~ 300 km s^-1, R_e ~ 6 kpc, and corresponding M_* ~ 5.9 +/- 3.5 x 10^11 M_sun. Our data support previous results that PG QSOs are related to gas-rich galaxy mergers that form intermediate-mass galaxies, while RL QSOs reside in massive early-type galaxies, most of which also show signs of recent mergers or interactions. Most previous work has drawn these conclusions by using estimates of the black hole mass and inferring host galaxy properties from that, while here we have relied purely on directly measured host galaxy properties.

  5. THE OPTICALLY UNBIASED GRB HOST (TOUGH) SURVEY. VI. RADIO OBSERVATIONS AT z {approx}< 1 AND CONSISTENCY WITH TYPICAL STAR-FORMING GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Michalowski, M. J.; Dunlop, J. S. [SUPA (Scottish Universities Physics Alliance), Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Kamble, A.; Kaplan, D. L. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Kruehler, T. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Reinfrank, R. F. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Bonavera, L. [Instituto de Fisica de Cantabria, CSIC-Universidad de Cantabria, Avda. de los Castros s/n, E-39005 Santander (Spain); Castro Ceron, J. M. [Department of Radio Astronomy, Madrid Deep Space Communications Complex (INTA-NASA/INSA), Ctra. M-531, km. 7, E-28.294 Robledo de Chavela (Madrid) (Spain); Ibar, E. [UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Garrett, M. A. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Jakobsson, P. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Massardi, M. [INAF-Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Pal, S. [ICRAR, University of Western Australia, 35 Stirling Highway, Crawley, WA (Australia); Sollerman, J. [Oskar Klein Centre, Department of Astronomy, AlbaNova, Stockholm University, SE-10691 Stockholm (Sweden); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Van der Horst, A. J., E-mail: mm@roe.ac.uk [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, 1098XH Amsterdam (Netherlands); and others

    2012-08-20

    The objective of this paper is to determine the level of obscured star formation activity and dust attenuation in a sample of gamma-ray burst (GRB) hosts, and to test the hypothesis that GRB hosts have properties consistent with those of the general star-forming galaxy populations. We present a radio continuum survey of all z < 1 GRB hosts in The Optically Unbiased GRB Host (TOUGH) sample supplemented with radio data for all (mostly pre-Swift) GRB-SN hosts discovered before 2006 October. We present new radio data for 22 objects and have obtained a detection for three of them (GRB 980425, 021211, 031203; none in the TOUGH sample), increasing the number of radio-detected GRB hosts from two to five. The star formation rate (SFR) for the GRB 021211 host of {approx}825 M{sub Sun} yr{sup -1}, the highest ever reported for a GRB host, places it in the category of ultraluminous infrared galaxies. We found that at least {approx}63% of GRB hosts have SFR < 100 M{sub Sun} yr{sup -1} and at most {approx}8% can have SFR > 500 M{sub Sun} yr{sup -1}. For the undetected hosts the mean radio flux (<35 {mu}Jy 3{sigma}) corresponds to an average SFR < 15 M{sub Sun} yr{sup -1}. Moreover, {approx}> 88% of the z {approx}< 1 GRB hosts have ultraviolet dust attenuation A{sub UV} < 6.7 mag (visual attenuation A{sub V} < 3 mag). Hence, we did not find evidence for large dust obscuration in a majority of GRB hosts. Finally, we found that the distributions of SFRs and A{sub UV} of GRB hosts are consistent with those of Lyman break galaxies, H{alpha} emitters at similar redshifts, and of galaxies from cosmological simulations. The similarity of the GRB population with other star-forming galaxies is consistent with the hypothesis that GRBs, a least at z {approx}< 1, trace a large fraction of all star formation, and are therefore less biased indicators than once thought.

  6. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Patrick L.; /KIPAC, Menlo Park /SLAC; Hicken, Malcolm; /Harvard-Smithsonian Ctr. Astrophys.; Burke, David L.; /KIPAC, Menlo Park /SLAC; Mandel, Kaisey S.; Kirshner, Robert P.; /Harvard-Smithsonian Ctr. Astrophys.

    2010-05-03

    From Sloan Digital Sky Survey u{prime} g{prime} r{prime} i{prime} z{prime} imaging, we estimate the stellar masses of the host galaxies of 70 low redshift SN Ia (0.015 < z < 0.08) from the hosts absolute luminosities and mass-to-light ratios. These nearby SN were discovered largely by searches targeting luminous galaxies, and we find that their host galaxies are substantially more massive than the hosts of SN discovered by the flux-limited Supernova Legacy Survey. Testing four separate light curve fitters, we detect {approx}2.5{sigma} correlations of Hubble residuals with both host galaxy size and stellar mass, such that SN Ia occurring in physically larger, more massive hosts are {approx}10% brighter after light curve correction. The Hubble residual is the deviation of the inferred distance modulus to the SN, calculated from its apparent luminosity and light curve properties, away from the expected value at the SN redshift. Marginalizing over linear trends in Hubble residuals with light curve parameters shows that the correlations cannot be attributed to a light curve-dependent calibration error. Combining 180 higher-redshift ESSENCE, SNLS, and HigherZ SN with 30 nearby SN whose host masses are less than 10{sup 10.8} M{circle_dot} n a cosmology fit yields 1 + w = 0.22{sub -0.108}{sup +0.152}, while a combination where the 30 nearby SN instead have host masses greater than 10{sup 10.8} M{circle_dot} yields 1 + w = ?0.03{sub -0.143}{sup +0.217}. Progenitor metallicity, stellar population age, and dust extinction correlate with galaxy mass and may be responsible for these systematic effects. Host galaxy measurements will yield improved distances to SN Ia.

  7. AGN host galaxies at redshift z~0.7: peculiar or not?

    CERN Document Server

    Boehm, Asmus; Bell, Eric F; Jahnke, Knud; Wolf, Christian; Bacon, David; Barden, Marco; Gray, Meghan E; Hoeppe, Goetz; Jogee, Sharda; McIntosh, Dan H; Peng, Chien Y; Robaina, Adai R; Balogh, Michael; Barazza, Fabio D; Caldwell, John A R; Heymans, Catherine; Haeussler, Boris; van Kampen, Eelco; Lane, Kyle; Meisenheimer, Klaus; Sanchez, Sebastian F; Taylor, Andy N; Zheng, Xianzhong

    2012-01-01

    We perform a quantitative morphological comparison between the hosts of Active Galactic Nuclei (AGN) and quiescent galaxies at intermediate redshifts (z~0.7). The imaging data are taken from the large HST/ACS mosaics of the GEMS and STAGES surveys. Our main aim is to test whether nuclear activity at this cosmic epoch is triggered by major mergers. Using images of quiescent galaxies and stars, we create synthetic AGN images to investigate the impact of an optical nucleus on the morphological analysis of AGN hosts. Galaxy morphologies are parameterized using the asymmetry index A, concentration index C, Gini coefficient G and M20 index. A sample of ~200 synthetic AGN is matched to 21 real AGN in terms of redshift, host brightness and host-to-nucleus ratio to ensure a reliable comparison between active and quiescent galaxies. The optical nuclei strongly affect the morphological parameters of the underlying host galaxy. Taking these effects into account, we find that the morphologies of the AGN hosts are clearly ...

  8. The physical properties of AGN host galaxies as a probe of SMBH feeding mechanisms

    CERN Document Server

    Gatti, M; Menci, N; Bongiorno, A; Fiore, F

    2014-01-01

    Using a state-of-the-art semi analytic model (SAM) for galaxy formation, we have investigated the statistical effects of assuming two different mechanisms for triggering AGN activity on the properties of AGN host galaxies. We have considered a first accretion mode where AGN activity is triggered by disk instabilities (DI) in isolated galaxies, and a second feeding mode where such an activity is triggered by galaxy mergers and fly-by events (interactions, IT). We obtained the following results:i) for hosts with $M_* \\lesssim 10^{11} M_{\\bigodot}$, both DI and IT modes are able to account for the observed AGN hosts stellar mass function; for more massive hosts, the DI scenario predicts a lower space density than the IT model, lying below the observational estimates for z>0.8.ii) The analysis of the color-magnitude diagram (CMD) of AGN hosts for redshift z < 1.5 can provide a good observational test to effectively discriminate between the DI and IT mode, since DIs are expected to yield AGN host galaxy colors ...

  9. Do Typical Galaxies in Adolescence Already Host Growing Black Holes?

    Science.gov (United States)

    Trump, Jonathan

    2012-10-01

    This archival grism proposal achieves a 100-fold gain in high-quality {5+sigma} information for discovering which properties of adolescent {0.7galaxies of typical mass and SFR are linked to AGN activity. We propose to analyze 147 WFC3 G141 and 111 ACS 800L pointings of 2-orbit grism data in the CANDELS fields, for a sample of 3000 galaxies reaching SFR 5 Msun/yr and stellar masses of log{M*/Msun} 9 at z 1.5. We will leverage spatially-resolved line ratios to uniquely distinguish a nuclear AGN from extended low-metallicity or shocked gas. Compared to our 30-galaxy published sample that hints at AGNs in low-mass z 2 galaxies {Trump et al. 2011}, this 3000 galaxy sample enables a 100-fold gain in divisions by galaxy morphology, SFR, and stellar mass to discover which galaxy properties correlate most with rapid SMBH growth. We will stack the deep {0.8-4 Ms} Chandra data available in these fields as an independent check of the grism AGN/SF diagnostics. The unique ancillary data in these fields also include ACS+WFC3 imaging for morphologies, deep multiwavelength data for well-sampled SEDs and stellar masses, and previous optical {and future near-IR} spectroscopy to supplement the G141 coverage. Based on discussions with the GOODS-N and 3D-HST teams, our proposed AGN science does not overlap with their proposed or funded science goals. As a value-added product for the community we will release, via the public Rainbow-CANDELS database server, an atlas of spatial maps of emission lines and line ratios {and associated errors} for the entire sample of 3000 galaxies.

  10. The Sloan Digital Sky Survey Reverberation Mapping Project: Post-Starburst Signatures in Quasar Host Galaxies at z < 1

    CERN Document Server

    Matsuoka, Yoshiki; Shen, Yue; Brandt, William N; Greene, Jenny E; Ho, Luis C; Schneider, Donald P; Sun, Mouyuan; Trump, Jonathan R

    2015-01-01

    Quasar host galaxies are key for understanding the relation between galaxies and the supermassive black holes (SMBHs) at their cores. We present a study of 191 unobscured quasars and their host galaxies at z < 1, using high signal-to-noise ratio (SNR) spectra produced by the Sloan Digital Sky Survey Reverberation Mapping project. Clear detection of stellar absorption lines allows a reliable decomposition of the observed spectra into nuclear and host components, using spectral models of quasar and stellar radiations as well as emission lines from the interstellar medium. We estimate age, mass (M*), and velocity dispersion (sigma*) of the host stars, the star formation rate (SFR), quasar luminosity, and SMBH mass (Mbh), for each object. The quasars are preferentially hosted by massive galaxies with M* ~ 10^{11} Msun characterized by stellar ages around a billion years, which coincides with the transition phase of normal galaxies from the blue cloud to the red sequence. The host galaxies have relatively low S...

  11. Keck Observations of the Young Metal-Poor Host Galaxy of the Super-Chandrasekhar-Mass Type Ia Supernova SN 2007if

    CERN Document Server

    Childress, M; Aragon, C; Antilogus, P; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Kerschhaggl, M; Kowalski, M; Hsiao, E Y; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Runge, K; Scalzo, R; Thomas, R C; Smadja, G; Tao, C; Weaver, B A; Wu, C

    2011-01-01

    We present Keck LRIS spectroscopy and $g$-band photometry of the metal-poor, low-luminosity host galaxy of the super-Chandrasekhar mass Type Ia supernova SN 2007if. Deep imaging of the host reveals its apparent magnitude to be $m_g=23.15\\pm0.06$, which at the spectroscopically-measured redshift of $z_{helio}=0.07450\\pm0.00015$ corresponds to an absolute magnitude of $M_g=-14.45\\pm0.06$. Galaxy $g-r$ color constrains the mass-to-light ratio, giving a host stellar mass estimate of $\\log(M_*/M_\\odot)=7.32\\pm0.17$. Balmer absorption in the stellar continuum, along with the strength of the 4000\\AA\\ break, constrain the age of the dominant starburst in the galaxy to be $t_\\mathrm{burst}=123^{+165}_{-77}$ Myr, corresponding to a main-sequence turn-off mass of $M/M_\\odot=4.6^{+2.6}_{-1.4}$. Using the R$_{23}$ method of calculating metallicity from the fluxes of strong emission lines, we determine the host oxygen abundance to be $12+\\log(O/H)_\\mathrm{KK04}=8.01\\pm0.09$, significantly lower than any previously reported...

  12. The hydrogen-poor superluminous supernova iPTF 13ajg and its host galaxy in absorption and emission

    Energy Technology Data Exchange (ETDEWEB)

    Vreeswijk, Paul M.; Gal-Yam, Avishay; De Cia, Annalisa; Rubin, Adam; Yaron, Ofer; Tal, David; Ofek, Eran O. [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Savaglio, Sandra [Max Planck Institute for Extraterrestrial Physics, D-85748 Garching bei München (Germany); Quimby, Robert M. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Cenko, S. Bradley; Filippenko, Alexei V.; Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Perley, Daniel A.; Cao, Yi [Astronomy Department, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos [Department of Astronomy, The Oskar Klein Center, Stockholm University, AlbaNova 10691 Stockholm (Sweden); Arcavi, Iair [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Kasliwal, Mansi M., E-mail: paul.vreeswijk@weizmann.ac.il [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); and others

    2014-12-10

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory, iPTF 13ajg. At a redshift of z = 0.7403, derived from narrow absorption lines, iPTF 13ajg peaked at an absolute magnitude of M {sub u,} {sub AB} = –22.5, one of the most luminous supernovae to date. The observed bolometric peak luminosity of iPTF 13ajg is 3.2 × 10{sup 44} erg s{sup –1}, while the estimated total radiated energy is 1.3 × 10{sup 51} erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the Very Large Telescope. From Voigt profile fitting, we derive the column densities log N(Mg I) =11.94 ± 0.06, log N(Mg II) =14.7 ± 0.3, and log N(Fe II) =14.25 ± 0.10. These column densities, as well as the Mg I and Mg II equivalent widths of a sample of hydrogen-poor SLSNe taken from the literature, are at the low end of those derived for gamma-ray bursts (GRBs) whose progenitors are also thought to be massive stars. This suggests that the environments of hydrogen-poor SLSNe and GRBs are different. From the nondetection of Fe II fine-structure absorption lines, we derive a lower limit on the distance between the supernova and the narrow-line absorbing gas of 50 pc. The neutral gas responsible for the absorption in iPTF 13ajg exhibits a single narrow component with a low velocity width, ΔV = 76 km s{sup –1}, indicating a low-mass host galaxy. No host galaxy emission lines are detected, leading to an upper limit on the unobscured star formation rate (SFR) of SFR{sub [O} {sub II]}<0.07M{sub ⊙}yr{sup −1}. Late-time imaging shows the iPTF 13ajg host galaxy to be faint, with g {sub AB} ≈ 27.0 and R {sub AB} ≥ 26.0 mag, corresponding to M {sub B,} {sub Vega} ≳ –17.7 mag.

  13. The Relation between Luminous AGNs and Star Formation in Their Host Galaxies

    Science.gov (United States)

    Xu, Lei; Rieke, G. H.; Egami, E.; Haines, C. P.; Pereira, M. J.; Smith, G. P.

    2015-08-01

    We study the relation of active galactic nuclei (AGNs) to star formation in their host galaxies. Our sample includes 205 Type-1 and 85 Type-2 AGNs, 162 detected with Herschel, from fields surrounding 30 galaxy clusters in the Local Cluster Substructure Survey. The sample is identified by optical line widths and ratios after selection to be brighter than 1 mJy at 24 μm. We show that Type-2 AGN [O iii]λ5007 line fluxes at high z can be contaminated by their host galaxies with typical spectrograph entrance apertures (but our sample is not compromised in this way). We use spectral energy distribution (SED) templates to decompose the galaxy SEDs and estimate star formation rates (SFRs), AGN luminosities, and host galaxy stellar masses (described in an accompanying paper). The AGNs arise from massive black holes (˜ 3× {10}8{M}⊙ ) accreting at ˜10% of the Eddington rate and residing in galaxies with stellar mass \\gt 3× {10}10{M}⊙ ; those detected with Herschel have IR luminosity from star formation in the range of {L}{SF,{IR}}˜ {10}10-{10}12{L}⊙ . We find that (1) the specific SFRs in the host galaxies are generally consistent with those of normal star-forming (main sequence) galaxies; (2) there is a strong correlation between the luminosities from star formation and the AGN; and (3) the correlation may not result from a causal connection, but could arise because the black hole mass (and hence AGN Eddington luminosity) and star formation are both correlated with the galaxy mass.

  14. Radio Loudness of AGNs: Host Galaxy Morphology and the Spin Paradigm

    Energy Technology Data Exchange (ETDEWEB)

    Stawarz, L.; Sikora, M.; Lasota, J.-P.

    2007-10-15

    We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. We find that AGNs form two distinct and well separated sequences on the radio-loudness -- Eddington-ratio plane. We argue that these sequences mark the real upper bounds of radio-loudness of two distinct populations of AGNs: those hosted respectively by elliptical and disk galaxies. Both sequences show the same dependence of the radio-loudness on the Eddington ratio (an increase with decreasing Eddington ratio), which suggests that another parameter in addition to the accretion rate must play a role in determining the jet production efficiency in active galactic nuclei, and that this parameter is related to properties of the host galaxy. The revealed host-related radio dichotomy breaks down at high accretion rates where the dominant fraction of luminous quasars hosted by elliptical galaxies is radio quiet. We argue that the huge difference between the radio-loudness reachable by AGNs in disc and elliptical galaxies can be explained by the scenario according to which the spin of a black hole determines the outflows power, and central black holes can reach large spins only in early type galaxies (following major mergers), and not (in a statistical sense) in spiral galaxies.

  15. A Statistical Study of H I Gas in Nearby Narrow-Line AGN-Hosting Galaxies

    CERN Document Server

    Zhu, Yi-Nan

    2015-01-01

    As a quenching mechanism, AGN feedback could suppress on-going star formation in their host galaxies. On the basis of a sample of galaxies selected from ALFALFA HI survey, the dependence of their HI mass M[HI], stellar mass M[*] & HI-to-stellar mass ratio M[HI]/M[*] on various tracers of AGN activity are presented and analyzed in this paper. Almost all the AGN-hostings in this sample are gas-rich galaxies, and there is no any evidence to be shown to indicate that the AGN activity could increase/decrease either M[HI] or M[HI]/M[*]. The cold neutral gas can not be fixed positions accurately just based on available HI data due to the large beam size of ALFALFA survey. In addition, even though AGN-hostings are more easily detected by HI survey compared with absorption line galaxies, these two types of galaxies show similar star formation history. If an AGN-hosting would ultimately evolve into an old red galaxy with few cold gas, then when and how the gas has been exhausted have to be solved by future hypothes...

  16. A statistical study of H i gas in nearby narrow-line AGN-hosting galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yi-Nan; Wu, Hong, E-mail: zyn@bao.ac.cn, E-mail: hwu@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2015-01-01

    As a quenching mechanism, active galactic nucleus (AGN) feedback could suppress on going star formation in host galaxies. On the basis of a sample of galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) H i survey, the dependence of the H i mass (M{sub H} {sub i}), stellar mass (M{sub *}), and H i-to-stellar mass ratio (M{sub H} {sub i}/M{sub *}) on various tracers of AGN activity are presented and analyzed in this paper. Almost all the AGN hostings in this sample are gas-rich galaxies, and there is not any evidence to indicate that the AGN activity could increase or decrease either M{sub H} {sub i} or M{sub H} {sub i}/M{sub *}. The position of the cold neutral gas cannot be fixed accurately based only on available H i data, due to the large beam size of ALFALFA survey. In addition, even though AGN hostings are more easily detected by an H i survey compared with absorption line galaxies, these two types of galaxies show similar star formation history. If an AGN hosting would ultimately evolve into an old red galaxy with low cold gas, then when and how the gas has been exhausted must be solved by future hypotheses and observations.

  17. Do Nuclear Star Clusters and Supermassive Black Holes Follow the Same Host-Galaxy Correlations?

    Directory of Open Access Journals (Sweden)

    Peter Erwin

    2012-01-01

    Full Text Available Studies have suggested that there is a strong correlation between the masses of nuclear star clusters (NSCs and their host galaxies, a correlation which is said to be an extension of the well-known correlations between supermassive black holes (SMBHs and their host galaxies. But careful analysis of disk galaxies—including 2D bulge/disk/bar decompositions—shows that while SMBHs correlate with the stellar mass of the bulge component of galaxies, the masses of NSCs correlate much better with the total galaxy stellar mass. In addition, the mass ratio MNSC/M⋆, tot for NSCs in spirals (at least those with Hubble types Sc and later is typically an order of magnitude smaller than the mass ratio MBH/M⋆, bul of SMBHs. The absence of a universal “central massive object” correlation argues against common formation and growth mechanisms for both SMBHs and NSCs. We also discuss evidence for a break in the NSC-host galaxy correlation, galaxies with Hubble types earlier than Sbc appear to host systematically more massive NSCs than do types Sc and later.

  18. Low redshift quasars in the SDSS Stripe 82. Host galaxy colors and close environment

    CERN Document Server

    Bettoni, D; Kotilainen, J K; Karhunen, K; Uslenghi, M

    2015-01-01

    We present a photometrical and morphological multicolor study of the properties of low redshift (z<0.3) quasar hosts based on a large and homogeneous dataset of quasars derived from the Sloan Digital Sky Survey (DR7). We used quasars that were imaged in the SDSS Stripe82 that is up to 2 mag deeper than standard Sloan images. This sample is part of a larger dataset of ~400 quasars at z<0.5 for which both the host galaxies and their galaxy environments were studied (Falomo et al. 2014,Karhunen et al. 2014). For 52 quasars we undertake a study of the color of the host galaxies and of their close environments in u,g,r,i and z bands. We are able to resolve almost all the quasars in the sample in the filters g,r,i and z and also in $u$ for about 50% of the targets. We found that the mean colors of the QSO host galaxy (g-i=0.82+-0.26; r-i=0.26+-0.16 and u-g=1.32+-0.25) are very similar to the values of a sample of inactive galaxies matched in terms of redshift and galaxy luminosity with the quasar sample. Ther...

  19. The Formation of Quasars in Low Luminosity Hosts via Galaxy Harassment

    CERN Document Server

    Lake, G; Moore, B; Lake, George; Katz, Neal; Moore, Ben

    1997-01-01

    We present hydrodynamical simulations of the continued bombardment of disk galaxies by other galaxies in a rich cluster---``galaxy harassment". The evolution over a few Gyrs is dramatic and strongest for smaller galaxies. Harassment provides an extremely effective mechanism to fuel a central source. Within a few billion years after a small disk galaxy enters the cluster environment, up to 90% of its gas can be driven to the inner 500 pc. Up to half of the mass is transferred in intervals of just 100-200 Myr. This transport of gas to the center of galaxy is far more efficient than any mechanism proposed before. Quasars at modest reshifts (z \\gsim 0.3) have been shown to lie in more clustered environments than those at lower redshift. Recent HST observations have shown that some luminous low redshift quasars have hosts that are fainter than L_* galaxies. We examine the 5 claimed quasars that are claimed to have low luminosity hosts and find that 3 are in rich clusters of galaxies, the fourth may be in a cluster...

  20. Star Cluster Complexes and the Host Galaxy in Three HII Galaxies: Mrk 36, UM 408, and UM 461

    CERN Document Server

    Lagos, Patricio; Nigoche-Netro, A; Carrasco, Eleazar Rodrigo

    2011-01-01

    We present a stellar population study of three HII galaxies (Mrk 36, UM 408, and UM 461) based on the analysis of new ground-based high resolution near-infrared J, H and Kp broad-band and Br narrow-band images obtained with Gemini/NIRI. We identify and determine relative ages and masses of the elementary star clusters and/or star cluster complexes of the starburst regions in each of these galaxies by comparing the colors with evolutionary synthesis models that include the contribution of stellar continuum, nebular continuum and emission lines. We found that the current star cluster formation efficiency in our sample of low luminosity HII galaxies is ~10%. Therefore, most of the recent star formation is not in massive clusters. Our findings seem to indicate that the star formation mode in our sample of galaxies is clumpy, and that these complexes are formed by a few massive star clusters with masses > 10^4 Mo. The age distribution of these star cluster complexes shows that the current burst started recently an...

  1. The Host in Blue Compact Galaxies: Structural Properties and Scaling Relations

    CERN Document Server

    Amorín, Ricardo; Muñoz-Tuñón, C; Cairós, L M

    2009-01-01

    We have characterized the underlying stellar host in a sample of 28 blue compact galaxies (BCGs), by fitting their 2D light distributions. Their structural parameters were related with galaxy properties such as colours and gas content. These properties were also compared with those of other galaxy types. All the BCG hosts but one show low Sersic indexes (0.5 =1.11$\\pm$0.74 kpc, and mean surface brightness = 22.59$\\pm$0.68 mag arcsec$^{-2}$. Host effective radii scale linearly with their luminosity, while n and $\\mu_{\\rm e}$ do not. In addition, host colours and structural parameters are not linearly correlated. Overall,the flux enhancement caused by the starburst is about 0.8 mag while their B-R colours decrease by about 0.2 mag. Galaxies with more luminous and extended hosts show larger and luminous starburst components. BCG hosts show B-R=0.95$\\pm$0.26 in median. Overall, BCG hosts are more compact (by a factor ~2) and have higher central surface brightnesses (by about ~2 mag) than dIs and most dEs. BCG ho...

  2. The abundance of satellites depends strongly on the morphology of the host galaxy

    CERN Document Server

    Ruiz, Pablo; Mármol-Queraltó, Esther

    2015-01-01

    Using the spectroscopic catalogue of the Sloan Digital Survey Data Release 10 (SDSS DR10), we have explored the abundance of satellites around a sample of 307 massive (M_star > 10^11 M_sun) local (z 10^9 M_sun and R < 300 kpc depends drastically on the morphology of the central galaxy. The average number of satellites per galaxy host (N_Sat/N_Host) down to a mass ratio of 1:100 is: 5.5 +/- 1.0 for E hosts, 2.7 +/- 0.4 for S0, 1.4 +/- 0.3 for Sa and 1.2 +/- 0.3 for Sb/c. The amount of stellar mass enclosed by the satellites around massive E-type galaxies is a factor of 2, 4, and 6 larger than the mass in the satellites of S0, Sa and Sb/c-types, respectively. If these satellites would eventually infall into the host galaxies, for all the morphological types, the merger channel will be largely dominated by satellites with a mass ratio satellite-host $\\mu$ < 0.1. The fact that massive elliptical galaxies have a significant larger number of satellites than massive spirals could point out that elliptical gal...

  3. Supernovae and their host galaxies - IV. The distribution of supernovae relative to spiral arms

    Science.gov (United States)

    Aramyan, L. S.; Hakobyan, A. A.; Petrosian, A. R.; de Lapparent, V.; Bertin, E.; Mamon, G. A.; Kunth, D.; Nazaryan, T. A.; Adibekyan, V.; Turatto, M.

    2016-07-01

    Using a sample of 215 supernovae (SNe), we analyse their positions relative to the spiral arms of their host galaxies, distinguishing grand-design (GD) spirals from non-GD (NGD) galaxies. We find that: (1) in GD galaxies, an offset exists between the positions of Ia and core-collapse (CC) SNe relative to the peaks of arms, while in NGD galaxies the positions show no such shifts; (2) in GD galaxies, the positions of CC SNe relative to the peaks of arms are correlated with the radial distance from the galaxy nucleus. Inside (outside) the corotation radius, CC SNe are found closer to the inner (outer) edge. No such correlation is observed for SNe in NGD galaxies nor for SNe Ia in either galaxy class; (3) in GD galaxies, SNe Ibc occur closer to the leading edges of the arms than do SNe II, while in NGD galaxies they are more concentrated towards the peaks of arms. In both samples of hosts, the distributions of SNe Ia relative to the arms have broader wings. These observations suggest that shocks in spiral arms of GD galaxies trigger star formation in the leading edges of arms affecting the distributions of CC SNe (known to have short-lived progenitors). The closer locations of SNe Ibc versus SNe II relative to the leading edges of the arms supports the belief that SNe Ibc have more massive progenitors. SNe Ia having less massive and older progenitors, have more time to drift away from the leading edge of the spiral arms.

  4. Supermassive black holes and central star clusters: Connection with the host galaxy kinematics and color

    Science.gov (United States)

    Zasov, A. V.; Cherepashchuk, A. M.

    2013-11-01

    The relationship between the masses of the central, supermassive black holes ( M bh) and of the nuclear star clusters ( M nc) of disk galaxies with various parameters galaxies are considered: the rotational velocity at R = 2 kpc V (2), the maximum rotational velocity V max, the indicative dynamical mass M 25, the integrated mass of the stellar population M *, and the integrated color index B-V. The rotational velocities andmasses of the central objects were taken from the literature. Themass M nc correlatesmore closely with the kinematic parameters and the disk mass than M bh, including with the velocity V max, which is closely related to the virial mass of the dark halo. On average, lenticular galaxies are characterized by higher masses M bh compared to other types of galaxies with similar characteristics. The dependence of the blackhole mass on the color index is bimodal: galaxies of the red group (red-sequence) with B-V >0.6-0.7 which are mostly early-type galaxies with weak star formation, differ appreciably from blue galaxies, which have higher values of M nc and M bh. At the dependences we consider between the masses of the central objects and the parameters of the host galaxies (except for the dependence of M bh on the central velocity dispersion), the red-group galaxies have systematically higher M bh values, even when the host-galaxy parameters are similar. In contrast, in the case of nuclear star clusters, the blue and red galaxies form unified sequences. The results agree with scenarios in which most red-group galaxies form as a result of the partial or complete loss of interstellar gas in a stage of high nuclear activity in galaxies whose central black-hole masses exceed 106-107 M ⊙ (depending on the mass of the galaxy itself). The bulk of disk galaxies with M bh > 107 M ⊙ are lenticular galaxies (types S0, E/S0) whose disks are practically devoid of gas.

  5. X-Ray bright active galactic nuclei in massive galaxy clusters - II. The fraction of galaxies hosting active nuclei

    DEFF Research Database (Denmark)

    Ehlert, S.; von der Linden, A.; Allen, S. W.;

    2013-01-01

    We present a measurement of the fraction of cluster galaxies hosting X-ray bright active galactic nuclei (AGN) as a function of clustercentric distance scaled in units of r500. Our analysis employs high-quality Chandra X-ray and Subaru optical imaging for 42 massive X-ray-selected galaxy cluster...... fields spanning the redshift range 0.2 z ..., both of which are also suppressed near cluster centres to a comparable extent. These results strongly support the idea that X-ray AGN activity and strong star formation are linked through their common dependence on available reservoirs of cold gas. © 2013 The Authors. Published by Oxford University...

  6. Spectroscopy of superluminous supernova host galaxies. A preference of hydrogen-poor events for extreme emission line galaxies

    CERN Document Server

    Leloudas, G; Kruehler, T; Gorosabel, J; Christensen, L; Mehner, A; Postigo, A de Ugarte; Amorin, R; Thoene, C C; Anderson, J P; Bauer, F E; Gallazzi, A; Helminiak, K G; Hjorth, J; Ibar, E; Malesani, D; Morell, N; Vinko, J; Wheeler, J C

    2014-01-01

    Superluminous supernovae (SLSNe) were only discovered recently due to their preference for occurring in faint dwarf galaxies. Understanding why stellar evolution yields different types of stellar explosions in these environments is fundamental in order to both uncover the elusive progenitors of SLSNe and to study star formation in dwarf galaxies. In this paper, we present the first results of our project to study SUperluminous Supernova Host galaxIES (SUSHIES), focusing on the sample for which we have obtained spectroscopy. We show that SLSNe-I and SLSNe-R (hydrogen-poor) often (~50% in our sample) occur in a class of galaxies that is known as Extreme Emission Line Galaxies (EELGs). The probability of this happening by chance is negligible and we therefore conclude that the extreme environmental conditions and the SLSN phenomenon are related. In contrast, SLSNe-II (hydrogen-rich) occur in more massive, more metal-rich galaxies with softer radiation fields. Therefore, if SLSNe-II constitute a uniform class, th...

  7. CEPHEID VARIABLES IN THE MASER-HOST GALAXY NGC 4258

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Samantha L.; Macri, Lucas M., E-mail: lmacri@tamu.edu [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)

    2015-06-15

    We present results of a ground-based survey for Cepheid variables in NGC 4258. This galaxy plays a key role in the Extragalactic Distance Scale due to its very precise and accurate distance determination via very long baseline interferometry observations of water masers. We imaged two fields within this galaxy using the Gemini North telescope and the Gemini Multi-Object Spectrograph, obtaining 16 epochs of data in the Sloan Digital Sky Survey gri bands over 4 yr. We carried out point-spread function photometry and detected 94 Cepheids with periods between 7 and 127 days, as well as an additional 215 variables which may be Cepheids or Population II pulsators. We used the Cepheid sample to test the absolute calibration of theoretical gri Period–Luminosity relations and found good agreement with the maser distance to this galaxy. The expected data products from the Large Synoptic Survey Telescope should enable Cepheid searches out to at least 10 Mpc.

  8. Cepheid Variables in the Maser-Host Galaxy NGC 4258

    CERN Document Server

    Hoffmann, Samantha L

    2015-01-01

    We present results of a ground-based survey for Cepheid variables in NGC 4258. This galaxy plays a key role in the Extragalactic Distance Scale due to its very precise and accurate distance determination via VLBI observations of water masers. We imaged two fields within this galaxy using the Gemini North telescope and GMOS, obtaining 16 epochs of data in the SDSS gri bands over 4 years. We carried out PSF photometry and detected 94 Cepheids with periods between 7 and 127 days, as well as an additional 215 variables which may be Cepheids or Population II pulsators. We used the Cepheid sample to test the absolute calibration of theoretical gri Period-Luminosity relations and found good agreement with the maser distance to this galaxy. The expected data products from the Large Synoptic Survey Telescope (LSST) should enable Cepheid searches out to at least 10 Mpc.

  9. Evidence that Gamma-Ray Burst 130702A Exploded in a Dwarf Satellite of a Massive Galaxy

    Science.gov (United States)

    Kelly, Patrick L.; Filippenko, Alexei V.; Fox, Ori D.; Zheng, Weikang; Clubb, Kelsey I.

    2013-09-01

    GRB 130702A is a nearby long-duration gamma-ray burst (LGRB) discovered by the Fermi satellite whose associated afterglow was detected by the Palomar Transient Factory. Subsequent photometric and spectroscopic monitoring has identified a coincident broad-lined Type Ic supernova (SN), and nebular emission detected near the explosion site is consistent with a redshift of z = 0.145. The SN-GRB exploded at an offset of ~7.''6 from the center of an inclined r = 18.1 mag red disk-dominated galaxy, and ~0.''6 from the center of a much fainter r = 23 mag object. We obtained Keck-II DEIMOS spectra of the two objects and find a 2σ upper limit on their line-of-sight velocity offset of lsim60 km s-1. If we calculate the inclination angle of the massive red galaxy from its axis ratio and assume that its light is dominated by a very thin disk, the explosion would have a ~60 kpc central offset, or ~9 times the galaxy's half-light radius. A significant bulge or a thicker disk would imply a higher inclination angle and greater central offset. The substantial offset suggests that the faint source is a separate dwarf galaxy. The star-formation rate of the dwarf galaxy is ~0.05 M ⊙ yr-1, and we place an upper limit on its oxygen abundance of 12 + log(O/H) < 8.16 dex. The identification of an LGRB in a dwarf satellite of a massive, metal-rich primary galaxy suggests that recent detections of LGRBs spatially coincident with metal-rich galaxies may be, in some cases, superpositions.

  10. Host-galaxy Properties of 32 Low-redshift Superluminous Supernovae from the Palomar Transient Factory

    Science.gov (United States)

    Perley, D. A.; Quimby, R. M.; Yan, L.; Vreeswijk, P. M.; De Cia, A.; Lunnan, R.; Gal-Yam, A.; Yaron, O.; Filippenko, A. V.; Graham, M. L.; Laher, R.; Nugent, P. E.

    2016-10-01

    We present ultraviolet through near-infrared photometry and spectroscopy of the host galaxies of all superluminous supernovae (SLSNe) discovered by the Palomar Transient Factory prior to 2013 and derive measurements of their luminosities, star formation rates, stellar masses, and gas-phase metallicities. We find that Type I (hydrogen-poor) SLSNe (SLSNe I) are found almost exclusively in low-mass ({M}* \\lt 2× {10}9 {M}ȯ ) and metal-poor (12 + log10[O/H] \\lt 8.4) galaxies. We compare the mass and metallicity distributions of our sample to nearby galaxy catalogs in detail and conclude that the rate of SLSNe I as a fraction of all SNe is heavily suppressed in galaxies with metallicities ≳ 0.5 {Z}ȯ . Extremely low metallicities are not required and indeed provide no further increase in the relative SLSN rate. Several SLSN I hosts are undergoing vigorous starbursts, but this may simply be a side effect of metallicity dependence: dwarf galaxies tend to have bursty star formation histories. Type II (hydrogen-rich) SLSNe (SLSNe II) are found over the entire range of galaxy masses and metallicities, and their integrated properties do not suggest a strong preference for (or against) low-mass/low-metallicity galaxies. Two hosts exhibit unusual properties: PTF 10uhf is an SLSN I in a massive, luminous infrared galaxy at redshift z = 0.29, while PTF 10tpz is an SLSN II located in the nucleus of an early-type host at z = 0.04.

  11. The Black Hole–Bulge Mass Relation in Megamaser Host Galaxies

    Science.gov (United States)

    Läsker, Ronald; Greene, Jenny E.; Seth, Anil; van de Ven, Glenn; Braatz, James A.; Henkel, Christian; Lo, K. Y.

    2016-07-01

    We present Hubble Space Telescope (HST) images for nine megamaser disk galaxies with the primary goal of studying photometric BH-galaxy scaling relations. The megamaser disks provide the highest-precision extragalactic BH mass measurements, while our high-resolution HST imaging affords us the opportunity to decompose the complex nuclei of their late-type hosts in detail. Based on the morphologies and shapes of the galaxy nuclei, we argue that most of these galaxies’ central regions contain secularly evolving components (pseudo-bulges), and in many cases we photometrically identify co-existing “classical” bulge components as well. Using these decompositions, we draw the following conclusions. (1) The megamaser BH masses span two orders of magnitude (106–{10}8 {M}ȯ ) while the stellar mass of their spiral host galaxies are all ˜ {10}11 {M}ȯ within a factor of three. (2) The BH masses at a given bulge mass or total stellar mass in the megamaser host spiral galaxies tend to be lower than expected when compared to an extrapolation of the BH-bulge relation based on early-type galaxies. (3) The observed large intrinsic scatter of BH masses in the megamaser host galaxies raises the question of whether scaling relations exist in spiral galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 12185.

  12. The host galaxies of BL Lac objects in the near-infrared

    CERN Document Server

    Kotilainen, J K; Scarpa, R

    1998-01-01

    We present the results of near-infrared H band (1.65 microns) imaging of 11 BL Lac objects with redshifts ranging from z = 0.05 to 0.9. We are able to clearly detect the host galaxy in seven low redshift (z<=0.24) BL Lacs, while the four unresolved BL Lacs have either high or unknown redshift. The galaxies hosting the low redshift BL Lacs are large (average bulge scale length R(e) = 8.8+-9.9 kpc) and luminous (average M(H) = -25.8+-0.5), i.e. slightly brighter than the typical galaxy luminosity L* (M*(H) = -25.0+-0.2), and of similar luminosity to or slightly fainter than brightest cluster galaxies (M(H) = -26.3+-0.3). The average optical/near-infrared colour and colour gradient of the BL Lac hosts (R-H = 2.2+-0.5; d(R-H)/d(log r) = -0.09$+-0.04) are consistent with the hosts being normal ellipticals, indicating that the nuclear activity has only a marginal effect on the star formation history and other properties of the hosts. The BL Lac hosts appear slightly less luminous than those of higher redshift fl...

  13. The HST Survey of BL Lacertae Objects: Morphological Properties of Low redshift Host Galaxies

    CERN Document Server

    Falomo, R; Treves, A; Urry, C M; 10.1086/317044

    2009-01-01

    We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range $0.03galaxies are fully resolved in the WFPC2 (F702W filter) images, allowing a quantitative analysis in two dimensions. Most and possibly all these galaxies have characteristics very similar to those of ``normal'' giant ellipticals. The luminosity, ellipticity, isophote twisting and amount of disky or boxy isophotes are consistent with those found in non-active ellipticals and in radio galaxies. In all cases the BL Lac nucleus is well centered in the main body of its host galaxy, a result that argues strongly against the microlensing hypothesis for any significant fraction of the population. A search for faint sub-structures in the host galaxies has not revealed notable signatures of tidal distortions or sub-components (faint disks, bars, X features, etc.), and with only one exception, there are no prominent dusty features in the central regions. Instead, the B...

