WorldWideScience

Sample records for central supermassive black

  1. Origin of supermassive black holes

    OpenAIRE

    Dokuchaev, V. I.; Eroshenko, Yu. N.; Rubin, S. G.

    2007-01-01

    The origin of supermassive black holes in the galactic nuclei is quite uncertain in spite of extensive set of observational data. We review the known scenarios of galactic and cosmological formation of supermassive black holes. The common drawback of galactic scenarios is a lack of time and shortage of matter supply for building the supermassive black holes in all galaxies by means of accretion and merging. The cosmological scenarios are only fragmentarily developed but propose and pretend to...

  2. Galaxy Bulge Formation: Interplay with Dark Matter Halo and Central Supermassive Black Hole

    CERN Document Server

    Xu, B X; Zhao, H S; Xu, Bing-Xiao; Wu, Xue-Bing; Zhao, HongSheng

    2007-01-01

    We present a simple scenario where the formation of galactic bulges was regulated by the dark halo gravity and regulated the growth of the central supermassive black hole. Assuming the angular momentum is low, we suggest that bulges form in a runaway collapse due to the "gravothermal" instability once the central gas density or pressure exceeds certain threshold (Xu & Zhao 2007). We emphasize that the threshold is nearly universal, set by the background NFW dark matter gravity $g_{DM} \\sim 1.2 \\times 10^{-8}{\\rm cm} {\\rm sec}^{-2}$ in the central cusps of halos. Unlike known thresholds for gradual formation of galaxy disks, we show that the universal "halo-regulated" star formation threshold for spheroids matches the very high star formation rate and star formation efficiency shown in high-redshift observations of central starburst regions. The starburst feedback also builds up a pressure shortly after the collapse. This large pressure could both act outward to halt further infall of gas from larger scale...

  3. XMM-Newton reveals matter accreting onto the central supermassive black hole of NGC 2617

    Science.gov (United States)

    Giustini, M.

    2016-06-01

    NGC 2617 (z=0.042) underwent a strong broad-band outburst during 2013/14, concurrently switching from being a Seyfert 1.8 to be a Seyfert 1.0 sometimes during the previous 10 years. Thanks to the combination of the large effective area and the good spectral resolution of the EPIC-pn onboard XMM-Newton, striking insights about the very inner accretion flow of this AGN have been revealed. In particular, persistent Fe K absorption redshifted by ˜ 35,000 km/s was solidly detected in two observations spaced by one month: a highly ionised flow of mass toward the central supermassive black hole of NGC 2617 has started to be traced. So far NGC 2617 is a quasi-unique observational example: what are the perspectives of enlarging these studies in the future? Thanks to current large and prolonged optical surveys like the SDSS/BOSS, many "optically changing-look AGN" like NGC 2617 are being discovered month after month: XMM-Newton has the ideal instruments to perform a proper X-ray study of such objects in the near future. I will assess the impact of XMM-Newton on studying the dynamics of the inner accretion flow in AGN in a systematic way and in synergy with near- and mid-future X-ray instruments such as (ASTRO-H)Hitomi and ATHENA.

  4. Growth of supermassive black holes, galaxy mergers and supermassive binary black holes

    OpenAIRE

    Komossa, S.; Baker, J G; Liu, F. K.

    2016-01-01

    The study of galaxy mergers and supermassive binary black holes (SMBBHs) is central to our understanding of the galaxy and black hole assembly and (co-)evolution at the epoch of structure formation and throughout cosmic history. Galaxy mergers are the sites of major accretion episodes, they power quasars, grow supermassive black holes (SMBHs), and drive SMBH-host scaling relations. The coalescing SMBBHs at their centers are the loudest sources of gravitational waves (GWs) in the universe, and...

  5. Joint Formation of Supermassive Black Holes and Galaxies

    OpenAIRE

    Haehnelt, Martin G.

    2003-01-01

    The tight correlation between black hole mass and velocity dispersion of galactic bulges is strong evidence that the formation of galaxies and supermassive black holes are closely linked. I review the modeling of the joint formation of galaxies and their central supermassive black holes in the context of the hierarchical structure formation paradigm.

  6. SUPERMASSIVE SEEDS FOR SUPERMASSIVE BLACK HOLES

    International Nuclear Information System (INIS)

    Recent observations of quasars powered by supermassive black holes (SMBHs) out to z ∼> 7 constrain both the initial seed masses and the growth of the most massive black holes (BHs) in the early universe. Here we elucidate the implications of the radiative feedback from early generations of stars and from BH accretion for popular models for the formation and growth of seed BHs. We show that by properly accounting for (1) the limited role of mergers in growing seed BHs as inferred from cosmological simulations of early star formation and radiative feedback, (2) the sub-Eddington accretion rates of BHs expected at the earliest times, and (3) the large radiative efficiencies ε of the most massive BHs inferred from observations of active galactic nuclei at high redshift (ε ∼> 0.1), we are led to the conclusion that the initial BH seeds may have been as massive as ∼> 105 M☉. This presents a strong challenge to the Population III seed model, which calls for seed masses of ∼100 M☉ and, even with constant Eddington-limited accretion, requires ε ∼4-106 M☉ seed BH. These results corroborate recent cosmological simulations and observational campaigns which suggest that these massive BHs were the seeds of a large fraction of the SMBHs residing in the centers of galaxies today.

  7. Supermassive black holes and spectral emission lines

    International Nuclear Information System (INIS)

    It is widely accepted that active galactic nuclei (AGN) are hosting a supermassive black hole in their center. The supermassive black hole is actively fueled by surrounding gas through an accretion disk, which produces a broad band continuum (from X-ray to radio emission). The hard photons from the accretion disk create the photoionized plasma around the central black hole, which emits a number of broad emission lines. Therefore, one of the signatures of the strong activity in galaxies is the emission of the broad spectral lines (line widths of several 1000 km/s), which are seen only in a fraction of AGN, so called Type 1 AGN. These broad emission lines often show very complex line profiles, usually strongly variable in time. Here we will describe the basic properties of the broad emission lines and how can we use them to derive the properties of the central supermassive black hole, i.e., the mass and spin, or see signatures of supermassive binary black holes

  8. Supermassive Black Hole Binaries as Galactic Blenders

    CERN Document Server

    Kandrup, H E; Terzic, B; Bohn, C L; Kandrup, Henry E.; Sideris, Ioannis V.; Terzic, Balsa; Bohn, Courtlandt L.

    2003-01-01

    This paper focuses on the dynamical implications of close supermassive black hole binaries both as an example of resonant phase mixing and as a potential explanation of inversions and other anomalous features observed in the luminosity profiles of some elliptical galaxies. The presence of a binary comprised of black holes executing nearly periodic orbits leads to the possibility of a broad resonant coupling between the black holes and various stars in the galaxy. This can result in efficient chaotic phase mixing and, in many cases, systematic increases in the energies of stars and their consequent transport towards larger radii. Allowing for the presence of a supermassive black hole binary with plausible parameter values near the center of a spherical, or nearly spherical, galaxy characterised initially by a Nuker density profile enables one to reproduce in considerable detail the central surface brightness distributions of such galaxies as NGC 3706.

  9. Supermassive black holes in scalar field galaxy halos

    OpenAIRE

    Ureña-López, L. Arturo; Liddle, Andrew R.

    2002-01-01

    Ultra-light scalar fields provide an interesting alternative to WIMPS as halo dark matter. In this paper we consider the effect of embedding a supermassive black hole within such a halo, and estimate the absorption probability and the accretion rate of dark matter onto the black hole. We show that the accretion rate would be small over the lifetime of a typical halo, and hence that supermassive central black holes can coexist with scalar field halos.

  10. Supermassive Black Holes from the SUNNS survey

    CERN Document Server

    Sarzi, M; Shields, J C; Rudnick, G; Ho, L C; McIntosh, D H; Filippenko, A V; Sargent, W L W; Sarzi, Marc; Rix, Hans-Walter; Shields, Joseph C.; Rudnick, Greg; Ho, Luis C.; Intosh, Daniel H. Mc; Filippenko, Alexei V.; Sargent, Wallace L. W.