  14. The Relation between Luminous AGNs and Star Formation in Their Host Galaxies

    CERN Document Server

    Xu, Lei; Egami, E; Haines, C P; Pereira, M J; Smith, G P

    2015-01-01

    We study the relation of active galactic nuclei (AGNs) to star formation in their host galaxies. Our sample includes 205 Type-1 and 85 Type-2 AGNs, 162 detected with Herschel, from fields surrounding 30 galaxy clusters in the Local Cluster Substructure Survey (LoCuSS). The sample is identified by optical line widths and ratios after selection to be brighter than 1 mJy at 24 microns. We show that Type-2 AGN [OIII]5007 line fluxes at high z can be contaminated by their host galaxies with typical spectrograph entrance apertures (but our sample is not compromised in this way). We use spectral energy distribution (SED) templates to decompose the galaxy SEDs and estimate star formation rates, AGN luminosities, and host galaxy stellar masses (described in an accompanying paper). The AGNs arise from massive black holes (~ 3 X 10^8 Msun) accreting at ~ 10% of the Eddington rate and residing in galaxies with stellar mass > 3 X 10^{10} Msun; those detected with Herschel have IR luminosity from star formation in the rang...

  15. The statistical investigation of type Ib/c and II supernovae and their host galaxies

    OpenAIRE

    Hakobyan, A. A.

    2008-01-01

    This is a statistical study of the properties of type Ib/c and II supernovae and of the integral parameters of their spiral host galaxies. The methods of one-dimensional and multivariate statistics were applied to the data sample. It was found that the Ib/c supernovae are more concentrated radially toward the centers of the galaxies than those of type II. The distributions of the radial distances R(SN)/R(25) for the type Ib/c and II supernovae in active galaxies are more concentrated toward t...

  16. The host galaxies of active galactic nuclei with powerful relativistic jets

    Science.gov (United States)

    Olguín-Iglesias, A.; León-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Añorve, C.; Valdés, J.; Carrasco, L.

    2016-08-01

    We present deep near-infrared (NIR) images of a sample of 19 intermediate-redshift (0.3 1027 W Hz-1), previously classified as flat-spectrum radio quasars. We also compile host galaxy and nuclear magnitudes for blazars from literature. The combined sample (this work and compilation) contains 100 radio-loud AGN with host galaxy detections and a broad range of radio luminosities L1.4 GHz ˜ 1023.7-1028.3 W Hz-1, allowing us to divide our sample into high-luminosity blazars (HLBs) and low-luminosity blazars (LLBs). The host galaxies of our sample are bright and seem to follow the μe-Reff relation for ellipticals and bulges. The two populations of blazars show different behaviours in the MK,nuclear -MK,bulge plane, where a statistically significant correlation is observed for HLBs. Although it may be affected by selection effects, this correlation suggests a close coupling between the accretion mode of the central supermassive black hole and its host galaxy, which could be interpreted in terms of AGN feedback. Our findings are consistent with semi-analytical models where low-luminosity AGN emit the bulk of their energy in the form of radio jets, producing a strong feedback mechanism, and high-luminosity AGN are affected by galaxy mergers and interactions, which provide a common supply of cold gas to feed both nuclear activity and star formation episodes.

  17. Tracing the evolution of active galactic nuclei host galaxies over the last 9 Gyr of cosmic time

    Energy Technology Data Exchange (ETDEWEB)

    Goulding, A. D.; Forman, W. R.; Jones, C.; Murray, S. S.; Paggi, A.; Ashby, M. L. N.; Huang, J.-S.; Kraft, R.; Willner, S. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hickox, R. C. [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Coil, A. L. [Department of Physics, Center for Astrophysics and Space Sciences, University of California at San Diego, 9500 Gilman Drive, La Jolla, San Diego, CA 92093 (United States); Cooper, M. C. [Center for Galaxy Evolution, Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Newman, J. A. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O' Hara Street, Pittsburgh, PA 15260 (United States); Weiner, B. J., E-mail: agoulding@cfa.harvard.edu [Steward Observatory, 933 North Cherry Street, University of Arizona, Tucson, AZ 85721 (United States)

    2014-03-01

    We present the results of a combined galaxy population analysis for the host galaxies of active galactic nuclei (AGN) identified at 0 < z < 1.4 within the Sloan Digital Sky Survey, Boötes, and DEEP2 surveys. We identified AGN in a uniform and unbiased manner at X-ray, infrared, and radio wavelengths. Supermassive black holes undergoing radiatively efficient accretion (detected as X-ray and/or infrared AGN) appear to be hosted in a separate and distinct galaxy population than AGN undergoing powerful mechanically dominated accretion (radio AGN). Consistent with some previous studies, radiatively efficient AGN appear to be preferentially hosted in modest star-forming galaxies, with little dependence on AGN or galaxy luminosity. AGN exhibiting radio-emitting jets due to mechanically dominated accretion are almost exclusively observed in massive, passive galaxies. Crucially, we now provide strong evidence that the observed host-galaxy trends are independent of redshift. In particular, these different accretion-mode AGN have remained as separate galaxy populations throughout the last 9 Gyr. Furthermore, it appears that galaxies hosting AGN have evolved along the same path as galaxies that are not hosting AGN with little evidence for distinctly separate evolution.

  18. Near-infrared imaging of the host galaxies of intermediate redshift steep spectrum radio quasars

    CERN Document Server

    Kotilainen, J K

    2000-01-01

    We present the results of near-infrared H-band (1.65 microns) imaging of 19 steep spectrum radio quasars (SSRQ) in the redshift range 0.5 < z < 1.0. This sample of SSRQs is matched with our previously studied complete sample of 20 flat spectrum radio quasars (FSRQ) with respect to redshift and optical and radio luminosity. We are able to clearly detect the host galaxy in 10 (53 %) SSRQs and marginally in 6 (32 %) others, while the host remains unresolved in 3 (16 %) SSRQs. The galaxies hosting the SSRQs are large (average bulge scale-length R(e) = 9.0+-1.7 kpc) and luminous (average M(H) = -27.2+-1.1). They are, therefore, about 2 mag more luminous than the typical galaxy luminosity L* (M*(H) = -25.0+-0.2), and about 1 mag more luminous than the brightest cluster galaxies (M(H) = -26.3+-0.3). The SSRQ hosts appear to have similar luminosity to those of the FSRQ hosts (M(H) = -27), and they fall between the luminosities of lower redshift (M(H) = -26) and higher redshift (M(H) = -29) radio-loud quasars. T...

  19. Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

    Energy Technology Data Exchange (ETDEWEB)

    D' Andrea, Chris B. [Univ. of Pennsylvania, Philadelphia, PA (United States); et al.

    2011-12-20

    We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

  20. Host Galaxy Properties and Hubble Residuals of Type Ia Supernovae from the Nearby Supernova Factory

    CERN Document Server

    Childress, M J; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Canto, A; Cellier-Holzem, F; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Guy, J; Hsiao, E Y; Kerschhaggl, M; Kim, A G; Kowalski, M; Loken, S; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Runge, K; Scalzo, R; Smadja, G; Tao, C; Thomas, R C; Weaver, B A; Wu, C

    2013-01-01

    We examine the relationship between Type Ia Supernova (SN Ia) Hubble residuals and the properties of their host galaxies using a sample of 115 SNe Ia from the Nearby Supernova Factory (SNfactory). We use host galaxy stellar masses and specific star-formation rates fitted from photometry for all hosts, as well as gas-phase metallicities for a subset of 69 star-forming (non-AGN) hosts, to show that the SN Ia Hubble residuals correlate with each of these host properties. With these data we find new evidence for a correlation between SN Ia intrinsic color and host metallicity. When we combine our data with those of other published SN Ia surveys, we find the difference between mean SN Ia brightnesses in low and high mass hosts is 0.077 +- 0.014 mag. When viewed in narrow (0.2 dex) bins of host stellar mass, the data reveal apparent plateaus of Hubble residuals at high and low host masses with a rapid transition over a short mass range (9.8 <= log(M_*/M_Sun) <= 10.4). Although metallicity has been a favored i...

  1. Host-Galaxy Properties of 32 Low-Redshift Superluminous Supernovae from the Palomar Transient Factory

    CERN Document Server

    Perley, Daniel A; Yan, Lin; Vreeswijk, Paul; De Cia, Annalisa; Lunnan, Ragnhild; Gal-Yam, Avishay; Yaron, Ofer; Filippenko, Alexei V; Graham, Melissa L; Nugent, Peter E

    2016-01-01

    We present ultraviolet through near-infrared photometry and spectroscopy of the host galaxies of all superluminous supernovae (SLSNe) discovered by the Palomar Transient Factory prior to 2013, and derive measurements of their luminosities, star-formation rates, stellar masses, and gas-phase metallicities. We find that Type I (hydrogen-poor) SLSNe are found almost exclusively in low-mass (M 0.5 Z_sun. Extremely low metallicities are not required, and indeed provide no further increase in the relative SLSN rate. Several SLSN-I hosts are undergoing vigorous starbursts, but this may simply be a side effect of metallicity dependence: dwarf galaxies tend to have bursty star-formation histories. Type-II (hydrogen-rich) SLSNe are found over the entire range of galaxy masses and metallicities, and their integrated properties do not suggest a strong preference for (or against) low-mass/low-metallicity galaxies. Two hosts exhibit unusual properties: PTF 10uhf is a Type I SLSN in a massive, luminous infrared galaxy at re...

  2. On the mass-metallicity relation, velocity dispersion and gravitational well depth of GRB host galaxies

    CERN Document Server

    Arabsalmani, Maryam; Fynbo, Johan P U; Christensen, Lise; Freudling, Wolfram; Savaglio, Sandra; Zafar, Tayyaba

    2014-01-01

    We analyze a sample of 16 absorption systems intrinsic to long duration GRB host galaxies at $z \\gtrsim 2$ for which the metallicities are known. We compare the relation between the metallicity and cold gas velocity width for this sample to that of the QSO-DLAs, and find complete agreement. We then compare the redshift evolution of the mass-metallicity relation of our sample to that of QSO-DLAs and find that also GRB hosts favour a late onset of this evolution, around a redshift of $\\approx 2.6$. We compute predicted stellar masses for the GRB host galaxies using the prescription determined from QSO-DLA samples and compare the measured stellar masses for the four hosts where stellar masses have been determined from SED fits. We find excellent agreement and conclude that, on basis of all available data and tests, long duration GRB-DLA hosts and intervening QSO-DLAs are consistent with being drawn from the same underlying population. GRB host galaxies and QSO-DLAs are found to have different impact parameter di...

  3. GRB091127/SN2009nz and the VLT/X-shooter spectroscopy of its host galaxy: probing the faint end of the mass-metallicity relation

    CERN Document Server

    Vergani, S D; Covino, S; Fugazza, D; Gorosabel, J; Levan, A J; Puech, M; Salvaterra, R; Tello, J C; Postigo, A de Ugarte; D'Avanzo, P; D'Elia, V; Fernández, M; Fynbo, J P U; Jelínek, M; Malesani, D; Palazzi, E; Piranomonte, S; Rodrigues, M; Sánchez-Ramírez, R; Terrón, V; Thöne, C C; Antonelli, L A; Campana, S; Castro-Tirado, A J; Goldoni, P; Hammer, F; Hjorth, J; Jakobsson, P; Kaper, L; Melandri, A; Milvang-Jensen, B; Sollerman, J; Tagliaferri, G; Tanvir, N R; Wiersema, K; Wijers, R A M J

    2011-01-01

    We perform a detailed study of the gamma-ray burst GRB091127/SN2009nz host galaxy at z=0.490 using the VLT/X-shooter spectrograph in long-slit and integral-field unit (IFU). From the analysis of the optical and X-ray afterglow data obtained from ground-based telescopes and Swift-XRT we confirm the presence of a bump associated with SN2009nz and find evidence of a possible jet break in the afterglow lightcurve. The X-shooter afterglow long-slit spectra reveal several emission lines from the underlying host, from which we derive its integrated properties. These are in agreement with those of previously studied GRB-SN hosts and, more generally, with those of the long GRB host population. We use the Hubble Space Telescope and ground based images of the host to determine its stellar mass (M_star). Our results extend to lower values the M_star and metallicities (Z) derived for the sample of long GRB hosts at 0.3host M-Z relation from that found in the emission line...

  4. The host galaxies of active galactic nuclei with powerful relativistic jets

    CERN Document Server

    Olguín-Iglesias, A; Kotilainen, J K; Chavushyan, V; Tornikoski, M; Valtaoja, E; Añorve, C; Valdes, J; Carrasco, L

    2016-01-01

    We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift ($0.310^{27}$ WHz$^{-1}$), previously classified as flat-spectrum radio quasars. We also compile host galaxy and nuclear magnitudes for blazars from literature. The combined sample (this work and compilation) contains 100 radio-loud AGN with host galaxy detections and a broad range of radio luminosities $L_{1.4GHz} \\sim 10^{23.7} - 10^{28.3}$~WHz$^{-1}$, allowing us to divide our sample into high-luminosity blazars (HLBs) and low-luminosity blazars (LLBs). The host galaxies of our sample are bright and seem to follow the $\\mu_{e}$-$R_{eff}$ relation for ellipticals and bulges. The two populations of blazars show different behaviours in the \\mnuc - \\mbulge plane, where a statistically significant correlation is observed for HLBs. Although it may be affected by selection effects, this correlation suggests a close coupling between the accretion mode of the central supermassive black hole and its host galaxy, that could be interpre...

  5. The Dependence of Type Ia Supernova Luminosities on their Host Galaxies

    CERN Document Server

    Sullivan, M; Howell, D A; Neill, J D; Astier, P; Balland, C; Basa, S; Carlberg, R G; Fouchez, D; Guy, J; Hardin, D; Hook, I M; Pain, R; Palanque-Delabrouille, N; Perrett, K M; Pritchet, C J; Regnault, N; Rich, J; Ruhlmann-Kleider, V; Baumont, S; Hsiao, E; Kronborg, T; Lidman, C; Perlmutter, S; Walker, E S

    2010-01-01

    (Abridged) Precision cosmology with Type Ia supernovae (SNe Ia) makes use of the fact that SN Ia luminosities depend on their light-curve shapes and colours. Using Supernova Legacy Survey (SNLS) and other data, we show that there is an additional dependence on the global characteristics of their host galaxies: events of the same light-curve shape and colour are, on average, 0.08mag (~4.0sigma) brighter in massive host galaxies (presumably metal-rich) and galaxies with low specific star-formation rates (sSFR). SNe Ia in galaxies with a low sSFR also have a smaller slope ("beta") between their luminosities and colours with ~2.7sigma significance, and a smaller scatter on SN Ia Hubble diagrams (at 95% confidence), though the significance of these effects is dependent on the reddest SNe. SN Ia colours are similar between low-mass and high-mass hosts, leading us to interpret their luminosity differences as an intrinsic property of the SNe and not of some external factor such as dust. If the host stellar mass is in...

  6. Type Ia Supernova Spectral Features in the Context of Their Host Galaxy Properties

    CERN Document Server

    Pan, Y -C; Maguire, K; Gal-Yam, A; Hook, I M; Howell, D A; Nugent, P E; Mazzali, P A

    2014-01-01

    We analyse spectroscopic measurements of 122 type Ia supernovae (SNe Ia) with $z3\\times10^9$\\,\\msun. We also find some evidence that these highest velocity SNe Ia explode in the inner regions of their host galaxies, similar to the study of \\citet{2013Sci...340..170W}, although the trend is not as significant in our data. We show that these trends are consistent with some SN Ia spectral models, if the host galaxy stellar mass is interpreted as a proxy for host galaxy metallicity. We study the strength of the high-velocity component of the \\Caii\\ near-IR absorption, and show that SNe Ia with stronger high-velocity components relative to photospheric components are hosted by galaxies with low \\mstellar, blue colour, and a high sSFR. Such SNe are therefore likely to arise from the youngest progenitor systems. This argues against a pure orientation effect being responsible for high-velocity features in SN Ia spectra and, when combined with other studies, is consistent with a scenario where high-velocity features a...

  7. Star-formation in the host galaxies of radio-AGN

    CERN Document Server

    Karouzos, Marios; Im, Myungshin; Malkan, Matthew

    2013-01-01

    There exist strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies. It is however still unclear what the exact role of nuclear activity, in the form of accretion onto these supermassive black holes, in this co-evolution is. We use a rich multi-wavelength dataset available for the North Ecliptic Pole field, most notably surveyed by the AKARI satellite infrared telescope to study the host galaxy properties of AGN. In particular we are interested in investigating star-formation in the host galaxies of radio-AGN and the putative radio feedback mechanism, potentially responsible for the eventual quenching of star-formation. Using both broadband SED modeling and optical spectroscopy, we simultaneously study the nu- clear and host galaxy components of our sources, as a function of their radio luminosity, bolo- metric luminosity, and radio-loudness. Here we present preliminary results concerning the AGN content of the radio sources in this field, while offering tentati...

  8. Supermassive Black Hole Binaries: Environment and Galaxy Host Properties of PTA and eLISA sources

    CERN Document Server

    Palafox, Eva Martínez; Colín, Pedro; Gottlöber, Stefan

    2014-01-01

    Supermassive black hole (BH) binaries would comprise the strongest sources of gravitational waves (GW) once they reach <<1 pc separations, for both pulsar timing arrays (PTAs) and space based (SB) detectors. While BH binaries coalescences constitute a natural outcome of the cosmological standard model and galaxy mergers, their dynamical evolution is still poorly understood and therefore their abundances at different stages. We use a dynamical model for the decay of BH binaries coupled with a cosmological simulation and semi-empirical approaches to the occupation of haloes by galaxies and BHs, in order to follow the evolution of the properties distribution of galaxies hosting BH binaries candidates to decay due to GWs emission. Our models allow us to relax simplifying hypothesis about the binaries occupation in galaxies and their mass, as well as redshift evolution. Following previously proposed electromagnetic (EM) signatures of binaries in the subpc regime, that include spectral features and variabilit...

  9. Revisiting the Scaling Relations of Black Hole Masses and Host Galaxy Properties

    CERN Document Server

    McConnell, Nicholas J

    2012-01-01

    New kinematic data and modeling efforts in the past few years have substantially expanded and revised dynamical measurements of black hole masses (Mbh) at the centers of nearby galaxies. Here we compile an updated sample of 72 black holes and their host galaxies, and present revised scaling relations between Mbh and stellar velocity dispersion (sigma), V-band luminosity (L), and bulge stellar mass (Mbulge), for different galaxy subsamples. Our best-fitting power law relations for the full galaxy sample are log(Mbh) = 8.33 + 5.57*log(sigma/200 kms), log(Mbh) = 9.23 + 1.11*log(L/10^{11} Lsun), and log(Mbh) = 8.46 + 1.05*log(Mbulge/10^{11} Msun). When the early- and late-type galaxies are fit separately, we obtain nearly identical slopes of ~5 for the Mbh-sigma relation but significantly different intercepts. Within early-type galaxies, we find a significantly higher intercept for galaxies with central core profiles than for those with central power-law profiles. At fixed sigma, our fits predict Mbh to be about ...

  10. Kinematics and host-galaxy properties suggest a nuclear origin for calcium-rich supernova progenitors

    Science.gov (United States)

    Foley, Ryan J.

    2015-09-01

    Calcium-rich supernovae (Ca-rich SNe) are peculiar low-luminosity SNe Ib with relatively strong Ca spectral lines at ˜2 months after peak brightness. This class also has an extended projected offset distribution, with several members of the class offset from their host galaxies by 30-150 kpc. There is no indication of any stellar population at the SN positions. Using a sample of 13 Ca-rich SNe, we present kinematic evidence that the progenitors of Ca-rich SNe originate near the centres of their host galaxies and are kicked to the locations of the SN explosions. Specifically, SNe with small projected offsets have large line-of-sight velocity shifts as determined by nebular lines, while those with large projected offsets have no significant velocity shifts. Therefore, the velocity shifts must not be primarily the result of the SN explosion. Additionally, nearly every Ca-rich SN is hosted by a galaxy with indications of a recent merger and/or is in a dense environment. We propose a progenitor model which fits all current data: the progenitor system for a Ca-rich SN is a double white dwarf (WD) system where at least one WD has a significant He abundance. This system, through an interaction with a super-massive black hole (SMBH) is ejected from its host galaxy and the binary is hardened, significantly reducing the merger time. After 10-100 Myr (on average), the system explodes with a large physical offset. The rate for such events is significantly enhanced for galaxies which have undergone recent mergers, potentially making Ca-rich SNe new probes of both the galaxy merger rate and (binary) SMBH population.

  11. Magellan LDSS3 emission confirmation of galaxies hosting metal-rich Lyman α absorption systems

    Science.gov (United States)

    Straka, Lorrie A.; Johnson, Sean; York, Donald G.; Bowen, David V.; Florian, Michael; Kulkarni, Varsha P.; Lundgren, Britt; Péroux, Celine

    2016-06-01

    Using the Low Dispersion Survey Spectrograph 3 at the Magellan II Clay Telescope, we target candidate absorption host galaxies detected in deep optical imaging (reaching limiting apparent magnitudes of 23.0-26.5 in g, r, i, and z filters) in the fields of three QSOs, each of which shows the presence of high metallicity, high N_{H I} absorption systems in their spectra (Q0826-2230: zabs = 0.9110, Q1323-0021: zabs = 0.7160, Q1436-0051: zabs = 0.7377, 0.9281). We confirm three host galaxies at redshifts 0.7387, 0.7401, and 0.9286 for two of the Lyman α absorption systems (one with two galaxies interacting). For these systems, we are able to determine the star formation rates (SFRs); impact parameters (from previous imaging detections); the velocity shift between the absorption and emission redshifts; and, for one system, also the emission metallicity. Based on previous photometry, we find these galaxies have L > L*. The [O II] SFRs for these galaxies are in the range 11-25 M⊙ yr-1 (uncorrected for dust), while the impact parameters lie in the range 35-54 kpc. Despite the fact that we have confirmed galaxies at 50 kpc from the QSO, no gradient in metallicity is indicated between the absorption metallicity along the QSO line of sight and the emission line metallicity in the galaxies. We confirm the anticorrelation between impact parameter and N_{H I} from the literature. We also report the emission redshift of five other galaxies: three at zem > zQSO, and two (L < L*) at zem < zQSO not corresponding to any known absorption systems.

  12. Optical imaging of the host galaxies of X-ray selected BL Lacertae objects

    CERN Document Server

    Falomo, R

    1999-01-01

    We investigate the properties of the host galaxies of X-ray selected (high frequency peaked) BL Lac objects using a large and homogeneous data set of high spatial resolution R-band observations of 52 BL Lacs in the EMSS and Slew samples. The redshift distribution of the BL Lacs ranges from z = 0.04 to z>0.7, with average and median redshifts z = 0.26 and z = 0.24, respectively. Eight objects are at unknown redshift. We are able to resolve 45 objects out of the 52 BL Lacs. For all the well-resolved sources, we find the host to be a luminous elliptical galaxy. In a few cases a disk is not ruled out but an elliptical model is still preferred. The average absolute magnitude of the host galaxies is = -23.9+-0.6, while the average scale length of the host is = 9+-5 kpc. There is no difference in the host properties between the EMSS and Slew samples. We find a good agreement between the results derived by the surveys of Wurtz et al. (ground-based data) and Urry et al. (HST data), and by our new deeper imaging. The...

  13. The Local Environments of Core-Collapse SNe within Host Galaxies

    CERN Document Server

    Anderson, Joseph P; James, Phil A; Hamuy, M

    2012-01-01

    We present constraints on core-collapse supernova progenitors through observations of their environments within host galaxies. This is achieved through 2 routes. Firstly, we investigate the spatial correlation of supernovae with host galaxy star formation using pixel statistics. We find that the main supernova types form a sequence of increasing association to star formation. The most logical interpretation is that this implies an increasing progenitor mass sequence going from the supernova type Ia arising from the lowest mass, through the type II, type Ib, and the supernova type Ic arising from the highest mass progenitors. We find the surprising result that the supernova type IIn show a lower association to star formation than type IIPs, implying lower mass progenitors. Secondly, we use host HII region spectroscopy to investigate differences in environment metallicity between different core-collapse types. We find that supernovae of types Ibc arise in slightly higher metallicity environments than type II ev...

  14. The Host Galaxy and the Extended Emission-Line Region of the Radio Galaxy 3C 79

    Science.gov (United States)

    Fu, Hai; Stockton, Alan

    2008-04-01

    We present extensive ground-based spectroscopy and HST imaging of 3C 79, an FR II radio galaxy associated with a luminous extended emission-line region (EELR). Surface brightness modeling of an emission-line-free HST R-band image reveals that the host galaxy is a massive elliptical with a compact companion 0.8'' away and 4 mag fainter. The host galaxy spectrum is best described by an intermediate-age (1.3 Gyr) stellar population (4% by mass), superimposed on a 10 Gyr old population and a power law (αλ = - 1.8); the stellar populations are consistent with supersolar metallicities, with the best fit given by the 2.5 Z⊙ models. We derive a dynamical mass of 4 × 1011 M⊙ within the effective radius from the velocity dispersion. The EELR spectra clearly indicate that the EELR is photoionized by the hidden central engine. Photoionization modeling shows evidence that the gas metallicity in both the EELR and the nuclear narrow-line region is mildly subsolar (0.3-0.7 Z⊙), significantly lower than the supersolar metallicities deduced from typical active galactic nuclei in the Sloan Digital Sky Survey. The more luminous filaments in the EELR exhibit a velocity field consistent with a common disk rotation. Fainter clouds, however, show high approaching velocities that are uncoupled from this apparent disk rotation. The striking similarities between this EELR and the EELRs around steep-spectrum radio-loud quasars provide further evidence for the orientation-dependent unification schemes. The metal-poor gas is almost certainly not native to the massive host galaxy. We suggest that the close companion galaxy could be the tidally stripped bulge of a late-type galaxy that is merging with the host galaxy. The interstellar medium of such a galaxy is probably the source for the low-metallicity gas in 3C 79. Based in part on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative

  15. ALFALFA HI Data Stacking II. HI content of the host galaxies of AGN

    CERN Document Server

    Fabello, S; Catinella, B; Giovanelli, R; Haynes, M P; Heckman, T M; Schiminovich, D

    2011-01-01

    We use a stacking technique to measure the average HI content of a volume-limited sample of 1871 AGN host galaxies from a parent sample of galaxies selected from the SDSS and GALEX imaging surveys with stellar masses greater than 10^10 M_sun and redshifts in the range 0.025galaxies correlates most strongly with the combination of optical/UV colour and stellar surface mass density. We therefore build a control sample of non-AGN matched to the AGN hosts in these two properties. We study trends in HI gas mass fraction (M(HI)/M_*), where M_* is the stellar mass) as a function of black hole accretion rate indicator L[OIII]/M(BH). We find no significant difference in HI content between AGN and control samples at all values of black hole accretion rate probed by the galaxies in our sample. This indicates that AGN do not influence the large-scale gaseous properties of galaxie...

  16. Constraining the properties of AGN host galaxies with Spectral Energy Distribution modeling

    CERN Document Server

    Ciesla, L; Georgakakis, A; Bernhard, E; Mitchell, P D; Buat, V; Elbaz, D; Floc'h, E Le; Lacey, C G; Magdis, G E; Xilouris, M

    2015-01-01

    [abridged] We use the latest release of CIGALE, a galaxy SED fitting model relying on energy balance, to study the influence of an AGN in estimating both the SFR and stellar mass in galaxies, as well as the contribution of the AGN to the power output of the host. Using the galaxy formation SAM GALFORM, we create mock galaxy SEDs using realistic star formation histories (SFH) and add an AGN of Type 1, Type 2, or intermediate type whose contribution to the bolometric luminosity can be variable. We perform an SED fitting of these catalogues with CIGALE assuming three different SFHs: a single- and double-exponentially-decreasing, and a delayed SFH. Constraining thecontribution of an AGN to the LIR (fracAGN) is very challenging for fracAGN<20%, with uncertainties of ~5-30% for higher fractions depending on the AGN type, while FIR and sub-mm are essential. The AGN power has an impact on the estimation of $M_*$ in Type 1 and intermediate type AGNs but has no effect for galaxies hosting Type 2 AGNs. We find that i...

  17. The Afterglow and ULIRG Host Galaxy of the Dark Short GRB 120804A

    CERN Document Server

    Berger, E; Levan, A; Margutti, R; Laskar, T; Fong, W; Mangano, V; Fox, D B; Tunnicliffe, R L; Chornock, R; Tanvir, N R; Menten, K M; Hjorth, J; Roth, K; Dupuy, T J

    2012-01-01

    We present the optical discovery and sub-arcsecond optical and X-ray localization of the afterglow of the short GRB 120804A, as well as optical, near-IR, and radio detections of its host galaxy. X-ray observations with Swift/XRT, Chandra, and XMM-Newton to ~19 d reveal a single power law decline. The optical afterglow is faint, and comparison to the X-ray flux indicates that GRB 120804A is "dark", with a rest-frame extinction of A_V~2.5 mag (at z~1.3). The intrinsic neutral hydrogen column density inferred from the X-ray spectrum, N_H~2x10^22 cm^-2, is commensurate with the large extinction. The host galaxy exhibits red optical/near-IR colors. Equally important, JVLA observations at 0.9-11 d reveal a constant 5.8 GHz flux density and an optically-thin spectrum, unprecedented for GRB afterglows, but suggestive instead of emission from the host galaxy. The optical/near-IR and radio fluxes are well fit with the scaled spectral energy distribution of the local ultra-luminous infrared galaxy (ULIRG) Arp 220 at z~1...

  18. Accreting SMBHs in the COSMOS field and the connection to their host galaxies

    CERN Document Server

    Bongiorno, A; Brusa, M; Magnelli, B; Salvato, M; Mignoli, M; Zamorani, G; Fiore, F; Rosario, D; Mainieri, V; Comastri, A; Vignali, C; Balestra, I; Bardelli, S; Berta, S; Civano, F; Kampczyk, P; Floc'h, E Le; Lusso, E; Lutz, D; Pozzetti, L; Pozzi, F; Riguccini, L; Shankar, F; Silverman, J

    2012-01-01

    Using the wide multi-band photometry available in the COSMOS field we explore the host galaxy properties of a large sample of Active Galactic Nuclei (AGN) obtained by combining X-ray and optical spectroscopic selections. Based on a careful study of their Spectral Energy Distribution (SED), which has been parametrized using a 2-component (AGN+galaxy) model fit, we derived dust-corrected rest-frame magnitudes, colors, stellar masses and star formation rates (SFRs). We find that AGN hosts span a large range of stellar masses and SFRs. No color-bimodality is seen at any redshift in the AGN hosts, which are found to be mainly massive, red galaxies. Once accounting for the color-mass degeneracy in well defined mass-matched samples, we find a residual marginal enhancement of AGN incidence in redder galaxies with lower specific star formation rates, and we argue that this result might emerge because of our ability to properly account for AGN light contamination and dust extinction. Interestingly, we find that the pro...

  19. The dependence of tidal stripping efficiency on the satellite and host galaxy morphology

    CERN Document Server

    Chang, Jiang; Kang, Xi

    2012-01-01

    In this paper we study the tidal stripping process for satellite galaxies orbiting around a massive host galaxy, and focus on its dependence on the morphology of both satellite and host galaxy. For this purpose, we use three different morphologies for the satellites: pure disc, pure bulge and a mixture bulge+disc. Two morphologies are used for the host galaxy: bulge+disc and pure bulge. We find that while the spheroidal stellar component experience a constant power-law like mass removal, the disc is exposed to an exponential mass loss when the tidal radius of the satellites is of the same order of the disc scale length. This dramatic mass loss is able to completely remove the stellar component on time scale of 100 Myears. As a consequence two satellites with the same stellar and dark matter masses, on the same orbit could either retain 60% of their stellar mass after 10 Gyrs or being completely destroyed, depending on their initial stellar morphology.We find that there are two characteristic time scales descr...

  20. The dark nature of GRB 130528A and its host galaxy

    CERN Document Server

    Jeong, S; Bremer, M; Winters, J M; Gorosabel, J; Guziy, S; Pandey, S B; Jelínek, M; Sánchez-Ramírez, R; Sokolov, Ilya V; Orekhova, N V; Moskvitin, A S; Tello, J C; Cunniffe, R; Lara-Gil, O; Pérez-Ramírez, D; Bai, J; Fan, Y; Wang, C; Park, I H

    2014-01-01

    We study the dark nature of GRB 130528A via the multi-wavelength observations and conclude that the main reason for this is the local extinction inside the host galaxy. Automatic observations were performed at BOOTES-4/MET robotic telescope. We also triggered Target of Opportunity (ToO) observation at the OSN, IRAM PdBI and the GTC+OSIRIS. The host galaxy photometric observations in optical to near-infrared (nIR) wavelengths were achieved through ground large aperture telescopes, such as the 10.4m GTC, the 4.2m WHT, and the 6m BTA telescope. Based on these observations, a spectral energy distributions (SED) model for the host galaxy and afterglow was constructed. We confirmed a clearly fading mm source within the XRT error circle thanks to our millimetre observations at PdBI while no credible optical source was found in early observation at the BOOTES-4/MET and 1.5m OSN telescopes. Spectroscopic observation of this galaxy at the GTC showed faint [OII] 3727\\{AA} emission line at a redshift of 1.250+/-0.001 imp...

  1. THE CLUSTERING OF ALFALFA GALAXIES: DEPENDENCE ON H I MASS, RELATIONSHIP WITH OPTICAL SAMPLES, AND CLUES OF HOST HALO PROPERTIES

    International Nuclear Information System (INIS)

    We use a sample of ≈6000 galaxies detected by the Arecibo Legacy Fast ALFA (ALFALFA) 21 cm survey to measure the clustering properties of H I-selected galaxies. We find no convincing evidence for a dependence of clustering on galactic atomic hydrogen (H I) mass, over the range MHI ≈ 108.5-1010.5 M☉. We show that previously reported results of weaker clustering for low H I mass galaxies are probably due to finite-volume effects. In addition, we compare the clustering of ALFALFA galaxies with optically selected samples drawn from the Sloan Digital Sky Survey (SDSS). We find that H I-selected galaxies cluster more weakly than even relatively optically faint galaxies, when no color selection is applied. Conversely, when SDSS galaxies are split based on their color, we find that the correlation function of blue optical galaxies is practically indistinguishable from that of H I-selected galaxies. At the same time, SDSS galaxies with red colors are found to cluster significantly more than H I-selected galaxies, a fact that is evident in both the projected as well as the full two-dimensional correlation function. A cross-correlation analysis further reveals that gas-rich galaxies 'avoid' being located within ≈3 Mpc of optical galaxies with red colors. Next, we consider the clustering properties of halo samples selected from the Bolshoi ΛCDM simulation. A comparison with the clustering of ALFALFA galaxies suggests that galactic H I mass is not tightly related to host halo mass and that a sizable fraction of subhalos do not host H I galaxies. Lastly, we find that we can recover fairly well the correlation function of H I galaxies by just excluding halos with low spin parameter. This finding lends support to the hypothesis that halo spin plays a key role in determining the gas content of galaxies

  2. Does the Amati Relation depend on the Luminosity of the GRB's Host Galaxy?

    Institute of Scientific and Technical Information of China (English)

    Jing Wang; Jing-Song Deng; Yu-Lei Qiu

    2008-01-01

    In order to test the systematics of the Amati relation, 24 long-duration GRBs with available Eγ,iso, and Ep are separated into two subgroups according to the B-band luminosity of their host galaxies. The Amati relations in the two subgroups are found to be in agreement with each other within the uncertainties. Taking into account of the well established luminosity-metallicity relation of galaxies, no strong evolution of the Amati relation with the GRB's environmental metallicity is implied in this study.

  3. Probing the Coevolution of Supermassive Black Holes and Quasar Host Galaxies

    CERN Document Server

    Peng, C Y; Ho, L C; Barton, E J; Rix, H W; Peng, Chien Y.; Impey, Chris D.; Ho, Luis C.; Barton, Elizabeth J.; Rix, Hans-Walter

    2006-01-01

    At low redshift, there are fundamental correlations between the mass of supermassive black holes (MBH) and the luminosity and mass of the host galaxy bulge. We investigate the same relation at z>=1. Using virial mass estimates for 15 quasars to measure their black hole mass, we find that black holes at high z (z>~2) fall nearly on the same MBH versus R-band magnitude (MR) relation (to ~0.5 mag) as low-redshift active and inactive galaxies, without making any correction for luminosity evolution. Using a set of conservative assumptions about the host galaxy stellar population, we show that the bulge stellar mass at a given MBH is probably smaller in the past than today by a factor of 3 to 6. Barring unknown systematic errors on the measurement of MBH, we also rule out scenarios in which moderately luminous quasar hosts at z>~2 were fully formed bulges that passively fade to the present epoch. On the other hand, z~1 hosts are consistent with current day MBH-MR relationship after taking into account evolution, ap...

  4. Outflowing Galactic Winds in Post-starburst and AGN Host Galaxies at 0.2

    CERN Document Server

    Coil, Alison L; Holz, Daniel E; Cooper, Michael C; Yan, Renbin; Aird, James

    2011-01-01

    We present Keck/LRIS-B spectra for a sample of ten AEGIS X-ray AGN host galaxies and thirteen post-starburst galaxies from SDSS and DEEP2 at 0.2galaxies that either host a low-luminosity AGN or have recently had their star formation quenched to test whether these galaxies have winds of sufficient velocity to potentially clear gas from the galaxy. We find, using absorption features of Fe II, Mg II, and Mg I, that six of our X-ray AGN host galaxies and four of our post-starburst galaxies have outflowing galactic winds, with typical velocities of ~200 km/s. We additionally find that most of the galaxies in our sample show line emission, presumably from the wind, in either Fe II* or Mg II. A total of 100% of our X-ray AGN host sample (including four red sequence galaxies) and 77% of our post-starburst sample has either blueshifted absorption or line emission from a wind....

  5. Morphologies of z~0.7 AGN Host Galaxies in CANDELS: No trend of merger incidence with AGN luminosity

    CERN Document Server

    Villforth, C; Rosario, D J; Santini, P; McGrath, E J; van der Wel, A; Chang, Y -Y; Guo, Yicheng; Dahlen, T; Bell, E F; Conselice, C J; Croton, D; Dekel, A; Faber, S M; Grogin, N; Hamilton, T; Hopkins, P F; Juneau, S; Kartaltepe, J; Kocevski, D; Koekemoer, A; Koo, D C; Lotz, J; McIntosh, D; Mozena, M; Somerville, R; Wild, V

    2014-01-01

    The processes that trigger Active Galactic Nuclei (AGN) remain poorly understood. While lower luminosity AGN may be triggered by minor disturbances to the host galaxy, stronger disturbances are likely required to trigger luminous AGN. Major wet mergers of galaxies are ideal environments for AGN triggering since they provide large gas supplies and galaxy scale torques. There is however little observational evidence for a strong connection between AGN and major mergers. We analyse the morphological properties of AGN host galaxies as a function of AGN and host galaxy luminosity and compare them to a carefully matched sample of control galaxies. AGN are X-ray selected in the redshift range 0.5 < z < 0.8 and have luminosities 41 < log(L_X [erg/s]) < 44.5. 'Fake AGN' are simulated in the control galaxies by adding point sources with the magnitude of the matched AGN. We find that AGN host and control galaxies have comparable assymetries, Sersic indices and ellipticities at restframe ~950nm. AGN host gala...

  6. Supernovae and their host galaxies - III. The impact of bars and bulges on the radial distribution of supernovae in disc galaxies

    CERN Document Server

    Hakobyan, A A; Barkhudaryan, L V; Mamon, G A; Kunth, D; Petrosian, A R; Adibekyan, V; Aramyan, L S; Turatto, M

    2016-01-01

    We present an analysis of the impact of bars and bulges on the radial distributions of the different types of supernovae (SNe) in the stellar discs of host galaxies with various morphologies. We use a well-defined sample of 500 nearby (< 100 Mpc) SNe and their low-inclined (i < 60 deg) and morphologically non-disturbed S0-Sm host galaxies from the Sloan Digital Sky Survey. We find that in Sa-Sm galaxies, all core-collapse (CC) and vast majority of SNe Ia belong to the disc, rather than the bulge component. The radial distribution of SNe Ia in S0-S0/a galaxies is inconsistent with their distribution in Sa-Sm hosts, which is probably due to the contribution of the outer bulge SNe Ia in S0-S0/a galaxies. In Sa-Sbc galaxies, the radial distribution of CC SNe in barred hosts is inconsistent with that in unbarred ones, while the distributions of SNe Ia are not significantly different. At the same time, the radial distributions of both types of SNe in Sc-Sm galaxies are not affected by bars. We propose that th...

  7. AGN host galaxy mass function in COSMOS: is AGN feedback responsible for the mass-quenching of galaxies?

    CERN Document Server

    Bongiorno, A; Merloni, A; Zamorani, G; Ilbert, O; La Franca, F; Peng, Y; Piconcelli, E; Mainieri, V; Silverman, J D; Brusa, M; Fiore, F; Salvato, M; Scoville, N

    2016-01-01

    We investigate the role of supermassive black holes in the global context of galaxy evolution by measuring the host galaxy stellar mass function (HGMF) and the specific accretion rate i.e., lambda_SAR, distribution function (SARDF) up to z~2.5 with ~1000 X-ray selected AGN from XMM-COSMOS. Using a maximum likelihood approach, we jointly fit the stellar mass function and specific accretion rate distribution function, with the X-ray luminosity function as an additional constraint. Our best fit model characterizes the SARDF as a double power-law with mass dependent but redshift independent break whose low lambda_SAR slope flattens with increasing redshift while the normalization increases. This implies that, for a given stellar mass, higher lambda_SAR objects have a peak in their space density at earlier epoch compared to the lower lambda_SAR ones, following and mimicking the well known AGN cosmic downsizing as observed in the AGN luminosity function. The mass function of active galaxies is described by a Schech...

  8. The host galaxy of the gamma-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    Energy Technology Data Exchange (ETDEWEB)

    León Tavares, J.; Chavushyan, V.; Puerari, I.; Patiño-Alvarez, V.; Carramiñana, A.; Carrasco, L.; Guichard, J.; Olguín-Iglesias, A.; Valdes, J. [Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE), Apartado Postal 51 y 216, 72000 Puebla (Mexico); Kotilainen, J. [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Piikkiö (Finland); Añorve, C. [Facultad de Ciencias de la Tierra y del Espacio (FACITE) de la Universidad Autónoma de Sinaloa, Blvd. de la Americas y Av. Universitarios S/N, Ciudad Universitaria, C.P. 80010, Culiacán Sinaloa (Mexico); Cruz-González, I. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Ap. 70-264, 04510 DF (Mexico); Antón, S. [Instituto de Astrofísica de Andalucía-CSIC, E-18008 Granada (Spain); Karhunen, K.; Sanghvi, J., E-mail: leon.tavares@inaoep.mx [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, FI-20100 Turku (Finland)

    2014-11-01

    We present optical and near-infrared (NIR) imaging data of the radio-loud, narrow-line Seyfert 1 galaxy 1H 0323+342, which shows intense and variable gamma-ray activity discovered by the Fermi satellite with the Large Area Telescope. Near-infrared and optical images are used to investigate the structural properties of the host galaxy of 1H 0323+342; this together with optical spectroscopy allows us to examine its black hole mass. Based on two-dimensional (2D) multiwavelength surface-brightness modeling, we find that statistically, the best model fit is a combination of a nuclear component and a Sérsic profile (n ∼ 2.8). However, the presence of a disk component (with a small bulge n ∼ 1.2) also remains a possibility and cannot be ruled out with the present data. Although at first glance a spiral-arm-like structure is revealed in our images, a 2D Fourier analysis of the imagery suggests that this structure corresponds to an asymmetric ring, likely associated with a recent violent dynamical interaction. We discuss our results in the context of relativistic jet production and galaxy evolution.

  9. Supermassive black holes and their host galaxies. II. The correlation with near-infrared luminosity revisited

    Energy Technology Data Exchange (ETDEWEB)

    Läsker, Ronald; Van de Ven, Glenn [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Ferrarese, Laura [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E2E7 (Canada); Shankar, Francesco, E-mail: laesker@mpia.de [GEPI Observatoire de Paris, CNRS, Univ. Paris Diderot, 5 Place Jules Janssen, F-92195 Meudon (France)

    2014-01-01

    We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M {sub •}, and their host galaxies' K-band bulge (L {sub bul}) and total (L {sub tot}) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope was used to obtain the deepest and highest resolution near-infrared images available for a sample of 35 galaxies with securely measured M {sub •}, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes, and spiral arms. We find that the present-day M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations have consistent intrinsic scatter, suggesting that M {sub •} correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations are 0.75 ± 0.10 and 0.92 ± 0.14, respectively. However, while the slope of the M {sub •}-L {sub bul} relation depends on the detail of the image decomposition, the characterization of M {sub •}-L {sub tot} does not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L {sub tot} is more suitable as a tracer of SMBH mass than L {sub bul}, and that the M {sub •}-L {sub tot} relation should be used when studying the co-evolution of SMBHs and galaxies.

  10. Herschel observed Stripe 82 quasars and their host galaxies: connections between the AGN activity and the host galaxy star formation

    CERN Document Server

    Dong, Xiaoyi

    2016-01-01

    In this work, we present a study of 207 quasars selected from the Sloan Digital Sky Survey quasar catalogs and the Herschel Stripe 82 survey. Quasars within this sample are high luminosity quasars with a mean bolometric luminosity of $10^{46.4}$ erg s$^{-1}$. The redshift range of this sample is within $z<4$, with a mean value of $1.5\\pm0.78$. Because we only selected quasars that have been detected in all three Herschel-SPIRE bands, the quasar sample is complete yet highly biased. Based on the multi-wavelength photometric observation data, we conducted a spectral energy distribution (SED) fitting through UV to FIR. Parameters such as active galactic nucleus (AGN) luminosity, FIR luminosity, stellar mass, as well as many other AGN and galaxy properties are deduced from the SED fitting results. The mean star formation rate (SFR) of the sample is 419 $M_{\\odot}$ yr$^{-1}$ and the mean gas mass is $\\sim 10^{11.3}$ $M_{\\odot}$. All these results point to an IR luminous quasar system. Comparing with star format...

  11. Molecular Gas in the Host Galaxy of a Quasar at Redshift z=6.42

    CERN Document Server

    Walter, F; Carilli, C; Cox, P; Lo, K Y; Neri, R; Fan, X; Omont, A; Strauss, M A; Menten, K M; Walter, Fabian; Bertoldi, Frank; Carilli, Chris; Cox, Pierre; Neri, Roberto; Fan, Xiaohui; Omont, Alain; Strauss, Michael A.; Menten, Karl M.

    2003-01-01

    Observations of the molecular gas phase in quasar host galaxies provide fundamental constraints on galaxy evolution at the highest redshifts. Molecular gas is the material out of which stars form; it can be traced by spectral line emission of carbon--monoxide (CO). To date, CO emission has been detected in more than a dozen quasar host galaxies with redshifts (z) larger 2, the record holder being at z=4.69. At these distances the CO lines are shifted to longer wavelengths, enabling their observation with sensitive radio and millimetre interferometers. Here we present the discovery of CO emission toward the quasar SDSS J114816.64+525150.3 (hereafter J1148+5251) at a redshift of z=6.42, when the universe was only 1/16 of its present age. This is the first detection of molecular gas at the end of cosmic reionization. The presence of large amounts of molecular gas (M(H_2)=2.2e10 M_sun) in an object at this time demonstrates that heavy element enriched molecular gas can be generated rapidly in the earliest galaxie...

  12. A RELATIONSHIP BETWEEN SUPERMASSIVE BLACK HOLE MASS AND THE TOTAL GRAVITATIONAL MASS OF THE HOST GALAXY

    International Nuclear Information System (INIS)

    We investigate the correlation between the mass of a central supermassive black hole (SMBH) and the total gravitational mass of the host galaxy (M tot). The results are based on 43 galaxy-scale strong gravitational lenses from the Sloan Lens ACS Surveys (SLACS) Survey whose black hole masses were estimated through two scaling relations: the relation between black hole mass and Sersic index (M bh-n) and the relation between black hole mass and stellar velocity dispersion (M bh-σ*). We use the enclosed mass within R 200, the radius within which the density profile of the early type galaxy exceeds the critical density of the universe by a factor of 200, determined by gravitational lens models fitted to Hubble Space Telescope imaging data, as a tracer of the total gravitational mass. The best-fit correlation, where M bh is determined from M bh-σ* relation, is log(M bh) = (8.18 ± 0.11) + (1.55 ± 0.31)(log(M tot)-13.0) over 2 orders of magnitude in M bh. From a variety of tests, we find that we cannot reliably infer a connection between M bh and M tot from the M bh-n relation. The M bh-M tot relation provides some of the first, direct observational evidence to test the prediction that SMBH properties are determined by the halo properties of the host galaxy.

  13. A tale of two feedbacks: star-formation in the host galaxies of radio-AGN

    CERN Document Server

    Karouzos, Marios; Trichas, Markos; Ruiz, Angel; Goto, Tomo; Malkan, Matt; Jeon, Yiseul; Kim, Ji Hoon; Lee, Hyung Mok; Kim, Seongjin; Oi, Nagisa; Matsuhara, Hideo; Takagi, Toshinobu; Murata, Kazumi; Wada, Takehiko; Wada, Kensuke; Shim, Hyunjin; Hanami, Hitoshi; Serheant, Stephen; White, Glenn J; Pearson, Crhis; Ohyama, Youichi

    2013-01-01

    Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star-formation activity in these galaxies. The exact nature of this link is still under debate. Radio jets have long been argued to be an ideal mechanism that allows AGN to interact with their host galaxy and regulate star-formation. In this context, we are using a sample of radio sources in the North Ecliptic Pole (NEP) field to study the nature of the putative link between AGN activity and star-formation. This is done by means of spectral energy distribution (SED) fitting. We use the excellent spectral coverage of the AKARI infrared space telescope together with the rich ancillary data available in the NEP to build SEDs extending from UV to far-IR wavelengths. Through SED fitting we constrain both the AGN and host galaxy components. We find a significant AGN component in our sample of relatively faint radio-sources ($<$mJy), that increases in power...

  14. Magellan LDSS3 emission confirmation of galaxies hosting metal-rich Lyman-alpha absorption systems

    CERN Document Server

    Straka, Lorrie A; York, Donald G; Bowen, David V; Florian, Michael; Kulkarni, Varsha P; Lundgren, Britt; Peroux, Celine

    2015-01-01

    Using the Low Dispersion Survey Spectrograph 3 at the Magellan II Clay Telescope in Chile, we target candidate absorption host galaxies detected in deep optical imaging (reaching limiting apparent magnitudes of 23.0-26.5 in g; r; i; and z filters) in the fields of three QSOs, each of which shows the presence of high metallicity, strong NHI absorption systems in their spectra (Q0826-2230: zabs=0.9110, Q1323-0021: zabs = 0.7160, Q1436-0051: zabs = 0.7377; 0.9281). We confirm host galaxies at redshifts 0.7387, 0.7401, and 0.9286 for two out of four of the Ly-alpha absorption systems. For these systems, we are able to determine the SFRs; impact parameters (known from previous imaging detections); the velocity shift between the absorption and emission redshifts; and, for one system, also the emission metallicity. Based on previous photometry, we find these galaxies have L>L*. The SFRs for these galaxies, based on [O II] emission, are in the range 11-25 M_sol/yr (uncorrected for dust), while the impact parameters l...

  15. Supermassive Black Holes and Their Host Galaxies - II. The correlation with near-infrared luminosity revisited

    CERN Document Server

    Läsker, Ronald; van de Ven, Glenn; Shankar, Francesco

    2013-01-01

    We present an investigation of the scaling relations between Supermassive Black Hole (SMBH) masses (Mbh), and their host galaxies' K-band bulge (Lbul) and total (Ltot) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope (CFHT) was used to obtain the deepest and highest resolution near infrared images available for a sample of 35 galaxies with securely measured Mbh, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes and spiral arms. We find that the present-day Mbh-Lbul and Mbh-Ltot relations have consistent intrinsic scatter, suggesting that Mbh correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the Mbh-Lbul and Mbh-Ltot relations are ...

  16. Co-evolution of nuclear star clusters, massive black holes and their host galaxies

    CERN Document Server

    Antonini, Fabio; Silk, Joseph

    2015-01-01

    Studying how nuclear star clusters (NSCs) form and how they are related to the growth of the central massive black holes (MBHs) and their host galaxies is fundamental for our understanding of the evolution of galaxies and the processes that have shaped their central structures. We present the results of a semi-analytical galaxy formation model that follows the evolution of dark matter halos along merger trees, as well as that of the baryonic components. This model allows us to study the evolution of NSCs in a cosmological context, by taking into account the growth of NSCs due to both dynamical friction-driven migration of stellar clusters and star formation triggered by infalling gas, while also accounting for dynamical heating from (binary) MBHs. We find that in-situ star formation contributes a significant fraction (up to ~40%) of the total mass of NSCs in our model. Both NSC growth through in-situ star formation and through star cluster migration are found to generate NSC -- host galaxy scaling correlation...

  17. The Degeneracy of Galaxy Formation Models

    OpenAIRE

    Neistein, Eyal; Weinmann, Simone M.

    2009-01-01

    We develop a new formalism for modeling the formation and evolution of galaxies within a hierarchical universe. Similarly to standard semi-analytical models we trace galaxies inside dark-matter merger-trees. The formalism includes treatment of feedback, star-formation, cooling, smooth accretion, gas stripping in satellite galaxies, and merger-induced star bursts. However, unlike in other models, each process is assumed to have an efficiency which depends only on the host halo mass and redshif...

  18. Dissecting the quasar main sequence: insight from host galaxy properties

    CERN Document Server

    Sun, Jiayi

    2015-01-01

    The diverse properties of broad-line quasars appear to follow a well-defined main sequence along which the optical FeII strength increases. It has been suggested that this sequence is mainly driven by the Eddington ratio (L/L_Edd) of the black hole (BH) accretion. Shen & Ho demonstrated with quasar clustering analysis that the average BH mass decreases with increasing FeII strength when quasar luminosity is fixed, consistent with this suggestion. Here we perform an independent test by measuring the stellar velocity dispersion sigma* (hence the BH mass via the M-sigma* relation) from decomposed host spectra in low-redshift Sloan Digital Sky Survey quasars. We found that at fixed quasar luminosity, sigma* systematically decreases with increasing FeII strength, confirming that Eddington ratio increases with FeII strength. We also found that at fixed luminosity and FeII strength, there is little dependence of sigma* on the broad Hbeta FWHM. These new results reinforce the framework put forward by Shen & H...

  19. Dissecting the Quasar Main Sequence: Insight from Host Galaxy Properties

    Science.gov (United States)

    Sun, Jiayi; Shen, Yue

    2015-05-01

    The diverse properties of broad-line quasars appear to follow a well-defined main sequence along which the optical Fe ii strength increases. It has been suggested that this sequence is mainly driven by the Eddington ratio (L/LEdd) of the black hole (BH) accretion. Shen & Ho demonstrated with quasar clustering analysis that the average BH mass decreases with increasing Fe ii strength when quasar luminosity is fixed, consistent with this suggestion. Here we perform an independent test by measuring the stellar velocity dispersion σ* (hence, the BH mass via the M-σ* relation) from decomposed host spectra in low-redshift Sloan Digital Sky Survey quasars. We found that at fixed quasar luminosity, σ* systematically decreases with increasing Fe ii strength, confirming that the Eddington ratio increases with Fe ii strength. We also found that at fixed luminosity and Fe ii strength, there is little dependence of σ* on the broad Hβ FWHM. These new results reinforce the framework that the Eddington ratio and orientation govern most of the diversity seen in broad-line quasar properties.

  20. DISSECTING THE QUASAR MAIN SEQUENCE: INSIGHT FROM HOST GALAXY PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jiayi [Tsinghua Center for Astrophysics, Department of Physics, Tsinghua University, Beijing 100084 (China); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2015-05-01

    The diverse properties of broad-line quasars appear to follow a well-defined main sequence along which the optical Fe ii strength increases. It has been suggested that this sequence is mainly driven by the Eddington ratio (L/L{sub Edd}) of the black hole (BH) accretion. Shen and Ho demonstrated with quasar clustering analysis that the average BH mass decreases with increasing Fe ii strength when quasar luminosity is fixed, consistent with this suggestion. Here we perform an independent test by measuring the stellar velocity dispersion σ{sub *} (hence, the BH mass via the M–σ{sub *} relation) from decomposed host spectra in low-redshift Sloan Digital Sky Survey quasars. We found that at fixed quasar luminosity, σ{sub *} systematically decreases with increasing Fe ii strength, confirming that the Eddington ratio increases with Fe ii strength. We also found that at fixed luminosity and Fe ii strength, there is little dependence of σ{sub *} on the broad Hβ FWHM. These new results reinforce the framework that the Eddington ratio and orientation govern most of the diversity seen in broad-line quasar properties.

  1. Dynamical friction and scratches of orbiting satellite galaxies on host systems

    CERN Document Server

    Ogiya, Go

    2015-01-01

    We study the dynamical response of extended systems, hosts, to smaller systems, satellites, orbiting around the hosts using extremely high-resolution N-body simulations with up to one billion particles. This situation corresponds to minor mergers which are ubiquitous in the scenario of hierarchical structure formation in the universe. According to Chandrasekhar (1943), satellites create density wakes along the orbit and the wakes cause a deceleration force on satellites, i.e. dynamical friction. This study proposes an analytical model to predict the dynamical response of hosts in the density distribution and finds not only traditional wakes but also mirror images of over- and underdensities centered on the host. Controlled N-body simulations with high resolutions verify the predictions of the analytical model directly. We apply our analytical model to the expected dynamical response of nearby interacting galaxy pairs, the Milky Way - Large Magellanic Cloud system and the M31 - M33 system.

  2. Dynamical friction and scratches of orbiting satellite galaxies on host systems

    Science.gov (United States)

    Ogiya, Go; Burkert, Andreas

    2016-04-01

    We study the dynamical response of extended systems, hosts, to smaller systems, satellites, orbiting around the hosts using extremely high-resolution N-body simulations with up to one billion particles. This situation corresponds to minor mergers which are ubiquitous in the scenario of hierarchical structure formation in the universe. According to Chandrasekhar, satellites create density wakes along the orbit and the wakes cause a deceleration force on satellites, i.e. dynamical friction. This study proposes an analytical model to predict the dynamical response of hosts as reflected in their density distribution and finds not only traditional wakes but also mirror images of over- and underdensities centred on the host. Our controlled N-body simulations with high resolutions verify the predictions of the analytical model. We apply our analytical model to the expected dynamical response of nearby interacting galaxy pairs, the Milky Way-Large Magellanic Cloud system and the M31-M33 system.

  3. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Michael A. [Princeton University

    2013-08-23

    The physical relation between the properties of Type Ia supernovae and their host galaxies is investigated. Such supernovae are used to constrain the properties of dark energy, making it crucial to understand their physical properties and to check for systematic effects relating to the stellar populations of the progenitor stars from which these supernovae arose. This grant found strong evidence for two distinct populations of supernovae, and correlations between the progenitor stellar populations and the nature of the supernova light curves.

  4. Rapid Coeval Black Hole and Host Galaxy Growth in MRC 1138-262: The Hungry Spider

    CERN Document Server

    Seymour, N; De Breuck, C; Barthel, P; Coia, D; Conversi, L; Dannerbauer, H; Dey, A; Dickinson, M; Drouart, G; Galametz, A; Greve, T R; Haas, M; Hatch, N; Ibar, E; Ivison, R; Jarvis, M; Kovacs, A; Kurk, J; Lehnert, M; Miley, G; Nesvadba, N; Rawlings, J I; Rettura, A; Rottgering, H; Rocca-Volmerange, B; Sanchez-Portal, M; Santos, J S; Stern, D; Stevens, J; Valtchanov, I; Vernet, J; Wylezalek, D

    2012-01-01

    We present a detailed study of the infrared spectral energy distribution of the high-redshift radio galaxy MRC 1138-26 at z = 2.156, also known as the Spiderweb Galaxy. By combining photometry from Spitzer, Herschel and LABOCA we fit the rest-frame 5-300 um emission using a two component, starburst and active galactic nucleus (AGN), model. The total infrared (8 - 1000 um) luminosity of this galaxy is (1.97+/-0.28)x10^13 Lsun with (1.17+/-0.27) and (0.79+/-0.09)x10^13 Lsun due to the AGN and starburst components respectively. The high derived AGN accretion rate of \\sim20% Eddington, and the measured star formation rate (SFR) of 1390pm150 Msun/yr, suggest that this massive system is in a special phase of rapid central black hole and host galaxy growth, likely caused by a gas rich merger in a dense environment. The accretion rate is sufficient to power both the jets and the previously observed large outflow. The high SFR and strong outflow suggest this galaxy could potentially exhaust its fuel for stellar growth...

  5. VCC 144 - a star-bursting dwarf galaxy in the Virgo Cluster

    OpenAIRE

    Brosch, N.; Almoznino, E.; L. Hoffman

    1997-01-01

    We describe results of a multi-spectral study of a blue compact dwarf galaxy in Virgo. The object was observed with broad-band and H$\\alpha$ imaging, UV observations, and radio synthesis. Our data were combined with published optical observations, with HI single-beam observation and with FIR data, and were compared to results of evolutionary synthesis programs. The radio observations revealed a compact source of HI coincident with the optical galaxy, embedded in a diffuse, HI cloud which has ...

  6. Kinematics and Host-Galaxy Properties Suggest a Nuclear Origin for Calcium-Rich Supernova Progenitors

    CERN Document Server

    Foley, Ryan J

    2015-01-01

    Calcium-rich supernovae (Ca-rich SNe) are peculiar low-luminosity SNe Ib with relatively strong Ca spectral lines at ~2 months after peak brightness. This class also has an extended projected offset distribution, with several members of the class offset from their host galaxies by 30 - 150 kpc. There is no indication of any stellar population at the SN positions. Using a sample of 13 Ca-rich SNe, we present kinematic evidence that the progenitors of Ca-rich SNe originate near the centers of their host galaxies and are kicked to the locations of the SN explosions. Specifically, SNe with small projected offsets have large line-of-sight velocity shifts as determined by nebular lines, while those with large projected offsets have no significant velocity shifts. Therefore, the velocity shifts must not be primarily the result of the SN explosion. There is an excess of SNe with blueshifted velocity shifts within two isophotal radii (5/6 SNe), indicating that the SNe are moving away from their host galaxies and redsh...

  7. SNLS: Relating the properties of type Ia supernovae to the stellar populations of their host galaxies

    Science.gov (United States)

    Sullivan, M.; Pritchet, C. J.; Le Borgne, D.; Hodsman, A.; Howell, D. A.; Astier, P.; Aubourg, E.; Balam, D.; Basa, S.; Carlberg, R.; Conley, A.; Fabbro, S.; Fouchez, D.; Guy, J.; Hook, I.; Lafoux, H.; Neill, J. D.; Pain, R.; Palanque-Delabrouille, N.; Perrett, K.; Regnault, N.; Rich, J.; Taillet, R.; Baumont, S.; Bronder, J.; Filliol, M.; Perlmutter, S.; Tao, C.; SNLS Collaboration

    2005-12-01

    We examine the rates and properties of type Ia supernovae (SNe Ia) in relation to the physical parameters defining their host galaxy stellar populations. Using a sample of 114 spectroscopically confirmed SNe Ia discovered via the Supernova Legacy Survey (SNLS) distributed over 0.2galaxies - more vigorously star-forming galaxies have a higher SN Ia rate. Further, we identify a dependence of the SN rate on both the stellar mass and the current total SFRs of the host systems, suggesting SNe Ia can be generated from both very young and old stellar populations. We further demonstrate a dependence of SN light-curve shapes on the mean age of the stellar population from which the progenitor is drawn -- older systems preferentially host faster/dimmer SNe Ia, as observed in the local Universe. Though with current sample sizes, existing analysis techniques adequately account for these trends when using SNe Ia to constrain cosmological parameters, identifying and understanding the relationship between SNe Ia and their environments will lead to a future improved cosmological candle.

  8. Distributions of quasar hosts on the galaxy main-sequence plane

    CERN Document Server

    Zhang, Zhoujian; Rieke, George H; Xia, Xiaoyang; Wang, Yikang; Sun, Bingqing; Wan, Linfeng

    2016-01-01

    The relation between star formation rates and stellar masses, i.e. the galaxy main sequence, is a useful diagnostic of galaxy evolution. We present the distributions relative to the main sequence of 55 optically-selected PG and 12 near-IR-selected 2MASS quasars at z <= 0.5. We estimate the quasar host stellar masses from Hubble Space Telescope or ground-based AO photometry, and the star formation rates through the mid-infrared aromatic features and far-IR photometry. We find that PG quasar hosts more or less follow the main sequence defined by normal star-forming galaxies while 2MASS quasar hosts lie systematically above the main sequence. PG and 2MASS quasars with higher nuclear luminosities seem to have higher specific SFRs (sSFRs), although there is a large scatter. No trends are seen between sSFRs and SMBH masses, Eddington ratios or even morphology types (ellipticals, spirals and mergers). Our results could be placed in an evolutionary scenario with quasars emerging during the transition from ULIRGs/m...

  9. Rates and Properties of Type Ia Supernovae as a Function of Mass and Star Formation in Their Host Galaxies

    Science.gov (United States)

    Sullivan, M.; Le Borgne, D.; Pritchet, C. J.; Hodsman, A.; Neill, J. D.; Howell, D. A.; Carlberg, R. G.; Astier, P.; Aubourg, E.; Balam, D.; Basa, S.; Conley, A.; Fabbro, S.; Fouchez, D.; Guy, J.; Hook, I.; Pain, R.; Palanque-Delabrouille, N.; Perrett, K.; Regnault, N.; Rich, J.; Taillet, R.; Baumont, S.; Bronder, J.; Ellis, R. S.; Filiol, M.; Lusset, V.; Perlmutter, S.; Ripoche, P.; Tao, C.

    2006-09-01

    We show that Type Ia supernovae (SNe Ia) are formed within both very young and old stellar populations, with observed rates that depend on the stellar mass and mean star formation rates (SFRs) of their host galaxies. Models in which the SN Ia rate depends solely on host galaxy stellar mass are ruled out with >99% confidence. Our analysis is based on 100 spectroscopically confirmed SNe Ia, plus 24 photometrically classified events, all from the Supernova Legacy Survey (SNLS) and distributed over 0.2host galaxies by fitting their broadband spectral energy distributions with the galaxy spectral synthesis code PÉGASE.2. We show that the SN Ia rate per unit mass is proportional to the specific SFR of the parent galaxies-more vigorously star-forming galaxies host more SNe Ia per unit stellar mass, broadly equivalent to the trend of increasing SN Ia rate in later type galaxies seen in the local universe. Following earlier suggestions for a simple ``two-component'' model approximating the SN Ia rate, we find bivariate linear dependencies of the SN Ia rate on both the stellar masses and the mean SFRs of the host systems. We find that the SN Ia rate can be well represented as the sum of 5.3+/-1.1×10-14 SNe yr-1 Msolar-1 and 3.9+/-0.7×10-4 SNe yr-1 (Msolar yr-1)-1 of star formation. We also demonstrate a dependence of distant SN Ia light-curve shapes on star formation in the host galaxy, similar to trends observed locally. Passive galaxies, with no star formation, preferentially host faster declining/dimmer SNe Ia, while brighter events are found in systems with ongoing star formation.

  10. The Sloan Digital Sky Survey Reverberation Mapping Project: Post-Starburst Signatures in Quasar Host Galaxies at z > 1

    Science.gov (United States)

    Matsuoka, Yoshiki; Strauss, Michael A.; Shen, Yue; Brandt, William N.; Greene, Jenny E.; Ho, Luis C.; Schneider, Donald P.; Sun, Mouyuan; Trump, Jonathan R.

    2015-10-01

    Quasar host galaxies are key for understanding the relation between galaxies and the supermassive black holes (SMBHs) at their centers. We present a study of 191 broad-line quasars and their host galaxies at z\\lt 1, using high signal-to-noise ratio (S/N) spectra produced by the Sloan Digital Sky Survey Reverberation Mapping project. Clear detection of stellar absorption lines allows a reliable decomposition of the observed spectra into nuclear and host components, using spectral models of quasar and stellar radiations as well as emission lines from the interstellar medium. We estimate age, mass {M}*, and velocity dispersion {σ }* of the host stars, the star formation rate (SFR), quasar luminosity, and SMBH mass {M}\\bullet , for each object. The quasars are preferentially hosted by massive galaxies with {M}*˜ {10}11 {M}⊙ characterized by stellar ages around 1 billion yr, which coincides with the transition phase of normal galaxies from the blue cloud to the red sequence. The host galaxies have relatively low SFRs and fall below the main sequence of star-forming galaxies at similar redshifts. These facts suggest that the hosts have experienced an episode of major star formation sometime in the past 1 billion yr, which was subsequently quenched or suppressed. The derived {M}\\bullet -{σ }* and {M}\\bullet -{M}* relations agree with our past measurements and are consistent with no evolution from the local universe. The present analysis demonstrates that reliable measurements of stellar properties of quasar host galaxies are possible with high-S/N fiber spectra, which will be acquired in large numbers with future powerful instruments such as the Subaru Prime Focus Spectrograph.

  11. A Burst to See

    Science.gov (United States)

    2008-04-01

    On 19 March, Nature was particularly generous and provided astronomers with the wealth of four gamma-ray bursts on the same day. But that was not all: one of them is the most luminous object ever observed in the Universe. Despite being located in a distant galaxy, billions of light years away, it was so bright that it could have been seen, for a brief while, with the unaided eye. ESO PR Photo 08a/08 ESO PR Photo 08a/08 The REM Telescope and TORTORA Camera Gamma-ray bursts (GRBs) are short flashes of energetic gamma-rays lasting from less than a second to several minutes. They release a tremendous quantity of energy in this short time making them the most powerful events since the Big Bang. It is now widely accepted that the majority of the gamma-ray bursts signal the explosion of very massive, highly evolved stars that collapse into black holes. Gamma-ray bursts, which are invisible to our eyes, are discovered by telescopes in space. After releasing their intense burst of high-energy radiation, they become detectable for a short while in the optical and in the near-infrared. This 'afterglow' fades very rapidly, making detailed analysis possible for only a few hours after the gamma-ray detection. This analysis is important in particular in order to determine the GRB's distance and, hence, intrinsic brightness. The gamma-ray burst GRB 080319B was detected by the NASA/STFC/ASI Swift satellite. "It was so bright that it almost blinded the Swift instruments for a while," says Guido Chincarini, Italian principal investigator of the mission. A bright optical counterpart was soon identified in the Boötes Constellation (the "Bear Driver" or "Herdsman"). A host of ground-based telescopes reacted promptly to study this new object in the sky. In particular, the optical emission was detected by a few wide-field cameras on telescopes that constantly monitor a large fraction of the sky, including the TORTORA camera in symbiosis with the 0.6-m REM telescope located at La Silla

  12. Ultraluminous X-ray bursts in two ultracompact companions to nearby elliptical galaxies

    CERN Document Server

    Irwin, Jimmy A; Sivakoff, Gregory R; Romanowsky, Aaron J; Lin, Dacheng; Speegle, Tyler; Prado, Ian; Mildebrath, David; Strader, Jay; Liu, Jifeng; Miller, Jon M

    2016-01-01

    An X-ray flaring source was found near the galaxy NGC 4697. Two flares were seen, separated by four years. The flux increased by a factor of 90 on a timescale of about one minute. Both flares were very brief. There is no optical counterpart at the position of the flares, but if the source was at the distance of NGC 4697, the luminosities were 10^39 erg/s. Here we report the results of a search of archival X-ray data for 70 nearby galaxies looking for similar such flares. We found two flaring sources in globular clusters or ultra-compact dwarf companions of parent elliptical galaxies. One source flared once to a peak luminosity of 9 x 10^40 erg/s, while the other flared five times to 10^40 erg/s. All of the flare rise times were <1 minute, and they then decayed over about an hour. When not flaring, the sources appear to be normal accreting neutron star or black hole X-ray binaries, but they are located in old stellar populations, unlike the magnetars, anomalous X-ray pulsars or soft gamma repeaters that hav...

  13. Using diffusion k-means for simple stellar population modeling of low S/N quasar host galaxy spectra

    Science.gov (United States)

    Mosby, Gregory; Tremonti, Christina A.; Hooper, Eric; Wolf, Marsha J.; Sheinis, Andrew; Richards, Joseph

    2016-01-01

    Quasar host galaxies (QHGs) represent a unique stage in galaxy evolution that can provide a glimpse into the relationship between an active supermassive black hole (SMBH) and its host galaxy. However, observing the hosts of high luminosity, unobscured quasars in the optical is complicated by the large ratio of quasar to host galaxy light. One strategy in optical spectroscopy is to use offset longslit observations of the host galaxy. This method allows the centers of QHGs to be analyzed apart from other regions of their host galaxies. But light from the accreting black hole's point spread function still enters the host galaxy observations, and where the contrast between the host and intervening quasar light is favorable, the host galaxy is faint, producing low signal-to-noise (S/N) data. This stymies traditional stellar population methods that might rely on high S/N features in galaxy spectra to recover key galaxy properties like its star formation history (SFH). In response to this challenge, we have developed a method of stellar population modeling using diffusion k-means (DFK) that can recover SFHs from rest frame optical data with S/N ~ 5 Å^-1. Specifically, we use DFK to cultivate a reduced stellar population basis set. This DFK basis set of four broad age bins is able to recover a range of SFHs. With an analytic description of the seeing, we can use this DFK basis set to simultaneously model the SFHs and the intervening quasar light of QHGs as well. We compare the results of this method with previous techniques using synthetic data and find that our new method has a clear advantage in recovering SFHs from QHGs. On average, the DFK basis set is just as accurate and decisively more precise. This new technique could be used to analyze other low S/N galaxy spectra like those from higher redshift or integral field spectroscopy surveys.This material is based upon work supported by the National Science Foundation under grant no. DGE -0718123 and the Advanced

  14. Clustering, host halos and environment of z$\\sim$2 galaxies as a function of their physical properties

    CERN Document Server

    Bethermin, Matthieu; Daddi, Emanuele; Gabor, Jared; Finoguenov, Alexis; McCracken, Henry; Wolk, Melody; Aussel, Herve; Strazzulo, Veronica; Floc'h, Emeric Le; Gobat, Raphael; Rodighiero, Giulia; Dickinson, Mark; Wang, Lingyu; Lutz, Dieter; Heinis, Sebastien

    2014-01-01

    Using a sample of 25683 star-forming and 2821 passive galaxies at $z\\sim2$, selected in the COSMOS field following the BzK color criterion, we study the hosting halo mass and environment of galaxies as a function of their physical properties. Spitzer and Herschel provide accurate SFR estimates for starburst galaxies. We measure the auto- and cross-correlation functions of various galaxy sub-samples and infer the properties of their hosting halos using both an HOD model and the linear bias at large scale. We find that passive and star-forming galaxies obey a similarly rising relation between the halo and stellar mass. The mean host halo mass of star forming galaxies increases with the star formation rate between 30 and 200 M$_\\odot$.yr$^{-1}$, but flattens for higher values, except if we select only main-sequence galaxies. This reflects the expected transition from a regime of secular co-evolution of the halos and the galaxies to a regime of episodic starburst. We find similar large scale biases for main-seque...

  15. Towards a comprehensive picture of powerful quasars, their host galaxies and quasar winds at z ~ 0.5

    CERN Document Server

    Wylezalek, Dominika; Liu, Guilin; Obied, Georges

    2016-01-01

    Luminous type-2 quasars in which the glow from the central black hole is obscured by dust are ideal targets for studying their host galaxies and the quasars' effect on galaxy evolution. Such feedback appears ubiquitous in luminous obscured quasars where high velocity ionized nebulae have been found. We present rest-frame yellow-band (~5000 Angstroms) observations using the Hubble Space Telescope for a sample of 20 luminous quasar host galaxies at 0.2 < z < 0.6 selected from the Sloan Digital Sky Survey. For the first time, we combine host galaxy observations with geometric measurements of quasar illumination using blue-band HST observations and [OIII] integral field unit observations probing the quasar winds. The HST images reveal bright merger signatures in about half the galaxies; a significantly higher fraction than in comparison inactive ellipticals. We show that the host galaxies are primarily bulge-dominated, with masses close to M*, but belong to < 30% of elliptical galaxies that are highly st...

  16. Rates and properties of type Ia supernovae as a function of mass and star-formation in their host galaxies

    CERN Document Server

    Sullivan, M; Pritchet, C J; Hodsman, A; Neill, J D; Howell, D A; Carlberg, R G; Astier, Pierre; Aubourg, E; Balam, D; Basa, S; Conley, A; Fabbro, S; Fouchez, D; Guy, J; Hook, I; Pain, R; Palanque-Delabrouille, Nathalie; Perrett, K; Regnault, N; Rich, J; Taillet, R; Baumont, S; Bronder, J; Ellis, Richard S; Filiol, M; Lusset, V; Perlmutter, S; Ripoche, P; Tao, C

    2006-01-01

    (ABRIDGED) We show that Type Ia supernovae (SNe Ia) are formed within both very young and old stellar populations, with observed rates that depend on the stellar mass and mean star-formation rates (SFRs) of their host galaxies. Models where the SN Ia rate depends solely on host galaxy stellar mass are ruled out with 99% confidence. Our analysis is based on 100 spectroscopically-confirmed SNe Ia, plus 24 photometrically-classified events, all from the Supernova Legacy Survey (SNLS) and distributed over 0.2host galaxies by fitting their broad-band spectral energy distributions with the galaxy spectral synthesis code, PEGASE.2. We show that the SN Ia rate per unit mass is proportional to the specific SFR of the parent galaxies -- more vigorously star-forming galaxies host more SNe Ia per unit stellar mass, broadly equivalent to the trend of increasing SN Ia rate in later-type galaxies seen in the local universe. Followi...

  17. Nuclear Star Clusters and the Stellar Spheroids of their Host Galaxies

    CERN Document Server

    Leigh, Nathan; Knigge, Christian

    2012-01-01

    (Abridged) We combine published photometry for the nuclear star clusters (NSCs) and stellar spheroids of 51 low-mass, early-type galaxies in the Virgo cluster with empirical mass-to-light ratios, in order to complement previous studies that explore the dependence of NSC masses (M_{NSC}) on various properties of their host galaxies. We confirm a roughly linear relationship between M_{NSC} and luminous host spheroid mass (M_{Sph}), albeit with considerable scatter (0.57 dex). We estimate velocity dispersions from the virial theorem, assuming all galaxies in our sample share a common DM fraction and are dynamically relaxed. We then find that M_{NSC} \\sim \\sigma^{2.73\\pm 0.29}, with a slightly reduced scatter of 0.54 dex. This confirms recent results that the shape of the M_{CMO} - \\sigma relation is different for NSCs and super-massive black holes (SMBHs). We discuss this result in the context of the generalized idea of "central massive objects" (CMOs). In order to assess which physical parameters drive the obse...

  18. On the dependence of the type Ia SNe luminosities on the metallicity of their host galaxies

    CERN Document Server

    Moreno-Raya, Manuel E; López-Sánchez, Ángel R; Galbany, Lluís; Vílchez, José; Carnero, Aurelio; Domínguez, Inma

    2015-01-01

    The metallicity of the progenitor system producing a type Ia supernova (SN Ia) could play a role in its maximum luminosity, as suggested by theoretical predictions. We present an observational study to investigate if such a relationship there exists. Using the 4.2m WHT we have obtained intermediate-resolution spectroscopy data of a sample of 28 local galaxies hosting SNe Ia, for which distances have been derived using methods independent to those based on the own SN Ia parameters. From the emission lines observed in their optical spectrum, we derived the gas-phase oxygen abundance in the region where each SN Ia exploded. Our data show a trend, with a 80% of chance not to be due to random fluctuation, between SNe Ia absolute magnitudes and the oxygen abundances of the host galaxies, in the sense that luminosities tend to be higher for galaxies with lower metallicities. This result seems like to be in agreement with both the theoretically expected behavior, and with other observational results. This dependence ...

  19. A metallicity study of 1987A-like supernova host galaxies

    CERN Document Server

    Taddia, F; Razza, A; Gafton, E; Pastorello, A; Fransson, C; Stritzinger, M D; Leloudas, G; Ergon, M

    2013-01-01

    The origin of the blue supergiant (BSG) progenitor of Supernova (SN) 1987A has long been debated, along with the role that its sub-solar metallicity played. We now have a sample of 1987A-like SNe that arise from the core collapse (CC) of BSGs. The metallicity of the explosion sites of the known BSG SNe is investigated, as well as their association to star-forming regions. Both indirect and direct metallicity measurements of 13 BSG SN host galaxies are presented, and compared to those of other CC SN types. Indirect measurements are based on the known luminosity-metallicity relation and on published metallicity gradients of spiral galaxies. To provide direct estimates based on strong line diagnostics, we obtained spectra of each BSG SN host both at the SN explosion site and at the positions of other HII regions. Continuum-subtracted Ha images allowed us to quantify the association between BSG SNe and star-forming regions. BSG SNe explode either in low-luminosity galaxies or at large distances from the nuclei of...

  20. The connection between the host halo and the satellite galaxies of the Milky Way

    CERN Document Server

    Lu, Yu; Mao, Yao-Yuan; Tonnesen, Stephanie; Peter, Annika H G; Wetzel, Andrew R; Boylan-Kolchin, Michael; Wechsler, Risa H

    2016-01-01

    Many properties of the Milky Way's dark matter halo, including its mass assembly history, concentration, and subhalo population, remain poorly constrained. We explore the connection between these properties of the Milky Way and its satellite galaxy population, especially the implication of the presence of the Magellanic Clouds for the properties of the Milky Way halo. Using a suite of high-resolution N-body simulations of Milky Way-mass halos, we find that the presence of Magellanic Cloud-like satellites strongly correlates with the assembly history, concentration, and subhalo population of the host halo, such that Milky Way-mass systems with Magellanic Clouds have lower concentration, more rapid recent accretion, and more massive subhalos than typical halos of the same mass. Using a flexible semi-analytic galaxy formation model that is tuned to reproduce the stellar mass function of the classical dwarf galaxies of the Milky Way with Markov-Chain Monte-Carlo, we show that adopting host halos with different ma...