    2000-01-01

    We report three new accurate mass measurements for the supermassive black holes hosted by the early-type disk galaxies NGC2787, NGC4459 and NGC4596. The targets were selected from a larger set of long-slit spectra obtained with the Hubble Space Telescope as part of the Survey of Nearby Nuclei with STIS (SUNNS). They display symmetric gas velocity curves that could be modeled as a rotating disk in the joint potential of the stellar bulge and a putative central black hole. They also show regular dust lane patterns that could be used to infer the nuclear disk orientation. These three galaxies fall in the black-hole mass vs. central stellar velocity dispersion plane in agreement with the recently reported relation between these two quantities.

  11. The connection between the formation of galaxies and that of their central supermassive black holes.

    Science.gov (United States)

    Haehnelt, Martin G

    2005-03-15

    Massive black holes appear to be an essential ingredient of massive galactic bulges but little is known yet to what extent massive black holes reside in dwarf galaxies and globular clusters. Massive black holes most likely grow by a mixture of merging and accretion of gas in their hierarchically merging host galaxies. While the hierarchical merging of dark matter structures extends to sub-galactic scales and very high redshift, it is uncertain if the same is true for the build-up of massive black holes. I discuss here some of the relevant problems and open questions. PMID:15681288

  12. Growth of supermassive black holes, galaxy mergers and supermassive binary black holes

    CERN Document Server

    Komossa, S; Liu, F K

    2016-01-01

    The study of galaxy mergers and supermassive binary black holes (SMBBHs) is central to our understanding of the galaxy and black hole assembly and (co-)evolution at the epoch of structure formation and throughout cosmic history. Galaxy mergers are the sites of major accretion episodes, they power quasars, grow supermassive black holes (SMBHs), and drive SMBH-host scaling relations. The coalescing SMBBHs at their centers are the loudest sources of gravitational waves (GWs) in the universe, and the subsequent GW recoil has a variety of potential astrophysical implications which are still under exploration. Future GW astronomy will open a completely new window on structure formation and galaxy mergers, including the direct detection of coalescing SMBBHs, high-precision measurements of their masses and spins, and constraints on BH formation and evolution in the high-redshift universe.

  13. Primordial seeds of supermassive black holes

    OpenAIRE

    Kawasaki, Masahiro(Institute for Cosmic Ray Research, the University of Tokyo, Chiba, 277-8582, Japan); Kusenko, Alexander; Yanagida, Tsutomu T.

    2012-01-01

    Supermassive black holes exist in the centers of galaxies, including Milky Way, but there is no compelling theory of their formation. Furthermore, observations of quasars imply that supermassive black holes have already existed at some very high redshifts, suggesting the possibility of their primordial origin. In a class of well-motivated models, inflationary epoch could include two or more periods of inflation dominated by different scalar fields. The transition between such periods of infla...

  14. Supermassive Black Holes in Galactic Nuclei

    CERN Document Server

    Ho, L C

    1998-01-01

    I review the status of observational determinations of central masses in nearby galactic nuclei. Results from a variety of techniques are summarized, including ground-based and space-based optical spectroscopy, radio VLBI measurements of luminous water vapor masers, and variability monitoring studies of active galactic nuclei. I will also discuss recent X-ray observations that indicate relativistic motions arising from the accretion disks of active nuclei. The existing evidence suggests that supermassive black holes are an integral component of galactic structure, at least in elliptical and bulge-dominated galaxies. The black hole mass appears to be correlated with the mass of the spheroidal component of the host galaxy. This finding may have important implications for many astrophysical issues.

  15. Formation of Supermassive Black Holes

    CERN Document Server

    Volonteri, Marta

    2010-01-01

    Evidence shows that massive black holes reside in most local galaxies. Studies have also established a number of relations between the MBH mass and properties of the host galaxy such as bulge mass and velocity dispersion. These results suggest that central MBHs, while much less massive than the host (~ 0.1%), are linked to the evolution of galactic structure. In hierarchical cosmologies, a single big galaxy today can be traced back to the stage when it was split up in hundreds of smaller components. Did MBH seeds form with the same efficiency in small proto-galaxies, or did their formation had to await the buildup of substantial galaxies with deeper potential wells? I briefly review here some of the physical processes that are conducive to the evolution of the massive black hole population. I will discuss black hole formation processes for `seed' black holes that are likely to place at early cosmic epochs, and possible observational tests of these scenarios.

  16. Supermassive Black Holes and Their Environments

    OpenAIRE

    Colberg, Joerg M.; Di Matteo, Tiziana

    2008-01-01

    We make use of the first high--resolution hydrodynamic simulations of structure formation which self-consistently follows the build up of supermassive black holes introduced in Di Matteo et al. (2007) to investigate the relation between black holes (BH), host halo and large--scale environment. There are well--defined relations between halo and black hole masses and between the activities of galactic nuclei and halo masses at low redshifts. A large fraction of black holes forms anti--hierarchi...

  17. Observational signatures of binary supermassive black holes

    International Nuclear Information System (INIS)

    Observations indicate that most massive galaxies contain a supermassive black hole, and theoretical studies suggest that when such galaxies have a major merger, the central black holes will form a binary and eventually coalesce. Here we discuss two spectral signatures of such binaries that may help distinguish them from ordinary active galactic nuclei. These signatures are expected when the mass ratio between the holes is not extreme and the system is fed by a circumbinary disk. One such signature is a notch in the thermal continuum that has been predicted by other authors; we point out that it should be accompanied by a spectral revival at shorter wavelengths and also discuss its dependence on binary properties such as mass, mass ratio, and separation. In particular, we note that the wavelength λ n at which the notch occurs depends on these three parameters in such a way as to make the number of systems displaying these notches ∝λn16/3; longer wavelength searches are therefore strongly favored. A second signature, first discussed here, is hard X-ray emission with a Wien-like spectrum at a characteristic temperature ∼100 keV produced by Compton cooling of the shock generated when streams from the circumbinary disk hit the accretion disks around the individual black holes. We investigate the observability of both signatures. The hard X-ray signal may be particularly valuable as it can provide an indicator of black hole merger a few decades in advance of the event.

  18. Dynamics of galaxy cores and supermassive black holes

    OpenAIRE

    Merritt, David

    2006-01-01

    Recent work on the dynamical evolution of galactic nuclei containing supermassive black holes is reviewed. Topics include galaxy structural properties; collisionless and collisional equilibria; loss-cone dynamics; and dynamics of binary and multiple supermassive black holes.

  19. Low-frequency gravitational waves from supermassive black holes

    OpenAIRE

    Haehnelt, M. G.

    1994-01-01

    Supermassive black holes are investigated as possible sources for low-frequency bursts of gravity waves. The event rate for `known' supermassive black holes at intermediate and high redshifts, inferred from the quasar luminosity function, is low $\\sim 0.1 \\yr^{-1}$. A space-based interferometer could therefore only see several events per year from supermassive black holes if an additional population of supermassive black holes existed and emitted gravitational waves efficiently. These might r...

  20. A New Concept of Transonic Galactic Outflows in a Cold Dark Matter Halo with a Central Super-Massive Black Hole

    CERN Document Server

    Igarashi, Asuka; Nitta, Shin-ya

    2014-01-01

    We study fundamental properties of isothermal, steady and spherically symmetric galactic outflow in the gravitational potential of a cold dark matter halo and a central super-massive black hole. We find that there are two transonic solutions having different properties: each solution is mainly produced by the dark matter halo and the super-massive black hole, respectively. Furthermore, we apply our model to the Sombrero galaxy. In this galaxy, Chandra X-ray observatory detected the diffuse hot gas as the trace of galactic outflows while the star-formation rate is low and the observed gas density distribution presumably indicates the hydrostatic equilibrium. To solve this discrepancy, we propose a solution that this galaxy has a transonic outflow, however, the transonic point forms in a very distant region from the galactic center (?$\\sim$ 127 kpc). In this slowly accelerated transonic outflow, the outflow velocity is less than the sound velocity for most of the galactic halo. Since the gas density distributio...