  1. ON THE DEPENDENCE OF TYPE Ia SNe LUMINOSITIES ON THE METALLICITY OF THEIR HOST GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Raya, Manuel E.; Mollá, Mercedes [Dpto.de Investigación Básica, C.I.E.M.A.T., Avda. Complutense 40, E-28040 Madrid (Spain); López-Sánchez, Ángel R. [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Galbany, Lluís [Millennium Institute of Astrophysics MAS, Nuncio Monseñor Sótero Sanz 100, Providencia, 7500011 Santiago (Chile); Vílchez, José Manuel [Instituto de Astrofísica de Andalucía (CSIC), Apdo. 3004, E-18080 Granada (Spain); Rosell, Aurelio Carnero [Observatório Nacional, and LIneA Laboratório Interinstitucional de e-Astronomia, Rua Gal. José Cristino 77 Rio de Janeiro, RJ 20921-400 (Brazil); Domínguez, Inmaculada, E-mail: manuelemilio.moreno@ciemat.es [Departamento de Física Teórica y del Cosmos, Universidad de Granada, E-18071 Granada (Spain)

    2016-02-10

    The metallicity of the progenitor system producing a type Ia supernova (SN Ia) could play a role in its maximum luminosity, as suggested by theoretical predictions. We present an observational study to investigate if such a relationship exists. Using the 4.2 m William Herschel Telescope (WHT) we have obtained intermediate-resolution spectroscopy data of a sample of 28 local galaxies hosting SNe Ia, for which distances have been derived using methods independent of those based on SN Ia parameters. From the emission lines observed in their optical spectra, we derived the gas-phase oxygen abundance in the region where each SN Ia exploded. Our data show a trend, with an 80% of chance not being due to random fluctuation, between SNe Ia absolute magnitudes and the oxygen abundances of the host galaxies, in the sense that luminosities tend to be higher for galaxies with lower metallicities. This result seems likely to be in agreement with both the theoretically expected behavior and with other observational results. This dependence M{sub B}–Z might induce systematic errors when it is not considered when deriving SNe Ia luminosities and then using them to derive cosmological distances.

  2. A Glimpse at Quasar Host Galaxy Far-UV Emission, Using DLAs as Natural Coronagraphs

    CERN Document Server

    Cai, Zheng; Noterdaeme, Pasquier; Wang, Ran; McGreer, Ian; Carithers, Bill; Bian, Fuyan; Escude, Jordi Miralda; Finley, Hayley; Paris, Isabelle; Schneider, Donald P; Zakamska, Nadia L; Ge, Jian; Petitjean, Patrick; Slosar, Anze

    2014-01-01

    In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density Damped Lyman Alpha (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. We have stacked the spectra of $\\sim$2,000 DLA systems (N_HI>10^{20.6} cm^{-2}) with a median absorption redshift = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the SDSS fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation fro...

  3. The Role of Radiation Pressure in the Narrow Line Regions of Seyfert Host Galaxies

    CERN Document Server

    Davies, Rebecca L; Kewley, Lisa J; Groves, Brent; Sutherland, Ralph; Hampton, Elise J; Shastri, Prajval; Kharb, Preeti; Bhatt, Harish; Scharwächter, Julia; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; James, Bethan; Juneau, Stéphanie; Srivastava, Shweta

    2016-01-01

    We investigate the relative significance of radiation pressure and gas pressure in the extended narrow line regions (ENLRs) of four Seyfert galaxies from the integral field Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). We demonstrate that there exist two distinct types of starburst-AGN mixing curves on standard emission line diagnostic diagrams which reflect the balance between gas pressure and radiation pressure in the ENLR. In two of the galaxies the ENLR is radiation pressure dominated throughout and the ionization parameter remains constant (log U ~ 0). In the other two galaxies radiation pressure is initially important, but gas pressure becomes dominant as the ionization parameter in the ENLR decreases from log U ~ 0 to -3.4 <= log U <= -3.2. Where radiation pressure is dominant, the AGN regulates the density of the interstellar medium on kpc scales and may therefore have a direct impact on star formation activity and/or the incidence of outflows in the host galaxy to scales fa...

  4. The Role of Radiation Pressure in the Narrow Line Regions of Seyfert Host Galaxies

    Science.gov (United States)

    Davies, Rebecca L.; Dopita, Michael A.; Kewley, Lisa; Groves, Brent; Sutherland, Ralph; Hampton, Elise J.; Shastri, Prajval; Kharb, Preeti; Bhatt, Harish; Scharwächter, Julia; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; James, Bethan; Juneau, Stéphanie; Srivastava, Shweta

    2016-06-01

    We investigate the relative significance of radiation pressure and gas pressure in the extended narrow line regions (ENLRs) of four Seyfert galaxies from the integral field Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). We demonstrate that there exist two distinct types of starburst-active galactic nucleus (AGN) mixing curves on standard emission line diagnostic diagrams, which reflect the balance between gas pressure and radiation pressure in the ENLR. In two of the galaxies the ENLR is radiation pressure dominated throughout and the ionization parameter remains constant (log U ∼ 0). In the other two galaxies radiation pressure is initially important, but gas pressure becomes dominant as the ionization parameter in the ENLR decreases from log U ∼ 0 to ‑3.2 ≲ log U ≲ ‑3.4. Where radiation pressure is dominant, the AGN regulates the density of the interstellar medium on kiloparsec scales and may therefore have a direct impact on star formation activity and/or the incidence of outflows in the host galaxy to scales far beyond the zone of influence of the black hole. We find that both radiation pressure dominated and gas pressure dominated ENLRs are dynamically active with evidence for outflows, indicating that radiation pressure may be an important source of AGN feedback even when it is not dominant over the entire ENLR.

  5. Supermassive Black Holes and Their Host Galaxies - I. Bulge luminosities from dedicated near-infrared data

    CERN Document Server

    Läsker, Ronald; van de Ven, Glenn

    2013-01-01

    In an effort to secure, refine and supplement the relation between central Supermassive Black Hole masses (Mbh), and the bulge luminosities of their host galaxies, (Lbul), we obtained deep, high spatial resolution K-band images of 35 nearby galaxies with securely measured Mbh, using the wide-field WIRCam imager at the Canada-France-Hawaii-Telescope (CFHT). A dedicated data reduction and sky subtraction strategy was adopted to estimate the brightness and structure of the sky, a critical step when tracing the light distribution of extended objects in the near-infrared. From the final image product, bulge and total magnitudes were extracted via two-dimensional profile fitting. As a first order approximation, all galaxies were modeled using a simple Sersic-bulge + exponential-disk decomposition. However, we found that such models did not adequately describe the structure that we observe in a large fraction of our sample galaxies which often include cores, bars, nuclei, inner disks, spiral arms, rings and envelope...

  6. The Molecular Gas Content of z<0.1 Radio Galaxies: Linking the AGN Accretion Mode to Host Galaxy Properties

    CERN Document Server

    Smolcic, V

    2011-01-01

    One of the main achievements in modern cosmology is the so-called `unified model', which successfully describes most classes of active galactic nuclei (AGN) within a single physical scheme. However, there is a particular class of radio-luminous AGN that presently cannot be explained within this framework -- the `low-excitation' radio AGN (LERAGN). Recently, a scenario has been put forward which predicts that LERAGN, and their regular `high-excitation' radio AGN (HERAGN) counterparts represent different (red sequence vs. green valley) phases of galaxy evolution. These different evolutionary states are also expected to be reflected in their host galaxy properties, in particular their cold gas content. To test this, here we present CO(1-0) observations toward a sample of 11 of these systems conducted with CARMA. Combining our observations with literature data, we derive molecular gas masses (or upper limits) for a complete, representative, sample of 21 z<0.1 radio AGN. Our results yield that HERAGN on average...

  7. SALT spectroscopic observations of galaxy clusters detected by ACT and a Type II quasar hosted by a brightest cluster galaxy

    CERN Document Server

    Kirk, Brian; Cress, Catherine; Crawford, Steven M; Hughes, John P; Battaglia, Nicholas; Bond, J Richard; Burke, Claire; Gralla, Megan B; Hajian, Amir; Hasselfield, Matthew; Hincks, Adam D; Infante, Leopoldo; Kosowsky, Arthur; Marriage, Tobias A; Menanteau, Felipe; Moodley, Kavilan; Niemack, Michael D; Sievers, Jonathan L; Sifón, Cristóbal; Wilson, Susan; Wollack, Edward J; Zunckel, Caroline

    2014-01-01

    We present Southern African Large Telescope (SALT) follow-up observations of seven massive clusters detected by the Atacama Cosmology Telescope (ACT) on the celestial equator using the Sunyaev-Zel'dovich (SZ) effect. We conducted multi-object spectroscopic observations with the Robert Stobie Spectrograph in order to measure galaxy redshifts in each cluster field, determine the cluster line-of-sight velocity dispersions, and infer the cluster dynamical masses. We find that the clusters, which span the redshift range 0.3 < z < 0.55, range in mass from (5 -- 20) x 10$^{14}$ solar masses (M200c). Their masses, given their SZ signals, are similar to those of southern hemisphere ACT clusters previously observed using Gemini and the VLT. We note that the brightest cluster galaxy in one of the systems studied, ACT-CL J0320.4+0032 at z = 0.38, hosts a Type II quasar. To our knowledge, this is only the third such system discovered, and therefore may be a rare example of a very massive halo in which quasar-mode fe...

  8. High Metallicity LGRB Hosts

    CERN Document Server

    Graham, J F; Levesque, E M; Kewley, L J; Tanvir, N R; Levan, A J; Patel, S K; Misra, K; Huang, K -H; Reichart, D E; Nysewander, M; Schady, P

    2015-01-01

    We present our imaging and spectroscopic observations of the host galaxies of two dark long bursts with anomalously high metallicities, LGRB 051022 and LGRB 020819B, which in conjunction with another LGRB event with an optical afterglow comprise the three LGRBs with high metallicity host galaxies in the Graham & Fruchter (2013) sample. In Graham & Fruchter (2013), we showed that LGRBs exhibit a strong and apparently intrinsic preference for low metallicity environments (12+log(O/H) < 8.4 in the KK04 scale) in spite of these three cases with abundances of about solar and above. These exceptions however are consistent with the general star-forming galaxy population of comparable brightness & redshift. This is surprising: even among a preselected sample of high metallicity LGRBs, were the metal aversion to remain in effect for these objects, we would expect their metallicity to still be lower than the typical metallicity for the galaxies at that luminosity and redshift. Therefore we deduce that it...

  9. A tale of two feedbacks: Star formation in the host galaxies of radio AGNs

    International Nuclear Information System (INIS)

    Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star formation activity in these galaxies. Radio jets have long been argued to be an ideal mechanism that allows active galactic nuclei (AGNs) to interact with their host galaxies and affect star formation. We use a sample of radio sources in the North Ecliptic Pole (NEP) field to study the nature of this putative link, by means of spectral energy distribution (SED) fitting. We employ the excellent spectral coverage of the AKARI infrared space telescope and the rich ancillary data available in the NEP to build SEDs extending from UV to far-IR wavelengths. We find a significant AGN component in our sample of relatively faint radio sources (host galaxy, independent of the radio luminosity. In contrast, for narrow redshift and AGN luminosity ranges, we find that increasing radio luminosity leads to a decrease in the specific star formation rate. The most radio-loud AGNs are found to lie on the main sequence of star formation for their respective redshifts. For the first time, we potentially see such a two-sided feedback process in the same sample. We discuss the possible suppression of star formation, but not total quenching, in systems with strong radio jets, that supports the maintenance nature of feedback from radio AGN jets.

  10. A tale of two feedbacks: Star formation in the host galaxies of radio AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Karouzos, Marios; Im, Myungshin; Jeon, Yiseul; Kim, Ji Hoon [CEOU-Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul (Korea, Republic of); Trichas, Markos [Airbus Defence and Space, Gunnels Wood Road, Stevenage SG1 2AS (United Kingdom); Goto, Tomo [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Malkan, Matt [Division of Astronomy and Astrophysics, 3-714 UCLA, CA 90095-1547 (United States); Ruiz, Angel [Inter-University Centre for Astronomy and Astrophysics (IUCAA), Post Bag 4, Ganeshkhind, 411 007 Pune (India); Lee, Hyung Mok; Kim, Seong Jin [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul (Korea, Republic of); Oi, Nagisa; Matsuhara, Hideo; Takagi, Toshinobu; Murata, K.; Wada, Takehiko; Wada, Kensuke [Institute of Space and Astronautical Science, JAXA, Yoshino-dai 3-1-1, Sagamihara, Kanagawa 229-8510 (Japan); Shim, Hyunjin [Department of Earth Science Education, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hanami, Hitoshi [Physics Section, Faculty of Humanities, Iwate University, Ueda 3 chome, 18-34 Morioka, Morioka, Iwate 020-8550 (Japan); Serjeant, Stephen; White, Glenn J., E-mail: mkarouzos@astro.snu.ac.kr [Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes (United Kingdom); and others

    2014-04-01

    Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star formation activity in these galaxies. Radio jets have long been argued to be an ideal mechanism that allows active galactic nuclei (AGNs) to interact with their host galaxies and affect star formation. We use a sample of radio sources in the North Ecliptic Pole (NEP) field to study the nature of this putative link, by means of spectral energy distribution (SED) fitting. We employ the excellent spectral coverage of the AKARI infrared space telescope and the rich ancillary data available in the NEP to build SEDs extending from UV to far-IR wavelengths. We find a significant AGN component in our sample of relatively faint radio sources (host galaxy, independent of the radio luminosity. In contrast, for narrow redshift and AGN luminosity ranges, we find that increasing radio luminosity leads to a decrease in the specific star formation rate. The most radio-loud AGNs are found to lie on the main sequence of star formation for their respective redshifts. For the first time, we potentially see such a two-sided feedback process in the same sample. We discuss the possible suppression of star formation, but not total quenching, in systems with strong radio jets, that supports the maintenance nature of feedback from radio AGN jets.

  11. A Spectroscopic Study of Type Ibc Supernova Host Galaxies from Untargeted Surveys

    CERN Document Server

    Sanders, Nathan E; Levesque, Emily M; Foley, Ryan J; Chornock, Ryan; Milisavljevic, Dan; Margutti, Raffaella; Berger, Edo; Drout, Maria R; Czekala, Ian; Dittmann, Jason A

    2012-01-01

    We present the largest spectroscopic study of the host environments of Type Ibc supernovae (SN Ibc) discovered exclusively by untargeted SN searches. Past studies of SN Ibc host environments have been biased towards high-mass, high-metallicity galaxies by focusing on SNe discovered in galaxy-targeted SN searches. Our new observations more than double the total number of spectroscopic stellar population age and metallicity measurements published for untargeted SN Ibc host environments, and extend to a median redshift about twice as large as previous statistical studies (z = 0.04). For the 12 SNe Ib and 21 SNe Ic in our metallicity sample, we find median metallicities of log(O/H)+12 = 8.48 and 8.61, respectively, but determine that the discrepancy in the full distribution of metallicities is not statistically significant. This median difference would correspond to only a small difference in the mass loss via metal-line driven winds (<30%), suggesting this does not play the dominant role in distinguishing SN ...

  12. THE AFTERGLOW AND ULIRG HOST GALAXY OF THE DARK SHORT GRB 120804A

    Energy Technology Data Exchange (ETDEWEB)

    Berger, E.; Zauderer, B. A.; Margutti, R.; Laskar, T.; Fong, W.; Chornock, R.; Dupuy, T. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Levan, A.; Tunnicliffe, R. L. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Mangano, V. [INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo (Italy); Fox, D. B. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Menten, K. M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Hjorth, J. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Roth, K. [Gemini Observatory, 670 North Aohoku Place, Hilo, HI 96720 (United States)

    2013-03-10

    We present the optical discovery and subarcsecond optical and X-ray localization of the afterglow of the short GRB 120804A, as well as optical, near-IR, and radio detections of its host galaxy. X-ray observations with Swift/XRT, Chandra, and XMM-Newton extending to {delta}t Almost-Equal-To 19 days reveal a single power-law decline. The optical afterglow is faint, and comparison to the X-ray flux indicates that GRB 120804A is ''dark'', with a rest-frame extinction of A {sup host}{sub V} Almost-Equal-To 2.5 mag (at z = 1.3). The intrinsic neutral hydrogen column density inferred from the X-ray spectrum, N{sub H,{sub int}}(z = 1.3) Almost-Equal-To 2 Multiplication-Sign 10{sup 22} cm{sup -2}, is commensurate with the large extinction. The host galaxy exhibits red optical/near-IR colors. Equally important, JVLA observations at Almost-Equal-To 0.9-11 days reveal a constant flux density of F{sub {nu}}(5.8 GHz) = 35 {+-} 4 {mu}Jy and an optically thin spectrum, unprecedented for GRB afterglows, but suggestive instead of emission from the host galaxy. The optical/near-IR and radio fluxes are well fit with the scaled spectral energy distribution of the local ultraluminous infrared galaxy (ULIRG) Arp 220 at z Almost-Equal-To 1.3, with a resulting star formation rate of x Almost-Equal-To 300 M{sub Sun} yr{sup -1}. The inferred extinction and small projected offset (2.2 {+-} 1.2 kpc) are also consistent with the ULIRG scenario, as is the presence of a companion galaxy at the same redshift and with a separation of about 11 kpc. The limits on radio afterglow emission, in conjunction with the observed X-ray and optical emission, require a circumburst density of n {approx} 10{sup -3} cm{sup -3}, an isotropic-equivalent energy scale of E{sub {gamma},{sub iso}} Almost-Equal-To E{sub K,{sub iso}} Almost-Equal-To 7 Multiplication-Sign 10{sup 51} erg, and a jet opening angle of {theta}{sub j} {approx}> 11 Degree-Sign . The expected fraction of luminous infrared

  13. THE CLUSTERING OF ALFALFA GALAXIES: DEPENDENCE ON H I MASS, RELATIONSHIP WITH OPTICAL SAMPLES, AND CLUES OF HOST HALO PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Papastergis, Emmanouil; Giovanelli, Riccardo; Haynes, Martha P.; Jones, Michael G. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Rodríguez-Puebla, Aldo, E-mail: papastergis@astro.cornell.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu, E-mail: jonesmg@astro.cornell.edu, E-mail: apuebla@astro.unam.mx [Instituto de Astronomía, Universidad Nacional Autónoma de México, A. P. 70-264, 04510 México, D.F. (Mexico)

    2013-10-10

    We use a sample of ≈6000 galaxies detected by the Arecibo Legacy Fast ALFA (ALFALFA) 21 cm survey to measure the clustering properties of H I-selected galaxies. We find no convincing evidence for a dependence of clustering on galactic atomic hydrogen (H I) mass, over the range M{sub H{sub I}} ≈ 10{sup 8.5}-10{sup 10.5} M{sub ☉}. We show that previously reported results of weaker clustering for low H I mass galaxies are probably due to finite-volume effects. In addition, we compare the clustering of ALFALFA galaxies with optically selected samples drawn from the Sloan Digital Sky Survey (SDSS). We find that H I-selected galaxies cluster more weakly than even relatively optically faint galaxies, when no color selection is applied. Conversely, when SDSS galaxies are split based on their color, we find that the correlation function of blue optical galaxies is practically indistinguishable from that of H I-selected galaxies. At the same time, SDSS galaxies with red colors are found to cluster significantly more than H I-selected galaxies, a fact that is evident in both the projected as well as the full two-dimensional correlation function. A cross-correlation analysis further reveals that gas-rich galaxies 'avoid' being located within ≈3 Mpc of optical galaxies with red colors. Next, we consider the clustering properties of halo samples selected from the Bolshoi ΛCDM simulation. A comparison with the clustering of ALFALFA galaxies suggests that galactic H I mass is not tightly related to host halo mass and that a sizable fraction of subhalos do not host H I galaxies. Lastly, we find that we can recover fairly well the correlation function of H I galaxies by just excluding halos with low spin parameter. This finding lends support to the hypothesis that halo spin plays a key role in determining the gas content of galaxies.

  14. Are LGRBs biased tracers of star formation? Clues from the host galaxies of the Swift/BAT6 complete sample of bright LGRBs. II: star formation rates and metallicities at z < 1

    CERN Document Server

    Japelj, J; Salvaterra, R; D'Avanzo, P; Mannucci, F; Fernandez-Soto, A; Boissier, S; Hunt, L K; Atek, H; Rodríguez-Muñoz, L; Scodeggio, M; Cristiani, S; Floc'h, E Le; Flores, H; Gallego, J; Ghirlanda, G; Gomboc, A; Hammer, F; Perley, D A; Pescalli, A; Petitjean, P; Puech, M; Rafelski, M; Tagliaferri, G

    2016-01-01

    Long gamma-ray bursts (LGRBs) are associated with the deaths of massive stars and could thus be a potentially powerful tool to trace cosmic star formation. However, especially at low redshifts (z < 1.5) LGRBs seem to prefer particular types of environment. Our aim is to study the host galaxies of a complete sample of bright LGRBs to investigate the impact of the environment on GRB formation. We study host galaxy spectra of the Swift/BAT6 complete sample of 14 z < 1 bright LGRBs. We use the detected nebular emission lines to measure the dust extinction, star formation rate (SFR) and nebular metallicity (Z) of the hosts and supplement the data set with previously measured stellar masses M$_{\\star}$. The distributions of the obtained properties and their interrelations (e.g. mass-metallicity and SFR-M$_{\\star}$ relations) are compared to samples of field star-forming galaxies.We find that LGRB hosts at z < 1 have on average lower SFRs than if they were direct star-formation tracers. By directly comparin...

  15. A Compact Group of Galaxies at z = 2.48 Hosting an AGN-driven Outflow

    Science.gov (United States)

    Shih, Hsin-Yi; Stockton, Alan

    2015-12-01

    We present observations of a remarkable compact group of galaxies at z = 2.48. Four galaxies, all within 40 kpc of each other, surround a powerful high-redshift radio source. This group comprises two compact red passive galaxies and a pair of merging galaxies. One of the red galaxies, with an apparent stellar mass of 3.6 × 1011M⊙ and an effective radius of 470 pc, is one of the most extreme examples of a massive quiescent compact galaxy found so far. One of the pair of merging galaxies hosts the active galactic nucleus (AGN) producing the large powerful radio structure. The merger is massive and enriched, consistent with the mass-metallicity relation expected at this redshift. Close to the merging nuclei, the emission lines exhibit broad and asymmetric profiles that suggest outflows powered either by a very young expanding radio jet or by AGN radiation. At ≳50 kpc from the system, we found a fainter extended-emission region that may be a part of a radio-jet-driven outflow. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The work is also based, in part, on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  16. The short gamma-ray burst revolution

    International Nuclear Information System (INIS)

    Swift, a dedicated gamma-ray burst (GRB) satellite with ultrarapid slewing capability, and a suite of ground-based (ESO) telescopes have recently achieved a major breakthrough: detecting the first afterglows of short-duration GRBs. The faintness of these afterglows and the diversity of old and young host galaxies lend support to the emerging 'standard model', in which they are created during the merging of two compact objects. However, the afterglow light-curve properties and possible high-redshift origin of some short bursts suggests that more than one progenitor type may be involved. (orig.)

  17. The Black Hole-Bulge Relationship in Luminous Broad-Line Active Galactic Nuclei and Host Galaxies

    CERN Document Server

    Shen, J; Schneider, D P; Hall, P B

    2007-01-01

    We have measured the stellar velocity dispersions (\\sigma_*) and estimated the central black hole (BH) masses for over 900 broad-line active galactic nuclei (AGNs) observed with the Sloan Digital Sky Survey. The sample includes objects which have redshifts up to z=0.452, high quality spectra, and host galaxy spectra dominated by an early-type (bulge) component. The AGN and host galaxy spectral components were decomposed using an eigenspectrum technique. The BH masses (M_BH) were estimated from the AGN broad-line widths, and the velocity dispersions were measured from the stellar absorption spectra of the host galaxies. The range of black hole masses covered by the sample is approximately 10^6 < M_BH < 10^9 M_Sun. The host galaxy luminosity-velocity dispersion relationship follows the well-known Faber-Jackson relation for early-type galaxies, with a power-law slope 4.33+-0.21. The estimated BH masses are correlated with both the host luminosities (L_{H}) and the stellar velocity dispersions (\\sigma_*), s...

  18. A Glimpse at Quasar Host Galaxy Far-UV Emission Using Damped Lyα's as Natural Coronagraphs

    Science.gov (United States)

    Cai, Zheng; Fan, Xiaohui; Noterdaeme, Pasquier; Wang, Ran; McGreer, Ian; Carithers, Bill; Bian, Fuyan; Miralda-Escudé, Jordi; Finley, Hayley; Pâris, Isabelle; Schneider, Donald P.; Zakamska, Nadia L.; Ge, Jian; Petitjean, Patrick; Slosar, Anze

    2014-10-01

    In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density damped Lyα (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. We have stacked the spectra of ~2000 DLA systems (N H I > 1020.6 cm-2) with a median absorption redshift langzrang = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the Sloan Digital Sky Survey fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation from the background quasar host galaxies (with medium redshift langzrang = 3.1) that is not blocked by the intervening DLA. Assuming that all of the detected flux originates from quasar hosts, for the highest quasar luminosity bin (langLrang = 2.5 × 1013 L ⊙), the host galaxy has an FUV intensity of 1.5 ± 0.2 × 1040 erg s-1 Å-1 this corresponds to an unobscured UV star formation rate of 9 M ⊙ yr-1.

  19. Driving the growth of the earliest supermassive black holes with major mergers of host galaxies

    International Nuclear Information System (INIS)

    The formation mechanism of supermassive black holes (SMBHs) in general, and of ∼109 m⊙ SMBHs observed as luminous quasars at redshifts z>6 in particular, remains an open fundamental question. The presence of such massive BHs at such early times, when the Universe was less than a billion years old, implies that they grew via either super-Eddington accretion, or nearly uninterrupted gas accretion near the Eddington limit; the latter, at first glance, is at odds with empirical trends at lower redshifts, where quasar episodes associated with rapid BH growth are rare and brief. In this work, I examine whether and to what extent the growth of the z>6 quasar SMBHs can be explained within the standard quasar paradigm, in which major mergers of host galaxies trigger episodes of rapid gas accretion below or near the Eddington limit. Using a suite of Monte Carlo merger tree simulations of the assembly histories of 40 likely z>6 quasar host halos, I investigate (i) their growth and major merger rates out to z∼40, and (ii) how long the feeding episodes induced by host mergers must last in order to explain the observed z≳6 quasar population without super-Eddington accretion. The halo major merger rate scales roughly as ∝ (1+z)5/2, consistent with cosmological simulations at lower redshifts, with quasar hosts typically experiencing ≳10 major mergers between 15>z>6 (≈650 Myr), compared to ∼1 for typical massive galaxies at 3>z>0 (≈11 Gyr). The high rate of major mergers allows for nearly continuous SMBH growth if (for example) a merger triggers feeding for a duration comparable to the halo dynamical time. These findings suggest that the growth mechanisms of the earliest quasar SMBHs need not have been drastically different from their counterparts at lower redshifts. (paper)

  20. Can supermassive black holes influence the evolution of their host galaxies?

    Science.gov (United States)

    Tombesi, F.; Cappi, M.; Reeves, J.; Braito, V.; Veilleux, S.; Reynolds, C.; Lobban, A.

    2016-06-01

    Powerful winds driven by active galactic nuclei (AGN) are often invoked to play a fundamental role in the evolution of both supermassive black holes (SMBHs) and their host galaxies, quenching star formation and explaining the tight SMBH-galaxy relations. A strong support of this "quasar mode" feedback came from the recent X-ray observation of a mildly relativistic accretion disk wind in an ultraluminous infrared galaxy and its connection with a large-scale molecular outflow observed in the IR with Herschel, suggesting a direct link between the SMBH and the gas out of which stars form. Spectroscopic observations, especially in the X-ray band, suggest that such accretion disk winds may be common in local AGN and quasars. However, their origin and characteristics are still not fully understood. Detailed theoretical models and simulations focused on radiation, magnetohydrodynamic (MHD) or a combination of these two processes, to investigate the possible acceleration mechanisms and dynamics of these winds. XMM-Newton provided a fundamental contribution to these studies and it will still provide the highest effective area in the critical Fe K band of the spectrum until the launch of Athena. Very important improvements are expected from the high energy resolution of the Hitomi X-ray Observatory.

  1. Deep Ly alpha imaging of two z=2.04 GRB host galaxy fields

    DEFF Research Database (Denmark)

    Fynbo, J.P.U.; Møller, Per; Thomsen, Bente;

    2002-01-01

    - I colour than the eastern component, suggesting the presence of at least some dust. We do not detect the host galaxy of GRB 000301C in neither Lyalpha emission nor in U and I broad-band images. The strongest limit comes from combining the narrow and U-band imaging where we infer a limit of U...... the spectral slopes (f(lambda) proportional to lambda(beta)) of the two components to beta = 2.4 +/- 0.3 (east)and -1.4 +/- 0.2 (west). This implies that both components contain at most small amounts of dust, consistent with the observed strong Lyalpha emission. The western component has a slightly redder V......(AB) > 27.7 (2sigma limit per arcsec(2)). The upper limits on the Lyalpha flux implies a Lyalpha equivalent width upper limit of similar to150 Angstrom. We find eleven and eight other galaxies with excess emission in the narrow filter in the fields of GRB 000301C and GRB 000926 respectively. These galaxies...

  2. Witnessing the transformation of a quasar host galaxy at z=1.6

    CERN Document Server

    Humphrey, A; Gomes, J M; Papaderos, P; Villar-Martín, M; Filho, M E; Emonts, B H C; Aretxaga, I; Binette, L; Flaquer, B Ocaña; Lagos, P; Torrealba, J

    2015-01-01

    A significant minority of high redshift radio galaxy (HzRG) candidates show extremely red broad band colours and remain undetected in emission lines after optical `discovery' spectroscopy. In this paper we present deep GTC optical imaging and spectroscopy of one such radio galaxy, 5C 7.245, with the aim of better understanding the nature of these enigmatic objects. Our g-band image shows no significant emission coincident with the stellar emission of the host galaxy, but does reveal faint emission offset by ~3" (26 kpc) therefrom along a similar position angle to that of the radio jets, reminiscent of the `alignment effect' often seen in the optically luminous HzRGs. This offset g-band source is also detected in several UV emission lines, giving it a redshift of 1.609, with emission line flux ratios inconsistent with photoionization by young stars or an AGN, but consistent with ionization by fast shocks. Based on its unusual gas geometry, we argue that in 5C 7.245 we are witnessing a rare (or rarely observed)...

  3. The Impact of Dust in Host Galaxies on Quasar Luminosity Functions

    CERN Document Server

    Shirakata, H; Enoki, M; Nagashima, M; Kobayashi, M A R; Ishiyama, T; Makiya, R

    2014-01-01

    We have investigated effects of dust attenuation on quasar luminosity functions using a semi-analytic galaxy formation model combined with a large cosmological N-body simulation. We estimate the dust attenuation of quasars self-consistently with that of galaxies by considering the dust in their host bulges.We find that the luminosity of the bright quasars is strongly dimmed by the dust attenuation, about 2 mag in the B-band, and that the faint end slope of the luminosity function is steepened. We also study for the first time the case in which gas fueling to a central black hole starts some time after the beginning of the starburst induced by a major merger. In this case, nuclei are less attenuated by the dust since the cold gas in the bulges is consumed by the starbursts and expelled by the stellar feedback. In order to make the dust attenuation of the quasars negligible, the accretion has to be delayed at least five times the dynamical timescale of their host bulges.

  4. Multi-Wavelength Studies on H2O Maser Host Galaxies

    Indian Academy of Sciences (India)

    J. S. Zhang; J. Wang

    2011-03-01

    H2O maser emissions have been found in external galaxies for more than 30 years. Main sciences associated with extragalactic H2O masers can be summarized roughly into three parts: maser emission itself, AGN sciences and cosmology exploration. Our work in this field focusses on two projects: X-ray data analysis of individual maser source using X-ray penetrability to explore maser host obscured AGN; multi-wavelength statistical properties of the whole published H2O maser sample. Here their nuclear radio properties were investigated in detail, based on their 6-cm and 20-cm radio observation data. Comparing the radio properties between maser-detected sources and non-detected sources at similar distance scale, we find that: (1) maser host galaxies tend to have higher nuclear radio luminosity; (2) the spectral index of both samples is comparable (∼ 0.6), within the error ranges. In addition, for AGN-maser sources, the isotropic maser luminosity tends to increase with rising radio luminosity. Thus we propose the nuclear radio luminosity as one good indicator for searching AGN-masers in the future.

  5. The host-galaxy response to the afterglow of GRB 100901A

    CERN Document Server

    Hartoog, Olga E; Vreeswijk, Paul M; Kaper, Lex; Tanvir, Nial R; Savaglio, Sandra; Berger, Edo; Chornock, Ryan; Covino, Stefano; D'Elia, Valerio; Flores, Hector; Fynbo, Johan P U; Goldoni, Paolo; Gomboc, Andreja; Melandri, Andrea; Pozanenko, Alexei; Schaye, Joop; Postigo, Antonio de Ugarte; Wijers, Ralph A M J

    2013-01-01

    For Gamma-Ray Burst 100901A, we have obtained Gemini-North and Very Large Telescope optical afterglow spectra at four epochs: one hour, one day, three days and one week after the burst, thanks to the afterglow remaining unusually bright at late times. Apart from a wealth of metal resonance lines, we also detect lines arising from fine-structure levels of the ground state of Fe II, and from metastable levels of Fe II and Ni II at the host redshift (z = 1.4084). These lines are found to vary significantly in time. The combination of the data and modelling results shows that we detect the fall of the Ni II 4 F9/2 metastable level population, which to date has not been observed. Assuming that the population of the excited states is due to the UV-radiation of the afterglow, we estimate an absorber distance of a few hundred pc. This appears to be a typical value when compared to similar studies. We detect two intervening absorbers (z = 1.3147, 1.3179). Despite the wide temporal range of the data, we do not see sign...

  6. Supermassive black holes and their host galaxies. I. Bulge luminosities from dedicated near-infrared data

    Energy Technology Data Exchange (ETDEWEB)

    Läsker, Ronald; Van de Ven, Glenn [Max-Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Ferrarese, Laura, E-mail: laesker@mpia.de [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E2E7 (Canada)

    2014-01-01

    In an effort to secure, refine, and supplement the relation between central supermassive black hole masses, M {sub •}, and the bulge luminosities of their host galaxies, L {sub bul}, we obtained deep, high spatial resolution K-band images of 35 nearby galaxies with securely measured M {sub •}, using the wide-field WIRCam imager at the Canada-France-Hawaii-Telescope. A dedicated data reduction and sky subtraction strategy was adopted to estimate the brightness and structure of the sky, a critical step when tracing the light distribution of extended objects in the near-infrared. From the final image product, bulge and total magnitudes were extracted via two-dimensional profile fitting. As a first order approximation, all galaxies were modeled using a simple Sérsic-bulge+exponential-disk decomposition. However, we found that such models did not adequately describe the structure that we observed in a large fraction of our sample galaxies which often include cores, bars, nuclei, inner disks, spiral arms, rings, and envelopes. In such cases, we adopted profile modifications and/or more complex models with additional components. The derived bulge magnitudes are very sensitive to the details and number of components used in the models, although total magnitudes remain almost unaffected. Usually, but not always, the luminosities and sizes of the bulges are overestimated when a simple bulge+disk decomposition is adopted in lieu of a more complex model. Furthermore, we found that some spheroids are not well fit when the ellipticity of the Sérsic model is held fixed. This paper presents the details of the image processing and analysis, while we discuss how model-induced biases and systematics in bulge magnitudes impact the M {sub •}-L {sub bul} relation in a companion paper.

  7. HOST GALAXIES, CLUSTERING, EDDINGTON RATIOS, AND EVOLUTION OF RADIO, X-RAY, AND INFRARED-SELECTED AGNs

    International Nuclear Information System (INIS)

    We explore the connection between different classes of active galactic nuclei (AGNs) and the evolution of their host galaxies, by deriving host galaxy properties, clustering, and Eddington ratios of AGNs selected in the radio, X-ray, and infrared (IR) wavebands. We study a sample of 585 AGNs at 0.25 -1 Mpc, and derive typical dark matter halo masses. We find that: (1) radio AGNs are mainly found in luminous red sequence galaxies, are strongly clustered (with M halo ∼ 3 x 1013 h -1 M sun), and have very low Eddington ratios λ ∼-3; (2) X-ray-selected AGNs are preferentially found in galaxies that lie in the 'green valley' of color-magnitude space and are clustered similar to the typical AGES galaxies (M halo ∼ 1013 h -1 M sun), with 10-3 ∼halo ∼12 h -1 M sun), and have λ>10-2. We interpret these results in terms of a simple model of AGN and galaxy evolution, whereby a 'quasar' phase and the growth of the stellar bulge occurs when a galaxy's dark matter halo reaches a critical mass between ∼1012 and 1013 M sun. After this event, star formation ceases and AGN accretion shifts from radiatively efficient (optical- and IR-bright) to radiatively inefficient (optically faint, radio-bright) modes.

  8. SN 2010ay Is a Luminous and Broad-Lined Type Ic Supernova Within a Low-Metallicity Host Galaxy

    Science.gov (United States)

    Sanders, N. E.; Soderberg, A. M.; Valenti, S.; Foley, R. J.; Chornock, R.; Chomiuk, L.; Berger, E.; Smartt, S.; Hurley, K.; Barthelmy, S. D.; Levesque, E. M.; Narayan, G.; Botticella, M. T.; Briggs, M. S.; Connaughton, V.; Terada, Y.; Gehrels, N.; Golenetskii, S.; Mazets, E.; Cline, T.; von Kienlin, A.; Boynton, W.; Chambers, K. C.; Grav, T.; Heasley, J. N.

    2012-01-01

    We report on our serendipitous pre-discovery detection and follow-up observations of the broad-lined Type Ic supernova (SN Ic) 2010ay at z = 0.067 imaged by the Pan-STARRS1 3pi survey just approximately 4 days after explosion. The supernova (SN) had a peak luminosity, MR approx. -20.2 mag, significantly more luminous than known GRB-SNe and one of the most luminous SNe Ib/c ever discovered. The absorption velocity of SN 2010ay is v Si (is) approx. 19×10(exp 3) km s-1 at approximately 40 days after explosion, 2-5 times higher than other broad-lined SNe and similar to the GRB-SN 2010bh at comparable epochs. Moreover, the velocity declines approximately 2 times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of 56Ni, MNi = 0.9 solar mass. Applying scaling relations to the light curve, we estimate a total ejecta mass, Mej (is) approx. 4.7 solar mass, and total kinetic energy, EK (is) approx. 11 × 10(exp 51) erg. The ratio of MNi to Mej is approximately 2 times as large for SN 2010ay as typical GRB-SNe and may suggest an additional energy reservoir. The metallicity (log(O/H)PP04 + 12 = 8.19) of the explosion site within the host galaxy places SN 2010ay in the low-metallicity regime populated by GRB-SNe, and (is) approximately 0.5(0.2) dex lower than that typically measured for the host environments of normal (broad-lined) SNe Ic. We constrain any gamma-ray emission with E(gamma) (is) approximately less than 6 × 10(exp 48) erg (25-150 keV), and our deep radio follow-up observations with the Expanded Very Large Array rule out relativistic ejecta with energy E (is) approximately greater than 10(exp 48) erg. We therefore rule out the association of a relativistic outflow like those that accompanied SN 1998bw and traditional long-duration gamma-ray bursts (GRBs), but we place less-stringent constraints on a weak afterglow like that seen from XRF

  9. The influence of host galaxy morphology on the properties of Type Ia supernovae from the JLA compilation

    CERN Document Server

    Henne, Vincent; Rosnet, Philippe; Leget, Pierre-Francois; Ishida, Emille; Ciulli, Alexandre; Gris, Philippe; Says, Louis-Pierre; Gangler, Emmanuel

    2016-01-01

    The observational cosmology with distant Type Ia supernovae (SNe) as standard candles claims that the Universe is in accelerated expansion, caused by a large fraction of dark energy. In this paper we investigate the SN Ia environment, studying the impact of the nature of their host galaxies on the Hubble diagram fitting. The supernovae (192 SNe) used in the analysis were extracted from Joint-Light-curves-Analysis (JLA) compilation of high-redshift and nearby supernovae which is the best one to date. The analysis is based on the empirical fact that SN Ia luminosities depend on their light curve shapes and colors. We confirm that the stretch parameter of Type Ia supernovae is correlated with the host galaxy type. The supernovae with lower stretch are hosted mainly in elliptical and lenticular galaxies. No significant correlation between SN Ia colour and host morphology was found. We also examine how the luminosities of SNe Ia change depending on host galaxy morphology after stretch and colour corrections. Our r...

  10. Star formation in z>1 3CR host galaxies as seen by Herschel

    CERN Document Server

    Podigachoski, P; Haas, M; Leipski, C; Wilkes, B; Kuraszkiewicz, J; Westhues, C; Willner, S P; Ashby, M L N; Chini, R; Clements, D L; Fazio, G G; Labiano, A; Lawrence, C; Meisenheimer, K; Peletier, R F; Siebenmorgen, R; Kleijn, G Verdoes

    2015-01-01

    We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z>1 3CR sources, from the Herschel GT project The Herschel Legacy of distant radio-loud AGN (PI: Barthel). Combining these with existing Spitzer photometric data, we perform an infrared (IR) spectral energy distribution (SED) analysis of these landmark objects in extragalactic research to study the star formation in the hosts of some of the brightest active galactic nuclei (AGN) known at any epoch. Accounting for the contribution from an AGN-powered warm dust component to the IR SED, about 40% of our objects undergo episodes of prodigious, ULIRG-strength star formation, with rates of hundreds of solar masses per year, coeval with the growth of the central supermassive black hole. Median SEDs imply that the quasar and radio galaxy hosts have similar FIR properties, in agreement with the orientation-based unification for radio-loud AGN. The star-forming properties of the AGN hosts are similar to those of the general popul...

  11. Molecular Gas and the Host-Galaxy System of the z ~ 0.3 QSO PG 1700+518

    NARCIS (Netherlands)

    Evans, A. S.; Hines, D. C.; Barthel, P.; Schneider, G.; Surace, J. A.; Sanders, D. B.; Vavilkin, T.; Frayer, D. T.; Tacconi, L. J.; Storrie-Lombardi, L. J.