  1. Supermassive Black Holes and Galaxy Formation

    OpenAIRE

    Silk, Joseph

    2001-01-01

    The formation of supermassive black holes (SMBH) is intimately related to galaxy formation, although precisely how remains a mystery. I speculate that formation of, and feedback from, SMBH may alleviate problems that have arisen in our understanding of the cores of dark halos of galaxies.

  2. Supermassive Black Hole Binaries: The Search Continues

    CERN Document Server

    Bogdanovic, Tamara

    2014-01-01

    Gravitationally bound supermassive black hole binaries (SBHBs) are thought to be a natural product of galactic mergers and growth of the large scale structure in the universe. They however remain observationally elusive, thus raising a question about characteristic observational signatures associated with these systems. In this conference proceeding I discuss current theoretical understanding and latest advances and prospects in observational searches for SBHBs.

  3. A mechanism of supermassive primordial black hole formation

    International Nuclear Information System (INIS)

    A mechanism of supermassive primordial black hole formation is proposed in the framework of a multidimensional gravity theory. Possible observable manifestations of primordial black holes are discussed

  4. M33 A Galaxy with No Supermassive Black Hole

    CERN Document Server

    Gebhardt, K; Kormendy, J; Pinkney, J C; Bower, G A; Green, R; Gull, T R; Hutchings, J B; Joseph, C L; Kaiser, M E; Nelson, C H; Richstone, D O; Weistrop, D; Gebhardt, Karl; Lauer, Tod R.; Kormendy, John; Pinkney, Jason; Bower, Gary A.; Green, Richard; Gull, Theodore; Joseph, Chuck; Nelson, Charles H.; Richstone, Douglas; Weistrop, Donna

    2001-01-01

    Galaxies that contain bulges appear to contain central black holes whose masses correlate with the velocity dispersion of the bulge. We show that no corresponding relationship applies in the pure disk galaxy M33. Three-integral dynamical models fit Hubble Space Telescope WFPC2 photometry and STIS spectroscopy best if the central black hole mass is zero. The upper limit is 1500 M_sun. This is significantly below the mass expected from the velocity dispersion of the nucleus and far below any mass predicted from the disk kinematics. Our results suggest that supermassive black holes are associated only with galaxy bulges and not with their disks or dark halos.

  5. Observational signatures of binary supermassive black holes

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, Constanze; Krolik, Julian H. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Miller, M. Coleman [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742 (United States)

    2014-04-20

    Observations indicate that most massive galaxies contain a supermassive black hole, and theoretical studies suggest that when such galaxies have a major merger, the central black holes will form a binary and eventually coalesce. Here we discuss two spectral signatures of such binaries that may help distinguish them from ordinary active galactic nuclei. These signatures are expected when the mass ratio between the holes is not extreme and the system is fed by a circumbinary disk. One such signature is a notch in the thermal continuum that has been predicted by other authors; we point out that it should be accompanied by a spectral revival at shorter wavelengths and also discuss its dependence on binary properties such as mass, mass ratio, and separation. In particular, we note that the wavelength λ {sub n} at which the notch occurs depends on these three parameters in such a way as to make the number of systems displaying these notches ∝λ{sub n}{sup 16/3}; longer wavelength searches are therefore strongly favored. A second signature, first discussed here, is hard X-ray emission with a Wien-like spectrum at a characteristic temperature ∼100 keV produced by Compton cooling of the shock generated when streams from the circumbinary disk hit the accretion disks around the individual black holes. We investigate the observability of both signatures. The hard X-ray signal may be particularly valuable as it can provide an indicator of black hole merger a few decades in advance of the event.

  6. Exploring Supermassive Black Hole Growth with ALMA

    CERN Document Server

    Kawakatu, N; Granato, G L; Danese, L; Kawakatu, Nozomu; Andreani, Paola; Granato, Gian Luigi; Danese, Luigi

    2007-01-01

    Massive tori with $\\approx 10^{8-9}M_{\\odot}$ are predicted to extend on $\\sim $100 pc scale around the centre of elliptical galaxy progenitors by a model of a supermassive black hole (SMBH) growth coeval to the spheroidal population of the host galaxy. Direct detection of such massive tori would cast light on a key physical condition that allows the rapid growth of SMBHs and the appearance of QSOs at high redshift. For this reason, we examine the detectability of such structures at substantial redshift with the Atacama Large Millimeter Array (ALMA). We propose that submillimeter galaxies (SMGs) are the best targets to test our predictions. In order to assess the observational feasibility, we estimate the expected number counts of SMGs with massive tori and check the detectability with the ALMA instrument, the unique facility which can resolve the central region of high redshift objects. Our work shows that ALMA will be able to resolve and detect high-$J$ ($J >$ 4) CO emissions from $\\sim$100 pc scale extende...

  7. Star formation around supermassive black holes.

    Science.gov (United States)

    Bonnell, I A; Rice, W K M

    2008-08-22

    The presence of young massive stars orbiting on eccentric rings within a few tenths of a parsec of the supermassive black hole in the galactic center is challenging for theories of star formation. The high tidal shear from the black hole should tear apart the molecular clouds that form stars elsewhere in the Galaxy, and transport of stars to the galactic center also appears unlikely during their lifetimes. We conducted numerical simulations of the infall of a giant molecular cloud that interacts with the black hole. The transfer of energy during closest approach allows part of the cloud to become bound to the black hole, forming an eccentric disk that quickly fragments to form stars. Compressional heating due to the black hole raises the temperature of the gas up to several hundred to several thousand kelvin, ensuring that the fragmentation produces relatively high stellar masses. These stars retain the eccentricity of the disk and, for a sufficiently massive initial cloud, produce an extremely top-heavy distribution of stellar masses. This potentially repetitive process may explain the presence of multiple eccentric rings of young stars in the presence of a supermassive black hole. PMID:18719276

  8. The Supermassive Black Hole—Galaxy Connection

    Science.gov (United States)

    King, Andrew

    2014-09-01

    The observed scaling relations imply that supermassive black holes (SMBH) and their host galaxies evolve together. Near-Eddington winds from the SMBH accretion discs explain many aspects of this connection. The wind Eddington factor should be in the range ˜1-30. A factor give black hole winds with velocities v˜0.1 c, observable in X-rays, just as seen in the most extreme ultrafast outflows (UFOs). Higher Eddington factors predict slower and less ionized winds, observable in the UV, as in BAL QSOs. In all cases the wind must shock against the host interstellar gas and it is plausible that these shocks should cool efficiently. There is detailed observational evidence for this in some UFOs. The wind sweeps up the interstellar gas into a thin shell and propels it outwards. For SMBH masses below a certain critical ( M- σ) value, all these outflows eventually stall and fall back, as the Eddington thrust of the wind is too weak to drive the gas to large radii. But once the SMBH mass reaches the critical M- σ value the global character of the outflow changes completely. The wind shock is no longer efficiently cooled, and the resulting thermal expansion drives the interstellar gas far from the black hole, which is unlikely to grow significantly further. Simple estimates of the maximum stellar bulge mass M b allowed by self-limited star formation show that the SMBH mass is typically about 10-3 M b at this point, in line with observation. The expansion-driven outflow reaches speeds v out≃1200 km s-1 and drives rates in cool (molecular) gas, giving a typical outflow mechanical energy L mech≃0.05 L Edd, where L Edd is the Eddington luminosity of the central SMBH. This is again in line with observation. These massive outflows may be what makes galaxies become red and dead, and can have several other potentially observable effects. In particular they have the right properties to enrich the intergalactic gas with metals. Our current picture of SMBH-galaxy coevolution is

  9. Astrophysical phenomena related to supermassive black holes

    Science.gov (United States)

    Pott, Jörg-Uwe

    2006-12-01

    The thesis contains the results of my recent projects in astrophysical research. All projects aim at pushing the limits of our knowledge about the interaction between a galaxy, the fundamental building block of today's universe, and a supermassive black hole (SMBH) at its center. Over the past years a lot of observational evidence has been gathered for the current understanding, that at least a major part of the galaxies with a stellar bulge contain central SMBHs. The typical extragalactic approach consists of searching for the spectroscopic pattern of Keplerian rotation, produced by stars and gas, when orbiting a central dark mass (Kormendy & Richstone 1995). It suggests that a significant fraction of large galaxies host in their very nucleus a SMBH of millions to billions of solar masses (Kormendy & Gebhardt 2001). In the closest case, the center of our Milky Way, the most central stars, which can be imaged, were shown to move on orbits with circulation times of a few decades only, evidencing a mass and compactness of the dark counter part of the Keplerian motion, which can only be explained by a SMBH (Eckart & Genzel 1996; Ghez et al. 2000; Schödel et al. 2002). Having acknowledged the widespread existence of SMBHs the obvious next step is investigating the interaction with their environment. Although the basic property of a SMBH, which is concentrating a huge amount of mass in a ludicrously small volume defined by the Schwarzschild radius, only creates a deep gravitational trough, its existence evokes much more phenomena than simply attracting the surrounding matter. It can trigger or exacerbate star formation via tidal forces (Morris 1993). It shapes the distribution of its surrounding matter to accretion discs, which themselves release gravitational potential energy as radiation, possibly due to magnetic friction (Blandford 1995). The radiation efficiency of such active galactic nuclei (AGN) can become roughly 100 times more efficient than atomic nuclear

  10. A Nearly Naked Supermassive Black Hole

    CERN Document Server

    Condon, J J; Kovalev, Y Y; Petrov, L

    2016-01-01

    During a systematic search for supermassive black holes (SMBHs) not in galactic nuclei, we identified the compact symmetric radio source B3 1715+425 with an emission-line galaxy offset ~ 8.5 kpc from the nucleus of the brightest cluster galaxy (BCG) in the redshift $z = 0.1754$ cluster ZwCl 8193. B3 1715+425 is too bright (brightness temperature $\\sim 3 \\times 10^{10}$ K at observing frequency 7.6 GHz) and too luminous (1.4 GHz luminosity $\\sim 10^{25}$ W/Hz) to be powered by anything but a SMBH, but its host galaxy is much smaller ($\\sim 0.9$ kpc $\\times$ 0.6 kpc full width between half-maximum points) and optically fainter (R-band absolute magnitude $\\sim -18.2$) than any other radio galaxy. Its high radial velocity $\\sim 1860$ km/s relative to the BCG, continuous ionized wake extending back to the BCG nucleus, and surrounding debris indicate that the radio galaxy was tidally shredded passing through the BCG core, leaving a nearly naked supermassive black hole fleeing from the BCG with space velocity $> 200...

  11. Supermassive Black Holes in the Early Universe

    CERN Document Server

    Melia, Fulvio

    2015-01-01

    The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only ~900 Myr after the big bang, and only ~500 Myr beyond the formation of Pop II and III stars. Aside from heralding the onset of cosmic reionization, these first and second generation stars could have reasonably produced the ~5-20 solar-mass seeds that eventually grew into z~6-7 quasars. But this process would have taken ~900 Myr, a timeline that appears to be at odds with the predictions of LCDM without an anomalously high accretion rate, or some exotic creation of ~10^5 solar-mass seeds. There is no evidence of either of these happening in the local universe. In this paper, we show that a much simpler, more elegant solution to the supermassive black hole anomaly is instead to view this process using the age-redshift relation predicted by the R_h=ct Universe, an FRW cosmology with zero active mass. In this context, cosm...

  12. Formation of supermassive black hole seeds

    CERN Document Server

    Latif, Muhammad A

    2016-01-01

    The detection of quasars at $z>6$ unveils the presence of supermassive black holes (BHs) of a few billion solar masses. The rapid formation process of these extreme objects remains a fascinating and open issue. Such discovery implies that seed black holes must have formed early on, and grown via either rapid accretion or BH/galaxy mergers. In this theoretical review, we discuss in detail various BH seed formation mechanisms and the physical processes at play during their assembly. We discuss the three most popular BH formation scenarios, involving the (i) core-collapse of massive stars, (ii) dynamical evolution of dense nuclear star clusters, (iii) collapse of a protogalactic metal free gas cloud. This article aims at giving a broad introduction and an overview of the most advanced research in the field.

  13. A Compact Supermassive Binary Black Hole System

    CERN Document Server

    Rodríguez, C; Zavala, R T; Peck, A B; Pollack, L K; Romani, R W

    2006-01-01

    We report on the discovery of a supermassive binary black hole system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the closest black hole pair yet found by more than two orders of magnitude. These results are based upon recent multi-frequency observations using the Very Long Baseline Array (VLBA) which reveal two compact, variable, flat-spectrum, active nuclei within the elliptical host galaxy of 0402+379. Multi-epoch observations from the VLBA also provide constraints on the total mass and dynamics of the system. Low spectral resolution spectroscopy using the Hobby-Eberly Telescope indicates two velocity systems with a combined mass of the two black holes of ~1.5 x 10^8 solar masses. The two nuclei appear stationary while the jets emanating from the weaker of the two nuclei appear to move out and terminate in bright hot spots. The discovery of this system has implications for the number of close binary black holes that might be sources of gravi...

  14. 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...

  15. Dark energy and supermassive black holes

    International Nuclear Information System (INIS)

    This paper deals with a cosmological model in which the universe is filled with tachyon dark energy in order to describe current and future accelerating expansion. We obtain that the simplest condition for the regime of phantom energy to occur in this scenario is that the scalar field be Wick rotated to imaginary values which correspond to an axionic field classically. By introducing analytical expressions for the scale factor or the Hubble parameter that satisfy all constraint equations of the used models we show that such models describe universes which may develop a big rip singularity in the finite future. It is argued that, contrary to a recent claim, the entropy for a universe filled with dark energy is definite positive even on the phantom regime where the universe would instead acquire a negative temperature. It is also seen that, whichever the fate of the tachyonic accelerating universe, it will be stable to any fluctuations of the scalar field, and that since the considered models have all an imaginary sound speed, any overdense regions will undergo an accelerated collapse leading rapidly to formation of giant black holes. Finally the conjecture is advanced that these black holes may be the supermassive black holes that most galaxies harbor at their center

  16. Hidden Pair of Supermassive Black Holes

    Science.gov (United States)

    Kohler, Susanna

    2015-08-01

    Could a pair of supermassive black holes (SMBHs) be lurking at the center of the galaxy Mrk 231? A recent study finds that this may be the case and the unique spectrum of this galaxy could be the key to discovering more hidden binary SMBH systems.Where Are the Binary Supermassive Black Holes?Its believed that most, if not all, galaxies have an SMBH at their centers. As two galaxies merge, the two SMBHs should evolve into a closely-bound binary system before they eventually merge. Given the abundance of galaxy mergers, we would expect to see the kinematic and visual signatures of these binary SMBHs among observed active galactic nuclei yet such evidence for sub-parsec binary SMBH systems remains scarce and ambiguous. This has led researchers to wonder: is there another way that we might detect these elusive systems?A collaboration led by Chang-Shuo Yan (National Astronomical Observatories, Chinese Academy of Sciences) thinks that there is. The group suggests that these systems might have distinct signatures in their optical-to-UV spectra, and they identify a system that might be just such a candidate: Mrk 231.A Binary CandidateProposed model of Mrk 231. Two supermassive black holes, each with their own mini-disk, orbit each other in the center of a circumbinary disk. The secondary black hole has cleared gap in the circumbinary disk as a result of its orbit around the primary black hole. [Yan et al. 2015]Mrk 231 is a galaxy with a disturbed morphology and tidal tails strong clues that it might be in the final stages of a galactic merger. In addition to these signs, Mrk 231 also has an unusual spectrum for a quasar: its continuum emission displays an unexpected drop in the near-UV band.Yan and her collaborators propose that the odd behavior of Mrk 231s spectrum can be explained if the center of the galaxy houses a pair of SMBHs each with its own mini accretion disk surrounded by a circumbinary accretion disk. As the secondary SMBH orbits the primary SMBH (with a

  17. Tidal disruption of asteroids by supermassive black holes

    Directory of Open Access Journals (Sweden)

    Gomboc A.