    2009-01-01

    The detection of CO(1 -> 0) emission in the massive (i.e., M(H) similar to -26.13 mag), z similar to 0.3 host-galaxy system of the broad absorption line quasi-stellar object (QSO) PG1700+518 is reported. The host system has a CO luminosity of L'(CO) similar to 1.4 x 10(10) K km s(-1) pc(2), and thus

  12. Near-infrared imaging of the host galaxies of three radio-loud quasars at z = 1.5

    CERN Document Server

    Falomo, R; Treves, A; Falomo, Renato; Kotilainen, Jari; Treves, Aldo

    2000-01-01

    We present high spatial resolution near-infrared H-band (1.65 microns) images, taken with ISAAC on UT1 of ESO VLT, of three radio-loud quasars at z = 1.5, as a pilot study for imaging of a larger sample of radio-loud and radio-quiet quasars in the redshift range 1 < z < 2. We are able to clearly detect the host galaxy in two quasars (PKS 0000-177 and PKS 0348-120) and marginally in the third (PKS 0402-362). The host galaxies appear compact (average bulge scale-length R(e) = 4 kpc) and luminous (average M(H) = -27.6+-0.1). They are 2.5 mag more luminous than the typical galaxy luminosity (M*(H) = -25.0+-0.2), and are comparable to the hosts of low redshift radio-loud quasars (M(H) = -26), taking into account passive stellar evolution. Their luminosities are also similar to those of high redshift radio galaxies. All three quasars have at least one close companion galaxy at a projected distance < 50 kpc from the quasar, assuming they are at the same redshift.

  13. THE ACS VIRGO CLUSTER SURVEY. XVII. THE SPATIAL ALIGNMENT OF GLOBULAR CLUSTER SYSTEMS WITH EARLY-TYPE HOST GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qiushi; Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); Blakeslee, John P.; Cote, Patrick; Ferrarese, Laura [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Jordan, Andres [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Mei, Simona [University of Paris 7 Denis Diderot, F-75205 Paris Cedex 13 (France); West, Michael J., E-mail: peng@pku.edu.cn [Maria Mitchell Observatory, 4 Vestal Street, Nantucket, MA 02554 (United States)

    2013-06-01

    We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation ({epsilon} > 0.2) and intermediate to high luminosities (M{sub z} < -19), the GCs are preferentially aligned along the major axis of the stellar light. The red (metal-rich) GC subpopulations show strong alignment with the major axis of the host galaxy, which supports the notion that these GCs are associated with metal-rich field stars. The metal-rich GCs in lenticular galaxies show signs of being more strongly associated with disks rather than bulges. Surprisingly, we also find that the blue (metal-poor) GCs can also show the same correlation. If the metal-poor GCs are part of the early formation of the halo and built up through mergers, then our results support a picture where halo formation and merging occur anisotropically, and that the present-day major axis is an indicator of the preferred merging axis.

  14. An evolutionary missing link? A modest-mass early-type galaxy hosting an over-sized nuclear black hole

    CERN Document Server

    van Loon, Jacco Th

    2015-01-01

    SAGE1C\\,J053634.78$-$722658.5 is a galaxy at redshift $z=0.14$, discovered behind the Large Magellanic Cloud in the {\\it Spitzer} Space Telescope "Surveying the Agents of Galaxy Evolution" Spectroscopy survey (SAGE-Spec). It has very strong silicate emission at 10 $\\mu$m but negligible far-IR and UV emission. This makes it a candidate for a bare AGN source in the IR, perhaps seen pole-on, without significant IR emission from the host galaxy. In this paper we present optical spectra taken with the Southern African Large Telescope (SALT) to investigate the nature of the underlying host galaxy and its AGN. We find broad H$\\alpha$ emission characteristic of an AGN, plus absorption lines associated with a mature stellar population ($>9$ Gyr), and refine its redshift determination to $z=0.1428\\pm0.0001$. There is no evidence for any emission lines associated with star formation. This remarkable object exemplifies the need for separating the emission from any AGN from that of the host galaxy when employing infrared ...

  15. HST Imaging of Fading AGN Candidates I: Host-Galaxy Properties and Origin of the Extended Gas

    CERN Document Server

    Keel, William C; Bennert, Vardha N; Lintott, Chris J; Chojnowski, S Drew; Moiseev, Alexei; Smirnova, Aleksandrina; Schawinski, Kevin; Urry, C Megan; Evans, Daniel A; Pancoast, Anna; Scott, Bryan; Showley, Charles; Flatland, Kelsi

    2014-01-01

    We present narrow- and medium-band HST imaging, with supporting data, for 8 galaxies hosting fading AGN. These are selected to have AGN-ionized gas projected >10 kpc from the nucleus, and a significant shortfall of ionizing radiation, indicating fading of the AGN on ~50,000-year timescales. This paper deals with the host-galaxy properties and origin of the gas. In every galaxy, we identify evidence of ongoing or past interactions. Several show multiple dust lanes in different orientations, broadly fit by differentially precessing disks of accreted material. The host systems are of early Hubble type, with one S0 and one SB0 galaxy. The gas, generally of low metallicity and lying near the galaxies' rotation curves, is consistent with an external tidal origin, although the ionized gas and stellar tidal features do not always match closely. Unlike the case in many radio-loud AGN, these clouds are kinematically quiet and generally follow organized rotation curves. [O III]/H-alpha ratios often trace distinct ioniza...

  16. A metallicity study of 1987A-like supernova host galaxies

    Science.gov (United States)

    Taddia, F.; Sollerman, J.; Razza, A.; Gafton, E.; Pastorello, A.; Fransson, C.; Stritzinger, M. D.; Leloudas, G.; Ergon, M.

    2013-10-01

    Context. The origin of the blue supergiant (BSG) progenitor of Supernova (SN) 1987A has long been debated, along with the role that its sub-solar metallicity played. We now have a sample of SN 1987A-like events that arise from the rare core collapse (CC) of massive (~20 M⊙) and compact (≲100 R⊙) BSGs. Aims: The metallicity of the explosion sites of the known BSG SNe is investigated, as well as the association of BSG SNe to star-forming regions. Methods: Both indirect and direct metallicity measurements of 13 BSG SN host galaxies are presented, and compared to those of other CC SN types. Indirect measurements are based on the known luminosity-metallicity relation and on published metallicity gradients of spiral galaxies. In order to provide direct metallicity measurements based on strong line diagnostics, we obtained spectra of each BSG SN host galaxy both at the exact SN explosion sites and at the positions of other H ii regions. We also observed these hosts with narrow Hα and broad R-band filters in order to produce continuum-subtracted Hα images. This allows us to measure the degree of association between BSG SNe and star-forming regions, and to compare it to that of other SN types. Results: BSG SNe are found to explode either in low-luminosity galaxies or at large distances from the nuclei of luminous hosts. Therefore, their indirectly measured metallicities are typically lower than those of SNe IIP and Ibc. This result is confirmed by the direct metallicity estimates, which show slightly sub-solar oxygen abundances (12 + log (O/H) ~ 8.3-8.4 dex) for the local environments of BSG SNe, similar to that of the Large Magellanic Cloud (LMC), where SN 1987A exploded. However, we also note that two objects of our sample (SNe 1998A and 2004em) were found at near solar metallicity. SNe IIb have a metallicity distribution similar to that of our BSG SNe. Finally, we find that the degree of association to star-forming regions is similar among BSG SNe, SNe IIP and

  17. Relative frequencies of supernovae types: dependence on host galaxy magnitude, galactocentric radius and local metallicity

    CERN Document Server

    Boissier, S

    2009-01-01

    Context: Stellar evolution theory suggests that the relationship between number ratios of supernova (SN) types and metallicity holds important clues as to the nature of the progenitor stars (mass, metallicity, rotation, binarity, etc). Aims: We investigate the metallicity dependence of number ratios of various SN types, using a large sample of SN along with information on their radial position in, and magnitude of, their host galaxy. Methods: We derive typical galaxian metallicities (using the well known metallicity-luminosity relation) and local metallicities, i.e. at the position of the SN; in the latter case, we use the empirical fact that the metallicity gradients in disk galaxies are ~ constant when expressed in dex/R25. Results: We confirm a dependence of the N(Ibc)/N(II) ratio on metallicity; recent single star models with rotation and binary star models with no rotation appear to reproduce equally well that metallicity dependence. The size of our sample does not allow significant conclusions on the N(...

  18. The Host Galaxies and Narrow Line Regions of Four Double-Peaked [OIII] AGN

    CERN Document Server

    Villforth, C

    2015-01-01

    Major gas-rich mergers of galaxies are expected to play an important role in triggering and fuelling luminous AGN. We present deep multi-band (u/r/z) imaging and long slit spectroscopy of four double-peaked [OIII] emitting AGN, a class of objects associated with either kcp-separated binary AGN or final stage major mergers, though AGN with complex narrow-line regions are known contaminants. Such objects are of interest since they represent the onset of AGN activity during the merger process. Three of the objects studied have been confirmed as major mergers using near-infrared imaging, one is a confirmed X-ray binary AGN. All AGN are luminous and have redshifts of 0.1 < z < 0.4. Deep r-band images show that a majority (3/4) of the sources have disturbed host morphologies and tidal features, while the remaining source is morphologically undisturbed down to low surface brightness limits. The lack of morphological disturbances in this galaxy despite the fact that is is a close binary AGN suggests that the me...

  19. Nearby supernova host galaxies from the CALIFA Survey: I. Sample, data analysis, and correlation to star-forming regions

    CERN Document Server

    Galbany, L; Mourão, A M; Rodrigues, M; Flores, H; García-Benito, R; Mast, D; Mendoza, M A; Sánchez, S F; Badenes, C; Barrera-Ballesteros, J; Bland-Hawthorn, J; Falcón-Barroso, J; García-Lorenzo, B; Gomes, J M; Delgado, R M González; Kehrig, C; Lyubenova, M; López-Sánchez, A R; de Lorenzo-Cáceres, A; Marino, R A; Meidt, S; Mollá, M; Papaderos, P; Pérez-Torres, M A; Rosales-Ortega, F F; van de Ven, G

    2014-01-01

    [Abridged] We use optical IFS of nearby SN host galaxies provided by the CALIFA Survey with the goal of finding correlations in the environmental parameters at the location of different SN types. We recover the sequence in association of different SN types to the star-forming regions by using several indicators of the ongoing and recent SF related to both the ionized gas and the stellar populations. While the total ongoing SF is on average the same for the three SN types, SNe Ibc/IIb tend to happen closer to star-forming regions and occur in higher SF density locations compared to SNe II and SNe~Ia, the latter showing the weakest correlation. SNe~Ia host galaxies have on average masses that are $\\sim$0.3-0.8~dex higher than CC SNe hosts due to a larger fraction of old stellar populations in the SNe~Ia hosts. Using the recent SN~Ia delay-time distribution and the SFHs of the galaxies, we show that the SN~Ia hosts in our sample should presently produce a factor 2 more SNe~Ia than the CC~SN hosts. Since both typ...

  20. SUPPRESSION OF STAR FORMATION IN THE HOSTS OF LOW-EXCITATION RADIO GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Pace, Cameron; Salim, Samir, E-mail: cameronpace@suu.edu, E-mail: salims@indiana.edu [Indiana University, Department of Astronomy, Swain Hall West 319, Bloomington, IN 47405-7105 (United States)

    2016-02-10

    The feedback from radio-loud active galactic nuclei (R-AGNs) may help maintain low star-formation (SF) rates in their early-type hosts, but the observational evidence for this mechanism has been inconclusive. We study systematic differences of aggregate spectral energy distributions (SEDs) of various subsets of ∼4000 low-redshift R-AGNs from Best and Heckman with respect to (currently) inactive control samples selected to have matching redshift, stellar mass, population age, axis ratio, and environment. Aggregate SEDs, ranging from the ultraviolet (UV) through mid-infrared (mid-IR, 22 μm), were constructed using a Bayesian method that eliminates biases from non-detections in Galaxy Evolution Explorer and Wide-field Infrared Survey Explorer. We study rare high-excitation sources separately from low-excitation ones, which we split by environment and host properties. We find that both the UV and mid-IR emission of non-cluster R-AGNs (80% of sample) are suppressed by ∼0.2 dex relative to that of the control group, especially for moderately massive galaxies (log M{sub *} ≲ 11). The difference disappears for high-mass R-AGNs and for R-AGNs in clusters, where other, non-AGN quenching/maintenance mechanisms may dominate, or where the suppression of SF due to AGNs may persist between active phases of the central engine, perhaps because of the presence of a hot gaseous halo storing AGN energy. High-excitation (high accretion rate) sources, which make up 2% of the R-AGN sample, do not show any evidence of SF suppression (their UV is the same as in controls), but they exhibit a strong mid-IR excess due to AGN dust heating.

  1. Short gamma-ray bursts: evidence for an origin in globular clusters?

    CERN Document Server

    Church, Ross P; Davies, Melvyn B; Tanvir, Nial

    2011-01-01

    We compare the observed spatial offsets of short gamma-ray bursts from their host galaxies with their predicted distributions, assuming that they originate in double neutron star binaries that form from field stars. We find that, for the majority of bursts, this model is sufficient to explain the observed offsets, although there is a trend towards larger offsets than predicted. One burst, GRB 060502B, has an offset that is clearly anomalous. We discuss possible reasons for the large offsets, including host galaxy misidentification, and suggest that some of the largest-offset bursts may originate in the merger of double neutron star binaries that form dynamically in the cores of globular clusters.

  2. Constraints on Black Hole/Host Galaxy Co-evolution and Binary Stalling Using Pulsar Timing Arrays

    CERN Document Server

    Simon, Joseph

    2016-01-01

    Pulsar timing arrays are now setting increasingly tight limits on the gravitational wave background from binary supermassive black holes. But as upper limits grow more constraining, what can be implied about galaxy evolution? We investigate which astrophysical parameters have the largest impact on strain spectrum predictions and provide a simple framework to directly translate between measured values for the parameters of galaxy evolution and PTA limits on the gravitational wave background of binary supermassive black holes. We find that the most influential observable is the relation between a host galaxy's central bulge and its central black hole, $\\mbox{$M_{\\bullet}$-$M_{\\rm bulge}$}$, which has the largest effect on the mean value of the characteristic strain amplitude. However, the variance of each prediction is dominated by uncertainties in the galaxy stellar mass function. Using this framework with the best published PTA limit, we can set limits on the shape and scatter of the $\\mbox{$M_{\\bullet}$-$M_{...

  3. Evidence of suppression of star formation by quasar-driven winds in gas-rich host galaxies at z < 1?

    Science.gov (United States)

    Wylezalek, Dominika; Zakamska, Nadia L.

    2016-10-01

    Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies through heating or driving gas out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been scarce. We have assembled a sample of 132 radio-quiet type-2 and red AGN at 0.1 < z < 1. We measure the kinematics of the AGN-ionized gas, the host galaxies' stellar masses and star formation rates (SFRs) and investigate the relationships between AGN luminosities, specific star formation rates (sSFRs) and outflow strengths W90 - the 90 per cent velocity width of the [O III]λ5007Å line power and a proxy for the AGN-driven outflow speed. Outflow strength is independent of sSFR for AGN selected on their mid-IR luminosity, in agreement with previous work demonstrating that star formation is not sufficient to produce the observed ionized gas outflows which have to be powered by AGN activity. More importantly, we find a negative correlation between W90 and sSFR in the AGN hosts with the highest SFRs, i.e. with the highest gas content, where presumably the coupling of the AGN-driven wind to the gas is strongest. This implies that AGN with strong outflow signatures are hosted in galaxies that are more `quenched' than galaxies with weaker outflow signatures. Despite the galaxies' high SFRs, we demonstrate that the outflows are not star formation driven but indeed due to AGN powering. This observation is consistent with the AGN having a net suppression, `negative' impact, through feedback on the galaxies' star formation history.

  4. The host galaxies and narrow-line regions of four double-peaked [OIII] AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Villforth, Carolin; Hamann, Fred [Department of Astronomy, University of Florida, 32611 Gainesville, FL (United States)

    2015-03-01

    Major gas-rich mergers of galaxies are expected to play an important role in triggering and fueling luminous active galactic nuclei (AGNs). The mechanism of AGN fueling during mergers, however, remains poorly understood. We present deep multi-band (u/r/z) imaging and long-slit spectroscopy of four double-peaked [OIII] emitting AGNs. This class of object is likely associated with either kiloparsec-separated binary AGNs or final stage major mergers, although AGNs with complex narrow-line regions (NLRs) are known contaminants. Such objects are of interest since they represent the onset of AGN activity during the merger process. Three of the four double-peaked [OIII] emitters studied have been confirmed as major mergers using near-infrared imaging and one is a confirmed X-ray binary AGN. All AGNs are luminous, radio-quiet to radio-intermediate, and have redshifts of 0.1host morphologies and tidal features, while the remaining source is morphologically undisturbed down to low surface brightness limits (∼27 mag arcsec{sup −2} in r). The lack of morphological disturbances in this galaxy despite the fact that it is a close binary AGN suggests that the merger of a binary black hole can take longer than 1 Gyr. All AGNs hosted by merging galaxies have companions at distances ⩽150 kpc. The NLRs have large sizes (10 kpc < r < 100 kpc) and consist of compact clumps with considerable relative velocities between components (∼200–650 km s{sup −1}). We detect broad, predominantly blue, wings with velocities up to ∼1500 km s{sup −1} in [OIII], indicative of powerful outflows. The outflows are compact (<5 kpc) and co-spatial with nuclear regions showing considerable reddening, consistent with enhanced star formation. One source shows an offset between gas and stellar kinematics, consistent with either a bipolar flow or a counter-rotating gas disk. In all other sources, the ionized gas

  5. A glimpse at quasar host galaxy far-UV emission using damped Lyα's as natural coronagraphs

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Zheng; Fan, Xiaohui; Wang, Ran; McGreer, Ian, E-mail: caize@arizona.edu [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Noterdaeme, Pasquier; Finley, Hayley; Petitjean, Patrick [Institut d' Astrophysique de Paris, CNRS-UPMC, UMR7095, 98bis bd Arago, F-75014 Paris (France); Carithers, Bill [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA (United States); Bian, Fuyan [Research School of Astronomy and Astrophysics, Australian National University, Canberra, Weston Creek, ACT, 2611 (Australia); Miralda-Escudé, Jordi [Institució Catalana de Recerca i Estudis Avançats, Barcelona (Spain); Pâris, Isabelle [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Zakamska, Nadia L. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Ge, Jian [Department of Astronomy, University of Florida, Gainesville, FL (United States); Slosar, Anze [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2014-10-01

    In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density damped Lyα (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. We have stacked the spectra of ∼2000 DLA systems (N {sub H} {sub I} > 10{sup 20.6} cm{sup –2}) with a median absorption redshift (z) = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the Sloan Digital Sky Survey fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation from the background quasar host galaxies (with medium redshift (z) = 3.1) that is not blocked by the intervening DLA. Assuming that all of the detected flux originates from quasar hosts, for the highest quasar luminosity bin ((L) = 2.5 × 10{sup 13} L {sub ☉}), the host galaxy has an FUV intensity of 1.5 ± 0.2 × 10{sup 40} erg s{sup –1} Å{sup –1}; this corresponds to an unobscured UV star formation rate of 9 M {sub ☉} yr{sup –1}.

  6. Driving the Growth of the Earliest Supermassive Black Holes with Major Mergers of Host Galaxies

    CERN Document Server

    Tanaka, Takamitsu L

    2014-01-01

    The formation mechanism of supermassive black holes (SMBHs) in general, and of $\\sim 10^9\\,{\\rm M}_{\\odot}$ SMBHs observed as luminous quasars at redshifts $z> 6$ in particular, remains an open fundamental question. The presence of such massive BHs at such early times, when the Universe was less than a billion years old, implies that they grew via either super-Eddington accretion, or nearly uninterrupted gas accretion near the Eddington limit; the latter, at first glance, is at odds with empirical trends at lower redshifts, where quasar episodes associated with rapid BH growth are rare and brief. In this work, I examine whether and to what extent the growth of the $z> 6$ quasar SMBHs can be explained within the standard quasar paradigm, in which major mergers of host galaxies trigger episodes of rapid gas accretion below or near the Eddington limit. Using a suite of Monte Carlo merger tree simulations of the assembly histories of the likely hosts of the $z> 6$ quasars, I investigate (i) their growth and major...

  7. Nearby supernova host galaxies from the CALIFA Survey: II. SN environmental metallicity

    CERN Document Server

    Galbany, L; Mourão, A M; Rodrigues, M; Flores, H; Walcher, C J; Sánchez, S F; García-Benito, R; Mast, D; Badenes, C; Delgado, R M González; Kehrig, C; Lyubenova, M; Marino, R A; Mollá, M; Meidt, S; Pérez, E; van de Ven, G; Vílchez, J M

    2016-01-01

    The metallicity of a supernova (SN) progenitor, together with its mass, is one of the main parameters that rules their outcome. We present a metallicity study of 115 nearby SN host galaxies (0.00510 dex) by targeted searches. We also found no evidence that the metallicity at the SN location differs from the average metallicity at the GCD of the SNe. By extending our SN sample with published metallicities at the SN location, we studied the metallicity distributions for all SN subtypes split into SN discovered in targeted and untargeted searches. We confirm a bias toward higher host masses and metallicities in the targeted searches. Combining data from targeted and untargeted searches we found a sequence from higher to lower local metallicity: SN Ia, Ic, and II show the highest metallicity, which is significantly higher than SN Ib, IIb, and Ic-BL. Our results support the picture of SN Ib resulting from binary progenitors and, at least part of, SN Ic being the result of single massive stars stripped of their out...

  8. Hubble Space Telescope observations of the host galaxies and environments of calcium-rich supernovae

    CERN Document Server

    Lyman, J D; James, P A; Angus, C R; Church, R P; Davies, M B; Tanvir, N R

    2016-01-01

    Calcium-rich supernovae represent a significant challenge for our understanding of the fates of stellar systems. They are less luminous than other supernova (SN) types and they evolve more rapidly to reveal nebular spectra dominated by strong calcium lines with weak or absent signatures of other intermediate- and iron-group elements, which are seen in other SNe. Strikingly, their explosion sites also mark them out as distinct from other SN types. Their galactocentric offset distribution is strongly skewed to very large offsets (around one third are offset greater than 20 kpc), meaning they do not trace the stellar light of their hosts. Many of the suggestions to explain this extreme offset distribution have invoked the necessity for unusual formation sites such as globular clusters or dwarf satellite galaxies, which are therefore difficult to detect. Building on previous work attempting to detect host systems of nearby Ca-rich SNe, we here present Hubble Space Telescope imaging of 5 members of the class - 3 e...

  9. SDSS-II Supernova Survey: An Analysis of the Largest Sample of Type Ia Supernovae and Correlations with Host-galaxy Spectral Properties

    Science.gov (United States)

    Wolf, Rachel C.; D’Andrea, Chris B.; Gupta, Ravi R.; Sako, Masao; Fischer, John A.; Kessler, Rick; Jha, Saurabh W.; March, Marisa C.; Scolnic, Daniel M.; Fischer, Johanna-Laina; Campbell, Heather; Nichol, Robert C.; Olmstead, Matthew D.; Richmond, Michael; Schneider, Donald P.; Smith, Mathew

    2016-04-01

    Using the largest single-survey sample of Type Ia supernovae (SNe Ia) to date, we study the relationship between properties of SNe Ia and those of their host galaxies, focusing primarily on correlations with Hubble residuals (HRs). Our sample consists of 345 photometrically classified or spectroscopically confirmed SNe Ia discovered as part of the SDSS-II Supernova Survey (SDSS-SNS). This analysis utilizes host-galaxy spectroscopy obtained during the SDSS-I/II spectroscopic survey and from an ancillary program on the SDSS-III Baryon Oscillation Spectroscopic Survey that obtained spectra for nearly all host galaxies of SDSS-II SN candidates. In addition, we use photometric host-galaxy properties from the SDSS-SNS data release such as host stellar mass and star formation rate. We confirm the well-known relation between HR and host-galaxy mass and find a 3.6σ significance of a nonzero linear slope. We also recover correlations between HR and host-galaxy gas-phase metallicity and specific star formation rate as they are reported in the literature. With our large data set, we examine correlations between HR and multiple host-galaxy properties simultaneously and find no evidence of a significant correlation. We also independently analyze our spectroscopically confirmed and photometrically classified SNe Ia and comment on the significance of similar combined data sets for future surveys.

  10. The host galaxy properties of variability selected AGN in the Pan-STARRS1 Medium-Deep Survey

    CERN Document Server

    Heinis, S; Kumar, S; Burgett, W S; Flewelling, H; Huber, M E; Kaiser, N; Wainscoat, R J; Waters, C

    2016-01-01

    We study the properties of 975 active galactic nuclei (AGN) selected by variability in the Pan-STARRS1 Medium-Deep Survey. Using complementary multi wavelength data from the ultraviolet to the far-infrared, we use SED fitting to determine the AGN and host properties at $z<1$, and compare to a well-matched control sample. We confirm the trend previously observed that the variability amplitude decreases with AGN luminosity, but on the other hand, we observe that the slope of this relation steepens with wavelength resulting in a "redder when brighter" trend at low luminosities. Our results show that AGN are hosted by more massive hosts than control sample galaxies, while the restframe, dust-corrected $NUV-r$ color distribution of AGN hosts is similar to control galaxies. We find a positive correlation between the AGN luminosity and star formation rate (SFR), independent of redshift. AGN hosts populate the whole range of SFRs within and outside the Main Sequence of star forming galaxies. Comparing the distribu...

  11. Bright [CII] and dust emission in three z>6.6 quasar host galaxies observed by ALMA

    CERN Document Server

    Venemans, B P; Zschaechner, L; Decarli, R; De Rosa, G; Findlay, J R; McMahon, R G; Sutherland, W J

    2015-01-01

    We present ALMA detections of the [CII] 158 micron emission line and the underlying far-infrared continuum of three quasars at 6.6~6 quasar hosts correlate with the quasar's bolometric luminosity. In one quasar, the [CII] line is significantly redshifted by ~1700 km/s with respect to the MgII broad emission line. Comparing to values in the literature, we find that, on average, the MgII is blueshifted by 480 km/s (with a standard deviation of 630 km/s) with respect to the host galaxy redshift, i.e. one of our quasars is an extreme outlier. Through modeling we can rule out a flat rotation curve for our brightest [CII] emitter. Finally, we find that the ratio of black hole mass to host galaxy (dynamical) mass is higher by a factor 3-4 (with significant scatter) than local relations.

  12. ALMA Observations of the Host Galaxy of GRB090423 at z=8.23: Deep Limits on Obscured Star Formation 630 Million Years After the Big Bang

    CERN Document Server

    Berger, E; Chary, R -R; Laskar, T; Chornock, R; Tanvir, N R; Stanway, E R; Levan, A J; Levesque, E M; Davies, J E

    2014-01-01

    We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB090423 at z=8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3-sigma limits of Fnu(222 GHz)4 (Lyman break galaxies, Ly-alpha emitters, and submillimeter galaxies), and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z>4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

  13. Hubble Space Telescope and Palomar Imaging of GRB 990123 Implications for the Nature of Gamma-Ray Bursts and Their Hosts

    CERN Document Server

    Fruchter, A S; Metzger, M R; Sahu, K C; Petro, L; Livio, M; Ferguson, H; Pian, E; Hogg, D W; Galama, T J; Gull, T R; Kouveliotou, C; Macchetto, D; Van Paradijs, J; Pedersen, H J; Smette, A; Fruchter, Andrew S.; Metzger, Mark R.; Sahu, Kailash C.; Petro, Larry; Livio, Mario; Ferguson, Henry; Pian, Elena; Hogg, David W.; Galama, Titus; Gull, Theodore R.; Kouveliotou, Chryssa; Macchetto, Duccio; Paradijs, Jan van; Pedersen, Holger; Smette, Alain

    1999-01-01

    We report on deep HST and Palomar optical images of the field of GRB~990123, obtained on 8 and 9 February 1999. We find that the optical transient (OT) associated with GRB~990123 is located on an irregular galaxy, with magnitude $V=24.20 \\pm 0.15$. The deep metal absoption lines seen in the spectrum of the OT, along with the low probablility of a chance superposition, lead us to conclude that this galaxy is the host of the GRB. The OT is projected within the $\\sim1''$ visible stellar field of the host, nearer the edge than the center. We cannot, on this basis, rule out the galactic nucleus as the site of the GRB, since the unusual morphology of the host may be the result of an ongoing galactic merger, but our demonstration that this host galaxy has extremely blue optical to infrared colors more strongly supports an association between GRBs and star formation. We find that the OT magnitude on 1999 Feb 9.05, $V = 25.45 \\pm 0.15$, is about 1.5 mag fainter than expected from extrapolation of the decay rate found ...

  14. Long gamma-ray bursts and core-collapse supernovae have differentenvironments

    Energy Technology Data Exchange (ETDEWEB)

    Fruchter, A.S.; Levan, A.J.; Strolger, L.; Vreeswijk, P.M.; Thorsett, S.E.; Bersier, D.; Burud, I.; Castro Ceren, J.M.; Castro-Tirado, A.J.; Conselice, C.; Dahlen, T.; Ferguson, H.C.; Fynbo,J.P.U.; Garnavich, P.M.; Gibbons, R.A.; Gorosabel, J.; Gull, T.R.; Hjorth, J.; Holland, S.T.; Kouveliotou, C.; Levay, Z.; Livio, M.; Metzger, M.R.; Nugent, P.E.; Petro, L.; Pian, E.; Rhoads, J.E.; Riess,A.G.; Sahu, K.C.; Smette, A.; Tanvir, N.R.; Wijers, R.A.M.J.; Woosley, S.E.

    2006-05-01

    When massive stars exhaust their fuel they collapse andoften produce the extraordinarily bright explosions known ascore-collapse supernovae. On occasion, this stellar collapse also powersan even more brilliant relativistic explosion known as a long-durationgamma-ray burst. One would then expect that long gamma-ray bursts andcore-collapse supernovae should be found in similar galacticenvironments. Here we show that this expectation is wrong. We find thatthe long gamma-ray bursts are far more concentrated on the very brightestregions of their host galaxies than are the core-collapse supernovae.Furthermore, the host galaxies of the long gamma-ray bursts aresignificantly fainter and more irregular than the hosts of thecore-collapse supernovae. Together theseresults suggest thatlong-duration gamma-ray bursts are associated with the most massive starsand may be restricted to galaxies of limited chemical evolution. Ourresults directly imply that long gamma-ray bursts are relatively rare ingalaxies such as our own MilkyWay.

  15. The Host Galaxies of X-ray Quasars Are Not Strong Star Formers

    CERN Document Server

    Barger, A J; Owen, F N; Chen, C -C; Hasinger, G; Hsu, L -Y; Li, Y

    2014-01-01

    We use ultradeep SCUBA-2 850um observations (~0.37 mJy rms) of the 2 Ms CDF-N and 4 Ms CDF-S X-ray fields to examine the amount of dusty star formation taking place in the host galaxies of high-redshift X-ray AGNs. Supplementing with COSMOS, we measure the submillimeter fluxes of the 4-8 keV sources at z>1, finding little flux at the highest X-ray luminosities but significant flux at intermediate luminosities. We determine grey body and MIR luminosities by fitting spectral energy distributions to each X-ray source and to each radio source in an ultradeep Karl G. Jansky VLA 1.4 GHz (11.5uJy at 5-sigma) image of the CDF-N. We confirm the FIR-radio and MIR-radio correlations to z=4 using the non-X-ray detected radio sources. Both correlations are also obeyed by the X-ray less luminous AGNs but not by the X-ray quasars. We interpret the low FIR luminosities relative to the MIR for the X-ray quasars as being due to a lack of star formation, while the MIR stays high due to the AGN contribution. We find that the FIR...

  16. SNe Ia host galaxy properties from Sloan Digital Sky Survey-II spectroscopy

    CERN Document Server

    Johansson, Jonas; Pforr, Janine; Maraston, Claudia; Nichol, Robert C; Smith, Mathew; Lampeitl, Hubert; Beifiori, Alessandra; Gupta, Ravi R; Schneider, Donald P

    2012-01-01

    We study the stellar populations of SNe Ia host galaxies using SDSS-II spectroscopy. We focus on the relationships of SNe Ia properties with stellar velocity dispersion and the stellar population parameters age, metallicity and element abundance ratios derived by fitting absorption line indices to stellar population models. We concentrate on a sub-sample of 84 SNe Ia from the SDSS-II Supernova Survey. In agreement with previous findings, we find that SALT2 stretch factor values show the strongest dependence on stellar population age. Hence, SNe Ia peak-luminosity is closely related to the age of the stellar progenitor systems, where more luminous SNe Ia appear in younger stellar populations. We find no statistically significant trends in the Hubble residual with any of the stellar population parameters studied, including age and metallicity contrary to the literature, as well as with stellar velocity dispersion. Moreover, we find that the method of stellar mass derivation is affecting the Hubble residual-mass...

  17. Dense magnetized plasma associated with a fast radio burst.

    Science.gov (United States)

    Masui, Kiyoshi; Lin, Hsiu-Hsien; Sievers, Jonathan; Anderson, Christopher J; Chang, Tzu-Ching; Chen, Xuelei; Ganguly, Apratim; Jarvis, Miranda; Kuo, Cheng-Yu; Li, Yi-Chao; Liao, Yu-Wei; McLaughlin, Maura; Pen, Ue-Li; Peterson, Jeffrey B; Roman, Alexander; Timbie, Peter T; Voytek, Tabitha; Yadav, Jaswant K

    2015-12-24

    Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

  18. The effects of host galaxy properties on merging compact binaries detectable by LIGO

    CERN Document Server

    O'Shaughnessy, Richard; Brooks, Alyson; Shen, Sijing; Governato, Fabio; Christensen, Charlotte

    2016-01-01

    Cosmological simulations of galaxy formation can produce present-day galaxies with a large range of assembly and star formation histories. A detailed study of the metallicity evolution and star formation history of such simulations can assist in predicting LIGO-detectable compact object binary mergers. Recent simulations of compact binary evolution suggest the compact object merger rate depends sensitively on the progenitor's metallicity. Rare low-metallicity star formation during galaxy assembly can produce more detected compact binaries than typical star formation. Using detailed simulations of galaxy and chemical evolution, we determine how sensitively the compact binary populations of galaxies with similar present-day appearance depend on the details of their assembly. We also demonstrate by concrete example the extent to which dwarf galaxies overabundantly produce compact binary mergers, particularly binary black holes, relative to more massive galaxies. We discuss the implications for transient multimes...

  19. WISE colours and star-formation in the host galaxies of radio-loud narrow-line Seyfert 1

    CERN Document Server

    Caccianiga, A; Ballo, L; Foschini, L; Maccacaro, T; Della Ceca, R; Severgnini, P; Marcha, M J; Mateos, S; Sani, E

    2015-01-01

    We investigate the mid-infrared properties of the largest (42 objects) sample of radio-loud narrow-line Seyfert 1 (RL NLS1) collected to date, using data from the Wide-field Infrared Survey Explorer (WISE). We analyse the mid-IR colours of these objects and compare them to what is expected from different combinations of AGN and galaxy templates. We find that, in general, the host-galaxy emission gives an importan contribution to the observed mid-IR flux in particular at the longest wavelengths (W3, at 12micron, and W4, at 22micron). In about half of the sources (22 objects) we observe a very red mid-IR colour (W4-W3>2.5) that can be explained only using a starburst galaxy template (M82). Using the 22micron luminosities, corrected for the AGN contribution, we have then estimated the star-formation rate for 20 of these "red" RL NLS1, finding values ranging from 10 to 500 Msun/y. For the RL NLS1 showing bluer colours, instead, we cannot exclude the presence of a star-forming host galaxy although, on average, we ...

  20. The disc-dominated host galaxy of FR-I radio source B2 0722+30

    CERN Document Server

    Emonts, B H C; Morganti, R; Oosterloo, T A; Holt, J; Brogt, E; Van Moorsel, G

    2009-01-01

    We present new observational results that conclude that the nearby radio galaxy B2 0722+30 is one of the very few known disc galaxies in the low-redshift Universe that host a classical double-lobed radio source. In this paper we use HI observations, deep optical imaging, stellar population synthesis modelling and emission-line diagnostics to study the host galaxy, classify the Active Galactic Nucleus and investigate environmental properties under which a radio-loud AGN can occur in this system. Typical for spiral galaxies, B2 0722+30 has a regularly rotating gaseous disc throughout which star formation occurs. Dust heating by the ongoing star formation is likely responsible for the high infrared luminosity of the system. The optical emission-line properties of the central region identify a Low Ionization Nuclear Emission-line Region (LINER)-type nucleus with a relatively low [OIII] luminosity, in particular when compared with the total power of the Fanaroff & Riley type-I radio source that is present in t...

  1. SDSS-II Supernova Survey: An Analysis of the Largest Sample of Type Ia Supernovae and Correlations with Host-Galaxy Spectral Properties

    CERN Document Server

    Wolf, Rachel C; Gupta, Ravi R; Sako, Masao; Fischer, John A; Kessler, Rick; Jha, Saurabh W; March, Marisa C; Scolnic, Daniel M; Fischer, Johanna-Laina; Campbell, Heather; Nichol, Robert C; Olmstead, Matthew D; Richmond, Michael; Schneider, Donald P; Smith, Mathew

    2016-01-01

    Using the largest single-survey sample of Type Ia supernovae (SNe Ia) to date, we study the relationship between properties of SNe Ia and those of their host galaxies, focusing primarily on correlations with Hubble residuals (HR). Our sample consists of 345 photometrically-classified or spectroscopically-confirmed SNeIa discovered as part of the SDSS-II Supernova Survey (SDSS-SNS). This analysis utilizes host-galaxy spectroscopy obtained during the SDSS-I/II spectroscopic survey and from an ancillary program on the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) that obtained spectra for nearly all host galaxies of SDSS-II SN candidates. In addition, we use photometric host-galaxy properties from the SDSS-SNS data release (Sako et al. 2014) such as host stellar mass and star-formation rate. We confirm the well-known relation between HR and host-galaxy mass and find a 3.6{\\sigma} significance of a non-zero linear slope. We also recover correlations between HR and host-galaxy gas-phase metallicity and s...

  2. Optical Identification of Cepheids in 19 Host Galaxies of Type Ia Supernovae and NGC 4258 with the Hubble Space Telescope

    CERN Document Server

    Hoffmann, Samantha L; Riess, Adam G; Yuan, Wenlong; Casertano, Stefano; Filippenko, Alexei V; Tucker, Brad E; Chornock, Ryan; Silverman, Jeffrey M; Welch, Douglas L; Goobar, Ariel; Amanullah, Rahman

    2016-01-01

    We present results of an optical search for Cepheid variable stars using the Hubble Space Telescope (HST) in 19 hosts of Type Ia supernovae (SNe Ia) and the maser-host galaxy NGC 4258, conducted as part of the SH0ES project (Supernovae and H0 for the Equation of State of dark energy). The targets include 9 newly imaged SN Ia hosts using a novel strategy based on a long-pass filter that minimizes the number of HST orbits required to detect and accurately determine Cepheid properties. We carried out a homogeneous reduction and analysis of all observations, including new universal variability searches in all SN Ia hosts, that yielded a total of 2200 variables with well-defined selection criteria -- the largest such sample identified outside the Local Group. These objects are used in a companion paper to determine the local value of H0 with a total uncertainty of 2.4%.

  3. Globular clusters as tracers of the host galaxy mass distribution: the Fornax dSph test case

    OpenAIRE

    Arca-Sedda, Manuel; Capuzzo-Dolcetta, Roberto

    2016-01-01

    The Fornax dwarf spheroidal galaxy is the most massive satellites of the Milky Way, claimed to be embedded in a huge dark matter halo, and the only among the Milky Way satellites hosting five globular clusters. Interestingly, their estimated masses, ages and positions seem hardly compatible with the presence of a significant dark matter component, as expected in the $\\Lambda$ CDM scheme. Indeed, if Fornax would have a CDM halo with a standard density profile, all its globular clusters should ...

  4. Blending bias impacts the host halo masses derived from a cross-correlation analysis of bright sub-millimetre galaxies

    CERN Document Server

    Cowley, William I; Baugh, Carlton M; Cole, Shaun; Wilkinson, Aaron

    2016-01-01

    Placing bright sub-millimetre galaxies (SMGs) within the broader context of galaxy formation and evolution requires accurate measurements of their clustering, which can constrain the masses of their host dark matter halos. Recent work has shown that the clustering measurements of these galaxies may be affected by a `blending bias,' which results in the angular correlation function of the sources extracted from single-dish imaging surveys being boosted relative to that of the underlying galaxies. This is due to confusion introduced by the coarse angular resolution of the single-dish telescope and could lead to the inferred halo masses being significantly overestimated. We investigate the extent to which this bias affects the measurement of the correlation function of SMGs when it is derived via a cross-correlation with a more abundant galaxy population. We find that the blending bias is essentially the same as in the auto-correlation case and conclude that the best way to reduce its effects is to calculate the...

  5. Constraints on Black Hole/Host Galaxy Co-evolution and Binary Stalling Using Pulsar Timing Arrays

    Science.gov (United States)

    Simon, Joseph; Burke-Spolaor, Sarah

    2016-07-01

    Pulsar timing arrays are now setting increasingly tight limits on the gravitational wave background from binary supermassive black holes (SMBHs). But as upper limits grow more constraining, what can be implied about galaxy evolution? We investigate which astrophysical parameters have the largest impact on predictions of the strain spectrum and provide a simple framework to directly translate between measured values for the parameters of galaxy evolution and pulsar timing array (PTA) limits on the gravitational wave background of binary SMBHs. We find that the most influential observable is the relation between a host galaxy's central bulge and its central black hole, {M}\\bullet {--}{M}{bulge}, which has the largest effect on the mean value of the characteristic strain amplitude. However, the variance of each prediction is dominated by uncertainties in galaxy stellar mass functions. Using this framework with the best published PTA limit, we can set limits on the shape and scatter of the {M}\\bullet {--}{M}{bulge} relation. We find our limits to be in contention with strain predictions using two leading measurements of this relation. We investigate several possible reasons for this disagreement. If we take the {M}\\bullet {--}{M}{bulge} relations to be correct within a simple power-law model for the gravitational wave background, then the inconsistency is reconcilable by allowing for an additional “stalling” time between a galaxy merger and evolution of a binary SMBH to sub-parsec scales, with lower limits on this timescale of ∼1–2 Gyr.