    2012-12-01

    Full Text Available The compact radio source Sgr A* at the centre of our Galaxy harbours a super-massive black hole, and is therefore the nearest laboratory for testing the super-massive black hole astrophysics and environment. Since it is not an active galactic nucleus, it also offers the possibility of observing the capture of low-mass objects, such as comets or asteroids, that may orbit the central black hole. In this paper we discuss conditions for tidal disruption of low-mass objects and predictions of the appearance and light curve of such events, as well as their relevance for the X-ray and infra-red flares detected in Sgr A*. The modelled light curves of such tidal disruption events bear marks of the strong gravitational field: tidal squeezing and elongation of the object, gravitational lensing, aberration of light, and Doppler effects. Finally, we show that this model is able to reproduce and fit X-ray flares.

  18. ECCENTRIC EVOLUTION OF SUPERMASSIVE BLACK HOLE BINARIES

    International Nuclear Information System (INIS)

    In recent numerical simulations, it has been found that the eccentricity of supermassive black hole (SMBH)-intermediate black hole (IMBH) binaries grows toward unity through interactions with the stellar background. This increase of eccentricity reduces the merging timescale of the binary through the gravitational radiation to a value well below the Hubble time. It also gives a theoretical explanation of the existence of eccentric binaries such as that in OJ287. In self-consistent N-body simulations, this increase of eccentricity is always observed. On the other hand, the result of the scattering experiment between SMBH binaries and field stars indicated that the eccentricity dose not change significantly. This discrepancy leaves the high eccentricity of the SMBH binaries in N-body simulations unexplained. Here, we present a stellar-dynamical mechanism that drives the increase of the eccentricity of an SMBH binary with a large mass ratio. There are two key processes involved. The first one is the Kozai mechanism under a non-axisymmetric potential, which effectively randomizes the angular momenta of surrounding stars. The other is the selective ejection of stars with prograde orbits. Through these two mechanisms, field stars extract the orbital angular momentum of the SMBH binary. Our proposed mechanism causes the increase in the eccentricity of most of SMBH binaries, resulting in the rapid merger through gravitational wave radiation. Our result has given a definite solution to the 'last-parsec problem'.

  19. Supermassive Black Holes at the Center of Galaxies

    OpenAIRE

    Greenwood, Christopher J.

    2005-01-01

    This was my final paper for the AST 308 Galaxies class at Michigan State University. Using many sources I was able to compile a moderate amount of information concerning the evidence for, and the formation of Supermassive Black Holes.

  20. Quasars a supermassive rotating toroidal black hole interpretation

    CERN Document Server

    Spivey, R J

    2000-01-01

    A supermassive rotating toroidal black hole (TBH) is proposed as the fundamental structure of quasars and other jet-producing active galactic nuclei. Rotating protogalaxies gather matter from the central gaseous region leading to the birth of massive toroidal stars whose internal nuclear reactions proceed very rapidly. Once the nuclear fuel is spent, gravitational collapse produces a slender ring-shaped TBH remnant. These events are typically the first supernovae of the host galaxies. Given time the TBH mass increases through continued accretion by several orders of magnitude, the event horizon swells whilst the central aperture shrinks. The difference in angular velocities between the accreting matter and the TBH induces a magnetic field that is strongest in the region of the central aperture and innermost ergoregion. Due to the presence of negative energy states when such a gravitational vortex is immersed in an electromagnetic field, circumstances are near ideal for energy extraction via non-thermal radiat...

  1. Astrophysics of super-massive black hole mergers

    International Nuclear Information System (INIS)

    We present here an overview of recent work in the subject of astrophysical manifestations of super-massive black hole (SMBH) mergers. This is a field that has been traditionally driven by theoretical work, but in recent years has also generated a great deal of interest and excitement in the observational astronomy community. In particular, the electromagnetic (EM) counterparts to SMBH mergers provide the means to detect and characterize these highly energetic events at cosmological distances, even in the absence of a space-based gravitational-wave observatory. In addition to providing a mechanism for observing SMBH mergers, EM counterparts also give important information about the environments in which these remarkable events take place, thus teaching us about the mechanisms through which galaxies form and evolve symbiotically with their central black holes. (paper)

  2. Astrophysics of Super-massive Black Hole Mergers

    CERN Document Server

    Schnittman, Jeremy D

    2013-01-01

    We present here an overview of recent work in the subject of astrophysical manifestations of super-massive black hole (SMBH) mergers. This is a field that has been traditionally driven by theoretical work, but in recent years has also generated a great deal of interest and excitement in the observational astronomy community. In particular, the electromagnetic (EM) counterparts to SMBH mergers provide the means to detect and characterize these highly energetic events at cosmological distances, even in the absence of a space-based gravitational-wave observatory. In addition to providing a mechanism for observing SMBH mergers, EM counterparts also give important information about the environments in which these remarkable events take place, thus teaching us about the mechanisms through which galaxies form and evolve symbiotically with their central black holes.

  3. Astrophysics of Super-Massive Black Hole Mergers

    Science.gov (United States)

    Schnittman, Jeremy D.

    2013-01-01

    We present here an overview of recent work in the subject of astrophysical manifestations of super-massive black hole (SMBH) mergers. This is a field that has been traditionally driven by theoretical work, but in recent years has also generated a great deal of interest and excitement in the observational astronomy community. In particular, the electromagnetic (EM) counterparts to SMBH mergers provide the means to detect and characterize these highly energetic events at cosmological distances, even in the absence of a space-based gravitational-wave observatory. In addition to providing a mechanism for observing SMBH mergers, EM counterparts also give important information about the environments in which these remarkable events take place, thus teaching us about the mechanisms through which galaxies form and evolve symbiotically with their central black holes.

  4. The Growth of Supermassive Black Holes Across Cosmic Time

    CERN Document Server

    Nandra, K; Alexander, D M; Ballantyne, D R; Barcons, X; Bauer, F E; Boller, T; Brandt, W N; Brusa, M; Cattaneo, A; Chartas, G; Coil, A L; Comastri, A; Croton, D J; Della Ceca, R; Dickinson, M; Fabian, A C; Fazio, G G; Fiore, F; Flanagan, K A; Forman, W R; Gehrels, N; Georgakakis, A; Georgantopoulos, I; Gilli, R; Hasinger, G; Hopkins, P F; Hornschemeier, A E; Ivison, R J; Kauffmann, G; King, A R; Koekemoer, A M; Koo, D C; Kunieda, H; Laird, E S; Levenson, N A; Li, Y; Madau, P; Ohashi, T; Pounds, K A; Primack, J R; Ranalli, P; Ricker, G R; Rossi, E M; Shemmer, O; Somerville, R S; Stern, D; Stiavelli, M; Tananbaum, H; Terashima, Y; Treister, E; Ueda, Y; Vignali, C; Volonteri, M; Watson, M G; White, N E; White, S D M

    2009-01-01

    One of the main themes in extragalactic astronomy for the next decade will be the evolution of galaxies over cosmic time. Many future observatories, including JWST, ALMA, GMT, TMT and E-ELT will intensively observe starlight over a broad redshift range, out to the dawn of the modern Universe when the first galaxies formed. It has, however, become clear that the properties and evolution of galaxies are intimately linked to the growth of their central black holes. Understanding the formation of galaxies, and their subsequent evolution, will therefore be incomplete without similarly intensive observations of the accretion light from supermassive black holes (SMBH) in galactic nuclei. To make further progress, we need to chart the formation of typical SMBH at z>6, and their subsequent growth over cosmic time, which is most effectively achieved with X-ray observations. Recent technological developments in X-ray optics and instrumentation now bring this within our grasp, enabling capabilities fully matched to those...