  6. AGN Feedback, Host Halo Mass and Central Cooling Time: Implications for Galaxy Formation Efficiency and $M_{BH} - \\sigma$

    CERN Document Server

    Main, Robert; Nulsen, Paul; Russell, Helen; Vantyghem, Adrian

    2015-01-01

    We derive X-ray mass, luminosity, and temperature profiles for 45 galaxy clusters to explore relationships between halo mass, AGN feedback, and central cooling time. We find that radio--mechanical feedback power (referred to here as "AGN power") in central cluster galaxies correlates with halo mass, but only in halos with central atmospheric cooling times shorter than 1 Gyr. This timescale corresponds approximately to the cooling time (entropy) threshold for the onset of cooling instabilities and star formation in central galaxies (Rafferty et al. 2008). No correlation is found in systems with central cooling times greater than 1 Gyr. The trend with halo mass is consistent with self-similar scaling relations assuming cooling is regulated by feedback. The trend is also consistent with galaxy and central black hole co-evolution along the $M_{BH} - \\sigma $ relation. AGN power further correlates with X-ray gas mass and the host galaxy's K-band luminosity. AGN power in clusters with central atmospheric cooling ti...

  7. The Type Ia Supernova Color-Magnitude Relation and Host Galaxy Dust: A Simple Hierarchical Bayesian Model

    CERN Document Server

    Mandel, Kaisey S; Shariff, Hikmatali; Foley, Ryan J; Kirshner, Robert P

    2016-01-01

    Conventional Type Ia supernova (SN Ia) cosmology analyses currently use a simplistic linear regression of magnitude versus color and light curve shape, which does not model intrinsic SN Ia variations and host galaxy dust as physically distinct effects, resulting in low color-magnitude slopes. We construct a probabilistic generative model for the distribution of dusty extinguished absolute magnitudes and apparent colors as a convolution of the intrinsic SN Ia color-magnitude distribution and the host galaxy dust reddening-extinction distribution. If the intrinsic color-magnitude (M_B vs. B-V) slope beta_int differs from the host galaxy dust law R_B, this convolution results in a specific curve of mean extinguished absolute magnitude vs. apparent color. The derivative of this curve smoothly transitions from beta_int in the blue tail to R_B in the red tail of the apparent color distribution. The conventional linear fit approximates this effective curve at this transition near the average apparent color, resultin...

  8. The Afterglow and Early-Type Host Galaxy of the Short GRB 150101B at z=0.1343

    CERN Document Server

    Fong, Wen-fai; Chornock, Ryan; Berger, Edo; Shappee, Benjamin J; Levan, Andrew J; Tanvir, Nial R; Smith, Nathan; Milne, Peter A; Laskar, Tanmoy; Fox, Derek B; Lunnan, Ragnhild; Blanchard, Peter K; Hjorth, Jens; Wiersema, Klaas; van der Horst, Alexander J; Zaritsky, Dennis

    2016-01-01

    We present the discovery of the X-ray and optical afterglows of the short-duration GRB 150101B, pinpointing the event to an early-type host galaxy at z=0.1343 +/- 0.0030. This makes GRB 150101B the most nearby short GRB with an early-type host galaxy discovered to date. Fitting the spectral energy distribution of the host galaxy results in an inferred stellar mass of ~7x10^10 M_sol, stellar population age of ~2-2.5 Gyr, and star formation rate of 9 deg. Using observations extending to ~30 days, we place upper limits of <(2-4)x10^41 erg s^-1 on associated kilonova emission. We compare searches following previous short GRBs to existing kilonova models, and demonstrate the difficulty of performing effective kilonova searches from cosmological short GRBs using current ground-based facilities. We show that at the Advanced LIGO/VIRGO horizon distance of 200 Mpc, searches reaching depths of ~23-24 AB mag are necessary to probe a meaningful range of kilonova models.

  9. Estimations of the Distances of Stellar Collapses in the Galaxy by Analyzing the Energy Spectrum of Neutrino Bursts

    CERN Document Server

    Kemp, Ernesto; Fulgione, Walter; 10.1142/S0218301311040591

    2012-01-01

    The neutrino telescopes of the present generation, depending on their specific features, can reconstruct the neutrino spectra from a galactic burst. Since the optical counterpart could be not available, it is desirable to have at hand alternative methods to estimate the distance of the supernova explosion using only the neutrino data. In this work we present preliminary results on the method we are proposing to estimate the distance from a galactic supernova based only on the spectral shape of the neutrino burst and assumptions on the gravitational binding energy released an a typical supernova explosion due to stellar collapses.

  10. The Swift Burst and Transient Telescope (BAT)

    Science.gov (United States)

    Mushotzky, Richard

    2008-01-01

    The Swift Burst and Transient telescope (BAT) has surveyed the entire sky for the last 3.5 years obtaining the first sensitive all sky survey of the 14-195 kev sky. At high galactic latitudes the vast majority of the detected sources are AGN. Since hard x-rays penetrate all but Compton thick obscuring material (Column densities of 1.6324 atms/sq cm) this survey is unbiased with respect to obscuration, host galaxy type, optical , radio or IR properties. We will present results on the broad band x-ray properties, the nature of the host galaxies, the luminosity function and will discuss a few of the optical, IR and x-ray results in detail.

  11. Galaxy Formation

    DEFF Research Database (Denmark)

    Sparre, Martin

    Galaxy formation is an enormously complex discipline due to the many physical processes that play a role in shaping galaxies. The objective of this thesis is to study galaxy formation with two different approaches: First, numerical simulations are used to study the structure of dark matter and how...... galaxies form stars throughout the history of the Universe, and secondly it is shown that observations of gamma-ray bursts (GRBs) can be used to probe galaxies with active star formation in the early Universe. A conclusion from the hydrodynamical simulations is that the galaxies from the stateof-the-art...

  12. Starbursts and Galaxy Evolution: results from COSMOS survey.

    Science.gov (United States)

    Muñoz-Tuñón, C.; Hinojosa Goñi, R.; Jairo Méndez Abreu, J.; Sánchez Alméida, J.

    2016-06-01

    The search for starbursts galaxies in COSMOS database by a tailored procedure that uses the photometry from SUBARU, results in 220 targets at zsimilar to that of the quiescent galaxies in the survey at the same redshift range. From the detailed analysis of the galaxies images using the HST, the star forming clumps are characterized. The galaxies are of three different kinds, Snot, Snot and diffuse light and multiple knots. The mass of the knots are typically one order of magnitude below that of the host galaxy and the clumps in multiple knot galaxies are bigger the closer they are to the center. The sSFR however does not change with the particular position of the burst in their host galaxy, which suggests a similar process independently of their location. This result applies also to the galaxies at the largest z range (0.9). Our interpretation is that the star formation is happening at all possible locations on the galaxy discs, possibly from gas accreted from the halo or the IGM, with clumps which grow as they spiral and get to the centermost regions. Our previous work on nearby SF -tadpole galaxies of similar mass reported metallicity drops coinciding with the location of the burst what we have interpreted as SF driven by cold flows. Our results in COSMOS would be consistent with a similar interpretation and a scenario in which medium mass disks are growing by gas accretion that show up as scattered starbursts knots.

  13. The abundance of satellites depends strongly on the morphology of the host galaxy

    Science.gov (United States)

    Ruiz, Pablo; Trujillo, Ignacio; Mármol-Queraltó, Esther

    2015-12-01

    Using the spectroscopic catalogue of the Sloan Digital Sky Survey Data Release 10, we have explored the abundance of satellites around a sample of 254 massive (1011 divided our sample into four morphological groups (E, S0, Sa, Sb/c). We find that the number of satellites with M⋆ ≳ 109 M⊙ and R 0.1. The fact that massive elliptical galaxies have a significant larger number of satellites than massive spirals could point out that elliptical galaxies inhabit heavier dark matter haloes than equally massive galaxies with later morphological types. If this hypothesis is correct, the dark matter haloes of late-type spiral galaxies are a factor of ˜2-3 more efficient on producing galaxies with the same stellar mass than those dark matter haloes of early-type galaxies.

  14. An origin in the local Universe for some short gamma-ray bursts.

    Science.gov (United States)

    Tanvir, N R; Chapman, R; Levan, A J; Priddey, R S

    2005-12-15

    Gamma-ray bursts (GRBs) divide into two classes: 'long', which typically have initial durations of T90 > 2 s, and 'short', with durations of T90 origin of short bursts has remained mysterious until recently. A subsecond intense 'spike' of gamma-rays during a giant flare from the Galactic soft gamma-ray repeater, SGR 1806-20, reopened an old debate over whether some short GRBs could be similar events seen in galaxies out to approximately 70 Mpc (refs 6-10; redshift z approximately 0.016). Shortly after that, localizations of a few short GRBs (with optical afterglows detected in two cases) have shown an apparent association with a variety of host galaxies at moderate redshifts. Here we report a correlation between the locations of previously observed short bursts and the positions of galaxies in the local Universe, indicating that between 10 and 25 per cent of short GRBs originate at low redshifts (z < 0.025).

  15. The formation and evolution of supermassive black holes and their host galaxies

    OpenAIRE

    Haehnelt, Martin G.; Kauffmann, Guinevere

    1999-01-01

    We discuss constraints on the assembly history of supermassive black holes from the observed remnant black holes in nearby galaxies and from the emission caused by accretion onto these black holes. We also summarize the results of a specific model for the evolution of galaxies and their central black holes which traces their hierachical build-up in CDM-like cosmogonies. The model assumes (i) that black holes, ellipticals and starburts form during major mergers of galaxies (ii) that the gas fr...

  16. No supernovae detected in two long-duration Gamma-Ray Bursts

    CERN Document Server

    Watson, D; Th"one, C C; Sollerman, J

    2007-01-01

    There is strong evidence that long duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. In the standard version of the Collapsar model, a broad-lined and luminous Type Ic core-collapse supernova (SN) accompanies the GRB. This association has been confirmed in observations of several nearby GRBs. Recent observations show that some long duration GRBs are different. No SN emission accompanied the long duration GRBs 060505 and 060614 down to limits fainter than any known Type Ic SN and hundreds of times fainter than the archetypal SN1998bw that accompanied GRB980425. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration. Furthermore, the bursts originated in star-forming galaxies, and in the case of GRBs060505 the burst was localised to a compact star-forming knot in a spiral arm of its host galaxy. We find that the properties of the host galaxies, the long duration of the bursts and, i...

  17. X-ray Flashes or soft Gamma-ray Bursts? The case of the likely distant XRF 040912

    CERN Document Server

    Stratta, G; Butler, N; Atteia, J L; Gendre, B; Pelangeon, A; Malacrino, F; Mellier, Y; Kann, D A; Klose, S; Zeh, A; Masetti, N; Palazzi, E; Gorosabel, J; Castro-Tirado, A J; De Postigo, A U; Jelinek, M; Cepa, J; Castaneda, H; Martínez-Delgado, D; Boër, M; Braga, J; Crew, G; Donaghy, T Q; Dezalay, J P; Doty, J; Fenimore, E E; Galassi, M; Graziani, C; Jernigan, J G; Kawai, N; Lamb, D Q; Levine, A; Manchanda, J; Martel, F; Matsuoka, M; Nakagawa, Y; Olive, J F; Pizzichini, G; Prigozhin, G Y; Ricker, G; Sakamoto, T; Shirasaki, Y; Sugita, S; Suzuki, M; Takagishi, K; Tamagawa, T; Vanderspek, R; Villasenor, J; Woosley, S E; Yamauchi, M; Yoshida, A

    2006-01-01

    In this work, we present a multi-wavelength study of XRF 040912, aimed at measuring its distance scale and the intrinsic burst properties. We performed a detailed spectral and temporal analysis of both the prompt and the afterglow emission and we estimated the distance scale of the likely host galaxy. We then used the currently available sample of XRFs with known distance to discuss the connection between XRFs and classical Gamma-ray Bursts (GRBs). We found that the prompt emission properties unambiguously identify this burst as an XRF, with an observed peak energy of E_p=17+/-13 keV and a burst fluence ratio S(2-30keV)/S(30-400keV)>1. A non-fading optical source with R~24 mag and with an apparently extended morphology is spatially consistent with the X-ray afterglow, likely the host galaxy. XRF 040912 is a very dark burst since no afterglow optical counterpart is detected down to R>25 mag (3 sigma limiting magnitude) at 13.6 hours after the burst. The host galaxy spectrum detected from 3800A to 10000A, shows...

  18. Origin of X-shaped radio-sources: further insights from the properties of their host galaxies

    CERN Document Server

    Gillone, Melissa; Rossi, Paola

    2015-01-01

    We analyze the properties of a sample of X-shaped radio-sources (XRSs). These objects show, in addition to the main lobes, a pair of wings producing their peculiar radio morphology. We obtain our sample by selecting from the initial list of Cheung (2007, AJ, 133, 2097) the 53 galaxies with the better defined wings and with available SDSS images. We identified the host galaxies and measured their optical position angle, obtaining a positive result in 22 cases. The orientation of the secondary radio structures shows a strong connection with the optical axis, with all (but one) wing forming a angle larger than 40 degrees with the host major axis. The probability that this is compatible with a uniform distribution is P = 0.9 10E-4. Spectra are available from the SDSS for 28 XRSs. We modeled them to extract information on their emission lines and stellar population properties. The sample is formed by approximately the same number of high and low excitation galaxies (HEG and LEG); this classification is essential f...

  19. Providing stringent star formation rate limits of z$\\sim$2 QSO host galaxies at high angular resolution

    CERN Document Server

    Vayner, Andrey; Do, Tuan; Larkin, James E; Armus, Lee; Gallagher, Sarah C

    2014-01-01

    We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z=2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini-North Observatories using OSIRIS and NIFS coupled with the LGS-AO systems. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z=2.15. We demonstrate that the combination of AO and IFS provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a PSF from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy. We detect H$\\alpha$ and [NII] for two sources, SDSS J1029+6510 and SDSS J0925+06 that have both star formation and extended narrow-line emission. Assuming that the majority of narrow-line H$\\alpha$ is from star formation, we inf...

  20. Three intervening galaxy absorbers towards GRB 060418

    DEFF Research Database (Denmark)

    Ellison, S. L.; Vreeswijk, P.; Ledoux, C.;

    2006-01-01

    Dust, extinction: galaxies: ISM: quasars: absorption lines: gamma-rays: bursts Udgivelsesdato: 10 August......Dust, extinction: galaxies: ISM: quasars: absorption lines: gamma-rays: bursts Udgivelsesdato: 10 August...

  1. Progenitor mass constraints for core-collapse supernovae from correlations with host galaxy star formation

    Science.gov (United States)

    Anderson, J. P.; Habergham, S. M.; James, P. A.; Hamuy, M.

    2012-08-01

    Using Hα emission as a tracer of ongoing ( 1An increasing progenitor mass sequence is observed, implied from an increasing association of SNe to host galaxy Hα emission. This commences with the Type Ia showing the weakest association, followed by the Type II, then the Ib, with the Type Ic showing the strongest correlation to star-forming regions. Thus, our progenitor mass sequence runs Ia-II-Ib-Ic. 2Overall, the Type Ibc SNe are found to occur nearer to bright H II regions than SNe of Type II. This implies that the former have shorter stellar lifetimes, thus arising from more massive progenitor stars. 3While Type IIP SNe do not closely follow the ongoing star formation, they accurately trace the recent formation. This implies that their progenitors arise from stars at the low end of the CC SN mass sequence, consistent with direct detections of progenitors in pre-explosion imaging. 4Similarly, the Type IIn SNe trace recent but not the ongoing star formation. This implies that, contrary to the general consensus, the majority of these SN do not arise from the most massive stars. Results and suggestive constraints are also presented for the less numerous SNe of Types IIL and IIb, and SN 'impostors'. Finally, we present an analysis of possible biases in the data, the results of which argue strongly against any selection effects that could explain the relative excess of Type Ibc SNe within bright H II regions. Thus, intrinsic progenitor differences in the sense of the mass sequence we propose remain the most plausible explanation of our findings. Based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, observations made with the Liverpool Telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de

  2. The Effects of X-Ray Feedback from AGN on Host Galaxy Evolution

    CERN Document Server

    Hambrick, D Clay; Naab, Thorsten; Johansson, Peter H

    2011-01-01

    Hydrodynamic simulations of galaxies with active galactic nuclei (AGN) have typically employed feedback that is purely local: i.e., an injection of energy to the immediate neighborhood of the black hole. We perform GADGET-2 simulations of massive elliptical galaxies with an additional feedback component: an observationally calibrated X-ray radiation field which emanates from the black hole and heats gas out to large radii from the galaxy center. We find that including the heating and radiation pressure associated with this X-ray flux in our simulations enhances the effects which are commonly reported from AGN feedback. This new feedback model is twice as effective as traditional feedback at suppressing star formation, produces 3 times less star formation in the last 6 Gyr, and modestly lowers the final BH mass (30%). It is also significantly more effective than an X-ray background in reducing the number of satellite galaxies.

  3. Understanding the formation and evolution of early-type galaxies based on newly developed single-burst stellar population synthesis models in the infrared

    Science.gov (United States)

    Roeck, Benjamin

    2015-12-01

    The detailed study of the different stellar populations which can be observed in galaxies is one of the most promising methods to shed light on the evolutionary histories of galaxies. So far, stellar population analysis has been carried out mainly in the optical wavelength range. The infrared spectral range, on the other hand, has been poorly studied so far, although it provides very important insights, particularly into the cooler stellar populations which are present in galaxies. However, in the last years, space telescopes like the Spitzer Space Telescope or the Wide-field Infrared Survey Explorer and instruments like the spectrograph X-Shooter on the Very Large Telescope have collected more and more photometric and spectroscopic data in this wavelength range. In order to analyze these observations, it is necessary to dispose of reliable and accurate stellar population models in the infrared. Only a small number of stellar population models in the infrared exist in the literature. They are mostly based on theoretical stellar libraries and very often cover only the near-infrared wavelength range at a rather low resolution. Hence, we developed new single-burst stellar population models between 8150 and 50000Å which are exclusively based on 180 spectra from the empirical Infrared Telescope Facility stellar library. We computed our single stellar population models for two different sets of isochrones and various types of initial mass functions of different slopes. Since the stars of the Infrared Telescope Facility library present only a limited coverage of the stellar atmospheric parameter space, our models are of sufficient quality only for ages larger than 1 Gyr and metallicities between [Fe/H] = 0.40 and 0.26. By combining our single stellar population models in the infrared with the extended medium-resolution Isaac Newton Telescope library of empirical spectra in the optical spectral range, we created the first single stellar population models covering the

  4. Detailed afterglow modelling and host galaxy properties of the dark GRB 111215A

    DEFF Research Database (Denmark)

    Horst, A. J. van der; Levan, A. J.; Pooley, G. G.;

    2015-01-01

    Gamma-ray burst (GRB) 111215A was bright at X-ray and radio frequencies, but not detected in the optical or near-infrared (nIR) down to deep limits. We have observed the GRB afterglow with the Westerbork Synthesis Radio Telescope and Arcminute Microkelvin Imager at radio frequencies, with the Wil...

  5. THE TRUE DURATIONS OF STARBURSTS: HUBBLE SPACE TELESCOPE OBSERVATIONS OF THREE NEARBY DWARF STARBURST GALAXIES

    International Nuclear Information System (INIS)

    The duration of a starburst is a fundamental parameter affecting the evolution of galaxies yet, to date, observational constraints on the durations of starbursts are not well established. Here we study the recent star formation histories of three nearby dwarf galaxies to rigorously quantify the duration of their starburst events using a uniform and consistent approach. We find that the bursts range from ∼200 to ∼400 Myr in duration resolving the tension between the shorter timescales often derived observationally with the longer timescales derived from dynamical arguments. If these three starbursts are typical of starbursts in dwarf galaxies, then the short timescales (3-10 Myr) associated with starbursts in previous studies are best understood as 'flickering' events which are simply small components of the larger starburst. In this sample of three nearby dwarfs, the bursts are not localized events. All three systems show bursting levels of star formation in regions of both high and low stellar density. The enhanced star formation moves around the galaxy during the bursts and covers a large fraction of the area of the galaxy. These massive, long-duration bursts can significantly affect the structure, dynamics, and chemical evolution of the host galaxy and can be the progenitors of 'superwinds' that drive much of the recently chemically enriched material from the galaxy into the intergalactic medium.

  6. Illuminating the Darkest Gamma-Ray Bursts with Radio Observations

    CERN Document Server

    Zauderer, B A; Margutti, R; Levan, A J; Olivares, F; Perley, D A; Fong, W; Horesh, A; Updike, A C; Greiner, J; Tanvir, N R; Laskar, T; Chornock, R; Soderberg, A M; Menten, K M; Nakar, E; Carpenter, J; Chandra, P

    2012-01-01

    We present X-ray, optical, near-infrared, and radio observations of GRBs 110709B and 111215A, as well as optical and near-IR observations of their host galaxies. The combination of X-ray detections and deep optical/near-infrared limits establish both bursts as "dark". Sub-arcsecond positions enabled by radio detections lead to robust host galaxy associations, with optical detections that indicate z 5.3 mag and GRB 111215A requires A_V > 8.5 mag (z=2), among the largest extinction values inferred for dark bursts to-date. The two bursts also exhibit large neutral hydrogen column densities (N_H > 10^22/cm^2; z=2) as inferred from their X-ray spectra, in agreement with the trend for dark GRBs. Finally, we find that for both bursts the afterglow emission is best explained by a collimated outflow with a total beaming-corrected energy of E_gamma+E_K ~ 7-9 x 10^51 erg (z=2) expanding into a wind medium with a high density (n~100-350 cm^-3 at 10^17 cm). While the energy release is typical of long GRBs, the inferred d...

  7. K-band Imaging of strong CaII-absorber host galaxies at z~1

    CERN Document Server

    Hewett, Paul

    2007-01-01

    We present K-band imaging of fields around 30 strong CaII absorption line systems, at 0.7galaxies is found within 6"0 (~50kpc) from the absorber line-of-sight. The excess galaxies are preferentially luminous compared to the population of field galaxies. A model in which field galaxies possess a luminosity-dependent cross-section for CaII absorption of the form (L/L*)^0.7 reproduces the observations well. The luminosity-dependent cross-section for the CaII absorbers appears to be significantly stronger than the established (L/L*)^0.4 dependence for MgII absorbers. The associated galaxies lie at large physical distances from the CaII-absorbing gas; we find a mean impact parameter of 24kpc (H0=70km\\s\\Mpc). Combined with the observed number density of CaII absorbers the large physical separations result in an inferred filling factor of only ~10 per cent. The physical origin of the strong CaII absorption remains unclear,...

  8. Evidence of suppression of star formation by quasar-driven winds in gas-rich host galaxies at z<1?

    CERN Document Server

    Wylezalek, Dominika

    2016-01-01

    Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies through heating or driving gas out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been scarce. We have assembled a sample of 132 radio-quiet type-2 and red AGN at 0.1host galaxies' stellar masses and star formation rates and investigate the relationships between AGN luminosities, specific star formation rates (sSFR) and outflow strengths W90 -- the 90\\% velocity width of the [OIII]5007 line power and a proxy for the AGN-driven outflow speed. Outflow strength is independent of sSFR for AGN selected on their mid-IR luminosity, in agreement with previous work demonstrating that star formation is not sufficient to produce the observed ionized gas outflows which have to be powered by AGN activity. More importantly, we find a negative correlation between W90...

  9. Bright [CII] 158$\\mu$m emission in a quasar host galaxy at $z=6.54$

    CERN Document Server

    Bañados, E; Walter, F; Venemans, B P; Farina, E P; Fan, X

    2015-01-01

    The [CII] 158$\\mu$m fine-structure line is known to trace regions of active star formation and is the main coolant of the cold, neutral atomic medium. In this \\textit{Letter}, we report a strong detection of the [CII] line in the host galaxy of the brightest quasar known at $z>6.5$, the Pan-STARRS1 selected quasar PSO J036.5078+03.0498 (hereafter P036+03), using the IRAM NOEMA millimeter interferometer. Its [CII] and total far-infrared luminosities are $(5.8 \\pm 0.7) \\times 10^9 \\,L_\\odot$ and $(7.6\\pm1.5) \\times 10^{12}\\,L_\\odot$, respectively. This results in a $L_{[CII]} /L_{TIR}$ ratio of $\\sim 0.8\\times 10^{-3}$, which is at the high end for those found for active galaxies, though it is lower than the average found in typical main sequence galaxies at $z\\sim 0$. We also report a tentative additional line which we identify as a blended emission from the $3_{22} - 3_{13}$ and $5_{23} - 4_{32}$ H$_2$O transitions. If confirmed, this would be the most distant detection of water emission to date. P036+03 riva...

  10. The Swift GRB Host Galaxy Legacy Survey - II. Rest-Frame NIR Luminosity Distribution and Evidence for a Near-Solar Metallicity Threshold

    CERN Document Server

    Perley, D A; Hjorth, J; Laskar, T; Berger, E; Chary, R; Postigo, A de Ugarte; Fynbo, J P U; Krühler, T; Levan, A J; Michałowski, M J; Schulze, S

    2016-01-01

    We present rest-frame NIR luminosities and stellar masses for a large and uniformly-selected population of GRB host galaxies using deep Spitzer Space Telescope imaging of 117 targets from the Swift GRB Host Galaxy Legacy Survey spanning 0.03 2; metals stifle GRB production in most galaxies at z<1.5 but have only minor impact at higher redshifts. The metallicity threshold we infer is much higher than predicted by single-star models and favors a binary progenitor. Our observations also constrain the fraction of cosmic star-formation in low-mass galaxies undetectable to Spitzer to be a small minority at most redshifts (~10% at z~2, ~25% at z~3, and ~50% at z=3.5-6.0).

  11. Two gamma-ray bursts from dusty regions with little molecular gas

    CERN Document Server

    Hatsukade, B; Endo, A; Nakanishi, K; Tamura, Y; Hashimoto, T; Kohno, K

    2014-01-01

    Long-duration gamma-ray bursts are associated with the explosions of massive stars and are accordingly expected to reside in star-forming regions with molecular gas (the fuel for star formation). Previous searches for carbon monoxide (CO), a tracer of molecular gas, in burst host galaxies did not detect any emission. Molecules have been detected as absorption in the spectra of gamma-ray burst afterglows, and the molecular gas is similar to the translucent or diffuse molecular clouds of the Milky Way. Absorption lines probe the interstellar medium only along the line of sight, so it is not clear whether the molecular gas represents the general properties of the regions where the bursts occur. Here we report spatially resolved observations of CO line emission and millimetre-wavelength continuum emission in two galaxies hosting gamma-ray bursts. The bursts happened in regions rich in dust, but not particularly rich in molecular gas. The ratio of molecular gas to dust (<9-14) is significantly lower than in sta...

  12. MUSE Reveals a Recent Merger in the Post-starburst Host Galaxy of the TDE ASASSN-14li

    CERN Document Server

    Prieto, J L; Anderson, J P; Galbany, L; Kochanek, C S; Aquino, E; Brown, J S; Dong, Subo; Förster, F; Holoien, T W -S; Kuncarayakti, H; Maureira, J C; Rosales-Ortega, F F; Sánchez, S F; Shappee, B J; Stanek, K Z

    2016-01-01

    We present MUSE integral field spectroscopic observations of the host galaxy (PGC 043234) of one of the closest ($z=0.0206$, $D\\simeq 90$ Mpc) and best-studied tidal disruption events (TDE), ASASSN-14li. The MUSE integral field data reveal asymmetric and filamentary structures that extend up to $\\gtrsim 10$ kpc from the post-starburst host galaxy of ASASSN-14li. The structures are traced only through the strong nebular [O III] $\\lambda$5007, [N II] $\\lambda$6584, and H$\\alpha$ emission lines. The total off nuclear [O III] $\\lambda$5007 luminosity is luminosity is $4.7\\times 10^{39}$ erg s$^{-1}$ and the ionized H mass is $\\rm \\sim 10^4(500/n_e)\\,M_{\\odot}$. Based on the BPT diagram, the nebular emission can be driven by either AGN photoionization or shock excitation, with AGN photoionization favored given the narrow intrinsic line widths. The emission line ratios and spatial distribution strongly resemble ionization nebulae around fading AGNs such as IC 2497 (Hanny's Voorwerp) and ionization "cones" around Se...

  13. PS1-10bzj: A Fast, Hydrogen-Poor Superluminous Supernova in a Metal Poor Host Galaxy

    CERN Document Server

    Lunnan, R; Berger, E; Milisavljevic, D; Drout, M; Sanders, N E; Challis, P M; Czekala, I; Foley, R J; Fong, W; Huber, M E; Kirshner, R P; Leibler, C; Marion, G H; McCrum, M; Narayan, G; Rest, A; Roth, K C; Scolnic, D; Smartt, S J; Smith, K; Soderberg, A M; Stubbs, C W; Tonry, J L; Burgett, W S; Chambers, K C; Kudritzki, R -P; Magnier, E A; Price, P A

    2013-01-01

    We present observations and analysis of PS1-10bzj, a superluminous supernova (SLSN) discovered in the Pan-STARRS Medium Deep Survey at a redshift z = 0.650. Spectroscopically, PS1-10bzj is similar to the hydrogen-poor SLSNe 2005ap and SCP 06F6, though with a steeper rise and lower peak luminosity (M_bol = -21.4 mag) than previous events. We construct a bolometric light curve, and show that while PS1-10bzj's energetics were less extreme than previous events, its luminosity still cannot be explained by radioactive nickel decay alone. We explore both a magnetar spin-down and circumstellar interaction scenario and find that either can fit the data. PS1-10bzj is located in the Extended Chandra Deep Field South (ECDF-S) and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (M_B ~ -18 mag, diameter < 800 pc), with a low stellar mass (M_* ~ 2.4 * 10^7 M_sun), young stellar population (\\tau_* ~ 5 Myr), and a star formation rate of ~ 2-3 M...

  14. Reaching the Peak of the quasar spectral energy distribution - II. Exploring the accretion disc, dusty torus and host galaxy

    CERN Document Server

    Collinson, James S; Landt, Hermine; Done, Chris; Elvis, Martin; McDowell, Jonathan C

    2016-01-01

    We continue our study of the spectral energy distributions (SEDs) of 11 AGN at 1.5 < z < 2.2, with optical-NIR spectra, X-ray data and mid-IR photometry. In a previous paper we presented the observations and models; in this paper we explore the parameter space of these models. We first quantify uncertainties on the black hole masses (M$_{\\rm BH}$) and degeneracies between SED parameters. The effect of BH spin is tested, and we find that while low to moderate spin values (a$_*$ $\\leq$ 0.9) are compatible with the data in all cases, maximal spin (a$_*$ = 0.998) can only describe the data if the accretion disc is face-on. The outer accretion disc radii are well constrained in 8/11 objects, and are found to be a factor ~5 smaller than the self-gravity radii. We then extend our modelling campaign into the mid-IR regime with WISE photometry, adding components for the host galaxy and dusty torus. Our estimates of the host galaxy luminosities are consistent with the M$_{\\rm BH}$-bulge relationship, and the meas...

  15. Optical Identification of Cepheids in 19 Host Galaxies of Type Ia Supernovae and NGC 4258 with the Hubble Space Telescope

    Science.gov (United States)

    Hoffmann, Samantha L.; Macri, Lucas M.; Riess, Adam G.; Yuan, Wenlong; Casertano, Stefano; Foley, Ryan J.; Filippenko, Alexei V.; Tucker, Brad E.; Chornock, Ryan; Silverman, Jeffrey M.; Welch, Douglas L.; Goobar, Ariel; Amanullah, Rahman

    2016-10-01

    We present results of an optical search conducted as part of the SH0ES project (Supernovae and H0 for the Equation of State of dark energy) for Cepheid variable stars using the Hubble Space Telescope (HST) in 19 hosts of Type Ia supernovae (SNe Ia) and the maser-host galaxy NGC 4258. The targets include nine newly imaged SN Ia hosts using a novel strategy based on a long-pass filter that minimizes the number of HST orbits required to detect and accurately determine Cepheid properties. We carried out a homogeneous reduction and analysis of all observations, including new universal variability searches in all SN Ia hosts, which yielded a total of 2200 variables with well-defined selection criteria, the largest such sample identified outside the Local Group. These objects are used in a companion paper to determine the local value of H0 with a total uncertainty of 2.4%. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  16. ALMA observations of the host galaxy of GRB 090423 at z = 8.23: deep limits on obscured star formation 630 million years after the big bang

    International Nuclear Information System (INIS)

    We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3σ limits of F ν(222 GHz) ≲ 33 μJy and F ν(3.6 μm) ≲ 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M 82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L IR(8-1000 μm) ≲ 3 × 1010 L ☉, corresponding to a limit on the obscured star formation rate of SFRIR≲5 M ☉ yr–1. For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFRUV ≲ 1 M ☉ yr–1. We also place a limit on the host galaxy stellar mass of M * ≲ 5 × 107 M ☉ (for a stellar population age of 100 Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z ≳ 4 (Lyman break galaxies, Lyα emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z ≳ 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

  17. ALMA observations of the host galaxy of GRB 090423 at z = 8.23: deep limits on obscured star formation 630 million years after the big bang

    Energy Technology Data Exchange (ETDEWEB)

    Berger, E.; Zauderer, B. A.; Chary, R.-R.; Laskar, T.; Chornock, R.; Davies, J. E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Stanway, E. R.; Levan, A. J. [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Levesque, E. M. [CASA, University of Colorado UCB 389, Boulder, CO 80309 (United States)

    2014-12-01

    We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3σ limits of F {sub ν}(222 GHz) ≲ 33 μJy and F {sub ν}(3.6 μm) ≲ 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M 82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L {sub IR}(8-1000 μm) ≲ 3 × 10{sup 10} L {sub ☉}, corresponding to a limit on the obscured star formation rate of SFR{sub IR}≲5 M {sub ☉} yr{sup –1}. For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFR{sub UV} ≲ 1 M {sub ☉} yr{sup –1}. We also place a limit on the host galaxy stellar mass of M {sub *} ≲ 5 × 10{sup 7} M {sub ☉} (for a stellar population age of 100 Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z ≳ 4 (Lyman break galaxies, Lyα emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z ≳ 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

  18. WHICH GALAXIES HOST BARS AND DISKS? A STUDY OF THE COMA CLUSTER

    International Nuclear Information System (INIS)

    We present a study of the bar fraction in the Coma Cluster galaxies based on a sample of ∼190 galaxies selected from the Sloan Digital Sky Survey Data Release 6 and observed with the Hubble Space Telescope (HST) Advanced Camera for Survey (ACS). The unprecedented resolution of the HST-ACS images allows us to explore the presence of bars, detected by visual classification, throughout a luminosity range of 9 mag (-23 ∼r ∼r ∼9∼*/Modot∼11). This result holds when compared with a sample of bright/massive field galaxies. In addition, we find that the bar fraction does not vary significantly when going from the center to the cluster outskirts, implying that cluster environment plays a second-order role in bar formation/evolution. The shape of the bar fraction distribution with respect to both luminosity and mass is well matched by the luminosity distribution of disk galaxies in Coma, indicating that bars are good tracers of cold stellar disks. We discuss the implications of our results for the formation and evolution scenarios of bars and disks.

  19. A Complete Sample of Ultraluminous X-ray Source Host Galaxies

    Science.gov (United States)

    Swartz, Douglas A.; Soria, Roberto; Tennant, Allyn F.; Yukita, Mihoko

    2011-11-01

    One hundred seven ultraluminous X-ray sources (ULXs) with 0.3-10.0 keV luminosities in excess of 1039 erg s-1 are identified in a complete sample of 127 nearby galaxies. The sample includes all galaxies within 14.5 Mpc above the completeness limits of both the Uppsala Galaxy Catalogue and the Infrared Astronomical Satellite survey. The galaxy sample spans all Hubble types, a four-decade range in mass, 7.5 model and on whether the ULX luminosities are estimated from their observed numbers of counts or, for a subset of candidates, from their spectral shapes. Extrapolating the observed luminosity function predicts at most one very luminous ULX, L X ~ 1041 erg s-1, within a distance as small as 100 Mpc. The luminosity distribution of ULXs within the local universe cannot account for the recent claims of luminosities in excess of 2 × 1041 erg s-1, requiring a new population class to explain these extreme objects.

  20. PS1-10bzj: A FAST, HYDROGEN-POOR SUPERLUMINOUS SUPERNOVA IN A METAL-POOR HOST GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Lunnan, R.; Chornock, R.; Berger, E.; Milisavljevic, D.; Drout, M.; Sanders, N. E.; Challis, P. M.; Czekala, I.; Foley, R. J.; Fong, W.; Kirshner, R. P.; Leibler, C.; Marion, G. H.; Narayan, G. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Huber, M. E. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); McCrum, M.; Smartt, S. J. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Rest, A. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Roth, K. C. [Gemini Observatory, 670 N. Aohoku Place, Hilo, HI 96720 (United States); Scolnic, D., E-mail: rlunnan@cfa.harvard.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); and others

    2013-07-10

    We present observations and analysis of PS1-10bzj, a superluminous supernova (SLSN) discovered in the Pan-STARRS Medium Deep Survey at a redshift z = 0.650. Spectroscopically, PS1-10bzj is similar to the hydrogen-poor SLSNe 2005ap and SCP 06F6, though with a steeper rise and lower peak luminosity (M{sub bol} {approx_equal} -21.4 mag) than previous events. We construct a bolometric light curve, and show that while PS1-10bzj's energetics were less extreme than previous events, its luminosity still cannot be explained by radioactive nickel decay alone. We explore both a magnetar spin-down and circumstellar interaction scenario and find that either can fit the data. PS1-10bzj is located in the Extended Chandra Deep Field South and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (M{sub B} Almost-Equal-To -18 mag, diameter {approx}< 800 pc), with a low stellar mass (M{sub *} Almost-Equal-To 2.4 Multiplication-Sign 10{sup 7} M{sub Sun }), young stellar population ({tau}{sub *} Almost-Equal-To 5 Myr), and a star formation rate of {approx}2-3 M{sub Sun} yr{sup -1}. The specific star formation rate is the highest seen in an SLSN host so far ({approx}100 Gyr{sup -1}). We detect the [O III] {lambda}4363 line, and find a low metallicity: 12 + (O/H) = 7.8 {+-} 0.2 ({approx_equal} 0.1 Z{sub Sun }). Together, this indicates that at least some of the progenitors of SLSNe come from young, low-metallicity populations.

  1. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    Energy Technology Data Exchange (ETDEWEB)

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States); Ryan, R. E.; Koekemoer, A. M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Schneider, G.; Fan, X. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hathi, N. P. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Keel, W. C. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Roettgering, H. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Strauss, M. A. [Princeton University Observatory, Princeton, NJ 08544 (United States); Yan, H. J. [Department of Physics and Astronomy, The University of Missouri, 701 South College Ave, Columbia, MO 65211 (United States)

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  2. A Search for "Dwarf" Seyfert Nuclei; 3, Spectroscopic Parameters and Properties of the Host Galaxies

    CERN Document Server

    Ho, L C; Sargent, W L W; Ho, Luis C.; Filippenko, Alexei V.; Sargent, Wallace L. W.

    1997-01-01

    We have completed an optical spectroscopic survey of the nuclear regions (r < 200 pc) of a large sample of nearby galaxies. Although the main objectives of the survey are to search for low-luminosity active galactic nuclei and to quantify their luminosity function, the database can be used for a variety of other purposes. This paper presents measurements of the spectroscopic parameters for the 418 emission-line nuclei, along with a compilation of the global properties of all 486 galaxies in the survey. Stellar absorption generally poses a serious obstacle to obtaining accurate measurement of emission lines in nearby galactic nuclei. We describe a procedure for removing the starlight from the observed spectra in an efficient and objective manner. The main parameters of the emission lines (intensity ratios, fluxes, profile widths, equivalent widths) are measured and tabulated, as are several stellar absorption-line and continuum indices useful for studying the stellar population. Using standard nebular diagn...

  3. Identifying the Location in the Host Galaxy of Short GRB 1111l7A with the Chandra Sub- Arcsecond Position

    Science.gov (United States)

    Sakamoto, Takanori; Troja, E.; Aoki, K.; Guiriec, S.; Im, M.; Leloudas, G.; Malesani, D.; Melandri, A.; deUgartePostigo, A.; Urata, Y.; Xu, D.; DAvanzo, P.; Gorosabel, J.; Anderson, M. I.; Fynbo, J. P. U.; Aoki, K.; Sanchez-Ramirez, R.

    2012-01-01

    We present our successful program using Chandra for identifying the X-ray afterglow with sub-arcsecond accuracy for the short GRB 111117A d iscovered by Swift and Fermi. Thanks to our rapid target of opportuni ty request, Chandra clearly detected the X-ray afterglow, whereas no optical afterglow was found in deep optical observations. Instead, we clearly detect the host galaxy in optica; and also in near-infrared b ands. We found that the best photometric redshift fitofthe host is z = 1.31:(+0.46/-0.23) (90% confidence), making it one of the highest redshift short GRBs. Furthermore, we see an offset of 1.0+/-O.2 arcseco nds, which corresponds to 8.4+/-1.7 kpc aSBuming z= 1.31, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining sub-arcsecond localization of the afterglow in X -rays for short GRBs to study GRB environments in great detail.