  5. Supermassive black holes in the distant universe

    CERN Document Server

    2004-01-01

    This book provides a unique overview of recent developments in studies of AGN and the evolution of supermassive black holes, with particular emphasis on the revolutionary results from the Chandra and XMM-Newton X-ray Observatories Each chapter is a comprehensive analysis and review by an expert in the field that should provide easy access to the subject The chapters progressively follow a single theme---the mapping of the accretion history of the universe---from both theoretical and observational points of view The chapters are written at a level that should be accessible to graduate students and non-specialists, yet the depth and innovation of the analyses will also make it highly informative to the specialist The topical nature of the subject matter means that the material presented in this book is not well covered in the present literature Moreover, the depth and interconnectedness of the chapters ensures that the coverage is much more comprehensive and informative than a conference proceeding would be The...

  6. Light or heavy supermassive black hole seeds: the role of internal rotation in the fate of supermassive stars

    CERN Document Server

    Fiacconi, Davide

    2016-01-01

    Supermassive black holes are a key ingredient of galaxy evolution. However, their origin is still highly debated. In one of the leading formation scenarios, a black hole of $\\sim100$ M$_{\\odot}$ results from the collapse of the inner core of a supermassive star ($\\gtrsim 10^{4-5}$ M$_{\\odot}$), created by the rapid accumulation ($\\gtrsim 0.1 $ M$_{\\odot}$ yr$^{-1}$) of pristine gas at the centre of newly formed galaxies at $z\\sim 15$. The subsequent evolution is still speculative: the remaining gas in the supermassive star can either directly plunge into the nascent black hole, or part of it can form a central accretion disc, whose luminosity sustains a surrounding, massive, and nearly hydrostatic envelope (a system called a "quasi-star"). To address this point, we consider the effect of rotation on a quasi-star, as angular momentum is inevitably transported towards the galactic nucleus by the accumulating gas. Using a model for the internal redistribution of angular momentum that qualitative matches results ...

  7. Formation of supermassive black holes through fragmentation of torodial supermassive stars.

    Science.gov (United States)

    Zink, Burkhard; Stergioulas, Nikolaos; Hawke, Ian; Ott, Christian D; Schnetter, Erik; Müller, Ewald

    2006-04-28

    We investigate new paths to supermassive black hole formation by considering the general relativistic evolution of a differentially rotating polytrope with a toroidal shape. We find that this polytrope is unstable to nonaxisymmetric modes, which leads to a fragmentation into self-gravitating, collapsing components. In the case of one such fragment, we apply a simplified adaptive mesh refinement technique to follow the evolution to the formation of an apparent horizon centered on the fragment. This is the first study of the onset of nonaxisymmetric dynamical instabilities of supermassive stars in full general relativity. PMID:16712210

  8. Binary pairs of supermassive black holes - Formation in merging galaxies

    International Nuclear Information System (INIS)

    A process in which supermassive binary blackholes are formed in nuclei of supergiant galaxies due to galaxy mergers is examined. There is growing evidence that mergers of galaxies are common and that supermassive black holes in center of galaxies are also common. Consequently, it is expected that binary black holes should arise in connection with galaxy mergers. The merger process in a galaxy modeled after M87 is considered. The capture probability of a companion is derived as a function of its mass. Assuming a correlation between the galaxy mass and the blackholes mass, the expected mass ratio in binary black holes is calculated. The binary black holes formed in this process are long lived, surviving longer than the Hubble time unless they are perturbed by black holes from successive mergers. The properties of these binaries agree with Gaskell's (1988) observational work on quasars and its interpretation in terms of binary black holes. 39 refs

  9. Blindly Detecting Merging Supermassive Black Holes with Radio Surveys

    OpenAIRE

    D. Kaplan; O'Shaughnessy, R.; Sesana, A.; Volonteri, M.

    2011-01-01

    Supermassive black holes presumably grow through numerous mergers throughout cosmic time. During each merger, supermassive black hole binaries are surrounded by a circumbinary accretion disk that imposes a significant (~1e4 G for a binary of 1e8 Msun) magnetic field. The motion of the binary through that field will convert the field energy to Poynting flux, with a luminosity ~1e43 erg/s (B/1e4 G)^2 (M/1e8 Msun)^2, some of which may emerge as synchrotron emission at frequencies near 1 GHz wher...

  10. Formation and coalescence of cosmological supermassive-black-hole binaries in supermassive-star collapse.

    Science.gov (United States)

    Reisswig, C; Ott, C D; Abdikamalov, E; Haas, R; Mösta, P; Schnetter, E

    2013-10-11

    We study the collapse of rapidly rotating supermassive stars that may have formed in the early Universe. By self-consistently simulating the dynamics from the onset of collapse using three-dimensional general-relativistic hydrodynamics with fully dynamical spacetime evolution, we show that seed perturbations in the progenitor can lead to the formation of a system of two high-spin supermassive black holes, which inspiral and merge under the emission of powerful gravitational radiation that could be observed at redshifts z is approximately equal or > to 10 with the DECIGO or Big Bang Observer gravitational-wave observatories, assuming supermassive stars in the mass range 10(4)-10(6)M[symbol: see text]. The remnant is rapidly spinning with dimensionless spin a*=0.9. The surrounding accretion disk contains ~10% of the initial mass. PMID:24160586

  11. Could supermassive black holes be quintessential primordial black holes?

    International Nuclear Information System (INIS)

    There is growing observational evidence for a population of supermassive black holes (SMBHs) in galactic bulges. We examine in detail the conditions under which these black holes must have originated from primordial black holes (PBHs). We consider the merging and accretion history experienced by SMBHs to find that, whereas it is possible that they were formed by purely astrophysical processes, this is unlikely and most probably a population of primordial progenitors is necessary. We identify the mass distribution and comoving density of this population and then propose a cosmological scenario producing PBHs with the right properties. Although this is not essential we consider PBHs produced at the end of a period of inflation with a blue spectrum of fluctuations. We constrain the value of the spectral tilt in order to obtain the required PBH comoving density. We then assume that PBHs grow by accreting quintessence, showing that their mass scales like the horizon mass while the quintessence field itself is scaling. We find that if scaling is broken just before nucleosynthesis (as is the case with some attractive nonminimally coupled models) we obtain the appropriate PBH mass distribution. Hawking evaporation is negligible in most cases, but we also discuss situations in which the interplay of accretion and evaporation is relevant

  12. Sterile neutrinos and the rapid formation of supermassive black holes

    International Nuclear Information System (INIS)

    The most massive black holes, lurking at the centers of large galaxies, must have formed less than a billion years after the big bang, as they are visible today in the form of bright quasars at redshift z ∼> 6. Their early appearance is mysterious, because the radiation pressure, generated by infalling ionized baryonic matter, inhibits the rapid growth of these black holes from stellar-mass black holes. Here we show that the supermassive black holes may, instead, form timeously through the accretion of degenerate sterile neutrino dark matter onto stellar-mass black holes.

  13. Multiple supermassive black hole systems: SKA's future leading role

    OpenAIRE

    Deane, Roger; Paragi, Zsolt; Jarvis, Matt; Coriat, Mickäel; Bernardi, Gianni; Frey, Sandor; Heywood, Ian; Klöckner, Hans-Rainer

    2015-01-01

    Galaxies and supermassive black holes (SMBHs) are believed to evolve through a process of hierarchical merging and accretion. Through this paradigm, multiple SMBH systems are expected to be relatively common in the Universe. However, to date there are poor observational constraints on multiple SMBHs systems with separations comparable to a SMBH gravitational sphere of influence (

  14. SuperMassive Black Holes in Bulges

    CERN Document Server

    Sarzi, M; Shields, J C; Rudnick, G; Ho, L C; McIntosh, D H; Filippenko, A V; Sargent, W L W; Sarzi, Marc; Rix, Hans-Walter; Shields, Joseph C.; Rudnick, Greg; Ho, Luis C.; Intosh, Daniel H. Mc; Filippenko, Alexei V.; Sargent, Wallace L. W.

    2001-01-01

    We present spatially extended gas kinematics at parsec-scale resolution for the nuclear regions of four nearby disk galaxies, and model them as rotation of a gas disk in the joint potential of the stellar bulge and a putative central black hole. The targets were selected from a larger set of long-slit spectra obtained with the Hubble Space Telescope as part of the Survey of Nearby Nuclei with STIS (SUNNS). They represents the 4 galaxies (of 24) that display symmetric gas velocity curves consistent with a rotating disk. We derive the stellar mass distribution from the STIS acquisition images adopting the stellar mass-to-light ratio normalized so as to match ground-based velocity dispersion measurements over a large aperture. Subsequently, we constrain the mass of a putative black hole by matching the gas rotation curve, following two distinct approaches. In the most general case we explore all the possible disk orientations, alternatively we constrain the gas disk orientation from the dust-lane morphology at s...

  15. Supermassive black holes formed by direct collapse of inflationary perturbations

    CERN Document Server

    Nakama, Tomohiro; Yokoyama, Jun'ichi

    2016-01-01

    We propose a mechanism of producing a new type of primordial perturbations which collapse to primordial black holes whose mass can be as large as necessary for them to grow to the supermassive black holes observed at high redshifts, without contradicting COBE/FIRAS upper limits on cosmic microwave background (CMB) spectral distortions. In our model, the observable Universe consists of two kinds of many small patches which experienced different expansion histories during inflation. Large amplitudes of primordial perturbations enough to form primordial black holes are realized on patches that experienced more Hubble expansion than the others. By making these patches the minor component, the rarity of supermassive black holes can be explained. On the other hand, most regions of the Universe experienced the standard history and hence have only standard almost scale-invariant adiabatic perturbations confirmed by observations of CMB or large-scale structures of the universe. Thus our mechanism can evade the constra...

  16. Gravitational waves from supermassive stars collapsing to a supermassive black hole

    Science.gov (United States)

    Shibata, Masaru; Sekiguchi, Yuichiro; Uchida, Haruki; Umeda, Hideyuki

    2016-07-01

    We derive the gravitational waveform from the collapse of a rapidly rotating supermassive star (SMS) core leading directly to a seed of a supermassive black hole (SMBH) in axisymmetric numerical-relativity simulations. We find that the peak strain amplitude of gravitational waves emitted during the black hole formation is ≈5 ×10-21 at the frequency f ≈5 mHz for an event at the cosmological redshift z =3 , if the collapsing SMS core is in the hydrogen-burning phase. Such gravitational waves will be detectable by space laser interferometric detectors like eLISA with signal-to-noise ratio ≈10 , if the sensitivity is as high as LISA for f =1 - 10 mHz . The detection of the gravitational wave signal will provide a potential opportunity for testing the direct-collapse scenario for the formation of a seed of SMBHs.

  17. Gravitational waves from supermassive stars collapsing to a supermassive black hole

    CERN Document Server

    Shibata, Masaru; Uchida, Haruki; Umeda, Hideyuki

    2016-01-01

    We derive the gravitational waveform from the collapse of a rapidly rotating supermassive star (SMS) core leading directly to a seed of a supermassive black hole (SMBH) in axisymmetric numerical-relativity simulations. We find that the peak strain amplitude of gravitational waves emitted during the black-hole formation is $\\approx 5 \\times 10^{-21}$ at the frequency $f \\approx 5$\\,mHz for an event at the cosmological redshift $z=3$, if the collapsing SMS core is in the hydrogen-burning phase. Such gravitational waves will be detectable by space laser interferometric detectors like eLISA with signal-to-noise ratio $\\approx 10$, if the sensitivity is as high as LISA for $f=1$--10\\,mHz. The detection of the gravitational-wave signal will provide a potential opportunity for testing the direct-collapse scenario for the formation of a seed of SMBHs.

  18. Quasars: a supermassive rotating toroidal black hole interpretation

    Science.gov (United States)

    Spivey, R. J.

    2000-08-01

    A supermassive rotating toroidal black hole (TBH) is proposed as the fundamental structure of quasars and other jet-producing active galactic nuclei. Rotating protogalaxies gather matter from the central gaseous region leading to the birth of massive toroidal stars, the internal nuclear reactions of which proceed very rapidly. Once the nuclear fuel is spent, gravitational collapse produces a slender ring-shaped TBH remnant. Transitory electron and neutron degeneracy stabilized collapse phases, although possible, are unlikely owing to the large masses involved thus these events are typically the first supernovae of the host galaxies. Given time, the TBH mass increases through continued accretion by several orders of magnitude, the event horizon swells whilst the central aperture shrinks. The difference in angular velocities between the accreting matter and the TBH induces a magnetic field that is strongest in the region of the central aperture and innermost ergoregion. Owing to the presence of negative energy states when such a gravitational vortex is immersed in an electromagnetic field, circumstances are near ideal for energy extraction via non-thermal radiation including the Penrose process and superradiant scattering. This establishes a self-sustaining mechanism whereby the transport of angular momentum away from the quasar by relativistic bi-directional jets reinforces both the modulating magnetic field and the TBH/accretion disc angular velocity differential. Continued mass-capture by the TBH results in contraction of the central aperture until the TBH topology transitions to being spheroidal, extinguishing quasar behaviour. Similar mechanisms may be operating in microquasars, supernovae and sources of repeating gamma-ray bursts when neutron density or black hole tori arise. Long-term TBH stability seems to require either a negative cosmological constant, a non-stationary space-time resulting from the presence of accreting matter or the intervention of quantum

  19. Cold, clumpy accretion onto an active supermassive black hole

    OpenAIRE

    Tremblay, Grant R.; Oonk, J. B. Raymond; Combes, Françoise; Salomé, Philippe; O'Dea, Christopher P.; Baum, Stefi A.; Voit, G. Mark; Donahue, Megan; McNamara, Brian R.; Davis, Timothy A.; McDonald, Michael A.; Edge, Alastair C.; Clarke, Tracy E.; Galván-Madrid, Roberto; Bremer, Malcolm N.

    2016-01-01

    Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecul...

  20. Theory of disk accretion onto supermassive black holes

    OpenAIRE

    Armitage, Philip J.

    2004-01-01

    Accretion onto supermassive black holes produces both the dramatic phenomena associated with active galactic nuclei and the underwhelming displays seen in the Galactic Center and most other nearby galaxies. I review selected aspects of the current theoretical understanding of black hole accretion, emphasizing the role of magnetohydrodynamic turbulence and gravitational instabilities in driving the actual accretion and the importance of the efficacy of cooling in determining the structure and ...

  1. A Supermassive Black Hole in a Nearby Galaxy

    Science.gov (United States)

    2001-03-01

    board the Hubble Space Telescope (HST) . That close view of the galaxy nucleus revealed a thin gaseous disk of material close to the center, which looked very much like an accretion disk that was feeding material into a central black hole. The HST image prompted further spectroscopic observations to probe the rotation of the disk, and thus to measure the mass of the central object. The ISAAC spectra ESO PR Photo 08b/01 ESO PR Photo 08b/01 [Preview - JPEG: 400 x 303 pix - 216k] [Normal - JPEG: 800 x 606 pix - 572k] [Hires - JPEG: 2274 x 3000 pix - 4.0M] Caption : PR Photo 08b/01 shows two wavelength regions of one of the infrared ISAAC spectra of the center of Centaurus A . The direction of the long spectrograph slit is vertical and the dispersion (wavelength) direction is horizontal; longer wavelengths are towards the right. The two emission lines shown originate in singly ionized Iron ([FeII]; rest wavelength 1256.68 nm) and in Hydrogen (Paschen-Beta; 1281.81 nm) and both are clearly tilted. This is due to the rapid rotation of the accretion disk surrounding the supermassive black hole in the center of the galaxy. The light from the receding edge of the disk is Doppler-shifted towards the red (to the right) and the light from the part of the disk approaching us is shifted to the left. This may be better seen in the inserted enlargements. Therefore the inclined disk shows a tilted spectrum. These motions may be represented in a rotation curve, cf. PR Photo 08c/01 . There are other emitting areas above and below the nucleus, especially in the Paschen-Beta line. Technical information about these photos is available below. ESO PR Photo 08c/01 ESO PR Photo 08c/01 [Preview - JPEG: 341 x 400 pix - 56k] [Normal - JPEG: 682 x 800 pix - 132k] Caption : PR Photo 08c/01 shows the rotation curve (velocity vrs. distance from the centre) of the disk surrounding the black hole at the centre of Centaurus A . From the ISAAC spectrum displayed in PR Photo 08b/01 , the `average' gas

  2. Testing models of supermassive black hole seed formation through gravity waves

    OpenAIRE

    Koushiappas, Savvas M.; Zentner, Andrew R.