  4. Identifying the Location in the Host Galaxy of Short GRB 111117A with the Chandra Sub-arcsecond Position

    CERN Document Server

    Sakamoto, T; Aoki, K; Guiriec, S; Im, M; Leloudas, G; Malesani, D; Melandri, A; Postigo, A de Ugarte; Urata, Y; Xu, D; D'Avanzo, P; Gorosabel, J; Jeon, Y; Sanchez-Ramirez, R; Andersen, M I; Bai, J; Barthelmy, S D; Briggs, M S; Foley, S; Fruchter, A S; Fynbo, J P U; Gehrels, N; Huang, K; Jang, M; Kawai, N; Korhonen, H; Mao, J; Norris, J P; Preece, R D; Racusin, J L; Thone, C C; Vida, K; Zhao, X

    2012-01-01

    We present our successful program using Chandra for identifying the X-ray afterglow with sub-arcsecond accuracy for the short GRB 111117A discovered by Swift and Fermi. Thanks to our rapid target of opportunity request, Chandra clearly detected the X-ray afterglow, whereas no optical afterglow was found in deep optical observations. Instead, we clearly detect the host galaxy in optical and also in near-infrared bands. We found that the best fit photometric redshift of the host is $z=1.31_{-0.23}^{+0.46}$ (90% confidence), making it one of the highest redshift short GRBs. Furthermore, we see an offset of $1.0 \\pm 0.2$ arcseconds, which corresponds to $8.4 \\pm 1.7$ kpc assuming z=1.31, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining sub-arcsecond localization of the afterglow in X-rays for short GRBs to study GRB environments in great detail.

  5. ILLUMINATING THE DARKEST GAMMA-RAY BURSTS WITH RADIO OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Zauderer, B. A.; Berger, E.; Margutti, R.; Fong, W.; Laskar, T.; Chornock, R.; Soderberg, A. M. [Department of Astronomy, Harvard University, Cambridge, MA 02138 (United States); Levan, A. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Olivares E, F.; Greiner, J. [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Perley, D. A.; Horesh, A.; Carpenter, J. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91225 (United States); Updike, A. C. [Department of Chemistry and Physics, Roger Williams University, Bristol, RI 02809 (United States); Tanvir, N. R. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Menten, K. M. [Max-Planck-Institut fuer Radioastronomie, D-53121 Bonn (Germany); Nakar, E. [Department of Astrophysics, Sackler School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv (Israel); Chandra, P. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune University Campus, Ganeshkhind, Pune 411007 (India); Castro-Tirado, A. J. [Instituto de Astrofisica de Andalucia (IAA-CSIC), P.O. Box 03004, E-18080 Granada (Spain); Bremer, M. [Institut de Radioastronomie Millimetrique, 300 rue de la Piscine, F-38406 Saint Martin d' Heres (France); and others

    2013-04-20

    We present X-ray, optical, near-infrared (IR), and radio observations of gamma-ray bursts (GRBs) 110709B and 111215A, as well as optical and near-IR observations of their host galaxies. The combination of X-ray detections and deep optical/near-IR limits establish both bursts as ''dark''. Sub-arcsecond positions enabled by radio detections lead to robust host galaxy associations, with optical detections that indicate z {approx}< 4 (110709B) and z Almost-Equal-To 1.8-2.9 (111215A). We therefore conclude that both bursts are dark due to substantial rest-frame extinction. Using the radio and X-ray data for each burst we find that GRB 110709B requires A{sub V}{sup host}{approx}>5.3 mag and GRB 111215A requires A{sub V}{sup host}{approx}>8.5 mag (assuming z = 2). These are among the largest extinction values inferred for dark bursts to date. The two bursts also exhibit large neutral hydrogen column densities of N{sub H,{sub int}} {approx}> 10{sup 22} cm{sup -2} (z = 2) as inferred from their X-ray spectra, in agreement with the trend for dark GRBs. Moreover, the inferred values are in agreement with the Galactic A{sub V} -N{sub H} relation, unlike the bulk of the GRB population. Finally, we find that for both bursts the afterglow emission is best explained by a collimated outflow with a total beaming-corrected energy of E{sub {gamma}} + E{sub K} Almost-Equal-To (7-9) Multiplication-Sign 10{sup 51} erg (z = 2) expanding into a wind medium with a high density, M Almost-Equal-To (6-20) Multiplication-Sign 10{sup -5} M{sub Sun} yr{sup -1} (n Almost-Equal-To 100-350 cm{sup -3} at Almost-Equal-To 10{sup 17} cm). While the energy release is typical of long GRBs, the inferred density may be indicative of larger mass-loss rates for GRB progenitors in dusty (and hence metal rich) environments. This study establishes the critical role of radio observations in demonstrating the origin and properties of dark GRBs. Observations with the JVLA and ALMA will provide a

  6. REDSHIFT 6.4 HOST GALAXIES OF 108 SOLAR MASS BLACK HOLES: LOW STAR FORMATION RATE AND DYNAMICAL MASS

    International Nuclear Information System (INIS)

    We present Atacama Large Millimeter Array observations of rest-frame far-infrared continuum and [C II] line emission in two z = 6.4 quasars with black hole masses of ≈108 M☉. CFHQS J0210–0456 is detected in the continuum with a 1.2 mm flux of 120 ± 35 μJy, whereas CFHQS J2329–0301 is undetected at a similar noise level. J2329–0301 has a star formation rate limit of ☉ yr–1, considerably below the typical value at all redshifts for this bolometric luminosity. Through comparison with hydro simulations, we speculate that this quasar is observed at a relatively rare phase where quasar feedback has effectively shut down star formation in the host galaxy. [C II] emission is also detected only in J0210–0456. The ratio of [C II] to far-infrared luminosity is similar to that of low-redshift galaxies of comparable luminosity, suggesting that the previous finding of an offset in the relationships between this ratio and far-infrared luminosity at low and high redshifts may be partially due to a selection effect due to the limited sensitivity of previous continuum data. The [C II] line of J0210–0456 is relatively narrow (FWHM = 189 ± 18 km s–1), indicating a dynamical mass substantially lower than expected from the local black hole-velocity dispersion correlation. The [C II] line is marginally resolved at 0.''7 resolution with the blue and red wings spatially offset by 0.''5 (3 kpc) and a smooth velocity gradient of 100 km s–1 across a scale of 6 kpc, possibly due to the rotation of a galaxy-wide disk. These observations are consistent with the idea that stellar mass growth lags black hole accretion for quasars at this epoch with respect to more recent times.

  7. The scaling relation between the mass of supermassive black holes and the kinetic energy of random motions of the host galaxies

    CERN Document Server

    Mancini, Luigi

    2011-01-01

    Thanks to the angular resolution of modern telescopes and kinematic models, the existence of supermassive black holes (SMBHs) in the inner part of galaxies has been established on quite solid grounds. A possible correlation between the mass of SMBHs and the evolutionary state of their host galaxies is expected. Based on the recent 2D decomposition of mid-infrared Spiter/IRAC images of local galaxies with M_bh measurements, we investigated various scaling laws, studying what the best predictor of the mass of the central SMBHs is. We focused on the M_bh-M_G sigma^2 law, the relation between the mass of SMBHs and the kinetic energy of random motions of the corresponding host galaxies. In order to find the best fit for each of the scaling laws examined, we performed a least-squares regression of M_bh on x for the considered sample of galaxies, x being a whatever known parameter of the galaxy bulge. Our analysis shows that M_bh-M_G sigma^2 law fits the examined experimental data successfully as much as the other k...

  8. Are LGRBs biased tracers of star formation? Clues from the host galaxies of the BAT6 complete sample of LGRBs. I: Stellar mass at z<1

    CERN Document Server

    Vergani, S D; Japelj, J; Floc'h, E Le; D'Avanzo, P; Fernandez-Soto, A; Krühler, T; Melandri, A; Boissier, S; Covino, S; Puech, M; Greiner, J; Hunt, L K; Perley, D; Petitjean, P; Hammer, F; Levan, A; Mannucci, F; Campana, S; Flores, H; Gomboc, A; Tagliaferri, G

    2014-01-01

    LGRBs are associated with massive stars and are therefore linked to star formation. The conditions necessary to produce LGRBs can affect the relation between the LGRB rate and star formation. By using the power of a complete LGRB sample, our aim is to understand whether such a bias exists and, if it does, what is its origin. In this first paper, we build the SED of the z<1 host galaxies of the BAT6 LGRB sample, and determine their stellar masses from SED fitting. We compare the resulting stellar mass distribution (i) with star-forming galaxies observed in deep surveys (UltraVISTA); (ii) with semi-analitical models of the z<1 star forming galaxy population and (iii) with numerical simulations of LGRB hosts having different metallicity thresholds for the progenitor star environment. We find that at z<1 LGRBs tend to avoid massive galaxies and are powerful in selecting faint low-mass star-forming galaxies. The stellar mass distribution of the hosts is not consistent with that of the UltraVISTA star-form...

  9. Structural Transition in the NGC 6251 Jet: An Interplay with the Supermassive Black Hole and Its Host Galaxy

    CERN Document Server

    Tseng, Chih-Yin; Nakamura, Masanori; Pu, Hung-Yi; Algaba, Juan-Carlos; Lo, Wen-Ping

    2016-01-01

    The structure of the NGC 6251 jet at the milliarcsecond scale is investigated using the images taken with the European VLBI Network and the Very Long Baseline Array. We detect a structural transition of the jet from a parabolic to a conical shape at a distance of (1-2) x 10^5 times the Schwarzschild radius from the central engine, which is close to the sphere of gravitational influence (SGI) of the supermassive black hole (SMBH). We also examine the jet pressure profiles with the synchrotron minimum energy assumption to discuss the physical origin of the structural transition. The NGC 6251 jet, together with the M 87 jet, suggests a fundamental process of the structural transition in active galactic nuclei (AGN) jets. The collimated AGN jets are characterized by their external galactic medium, showing that AGN jets interplay with the SMBH and its host galaxy.

  10. Globular clusters as tracers of the host galaxy mass distribution: the Fornax dSph test case

    CERN Document Server

    Arca-Sedda, Manuel

    2016-01-01

    The Fornax dwarf spheroidal galaxy is the most massive satellites of the Milky Way, claimed to be embedded in a huge dark matter halo, and the only among the Milky Way satellites hosting five globular clusters. Interestingly, their estimated masses, ages and positions seem hardly compatible with the presence of a significant dark matter component, as expected in the $\\Lambda$ CDM scheme. Indeed, if Fornax would have a CDM halo with a standard density profile, all its globular clusters should have sunk to the galactic centre many Gyr ago due to dynamical friction. Due to this, some authors proposed that the most massive clusters may have formed out of Fornax and later tidally captured. In this paper we investigate the past evolution of the Fornax GC system by using both a recently developed, semi-analytical treatment of dynamical friction and direct $N$-body simulations of the orbital evolution of the globular clusters within Fornax and of Fornax galaxy around the Milky Way. Our results suggest that an "in-sit...

  11. Providing Stringent Star Formation Rate Limits of z ˜ 2 QSO Host Galaxies at High Angular Resolution

    Science.gov (United States)

    Vayner, Andrey; Wright, Shelley A.; Do, Tuan; Larkin, James E.; Armus, Lee; Gallagher, S. C.

    2016-04-01

    We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ˜ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ˜0.″2 (˜1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (zHα = 2.182) and SDSS J0925+0655 (zHα = 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M⊙ yr-1 originating from a compact region that is kinematically offset by 290-350 km s-1. For SDSS J0925+0655 we infer a SFR of 29 M⊙ yr-1 distributed over three clumps that are spatially offset by ˜7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M⊙ yr-1 kpc-2. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M⊙ yr-1 kpc-2. These IFS observations indicate that while the central black hole is accreting mass at 10%-40% of the Eddington rate, if star formation is present in the host (1.4-20 kpc) it would have to occur diffusely with significant

  12. The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements. II. The Full Sample of Reverberation-Mapped AGNs

    DEFF Research Database (Denmark)

    Bentz, Misty C.; Peterson, Bradley M.; Netzer, Hagai;

    2009-01-01

    We present high-resolution Hubble Space Telescope images of all 35 active galactic nuclei (AGNs) with optical reverberation-mapping results, which we have modeled to create a nucleus-free image of each AGN host galaxy. From the nucleus-free images, we determine the host-galaxy contribution...... to ground-based spectroscopic luminosity measurements at 5100 Å. After correcting the luminosities of the AGNs for the contribution from starlight, we re-examine the Hß R BLR-L relationship. Our best fit for the relationship gives a power-law slope of 0.52 with a range of 0.45-0.59 allowed...... by the uncertainties. This is consistent with our previous findings, and thus still consistent with the naive assumption that all AGNs are simply luminosity-scaled versions of each other. We discuss various consistency checks relating to the galaxy modeling and starlight contributions, as well as possible systematic...

  13. Host Galaxies, Obscuration and Nuclear Structure of Three Nearby Compact Symmetric Objects

    CERN Document Server

    Perlman, E S; Conway, J; Reynolds, C; Perlman, Eric S.; Stocke, John T.; Conway, John; Reynolds, Christopher S

    2001-01-01

    We present 3-band HST imaging of three z/= 10^8 years ago. Such a merger could have "triggered" the current activity in these objects, but our data require a significant time delay between the merger and the onset of nuclear activity. However, these data are also consistent with the hypothesis that the onset of nuclear activity in radio galaxies is due to relatively minor "feeding" events and/or the formation of "bars within bars", which would disturb the internal kinematics only slightly.

  14. Type Ia Supernova Properties as a Function of the Distance to the Host Galaxy in the SDSS-II SN Survey

    Energy Technology Data Exchange (ETDEWEB)

    Galbany, Lluis [Institut de Fisica d' Altes Energies (IFAE), Barcelona (Spain); et al.

    2012-08-20

    We use type-Ia supernovae (SNe Ia) discovered by the SDSS-II SN Survey to search for dependencies between SN Ia properties and the projected distance to the host galaxy center, using the distance as a proxy for local galaxy properties (local star-formation rate, local metallicity, etc.). The sample consists of almost 200 spectroscopically or photometrically confirmed SNe Ia at redshifts below 0.25. The sample is split into two groups depending on the morphology of the host galaxy. We fit light-curves using both MLCS2k2 and SALT2, and determine color (AV, c) and light-curve shape (delta, x1) parameters for each SN Ia, as well as its residual in the Hubble diagram. We then correlate these parameters with both the physical and the normalized distances to the center of the host galaxy and look for trends in the mean values and scatters of these parameters with increasing distance. The most significant (at the 4-sigma level) finding is that the average fitted AV from MLCS2k2 and c from SALT2 decrease with the projected distance for SNe Ia in spiral galaxies. We also find indications that SNe in elliptical galaxies tend to have narrower light-curves if they explode at larger distances, although this may be due to selection effects in our sample. We do not find strong correlations between the residuals of the distance moduli with respect to the Hubble flow and the galactocentric distances, which indicates a limited correlation between SN magnitudes after standardization and local host metallicity.

  15. ALMA resolves extended star formation in high-z AGN host galaxies

    CERN Document Server

    Harrison, C M; Stanley, F; Alexander, D M; Daddi, E; Mullaney, J R; Pannella, M; Rosario, D J; Smail, Ian

    2015-01-01

    We present high-resolution Atacama Large Millimeter Array (ALMA) 870um imaging of five z~1.5-4.5 X-ray detected AGN (with luminosities of L(X)>10^42 erg/s). The sub-millimetre emission is extended on scales of FWHM~0.2"-0.5", corresponding to physical sizes of 1-3 kpc (median value of 1.8 kpc). These sizes are comparable to the majority of z=1-5 sub-millimetre galaxies (SMGs) with equivalent ALMA measurements. In combination with spectral energy distribution analyses, we attribute this rest-frame far-infrared (FIR) emission to dust heated by star formation. The implied star-formation rate surface densities are 20-200 Msol/yr/kpc^2, which are consistent with SMGs of comparable FIR luminosities (i.e., L(IR)~ [1-5]x10^12 Lsol). Although limited by a small sample of AGN, which all have high FIR luminosities, our study suggests that the kpc-scale spatial distribution and surface density of star formation in high-redshift star-forming galaxies is the same irrespective of the presence of X-ray detected AGN.

  16. Magnaporthe oryzae Effector AVR-Pii Helps to Establish Compatibility by Inhibition of the Rice NADP-Malic Enzyme Resulting in Disruption of Oxidative Burst and Host Innate Immunity.

    Science.gov (United States)

    Singh, Raksha; Dangol, Sarmina; Chen, Yafei; Choi, Jihyun; Cho, Yoon-Seong; Lee, Jea-Eun; Choi, Mi-Ok; Jwa, Nam-Soo

    2016-05-31

    Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen. PMID:27126515

  17. EmpiriciSN: Re-sampling Observed Supernova/Host Galaxy Populations using an XD Gaussian Mixture Model

    CERN Document Server

    Holoien, Thomas W -S; Wechsler, Risa H

    2016-01-01

    We describe two new open source tools written in Python for performing extreme deconvolution Gaussian mixture modeling (XDGMM) and using a conditioned model to re-sample observed supernova and host galaxy populations. XDGMM is new program for using Gaussian mixtures to do density estimation of noisy data using extreme deconvolution (XD) algorithms that has functionality not available in other XD tools. It allows the user to select between the AstroML (Vanderplas et al. 2012; Ivezic et al. 2015) and Bovy et al. (2011) fitting methods and is compatible with scikit-learn machine learning algorithms (Pedregosa et al. 2011). Most crucially, it allows the user to condition a model based on the known values of a subset of parameters. This gives the user the ability to produce a tool that can predict unknown parameters based on a model conditioned on known values of other parameters. EmpiriciSN is an example application of this functionality that can be used for fitting an XDGMM model to observed supernova/host datas...

  18. Host Galaxies of Luminous Type 2 Quasars at z ~ 0.5

    CERN Document Server

    Liu, Xin; Greene, Jenny E; Strauss, Michael A; Krolik, Julian H; Heckman, Timothy M

    2009-01-01

    We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z ~ 0.5, drawn from the SDSS type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (M_V 1 Gyr) which dominates the stellar mass. Broad emission complexes around He II 4686 A with luminosities up to 10^8.3 L_sun are unambiguously detected in three out of the nine targets, indicative of Wolf-Rayet populations. Population synthesis shows that ~ 5-Myr post-starburst populations contribute substantially to the luminosities (> 50% of L_5100) of all three objects with Wolf-Rayet detections. We find two objects with double cores and four with close companions. Our res ults may suggest that luminous type 2 quasars trace an early stage of galaxy interaction, perhaps responsible for both the quasar and the starburst activity.

  19. Active Galactic Nuclei in Groups and Clusters of Galaxies: Detection and Host Morphology

    CERN Document Server

    Arnold, Timothy J; Mulchaey, John S; Berti, Angela; Jeltema, Tesla E

    2009-01-01

    The incidence and properties of Active Galactic Nuclei (AGN) in the field, groups, and clusters can provide new information about how these objects are triggered and fueled, similar to how these environments have been employed to study galaxy evolution. We have obtained new XMM-Newton observations of seven X-ray selected groups and poor clusters with 0.02 10^{41}; M_R2.5}(L_X>10^{41}; M_R

  20. GRB hosts through cosmic time - VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1 < z < 3.6

    CERN Document Server

    Krühler, T; Fynbo, J P U; Hartoog, O E; Hjorth, J; Jakobsson, P; Perley, D A; Rossi, A; Schady, P; Schulze, S; Tanvir, N R; Vergani, S D; Wiersema, K; Afonso, P M J; Bolmer, J; Cano, Z; Covino, S; D'Elia, V; Postigo, A de Ugarte; Filgas, R; Friis, M; Graham, J F; Greiner, J; Goldoni, P; Gomboc, A; Hammer, F; Japelj, J; Kann, D A; Kaper, L; Klose, S; Levan, A J; Leloudas, G; Milvang-Jensen, B; Guelbenzu, A Nicuesa; Palazzi, E; Pian, E; Piranomonte, S; Sanchez-Ramirez, R; Savaglio, S; Selsing, J; Tagliaferri, G; Vreeswijk, P M; Watson, D J; Xu, D

    2015-01-01

    We present data and initial results from VLT/X-shooter emission-line spectroscopy of 96 GRB-selected galaxies at 0.1host spectroscopy available to date. The majority of our GRBs was detected by Swift and 76% are at 0.5hosts with redshift. The median SFR, for example, increases from ~0.6 M_sun/yr at z~0.6 up to ~15 M_sun/yr at z~2. A higher ratio of [OIII]/[OII] at higher redshifts leads to an increasing distance of GRB-selected galaxies to the locus of local galaxies in the BPT diagram. Oxygen abundances of the galaxies are distributed between 12+log(O/H)=7.9 and 12+log(O/H)=9.0 with a median of 12+log(O/H)~8.5. The fraction of GRB-selected galaxies with super-solar metallic...

  1. GRB 051008: A long, spectrally-hard dust-obscured GRB in a Lyman-Break Galaxy at z ~ 2.8

    CERN Document Server

    Volnova, A A; Gorosabel, J; Perley, D A; Frederiks, D D; Kann, D A; Rumyantsev, V V; Biryukov, V V; Burkhonov, O; Castro-Tirado, A J; Ferrero, P; Golenetskii, S V; Klose, S; Loznikov, V M; Minaev, P Yu; Stecklum, B; Svinkin, D S; Tsvetkova, A E; Postigo, A de Ugarte; Ulanov, M V

    2014-01-01

    We present observations of the dark Gamma-Ray Burst GRB 051008 provided by Swift/BAT, Swift/XRT, Konus-WIND, INTEGRAL/SPI-ACS in the high-energy domain and the Shajn, Swift/UVOT, Tautenburg, NOT, Gemini and Keck I telescopes in the optical and near-infrared bands. The burst was detected only in gamma- and X-rays and neither a prompt optical nor a radio afterglow were detected down to deep limits. We identified the host galaxy of the burst, which is a typical Lyman-break Galaxy (LBG) with R-magnitude of 24.06 +/- 0.10. A redshift of the galaxy of z = 2.77 (-0.20,+0.15) is measured photometrically due to the presence of a clear, strong Lyman-break feature. The host galaxy is a small starburst galaxy with moderate intrinsic extinction (A_V = 0.3 mag) and has a SFR of ~ 60 M_Sun / yr typical for LBGs. It is one of the few cases where a GRB host has been found to be a classical Lyman-break galaxy. Using the redshift we estimate the isotropic-equivalent radiated energy of the burst to be E_iso = (1.15 +/- 0.20) x 1...

  2. On the origin of the scatter broadening of fast radio burst pulses and astrophysical implications

    CERN Document Server

    Xu, Siyao

    2016-01-01

    Fast radio bursts (FRBs) have been identified as extragalactic sources which can make a probe of turbulence in the intergalactic medium (IGM) and their host galaxies. To account for the observed millisecond pulses caused by scatter broadening, we examine a variety of possible models of electron density fluctuations in both the IGM and the host galaxy medium. We find that a shallow power-law spectrum of density, which may arise in highly supersonic turbulence with pronounced local dense structures of shock-compressed gas in the host interstellar medium (ISM), can produce the required density enhancements at sufficiently small scales to interpret the scattering timescale of FRBs. It implies that an FRB residing in a galaxy with efficient star formation in action tends to have a broadened pulse. The scaling of the scattering time with dispersion measure (DM) in the host galaxy varies in different turbulence and scattering regimes. The host galaxy can be the major origin of scatter broadening, but contribute to a...

  3. Determining Type Ia Supernovae Host galaxy extinction probabilities and a statistical approach to estimating the absorption-to-reddening ratio $R_V$

    CERN Document Server

    Cikota, Aleksandar; Marleau, Francine

    2016-01-01

    We investigate limits on the extinction values of Type Ia supernovae to statistically determine the most probable color excess, E(B-V), with galactocentric distance, and use these statistics to determine the absorption-to-reddening ratio, $R_V$, for dust in the host galaxies. We determined pixel-based dust mass surface density maps for 59 galaxies from the Key Insight on Nearby Galaxies: a Far-Infrared Survey with \\textit{Herschel} (KINGFISH, Kennicutt et al. (2011)). We use Type Ia supernova spectral templates (Hsiao et al. 2007) to develop a Monte Carlo simulation of color excess E(B-V) with $R_V$ = 3.1 and investigate the color excess probabilities E(B-V) with projected radial galaxy center distance. Additionally, we tested our model using observed spectra of SN 1989B, SN 2002bo and SN 2006X, which occurred in three KINGFISH galaxies. Finally, we determined the most probable reddening for Sa-Sap, Sab-Sbp, Sbc-Scp, Scd-Sdm, S0 and Irregular galaxy classes as a function of $R/R_{25}$. We find that the larges...

  4. Globular clusters as tracers of the host galaxy mass distribution: the Fornax dSph test case

    Science.gov (United States)

    Arca-Sedda, M.; Capuzzo-Dolcetta, R.

    2016-10-01

    The Fornax dwarf spheroidal galaxy is the most massive satellites of the Milky Way, claimed to be embedded in a huge dark matter halo, and the only among the Milky Way satellites hosting five globular clusters. Interestingly, their estimated masses, ages and positions seem hardly compatible with the presence of a significant dark matter component, as expected in the ΛCDM scheme. Indeed, if Fornax would have a CDM halo with a standard density profile, all its globular clusters should have sunk to the galactic centre many Gyr ago due to dynamical friction. Due to this, some authors proposed that the most massive clusters may have formed out of Fornax and later tidally captured. In this paper, we investigate the past evolution of the Fornax GC system by using both a recently developed, semi-analytical treatment of dynamical friction and direct N-body simulations of the orbital evolution of the globular clusters within Fornax and of Fornax galaxy around the Milky Way. Our results suggest that an `in situ' origin for all the clusters is likely if their observed positions are close to their spatial ones and their orbits are almost circular. Moreover, the Milky Way seems to accelerate the GC decay reducing the decay time of 15 per cent. Nevertheless, our results indicate that the GCs survival probability exceeds 50 per cent, even in the case of cuspy density profiles. We conclude that more detailed data are required to shed light on the Fornax dark matter content, to distinguish between a cuspy or a cored profile.

  5. Magnetar Bursts

    Science.gov (United States)

    Kouveliotou, Chryssa

    2014-01-01

    The Fermi/Gamma-ray Burst Monitor (GBM) was launched in June 2008. During the last five years the instrument has observed several hundreds of bursts from 8 confirmed magnetars and 19 events from unconfirmed sources. I will discuss the results of the GBM magnetar burst catalog, expand on the different properties of their diverse source population, and compare these results with the bursting activity of past sources. I will then conclude with thoughts of how these properties fit the magnetar theoretical models.

  6. A Tidal Disruption Event in a Nearby Galaxy Hosting an Intermediate Mass Black Hole

    Science.gov (United States)

    Donato, D; Cenko, S. B.; Covino, S.; Troja, E.; Pursimo, T.; Cheung, C. C.; Fox, O.; Kutyrev, A.; Campana, S.; Fugazza, D.; Landt, H.; Butler, N. R.

    2014-01-01

    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 kiloelectronvolt flux declined by a factor of approximately 2300 over a time span of 6 years, following a power-law decay with index approximately equal to 2.44 plus or minus 0.40. The Chandra data alone vary by a factor of approximately 20. The spectrum is well fit by a blackbody with a constant temperature of kiloteslas approximately equal to 0.09 kiloelectronvolts (approximately equal to 10 (sup 6) Kelvin). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1 sigma level with the cluster (redshift = 0.062476).We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log(M (sub BH) / M (sub 1 solar mass)) approximately equal to 5.5 plus or minus 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  7. A tidal disruption event in a nearby galaxy hosting an intermediate mass black hole

    International Nuclear Information System (INIS)

    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 keV flux declined by a factor of ∼2300 over a time span of 6 yr, following a power-law decay with index ∼2.44 ± 0.40. The Chandra data alone vary by a factor of ∼20. The spectrum is well fit by a blackbody with a constant temperature of kT ∼ 0.09 keV (∼106 K). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1σ level with the cluster (z = 0.062476). We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log (M BH/M ☉) ∼ 5.5 ± 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  8. Suppression of Star Formation in the Hosts of Low-Excitation Radio Galaxies

    CERN Document Server

    Pace, Cameron

    2015-01-01

    The feedback from radio-loud active galactic nuclei (R-AGN) may help maintain low star formation (SF) rates in their early-type hosts, but the observational evidence for this mechanism has been inconclusive. We study systematic differences of aggregate spectral energy distributions (SEDs) of various subsets of $\\sim$4000 low-redshift R-AGN from Best & Heckman (2012) with respect to (currently) inactive control samples selected to have matching redshift, stellar mass, population age, axis ratio, and environment. Aggregate SEDs, ranging from the ultraviolet (UV) through mid-infrared (mid-IR, 22 $\\mu$m), were constructed using a Bayesian method that eliminates biases from non-detections in GALEX and WISE. We study rare high-excitation sources separately from low-excitation ones, which we split by environment and host properties. We find that both the UV and mid-IR emission of non-cluster R-AGNs (80% of sample) are suppressed by $\\sim$0.2 dex relative to that of the control group, especially for moderately ma...

  9. PROVIDING STRINGENT STAR FORMATION RATE LIMITS OF z ∼ 2 QSO HOST GALAXIES AT HIGH ANGULAR RESOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Vayner, Andrey; Wright, Shelley A. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Do, Tuan [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON, M5S 3H4 (Canada); Larkin, James E. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Armus, Lee [Spitzer Science Center, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Gallagher, S. C. [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)

    2016-04-10

    We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ∼ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ∼0.″2 (∼1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (z{sub Hα} = 2.182) and SDSS J0925+0655 (z{sub Hα} = 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M{sub ⊙} yr{sup −1} originating from a compact region that is kinematically offset by 290–350 km s{sup −1}. For SDSS J0925+0655 we infer a SFR of 29 M{sub ⊙} yr{sup −1} distributed over three clumps that are spatially offset by ∼7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M{sub ⊙} yr{sup −1} kpc{sup −2}. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M{sub ⊙} yr{sup −1} kpc{sup −2}. These IFS observations indicate that while the central black hole is accreting mass at 10%–40% of the Eddington rate, if

  10. Radio Wave Propagation and the Provenance of Fast Radio Bursts

    CERN Document Server

    Cordes, J M; Spitler, L G; Chatterjee, S; Wasserman, I

    2016-01-01

    We analyze plasma dispersion and scattering of fast radio bursts (FRBs) to identify the dominant locations of free electrons along their lines of sight and thus constrain the distances of the burst sources themselves. We establish the average $\\tau$-DM relation for Galactic pulsars and use it as a benchmark for discussing FRB scattering. Though scattering times $\\tau$ for FRBs are large in the majority of the 17 events we analyze, they are systematically smaller than those of Galactic pulsars that have similar dispersion measures (DMs). The lack of any correlation between $\\tau$ and DM for FRBs suggests that the intergalactic medium (IGM) cannot account for both $\\tau$ and DM. We therefore consider mixed models involving the IGM and host galaxies. If the IGM contributes significantly to DM while host galaxies dominate $\\tau$, the scattering deficit with respect to the mean Galactic trend can be explained with a $\\tau$-DM relation in the host that matches that for the Milky Way. However, it is possible that ho...

  11. The hydrogen-poor superluminous supernova iPTF13ajg and its host galaxy in absorption and emission

    CERN Document Server

    Vreeswijk, Paul M; Gal-Yam, Avishay; De Cia, Annalisa; Quimby, Robert M; Sullivan, Mark; Cenko, S Bradley; Perley, Daniel A; Filippenko, Alexei V; Clubb, Kelsey I; Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos; Arcavi, Iair; Rubin, Adam; Kasliwal, Mansi M; Cao, Yi; Yaron, Ofer; Tal, David; Ofek, Eran O; Capone, John; Kutyrev, Alexander S; Toy, Vicki; Nugent, Peter E; Laher, Russ; Surace, Jason; Kulkarni, Shrinivas R

    2014-01-01

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory: iPTF13ajg. At a redshift of z=0.7403, derived from narrow absorption lines, iPTF13ajg peaked at an absolute magnitude M(u,AB)=-22.5, one of the most luminous supernovae to date. The uBgRiz light curves, obtained with the P48, P60, NOT, DCT, and Keck telescopes, and the nine-epoch spectral sequence secured with the Keck and the VLT (covering 3 rest-frame months), are tied together photometrically to provide an estimate of the flux evolution as a function of time and wavelength. The observed bolometric peak luminosity of iPTF13ajg is 3.2x10^44 erg/s, while the estimated total radiated energy is 1.3x10^51 erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the VLT. From Voigt-profile fitting, we derive the column densities log N(Mg I)=11.94+-0.06, log ...

  12. Far-infrared and Molecular CO Emission From the Host Galaxies of Faint Quasars at z~6

    CERN Document Server

    Wang, Ran; Carilli, Chris L; Neri, Roberto; Walter, Fabian; Omont, Alain; Riechers, Dominik A; Bertoldi, Frank; Menten, Karl M; Cox, Pierre; Strauss, Michael A; Fan, Xiaohui; Jiang, Linhua

    2011-01-01

    We present new millimeter and radio observations of nine z~6 quasars discovered in deep optical and near-infrared surveys. We observed the 250 GHz continuum in eight of the nine objects and detected three of them. New 1.4 GHz radio continuum data have been obtained for four sources, and one has been detected. We searched for molecular CO (6-5) line emission in the three 250 GHz detections and detected two of them. We study the FIR and radio emission and quasar-host galaxy evolution with a sample of 18 z~6 quasars that are faint at UV/optical wavelengths (rest-frame 1450A magnitudes of m_1450\\ge20.2). The average FIR-to-AGN UV luminosity ratio of this faint quasar sample is about two times higher than that of the bright quasars at z~6 (m_1450<20.2). A fit to the average FIR and AGN bolometric luminosities of both the UV/optically faint and bright z~6 quasars, and the average luminosities of samples of submillimeter /millimeter-observed quasars at z~2 to 5, yields a relationship of L_{FIR} {L_{bol}}^{0.62}. ...

  13. On the multiple supernova population of Arp 299: constraints on progenitor properties and host galaxy star formation characteristics

    CERN Document Server

    Anderson, J P; James, P A

    2011-01-01

    Throughout the last 20 years 7 supernovae (SNe) have been discovered within Arp 299. One of these is unclassified, leaving 6 core-collapse events; 2 type II, 2 type Ib, a type IIb and one object of indistinct type; Ib/IIb. We analyse the relative numbers of these types, together with their positions with respect to host galaxy properties, to investigate implications for both progenitor characteristics and star formation (SF) properties. Our findings are: 1) the ratio of 'stripped envelope' (SE) events to other type II is higher than that found in the local Universe. 2) All SE SNe are more centrally concentrated within the system than the other type II. 3) All SN environments have similar metallicities and there are no significant metallicity gradients across the system. 4) The SE SNe all fall on bright SF regions while the other type II are found to occur away from bright HII regions. We draw two different -but non-mutually exclusive- interpretations on the system and its supernovae: 1) The distribution of SN...

  14. Supplement: Going the Distance: Mapping Host Galaxies of LIGO and Virgo Sources in Three Dimensions Using Local Cosmography and Targeted Follow-up

    CERN Document Server

    Singer, L P; Holz, D E; Farr, W M; Price, L R; Raymond, V; Cenko, S B; Gehrels, N; Cannizzo, J; Kasliwal, M M; Nissanke, S; Coughlin, M; Farr, B; Urban, Alex L; Vitale, S; Veitch, J; Graff, P; Berry, C P L; Mohapatra, S; Mandel, I

    2016-01-01

    This is an online supplement to https://arxiv.org/abs/1603.07333 . In the main Letter, we demonstrated a rapid algorithm for obtaining joint three-dimensional estimates of sky location and luminosity distance from observations of binary neutron star mergers with Advanced LIGO and Virgo. We argued that combining the reconstructed volumes with positions and redshifts of possible host galaxies can provide large-aperture but small field of view instruments with a manageable list of targets to search for optical or infrared emission. In this Supplement, we document the new HEALPix-based file format for 3D localizations of gravitational wave transients. We include Python sample code to show the reader how to perform simple manipulations of the 3D sky maps and extract ranked lists of likely host galaxies. Finally, we include mathematical details of the rapid volume reconstruction algorithm.

  15. VLT adaptive optics imaging of QSO host galaxies and close environment at z ~2.5: results from a pilot program

    CERN Document Server

    Falomo, R; Scarpa, R; Treves, A

    2004-01-01

    We report ESO-VLT near-infrared adaptive optics imaging of one radio-loud (PKS 0113-283) and two radio-quiet (Q 0045-3337 and Q 0101-337) QSOs at z > 2. In the first case, we are able to resolve the QSO and find that it is hosted by an elliptical of absolute magnitude M(K) = -27.6. For the other two objects, no extended emission has been unambiguously detected. This result, though restricted to a single object, extends up to z ~2.5 the finding that cosmic evolution of radio-loud QSO hosts follows the trend expected for luminous and massive spheroids undergoing passive evolution. For Q 0045-3337, our high resolution images show that it is located 1.2 arcsec from a K = 17.5 foreground disc galaxy, which may act as a gravitational lens, since the QSO most probably lies within the galaxy Einstein radius.

  16. Chandra X-ray and Hubble Space Telescope Imaging of Optically Selected Kiloparsec-Scale Binary Active Galactic Nuclei II: Host Galaxy Morphology and AGN Activity

    CERN Document Server

    Shangguan, Jinyi; Ho, Luis C; Shen, Yue; Peng, Chien Y; Greene, Jenny E; Strauss, Michael A

    2016-01-01

    Binary active galactic nuclei (AGNs) provide clues to how gas-rich mergers trigger and fuel AGNs and how supermassive black hole (SMBH) pairs evolve in a gas-rich environment. While significant effort has been invested in their identification, the detailed properties of binary AGNs and their host galaxies are still poorly constrained. In a companion paper, we examined the nature of ionizing sources in the double nuclei of four kpc-scale binary AGNs with redshifts between 0.1~0.2. Here, we present their host galaxy morphology based on F336W (U-band) and F105W (Y-band) images taken by the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope. Our targets have double-peaked narrow emission lines and were confirmed to host binary AGNs with follow up observations. We find that kpc-scale binary AGNs occur in galaxy mergers with diverse morphological types. There are three major mergers with intermediate morphologies and a minor merger with a dominant disk component. We estimate the masses of the SMBHs from ...

  17. A Molecular Einstein Ring at z=4.12: Imaging the Dynamics of a Quasar Host Galaxy Through a Cosmic Lens

    CERN Document Server

    Riechers, Dominik A; Brewer, Brendon J; Carilli, Christopher L; Lewis, Geraint F; Bertoldi, Frank; Cox, Pierre

    2008-01-01

    We present high-resolution (0.3") Very Large Array (VLA) imaging of the molecular gas in the host galaxy of the high redshift quasar PSS J2322+1944 (z=4.12). These observations confirm that the molecular gas (CO) in the host galaxy of this quasar is lensed into a full Einstein ring, and reveal the internal dynamics of the molecular gas in this system. The ring has a diameter of ~1.5", and thus is sampled over ~20 resolution elements by our observations. Through a model-based lens inversion, we recover the velocity gradient of the molecular reservoir in the quasar host galaxy of PSS J2322+1944. The Einstein ring lens configuration enables us to zoom in on the emission and to resolve scales down to ~1 kpc. From the model-reconstructed source, we find that the molecular gas is distributed on a scale of 5 kpc, and has a total mass of M(H2)=1.7 x 10^10 M_sun. A basic estimate of the dynamical mass gives M_dyn = 4.4 x 10^10 (sin i)^-2 M_sun, that is, only ~2.5 times the molecular gas mass, and ~30 times the black h...

  18. The clustering of ALFALFA galaxies: dependence on HI mass, relationship to optical samples & clues on host halo properties

    CERN Document Server

    Papastergis, Emmanouil; Haynes, Martha P; Rodríguez-Puebla, Aldo; Jones, Michael G

    2013-01-01

    We use a sample of ~6000 galaxies detected by the Arecibo Legacy Fast ALFA (ALFALFA) 21cm survey, to measure the clustering properties of HI-selected galaxies. We find no convincing evidence for a dependence of clustering on the galactic atomic hydrogen (HI) mass, over the range M_HI ~ 10^{8.5} - 10^{10.5} M_sun. We show that previously reported results of weaker clustering for low-HI mass galaxies are probably due to finite-volume effects. In addition, we compare the clustering of ALFALFA galaxies with optically selected samples drawn from the Sloan Digital Sky Survey (SDSS). We find that HI-selected galaxies cluster more weakly than even relatively optically faint galaxies, when no color selection is applied. Conversely, when SDSS galaxies are split based on their color, we find that the correlation function of blue optical galaxies is practically indistinguishable from that of HI-selected galaxies. At the same time, SDSS galaxies with red colors are found to cluster significantly more than HI-selected gala...

  19. The ``Christmas burst'' GRB 101225A revisited

    Science.gov (United States)

    Thöne, C. C.; de Ugarte Postigo, A.; Fryer, C. L.; Kann, D. A.

    2015-03-01

    Long GRBs are related to the death of massive stars and reveal themselves through synchrotron emission from highly relativistic jets. The `Christmas Burst' GRB 101225A was an exceptionally long GRB with a thermal afterglow, very different from the standard GRB. Initially, no spectroscopic redshift could be obtained and SED modeling yielded z=0.33. A plausible model was a He-NS star merger where the He-star had ejected part of its envelope in the common envelope phase during inspiral. The interaction between the jet and the previously ejected shell can explains the thermal emission. We obtained deep spectroscopy of the host galaxy which leads to a correction of the redshift to z=0.847. Despite the higher redshift, our model is still valid and theoretically better justified than the alternative suggestion of a blue supergiant progenitor proposed by Levan et al. (2014) for several ``ultra-long'' GRBs.

  20. Black hole variability and the star formation-active galactic nucleus connection: Do all star-forming galaxies host an active galactic nucleus?

    International Nuclear Information System (INIS)

    We investigate the effect of active galactic nucleus (AGN) variability on the observed connection between star formation and black hole accretion in extragalactic surveys. Recent studies have reported relatively weak correlations between observed AGN luminosities and the properties of AGN hosts, which has been interpreted to imply that there is no direct connection between AGN activity and star formation. However, AGNs may be expected to vary significantly on a wide range of timescales (from hours to Myr) that are far shorter than the typical timescale for star formation (≳100 Myr). This variability can have important consequences for observed correlations. We present a simple model in which all star-forming galaxies host an AGN when averaged over ∼100 Myr timescales, with long-term average AGN accretion rates that are perfectly correlated with the star formation rate (SFR). We show that reasonable prescriptions for AGN variability reproduce the observed weak correlations between SFR and L AGN in typical AGN host galaxies, as well as the general trends in the observed AGN luminosity functions, merger fractions, and measurements of the average AGN luminosity as a function of SFR. These results imply that there may be a tight connection between AGN activity and SFR over galaxy evolution timescales, and that the apparent similarities in rest-frame colors, merger rates, and clustering of AGNs compared to 'inactive' galaxies may be due primarily to AGN variability. The results provide motivation for future deep, wide extragalactic surveys that can measure the distribution of AGN accretion rates as a function of SFR.

  1. Afterglows, Redshifts, and Properties of Swift Gamma-Ray Bursts

    Science.gov (United States)

    Berger, E.; Kulkarni, S. R.; Fox, D. B.; Soderberg, A. M.; Harrison, F. A.; Nakar, E.; Kelson, D. D.; Gladders, M. D.; Mulchaey, J. S.; Oemler, A.; Dressler, A.; Cenko, S. B.; Price, P. A.; Schmidt, B. P.; Frail, D. A.; Morrell, N.; Gonzalez, S.; Krzeminski, W.; Sari, R.; Gal-Yam, A.; Moon, D.-S.; Penprase, B. E.; Jayawardhana, R.; Scholz, A.; Rich, J.; Peterson, B. A.; Anderson, G.; McNaught, R.; Minezaki, T.; Yoshii, Y.; Cowie, L. L.; Pimbblet, K.

    2005-11-01

    a search for bright host galaxies in untriggered BAT localizations may increase the chance of finding nearby low-luminosity GRBs.

  2. The Arecibo Fast Radio Burst: Dense Circum-burst Medium

    CERN Document Server

    Kulkarni, S R; Neill, J D

    2015-01-01

    The nature of fast radio bursts (FRB) has been extensively debated. Here we investigate FRB121102, detected at Arecibo telescope and remarkable for its unusually large spectral index. After extensive study we conclude that the spectral index is caused by a nebula with free-free absorption. We find that putative nebula must lie beyond the Milky Way. We conclude that FRBs are of extra-galactic origin and that they arise in dense star-forming regions. The challenge with extra-galactic models is the the high volumetric rate of FRBs. This high rate allows us to eliminate all models of catastrophic stellar deaths. Hyper-giant flares from young magnetars emerge as the most likely progenitors. Some of the consequences are: (i) Intergalactic FRB models can be safely ignored. (ii) The rich ISM environment of young magnetars can result in significant contribution to DM, Rotation Measure (RM) and in some cases to significant free-free optical depth. (iii) The star-forming regions in the host galaxies can contribute signi...

  3. HUBBLE STAYS ON TRAIL OF FADING GAMMA-RAY BURST FIREBALL

    Science.gov (United States)

    2002-01-01

    A Hubble Space Telescope image of the fading fireball from one of the universe's most mysterious phenomena, a gamma-ray burst. Though the visible component has faded to 1/500th its brightness (27.7 magnitude) from the time it was first discovered by ground- based telescopes last March (the actual gamma-ray burst took place on February 28), Hubble continues to clearly see the fireball and discriminated a surrounding nebulosity (at 25th magnitude) which is considered a host galaxy. The continued visibility of the burst, and the rate of its fading, support theories that the light from a gamma-ray burst is an expanding relativistic (moving near the speed of light) fireball, possibly produced by the collision of two dense objects, such as an orbiting pair of neutron stars. If the burst happened nearby, within our own galaxy, the resulting fireball should have had only enough energy to propel it into space for a month. The fact that this fireball is still visible after six months means the explosion was truly titanic and, to match the observed brightness, must have happened at the vast distances of galaxies. The energy released in a burst, which can last from a fraction of a second to a few hundred seconds, is equal to all of the Sun's energy generated over its 10 billion year lifetime. The false-color image was taken Sept. 5, 1997 with the Space Telescope Imaging Spectrograph. Credit: Andrew Fruchter (STScI), Elena Pian (ITSRE-CNR), and NASA

  4. The Unusually Long Duration Gamma-ray Burst GRB 000911

    CERN Document Server

    Price, P A; Kulkarni, S R; Djorgovski, S G; Fox, D W; Mahabal, A A; Hurley, K; Bloom, J S; Frail, D A; Galama, T J; Harrison, F A; Morrison, G; Reichart, D E; Yost, S A; Sari, R; Axelrod, T S; Cline, T; Golenetskii, S V; Mazets, E; Schmidt, B P; Trombka, J I

    2002-01-01

    Of all the well localized gamma-ray bursts, GRB 000911 has the longest duration (T_90 ~ 500 s), and ranks in the top 1% of BATSE bursts for fluence. Here, we report the discovery of the afterglow of this unique burst. In order to simultaneously fit our radio and optical observations, we are required to invoke a model involving an hard electron distribution, p ~ 1.5 and a jet-break time less than 1.5 day. A spectrum of the host galaxy taken 111 days after the burst reveals a single emission line, interpreted as [OII] at a redshift z = 1.0585, and a continuum break which we interpret as the Balmer limit at this redshift. Despite the long T_90, the afterglow of GRB 000911 is not unusual in any other way when compared to the set of afterglows studied to date. We conclude that the duration of the GRB plays little part in determining the physics of the afterglow.

  5. The SAMI Galaxy Survey: extraplanar gas, galactic winds and their association with star formation history

    Science.gov (United States)

    Ho, I.-Ting; Medling, Anne M.; Bland-Hawthorn, Joss; Groves, Brent; Kewley, Lisa J.; Kobayashi, Chiaki; Dopita, Michael A.; Leslie, Sarah K.; Sharp, Rob; Allen, James T.; Bourne, Nathan; Bryant, Julia J.; Cortese, Luca; Croom, Scott M.; Dunne, Loretta; Fogarty, L. M. R.; Goodwin, Michael; Green, Andy W.; Konstantopoulos, Iraklis S.; Lawrence, Jon S.; Lorente, Nuria P. F.; Owers, Matt S.; Richards, Samuel; Sweet, Sarah M.; Tescari, Edoardo; Valiante, Elisabetta

    2016-04-01

    We investigate a sample of 40 local, main-sequence, edge-on disc galaxies using integral field spectroscopy with the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey to understand the link between properties of the extraplanar gas and their host galaxies. The kinematics properties of the extraplanar gas, including velocity asymmetries and increased dispersion, are used to differentiate galaxies hosting large-scale galactic winds from those dominated by the extended diffuse ionized gas. We find rather that a spectrum of diffuse gas-dominated to wind-dominated galaxies exist. The wind-dominated galaxies span a wide range of star formation rates (SFRs; -1 ≲ log (SFR/M⊙ yr-1) ≲ 0.5) across the whole stellar mass range of the sample (8.5 ≲ log (M*/M⊙) ≲ 11). The wind galaxies also span a wide range in SFR surface densities (10- 3-10- 1.5 M⊙ yr- 1 kpc- 2) that is much lower than the canonical threshold of 0.1 M⊙ yr- 1 kpc- 2. The wind galaxies on average have higher SFR surface densities and higher HδA values than those without strong wind signatures. The enhanced HδA indicates that bursts of star formation in the recent past are necessary for driving large-scale galactic winds. We demonstrate with Sloan Digital Sky Survey data that galaxies with high SFR surface density have experienced bursts of star formation in the recent past. Our results imply that the galactic winds revealed in our study are indeed driven by bursts of star formation, and thus probing star formation in the time domain is crucial for finding and understanding galactic winds.

  6. THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI: THE EFFECT OF HOST-GALAXY STARLIGHT ON LUMINOSITY MEASUREMENTS. II. THE FULL SAMPLE OF REVERBERATION-MAPPED AGNs

    International Nuclear Information System (INIS)

    We present high-resolution Hubble Space Telescope images of all 35 active galactic nuclei (AGNs) with optical reverberation-mapping results, which we have modeled to create a nucleus-free image of each AGN host galaxy. From the nucleus-free images, we determine the host-galaxy contribution to ground-based spectroscopic luminosity measurements at 5100 A. After correcting the luminosities of the AGNs for the contribution from starlight, we re-examine the Hβ R BLR-L relationship. Our best fit for the relationship gives a power-law slope of 0.52 with a range of 0.45-0.59 allowed by the uncertainties. This is consistent with our previous findings, and thus still consistent with the naive assumption that all AGNs are simply luminosity-scaled versions of each other. We discuss various consistency checks relating to the galaxy modeling and starlight contributions, as well as possible systematic errors in the current set of reverberation measurements from which we determine the form of the R BLR-L relationship.

  7. The Degeneracy of Galaxy Formation Models

    CERN Document Server

    Neistein, Eyal

    2009-01-01

    We develop a new formalism for modeling the formation and evolution of galaxies within a hierarchical universe. Similarly to standard semi-analytical models we trace galaxies inside dark-matter merger-trees. The formalism includes treatment of feedback, star-formation, cooling, smooth accretion, gas stripping in satellite galaxies, and merger-induced star bursts. However, unlike in other models, each process is assumed to have an efficiency which depends only on the host halo mass and redshift. This allows us to describe the various components of the model in a simple and transparent way. By allowing the efficiencies to have any value for a given halo mass and redshift, we can easily encompass a large range of scenarios. To demonstrate this point, we examine several different galaxy formation models, which are all consistent with the observational data. Each model is characterized by a different unique feature: cold accretion in low mass haloes, zero feedback, stars formed only in merger-induced bursts, and s...

  8. Study of a Population of Gamma-ray Bursts with Low-Luminosity Afterglows

    CERN Document Server

    Dereli, Hüsne

    2015-01-01

    Gamma-ray bursts (GRB) are extreme events. They are crudely classified into two groups based on their duration, namely the short and long bursts. Such a classification has proven to be useful to determine their progenitors: the merger of two compact objects for short bursts and the explosion of a massive star for long bursts. Further classifying the long GRBs might give tighter constraints on their progenitor and on the emission mechanism(s). In my thesis, I present evidence for the existence of a sub-class of long GRBs, based on their faint afterglow emission. These bursts were named low-luminosity afterglow (LLA) GRBs. I discuss the data analysis and the selection method, and their main properties are described. Their link to supernova is strong as 64% of all the bursts firmly associated to SNe are LLA GRBs. Finally, I present additional properties of LLA GRBs: the study of their rate density, which seems to indicate a new distinct third class of events, the properties of their host galaxies, which show tha...

  9. Galaxy counterparts of intervening high-z sub-DLAs/DLAs and MgII absorbers towards gamma-ray bursts

    CERN Document Server

    Schulze, S; Milvang-Jensen, B; Rossi, A; Jakobsson, P; Ledoux, C; De Cia, A; Kruehler, T; Mehner, A; Bjoernsson, G; Chen, H -W; Vreeswijk, P M; Perley, D A; Hjorth, J; Levan, A J; Tanvir, N R; Ellison, S; Moller, P; Worseck, G; Chapman, R; Dall'Aglio, A; Letawe, G

    2012-01-01

    We present the first search for galaxy counterparts of intervening high-z (2galaxy counterparts of the absorbers we use deep optical and near-infrared imaging, and low-, mid- and high-resolution spectroscopy acquired with 6 to 10-m class telescopes, the Hubble and the Spitzer space telescopes. Furthermore, we use the spectroscopic information and spectral-energy-distribution fitting techniques to study them in detail. Our main result is the detection and spectroscopic confirmation of the galaxy counterpart of the intervening DLA at z=3.096 in the field of GRB 070721B (z_GRB=3.6298) as proposed by other authors. We also identify good candidates for the galaxy counterparts of the two strong MgII absorbers at z=0.6915 and 1.4288 towards GRB 050820A (z_GRB=2.615). The properties of the detected DLA galaxy are typical for Lyman-break galaxies (LBGs) at similar re...

  10. On the cosmic evolution of the scaling relations between black holes and their host galaxies: Broad Line AGN in the zCOSMOS survey

    CERN Document Server

    Merloni, A; Bolzonella, M; Brusa, M; Civano, F; Comastri, A; Elvis, M; Fiore, F; Gilli, R; Hao, H; Jahnke, K; Koekemoer, A M; Lusso, E; Mainieri, V; Mignoli, M; Miyaji, T; Renzini, A; Salvato, M; Silverman, Joseph; Trump, J; Vignali, C; Zamorani, G; Capak, P; Lilly, S J; Sanders, D; Taniguchi, Y; Bardelli, S; Carollo, C M; Caputi, K; Contini, T; Coppa, G; Cucciati, O; De la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Hasinger, G; Impey, C; Iovino, A; Iwasawa, K; Kampczyk, P; Kneib, J -P; Knobel, C; Kovac, K; Lamareille, F; Le Borgne, J F; Le Brun, V; Le Fèvre, O; Maier, C; Pellò, R; Peng, Y; Montero, E Perez; Ricciardelli, E; Scodeggio, M; Tanaka, M; Tasca, L A M; Tresse, L; Vergani, D; Zucca, E

    2009-01-01

    (Abriged) We report on the measurement of the rest frame K-band luminosity and total stellar mass of the hosts of 89 broad line Active Galactic Nuclei detected in the zCOSMOS survey in the redshift range 1host galaxy from that of the nuclear black hole in their Spectral Energy Distributions. We derive an estimate of black hole masses through the analysis of the broad Mg II emission lines observed in the medium-resolution spectra taken with VIMOS/VLT as part of the zCOSMOS project. We found that, as compared to the local value, the average black hole to host galaxy mass ratio appears to evolve positively with redshift, with a best fit evolution of the form (1+z)^{0.68 \\pm0.12 +0.6 -0.3}, where the large asymmetric systematic errors stem from the uncertainties in the choice of IMF, in the calibration of the virial relation used to estimate BH masses and in the mean QSO SED adopted. A thoroug...

  11. Outliers from the Mass--Metallicity Relation II: A Sample of Massive Metal-Poor Galaxies from SDSS

    CERN Document Server

    Peeples, Molly S; Stanek, K Z

    2008-01-01

    We present a sample of 42 high-mass low-metallicity outliers from the mass--metallicity relation of star-forming galaxies. These galaxies have stellar masses that span log(M_*/M_sun) ~9.4 to 11.1 and are offset from the mass--metallicity relation by -0.3 to -0.85 dex in 12+log(O/H). In general, they are extremely blue, have high star formation rates for their masses, and are morphologically disturbed. Tidal interactions are expected to induce large-scale gas inflow to the galaxies' central regions, and we find that these galaxies' gas-phase oxygen abundances are consistent with large quantities of low-metallicity gas from large galactocentric radii diluting the central metal-rich gas. We conclude with implications for deducing gas-phase metallicities of individual galaxies based solely on their luminosities, specifically in the case of long gamma-ray burst host galaxies.

  12. Gamma-Ray Bursts Trace UV Metrics of Star Formation over 3 < z < 5

    Science.gov (United States)

    Greiner, J.; Fox, D. B.; Schady, P.; Krühler, T.; Trenti, M.; Cikota, A.; Bolmer, J.; Elliott, J.; Delvaux, C.; Perna, R.; Afonso, P.; Kann, D. A.; Klose, S.; Savaglio, S.; Schmidl, S.; Schweyer, T.; Tanga, M.; Varela, K.

    2015-08-01

    We present the first uniform treatment of long duration gamma-ray burst (GRB) host galaxy detections and upper limits over the redshift range 3imaging observations of 13 GRB positions yielding the discovery of 8 new host galaxies. We use this data set in tandem with previously published observations of 31 further GRB positions to estimate or constrain the host galaxy rest-frame ultraviolet (UV; λ =1600 Å) absolute magnitudes MUV. We then use the combined set of 44 MUV estimates and limits to construct the MUV luminosity function (LF) for GRB host galaxies over 3-15.6 mag, and with extrapolations of the assumed Schechter-type LF well beyond this range. We review proposed astrophysical and observational biases for our sample, and find that they are for the most part minimal. We therefore conclude, as the simplest interpretation of our results, that GRBs successfully trace UV metrics of cosmic SF over the range 3Organisation for Astronomical Research in the Southern Hemisphere under IDs 089.A-0120(A) and 091.A-0786(A).

  13. Molecular Gas in Lensed z>2 Quasar Host Galaxies and the Star Formation Law for Galaxies with Luminous Active Galactic Nuclei

    CERN Document Server

    Riechers, Dominik A

    2011-01-01

    We report the detection of luminous CO(2-1), CO(3-2), and CO(4-3) emission in the strongly lensed high-redshift quasars B1938+666 (z=2.059), HE0230-2130 (z=2.166), HE1104-1805 (z=2.322), and B1359+154 (z=3.240), using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). B1938+666 was identified in a `blind' CO redshift search, demonstrating the feasibility of such investigations with millimeter interferometers. These galaxies are lensing-amplified by factors of mu_L~11-170, and thus allow us to probe molecular gas in intrinsically fainter galaxies than currently possible without the aid of gravitational lensing. We report lensing-corrected intrinsic CO line luminosities of L'(CO) = 0.65-21 x 10^9 K km/s pc^2, translating to H2 masses of M(H2) = 0.52-1.7 x 10^9 (alpha_CO/0.8) M_sun. To investigate whether or not the AGN in luminous quasars substantially contribute to L_FIR, we study the L'(CO)-L_FIR relation for quasars relative to galaxies without a luminous AGN as a function of redshift. We ...

  14. A Massive Molecular Gas Reservoir in the z=2.221 Type-2 Quasar Host Galaxy SMM J0939+8315 Lensed by the Radio Galaxy 3C220.3

    CERN Document Server

    Leung, T K Daisy

    2016-01-01

    We report the detection of CO(J=3-2) line emission in the strongly-lensed submillimeter galaxy (SMG) SMM J0939+8315 at z=2.221, using the Combined Array for Research in Millimeter-wave Astronomy. SMM J0939+8315 hosts a type-2 quasar, and is gravitationally lensed by the radio galaxy 3C220.3 and its companion galaxy at z=0.685. The 104 GHz continuum emission underlying the CO line is detected toward 3C220.3 with an integrated flux density of S_cont = 7.4 +/- 1.4 mJy. Using the CO(J=3-2) line intensity of I_(CO(3-2)) = (12.6 +/- 2.0) Jy km s^-1, we derive a lensing- and excitation-corrected CO line luminosity of L'(CO(3-2)) = (3.4 +/- 0.7) x 10^10 (10.1/mu_L) K km s^-1 pc^2 for the SMG, where mu_L is the lensing magnification factor inferred from our lens modeling. This translates to a molecular gas mass of M_gas = (2.7 +/- 0.6) x 10^10 (10.1/mu_L) Msun. Fitting spectral energy distribution models to the (sub)-millimeter data of this SMG yields a dust temperature of T = 63.1^{+1.1}_{-1.3} K, a dust mass of M_du...

  15. A new population of ultra-long duration gamma-ray bursts

    CERN Document Server

    Levan, A J; Starling, R L C; Wiersema, K; Page, K L; Perley, D A; Schulze, S; Wynn, G A; Chornock, R; Hjorth, J; Cenko, S B; Fruchter, A S; O'Brien, P T; Brown, G C; Tunnicliffe, R L; Malesani, D; Jakobsson, P; Watson, D; Berger, E; Bersier, D; Cobb, B E; Covino, S; Cucchiara, A; Postigo, A de Ugarte; Fox, D B; Gal-Yam, A; Goldoni, P; Gorosabel, J; Kaper, L; Kruehler, T; Karjalainen, R; Osborne, J P; Pian, E; Sanchez-Ramirez, R; Schmidt, B; Skillen, I; Tagliaferri, G; Thone, C; Vaduvescu, O; Wijers, R A M J; Zauderer, B A

    2014-01-01

    We present comprehensive multiwavelength observations of three gamma-ray bursts (GRBs) with durations of several thousand seconds. We demonstrate that these events are extragalactic transients; in particular we resolve the long-standing conundrum of the distance of GRB 101225A (the "Christmas-day burst"), finding it to have a redshift z=0.847, and showing that two apparently similar events (GRB 111209A and GRB 121027A) lie at z=0.677 and z=1.773 respectively. The systems show extremely unusual X-ray and optical lightcurves, very different from classical GRBs, with long lasting highly variable X-ray emission and optical light curves that exhibit little correlation with the behaviour seen in the X-ray. Their host galaxies are faint, compact, and highly star forming dwarf galaxies, typical of "blue compact galaxies". We propose that these bursts are the prototypes of a hitherto largely unrecognized population of ultra-long GRBs, that while observationally difficult to detect may be astrophysically relatively com...

  16. Detection of the optical afterglow of GRB 000630: Implications for dark bursts

    DEFF Research Database (Denmark)

    Fynbo, J.U.; Jensen, B.L.; Gorosabel, J.;

    2001-01-01

    a power-law decline characterized by a decay slope of alpha = -1.035 +/- 0.097. A deep image obtained 25 days after the burst shows no indication of a contribution from a supernova or a host galaxy at the position of the transient. The closest detected galaxy is a R = 324.68 +/- 0.15 galaxy 2......We present the discovery of the optical transient of the long-duration gamma-ray burst GRB 000630. The optical transient was detected with the Nordic Optical Telescope 21.1 hours after the burst. At the time of discovery the magnitude of the transient was R = 23.04 +/- 0.08. The transient displayed...... conclude that i) based on the gamma-ray: properties of the current sample we cannot conclude that GRBs with no detected OTs belong to another class of GRBs than GRBs with detected OTs and ii) the majority (greater than or similar to 75%) of GRBs for which searches for optical afterglow have been...

  17. Exploring the Galaxy Mass-Metallicity Relation at z~3-5

    CERN Document Server

    Laskar, Tanmoy; Chary, Ranga-Ram

    2011-01-01

    Long-duration gamma-ray bursts (GRBs) provide a premier tool for studying high-redshift star-forming galaxies thanks to their extreme brightness and association with massive stars. Here we use GRBs to study the galaxy stellar mass-metallicity (M*-Z) relation at z~3-5, where conventional direct metallicity measurements are extremely challenging. We use the ISM metallicities of LGRB hosts derived from afterglow absorption spectroscopy (Z~0.01-1 solar), in conjunction with host galaxy stellar masses determined from deep Spitzer 3.6 micron observations of 20 GRB hosts. We detect about 1/4 of the hosts with I-band magnitudes ~ -21.5 to -22.5 AB mag, and place a limit of M > -19 mag on the remaining hosts from a stacking analysis. Using these observations, we present the first rest-frame optical luminosity distribution of long GRB hosts at z>3 and find that it is similar to the distribution of long GRB hosts at z~1. In comparison to Lyman-break galaxies at the same redshift, GRB hosts are generally fainter, but the...

  18. The Diversity and Versatility of Gamma-Ray Bursts

    Science.gov (United States)

    Laskar, Tanmoy

    2015-11-01

    Gamma-ray bursts (GRBs) are the most energetic explosions in the Universe, thus providing a unique laboratory for the study of extreme astrophysical processes. In parallel, their large luminosity makes GRBs a premier probe of the early Universe. My thesis has explored and exploited both aspects of GRB science by addressing the following fundamental open questions: 1) what is the nature of the GRB ejecta?, 2) how does the GRB progenitor population evolve with redshift, and 3) how can GRBs be used to probe the high-redshift Universe? To answer these questions, I present the first multi-wavelength detection and modeling of a GRB reverse shock, a comprehensive analysis of the plateau phase of GRB light curves, studies of the evolution of the progenitor population to redshifts, z~9, and demonstrate the use of GRBs as probes of galaxy formation and evolution through the first galaxy mass-metallicity relation at z~3-5. I find support for baryonic ejecta in GRB 130427A, evidence that GRB jets contain a large amount of energy in slow-moving ejecta, and proof that the GRB progenitor population does not evolve to the highest redshifts at which it has yet been observed. Building on the decade of observations by the Swift GRB mission, future observations and modeling of GRBs and their host galaxies will provide clues to these and other open questions in GRB science, allowing for the first statistical studies of their progenitors and host environments to the epoch of reionization and beyond.

  19. Cosmological fast radio bursts as a cosmic ruler?

    CERN Document Server

    Zhou, Bei; Wang, Tao; Fan, Yi-Zhong; Wei, Da-Ming

    2014-01-01

    We discuss the possibility of using cosmological fast radio bursts (FRBs) as a viable cosmic ruler. We find out that the contribution of the host galaxies to the detected dispersion measures may be ignorable for the FRBs not from galaxy centers or star forming regions. The inhomogeneity of the intergalactic medium (IGM), however, causes significant deviation of the dispersion measure from that predicted in the simplified homogeneous IGM model for individual event. Fortunately, with sufficient FRBs along different sightlines but within a very narrow redshift interval (e.g., $\\Delta z \\sim 0.05$), the mean from averaging observed dispersion measures does not suffer such a problem and hence may be used as a cosmic ruler. We show that in the optimistic case (e.g., tens FRBs in each $\\Delta z$ have been measured; the most distant FRBs were at redshift $\\geq 3$; the host galaxies and the FRB sources contribute little to the detected dispersion measures), FRBs could help constrain the equation of state of dark energ...

  20. The co-evolution of the obscured quasar PKS1549-79 and its host galaxy: evidence for a high accretion rate and warm outflow

    CERN Document Server

    Holt, J; Morganti, R; Bellamy, M; González-Delgado, R M; Tzioumis, A K; Inskip, K J

    2006-01-01

    ABRIDGED: We use deep optical, IR and radio observations to explore the symbiosis between the nuclear activity and galaxy evolution in the southern compact radio source PKS1549-79 (z=0.1523). The optical imaging observations reveal the presence of tidal tail features which provide strong evidence that the host galaxy has undergone a major merger in the recent past. This is further supported by the detection of a young stellar population which was formed 50-250Myr ago and makes up 1-30% of the total stellar mass. Despite the core-jet structure of the radio source we detect HI absorption associated with both the core and the jet. The luminous, quasar-like AGN (M_V 4.9) at optical wavelengths and shows many properties in common with narrow line Seyfert 1 galaxies (NLS1), including relatively narrow permitted lines (FWHM ~ 1940 km/s), highly blueshifted [OIII] lines (~680 km/s), and evidence that the putative supermassive black hole is accreting at a high Eddington ratio. This suggests that accretion at high Edd...

  1. Resolved Host Studies of Stellar Explosions

    CERN Document Server

    Levesque, Emily M

    2016-01-01

    The host galaxies of nearby (z<0.3) core-collapse supernovae and long-duration gamma-ray bursts offer an excellent means of probing the environments and populations that produce these events' varied massive progenitors. These same young stellar progenitors make LGRBs and SNe valuable and potentially powerful tracers of star formation, metallicity, the IMF, and the end phases of stellar evolution. However, properly utilizing these progenitors as tools requires a thorough understanding of their formation and, consequently, the physical properties of their parent host environments. This review looks at some of the recent work on LGRB and SN hosts with resolved environments that allows us to probe the precise explosion sites and surrounding environments of these events in incredible detail.

  2. The co-evolution of the obscured quasar PKS 1549-79 and its host galaxy: evidence for a high accretion rate and warm outflow

    Science.gov (United States)

    Holt, J.; Tadhunter, C.; Morganti, R.; Bellamy, M.; González Delgado, R. M.; Tzioumis, A.; Inskip, K. J.

    2006-08-01

    We use deep optical, infrared and radio observations to explore the symbiosis between nuclear activity and galaxy evolution in the southern compact radio source PKS 1549-79 (z = 0.1523). The optical imaging observations reveal the presence of tidal tail features which provide strong evidence that the host galaxy has undergone a major merger in the recent past. The merger hypothesis is further supported by the detection of a young stellar population (YSP), which, on the basis of spectral synthesis modelling of our deep Very Large Telescope (VLT) optical spectra, was formed 50-250 Myr ago and makes up a significant fraction of the total stellar mass (1-30 per cent). Despite the core-jet structure of the radio source, which is consistent with the idea that the jet is pointing close to our line of sight, our HI 21-cm observations reveal significant HI absorption associated with both the core and the jet. Moreover, the luminous, quasar-like active galactic nucleus (AGN) (MV extinguished (Av > 6.4) at optical wavelengths and show many properties in common with narrow-line Seyfert 1 galaxies (NLS1), including relatively narrow permitted lines [full width at half-maximum (FWHM) ~ 1940 km s-1], highly blueshifted [OIII] λλ5007,4959 lines (ΔV ~ 680 km s-1) and evidence that the putative supermassive black hole is accreting at a high Eddington ratio (0.3 black hole grows rapidly through merger-induced accretion following the coalescence of the nuclei of two merging galaxies, and the major growth phase is largely hidden at optical wavelengths by the natal gas and dust. Although the models also predict that AGN-driven outflows will eventually remove the gas from the bulge of the host galaxy, the visible warm outflow in PKS 1549-79 is not currently capable of doing so. However, much of the outflow may be hidden by the material obscuring the quasar and/or tied up in hotter or cooler phases of the interstellar medium. By combining our estimates of the reddening of the quasar

  3. Molecular Gas in Lensed z >2 Quasar Host Galaxies and the Star Formation Law for Galaxies with Luminous Active Galactic Nuclei

    OpenAIRE

    Riechers, Dominik A.

    2011-01-01

    We report the detection of luminous CO(J = 2→1), CO(J = 3→2), and CO(J = 4→3) emission in the strongly lensed high-redshift quasars B1938+666 (z = 2.059), HE 0230-2130 (z = 2.166), HE 1104-1805 (z = 2.322), and B1359+154 (z = 3.240), using the Combined Array for Research in Millimeter-wave Astronomy. B1938+666 was identified in a "blind" CO redshift search, demonstrating the feasibility of such investigations with millimeter interferometers. These galaxies are lensing-amplified by factors of ...

  4. Chandra X-Ray and Hubble Space Telescope Imaging of Optically Selected Kiloparsec-scale Binary Active Galactic Nuclei. II. Host Galaxy Morphology and AGN Activity

    Science.gov (United States)

    Shangguan, Jinyi; Liu, Xin; Ho, Luis C.; Shen, Yue; Peng, Chien Y.; Greene, Jenny E.; Strauss, Michael A.

    2016-05-01

    Binary active galactic nuclei (AGNs) provide clues to how gas-rich mergers trigger and fuel AGNs and how supermassive black hole (SMBH) pairs evolve in a gas-rich environment. While significant effort has been invested in their identification, the detailed properties of binary AGNs and their host galaxies are still poorly constrained. In a companion paper, we examined the nature of ionizing sources in the double nuclei of four kiloparsec-scale binary AGNs with redshifts between 0.1 and 0.2. Here, we present their host galaxy morphology based on F336W (U-band) and F105W (Y-band) images taken by the Wide Field Camera 3 on board the Hubble Space Telescope. Our targets have double-peaked narrow emission lines and were confirmed to host binary AGNs with follow-up observations. We find that kiloparsec-scale binary AGNs occur in galaxy mergers with diverse morphological types. There are three major mergers with intermediate morphologies and a minor merger with a dominant disk component. We estimate the masses of the SMBHs from their host bulge stellar masses and obtain Eddington ratios for each AGN. Compared with a representative control sample drawn at the same redshift and stellar mass, the AGN luminosities and Eddington ratios of our binary AGNs are similar to those of single AGNs. The U ‑ Y color maps indicate that clumpy star-forming regions could significantly affect the X-ray detection of binary AGNs, e.g., the hardness ratio. Considering the weak X-ray emission in AGNs triggered in merger systems, we suggest that samples of X-ray-selected AGNs may be biased against gas-rich mergers. Based, in part, on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program number GO 12363.

  5. Host galaxies and environment of active galactic nuclei : a study of the XMM large scale structure survey

    NARCIS (Netherlands)

    Tasse, Cyril

    2008-01-01

    Active galactic nuclei (AGN) result from the infall of matter onto the super-massive black holes that are situated at the centres of galaxies. This process releases an enormous amount of energy into the inter-stellar and inter-galactic medium. Hence, the study of AGN becomes essential in the context

  6. Two high-redshift DLAs towards a z~5 gamma-ray burst

    CERN Document Server

    Sparre, M; Krühler, T; Fynbo, J P U; Watson, D J; Wiersema, K; D'Elia, V; De Cia, A; Afonso, P M J; Covino, S; Postigo, A de Ugarte; Flores, H; Goldoni, P; Greiner, J; Hjorth, J; Jakobsson, P; Kaper, L; Klose, S; Malesani, D; Milvang-Jensen, B; Nardini, M; Piranomonte, S; Sollerman, J; Ramirez, R Sanchez; Schulze, S; Tanvir, N R; Vergani, S D; Wijers, R A M J; Zafar, T

    2013-01-01

    Observations of the afterglows of long gamma-ray bursts (GRBs) allow the study of star-forming galaxies across most of cosmic history. Here we present observations of GRB 111008A from which we can measure abundance patterns, metallicity, dust content and extinction of the GRB host galaxy (z=5.0) as well as a Damped Lyman-alpha Absorber (DLA) galaxy along the line of sight (z=4.6). These systems have column densities of log N =22.30 +/- 0.06 and 21.34 +/- 0.10, respectively. The GRB host galaxy has a metallicity of 2% solar (based on sulfur), and a lower limit of the metallicity for the intervening DLA is 3% (based on silicon). For the intervening absorber we also measure -1.73<[Fe/H]<-1.09, but the true metallicity can be higher, because it is unclear how much the abundances are affected by dust depletion. The presence and variability of fine-structure lines confirms the z=5.0 system as the GRB host. This is the highest redshift where Fe II fine-structure lines have been detected. The afterglow is only ...

  7. Disk Galaxies and Galaxy Disks

    CERN Document Server

    Funes, J G

    2000-01-01

    The conference Galaxy Disks and Disk Galaxies, sponsored by the Vatican Observatory, was held in June 12-16, 2000 at the Pontifical Gregorian University, in Rome (Italy). The meeting hosted about 230 participants coming from 30 countries. The very full program consisted of 29 review papers, 34 invited talks, and more than 180 posters. The meeting covered topics regarding the structure, formation and evolution of galaxies with disks. Particular attention was dedicated to the stellar and gaseous disk of the Milky Way, the global characteristics of galaxy disks, their structure, morphology and dynamics, the gaseous components, star formation, and chemical evolution, the interactions, accretion, mergers and starbursts, the dark and luminous matter, the establishment of the scaling laws, and the formation and evolution of disk galaxies from a theoretical and observational point of view.

  8. Galaxy harassment and the evolution of clusters of galaxies

    CERN Document Server

    Moore, B; Lake, G; Dressler, A; Oemler, A E; Moore, Ben; Katz, Neal; Lake, George; Dressler, Alan; Oemler, Augustus

    1995-01-01

    Disturbed spiral galaxies with high rates of star formation pervaded clusters of galaxies just a few billion years ago, but nearby clusters exclude spirals in favor of ellipticals. ``Galaxy harassment" (frequent high speed galaxy encounters) drives the morphological transformation of galaxies in clusters, provides fuel for quasars in subluminous hosts and leaves detectable debris arcs. Simulated images of harassed galaxies are strikingly similar to the distorted spirals in clusters at z \\sim 0.4 observed by the Hubble Space Telescope.

  9. Constraints on the distribution and energetics of fast radio bursts using cosmological hydrodynamic simulations

    Science.gov (United States)

    Dolag, K.; Gaensler, B. M.; Beck, A. M.; Beck, M. C.

    2015-08-01

    We present constraints on the origins of fast radio bursts (FRBs) using large cosmological simulations. We calculate contributions to FRB dispersion measures (DMs) from the Milky Way, from the Local Universe, from cosmological large-scale structure, and from potential FRB host galaxies, and then compare these simulations to the DMs of observed FRBs. We find that the Milky Way contribution has previously been underestimated by a factor of ˜2, and that the foreground-subtracted DMs are consistent with a cosmological origin, corresponding to a source population observable to a maximum redshift z ˜ 0.6-0.9. We consider models for the spatial distribution of FRBs in which they are randomly distributed in the Universe, track the star formation rate of their host galaxies, track total stellar mass, or require a central supermassive black hole. Current data do not discriminate between these possibilities, but the predicted DM distributions for different models will differ considerably once we begin detecting FRBs at higher DMs and higher redshifts. We additionally consider the distribution of FRB fluences, and show that the observations are consistent with FRBs being standard candles, each burst producing the same radiated isotropic energy. The data imply a constant isotropic burst energy of ˜7 × 1040 erg if FRBs are embedded in host galaxies, or ˜9 × 1040 erg if FRBs are randomly distributed. These energies are 10-100 times larger than had previously been inferred. Within the constraints of the available small sample of data, our analysis favours FRB mechanisms for which the isotropic radiated energy has a narrow distribution in excess of 1040 erg.

  10. GRB 070518: A Gamma-ray Burst with Optically Dim Luminosity

    CERN Document Server

    Xin, L P; Wang, J; Deng, J S; Urata, Y; Qiu, Y L; Huang, K Y; Hu, J Y; Wei, J Y

    2009-01-01

    We present our optical observations of {\\em Swift} GRB 070518 afterglow obtained at the 0.8-m Tsinghua University-National Astronomical Observatory of China telescope (TNT) at Xinglong Observatory. Our follow-up observations were performed from 512 sec after the burst trigger. With the upper limit of redshift $\\sim$0.7, GRB 070518 is found to be an optically dim burst. The spectra indices $\\beta_{ox}$ of optical to X-ray are slightly larger than 0.5, which implies the burst might be a dark burst. The extinction $A_{V}$ of the host galaxy is 3.2 mag inferred from the X-ray hydrogen column density with Galactic extinction law, and 0.3 mag with SMC extinction law. Also, it is similar to three other low-redshift optically dim bursts, which belong to XRR or XRF, and mid-term duration($T_{90}<10$, except for GRB 070419A, $T_{90}$=116s). Moreover, its $R$ band afterglow flux is well fitted by a single power-law with an index of 0.87. The optical afterglow and the X-ray afterglow in the normal segment might have t...

  11. Gamma-Ray Bursts and the Fireball Model

    CERN Document Server

    Piran, T

    1999-01-01

    Gamma-ray bursts (GRBs) have puzzled astronomers since their accidental discovery in the late sixties. The BATSE detector on the COMPTON-GRO satellite has been detecting one burst per day for the last six years. Its findings have revolutionized our ideas about the nature of these objects. They have shown that GRBs are at cosmological distances. This idea was accepted with difficulties at first. The recent discovery of an X-ray afterglow by the Italian/Dutch satellite BeppoSAX has led to a detection of high red-shift absorption lines in the optical afterglow of GRB970508 and in several other bursts and to the identification of host galaxies to others. This has confirmed the cosmological origin. Cosmological GRBs release $\\sim 10^{51}-10^{53}$ergs in a few seconds making them the most (electromagnetically) luminous objects in the Universe. The simplest, most conventional, and practically inevitable, interpretation of these observations is that GRBs result from the conversion of the kinetic energy of ultra-relat...

  12. Using STIS to find $\\gamma$-Ray Burst Redshifts

    CERN Document Server

    Bloom, J S; Wijers, R A M J; Almaini, O; Tanvir, N R; Johnson, R A; Bloom, Joshua S.; Sigurdsson, Steinn; Wijers, Ralph A. M. J.; Almaini, Omar; Tanvir, Nial R.; Johnson, Rachel A.

    1997-01-01

    A recent spectrum of the optical afterglow of GRB 970508 suggests that gamma-ray bursts (GRBs) are cosmological in origin and it is of crucial importance to derive an accurate distance to each burst. If GRBs occur near their host galaxies then Lyman limit absorption should be observable in roughly half the GRB afterglow spectra. Here we outline the methodology to obtain a redshift from the GRB afterglow spectrum using the recently installed Space Telescope Imaging Spectrograph (STIS) instrument onboard the Hubble Space Telescope. A low-resolution spectrum with the Multi-Anode Microchannel Array (MAMA) detector gives complete spectral coverage over the wavelength range 157.0-318.0 nm (Near UV) and 115.0-174.0 nm (Far UV). Assuming a Target of Opportunity observation is conducted soon (< 3 weeks) after a bright burst, a relatively small integration time (about 3 orbits) would be sufficient to detect the Lyman limit over a wide redshift range (0.3 < z < 2.2). Detection (or non-detection) of the Lyman li...

  13. Light Dawns on Dark Gamma-ray Bursts

    Science.gov (United States)

    2010-12-01

    [1] Gamma-ray bursts lasting longer than two seconds are referred to as long bursts and those with a shorter duration are known as short bursts. Long bursts, which were observed in this study, are associated with the supernova explosions of massive young stars in star