    2005-01-01

    We study the gravitational wave background produced from the formation and assembly of supermassive black holes within the cosmological paradigm of hierarchical structure formation. In particular, we focus on a supermassive black hole formation scenario in which the present-day population of supermassive black holes is built from high-mass seed black holes and we compute the concomitant spectrum of gravitational radiation produced by mergers of the seed black holes. We find that this scenario...

  3. The growth of supermassive black holes fed by accretion disks

    CERN Document Server

    Armijo, M A Montesinos

    2010-01-01

    Supermassive black holes are probably present in the centre of the majority of the galaxies. There is a consensus that these exotic objects are formed by the growth of seeds either by accreting mass from a circumnuclear disk and/or by coalescences during merger episodes. The mass fraction of the disk captured by the central object and the related timescale are still open questions, as well as how these quantities depend on parameters like the initial mass of the disk or the seed or on the angular momentum transport mechanism. This paper is addressed to these particular aspects of the accretion disk evolution and of the growth of seeds. The time-dependent hydrodynamic equations were solved numerically for an axi-symmetric disk in which the gravitational potential includes contributions both from the central object and from the disk itself. The numerical code is based on a Eulerian formalism, using a finite difference method of second-order, according to the Van Leer upwind algorithm on a staggered mesh. The pr...

  4. PHYSICS OF COEVOLUTION OF GALAXIES AND SUPERMASSIVE BLACK HOLES

    Energy Technology Data Exchange (ETDEWEB)

    Cen Renyue, E-mail: cen@astro.princeton.edu [Princeton University Observatory, Princeton, NJ 08544 (United States)

    2012-08-10

    A new physically based model for coevolution of galaxies and supermassive black holes (SMBHs) is presented. The evolutionary track starts with an event that triggers a significant starburst in the central region of a galaxy. In this model, the main SMBH growth takes place in the post-starburst phase, fueled by recycled gas from inner bulge stars in a self-regulated fashion on a timescale that is substantially longer than 100 Myr and at a diminishing Eddington ratio with time. We argue that the SMBH cannot gorge itself during the starburst phase, despite the abundant supply of cold gas, because star formation (SF) is a preferred mode of gas consumption over accretion to the central SMBH in such an environment. We also show that feedback from SF is at least as strong as that from an active galactic nucleus (AGN); thus, if SF is in need of being quenched, AGN feedback generally does not play the primary role. The predicted relation between SMBH mass and bulge mass/velocity dispersion is consistent with observations. A clear prediction is that early-type galaxy hosts of high-Eddington-rate AGNs are expected to be light blue to green in optical color, gradually evolving to the red sequences with decreasing AGN luminosity. A suite of falsifiable predictions and implications with respect to relationships between various types of galaxies, AGNs, and others are made. For those where comparisons to extant observations are possible, the model appears to be in good standing.

  5. PHYSICS OF COEVOLUTION OF GALAXIES AND SUPERMASSIVE BLACK HOLES

    International Nuclear Information System (INIS)

    A new physically based model for coevolution of galaxies and supermassive black holes (SMBHs) is presented. The evolutionary track starts with an event that triggers a significant starburst in the central region of a galaxy. In this model, the main SMBH growth takes place in the post-starburst phase, fueled by recycled gas from inner bulge stars in a self-regulated fashion on a timescale that is substantially longer than 100 Myr and at a diminishing Eddington ratio with time. We argue that the SMBH cannot gorge itself during the starburst phase, despite the abundant supply of cold gas, because star formation (SF) is a preferred mode of gas consumption over accretion to the central SMBH in such an environment. We also show that feedback from SF is at least as strong as that from an active galactic nucleus (AGN); thus, if SF is in need of being quenched, AGN feedback generally does not play the primary role. The predicted relation between SMBH mass and bulge mass/velocity dispersion is consistent with observations. A clear prediction is that early-type galaxy hosts of high-Eddington-rate AGNs are expected to be light blue to green in optical color, gradually evolving to the red sequences with decreasing AGN luminosity. A suite of falsifiable predictions and implications with respect to relationships between various types of galaxies, AGNs, and others are made. For those where comparisons to extant observations are possible, the model appears to be in good standing.

  6. Supermassive Black Holes and Kinematics of Disc Galaxies

    CERN Document Server

    Zasov, A V; Katkov, I Yu

    2011-01-01

    The statistical relations between the masses of supermassive black holes (SMBHs) in disk galaxies and the kinematic properties of their host galaxies are analyzed. We use the radial velocity profiles for several galaxies obtained earlier at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences parallel with the data for other galaxies taken from the literature. We demonstrate that the SMBH masses correlate well with the velocities of rotation of disks at a fixed distance R \\approx 1 kpc (V1), which characterize the mean density of the central region of the galaxy. The SMBH masses correlate appreciably weaker with the asymptotic velocity at large distances from the center and with the angular velocity at the optical radius R_{25}. We suggest that the growth of the SMBH occurs inside of the forming "classical" bulge during a monolithic collapse of gas in the central kpc-size region of the protogalaxy. We have also found a correlation between the SMBH mass and the total (i...

  7. Magnetically-levitating disks around supermassive black holes

    CERN Document Server

    Gaburov, Evghenii; Levin, Yuri

    2012-01-01

    In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds. We find that the resulting disks are entirely supported by the pressure of the magnetic fields against the component of gravitational force directed perpendicular to the disks. The magnetic field shows ordered large-scale geometry that remains stable for the duration of our numerical experiments extending over 10% of the disk lifetime. Strong magnetic pressure allows high accretion and inhibits disk fragmentation. This in combination with the repeated feeding of manetized molecular clouds to a supermassive black hole yields a possible solution to the long-standing puzzle of black hole growth in the centres of galaxies.

  8. Cold, clumpy accretion onto an active supermassive black hole

    CERN Document Server

    Tremblay, Grant R; Combes, Françoise; Salomé, Philippe; O'Dea, Christopher P; Baum, Stefi A; Voit, G Mark; Donahue, Megan; McNamara, Brian R; Davis, Timothy A; McDonald, Michael A; Edge, Alastair C; Clarke, Tracy E; Galván-Madrid, Roberto; Bremer, Malcolm N; Edwards, Louise O V; Fabian, Andrew C; Hamer, Stephen L; Li, Yuan; Maury, Anaëlle; Russell, Helen R; Quillen, Alice C; Urry, C Megan; Sanders, Jeremy S; Wise, Michael

    2016-01-01

    Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecular clouds - a departure from the "hot mode" accretion model - although unambiguous observational support for this prediction remains elusive. Here we report observations that reveal a cold, clumpy accretion flow towards a supermassive black hole fuel reservoir in the nucleus of the Abell 2597 Brightest Cluster Galaxy (BCG), a nearby (redshift z=0.0821) giant elliptical galaxy surrounded by a dense halo of hot plasma. Under the right conditions, thermal instabilities can precipitate from this hot gas, producing a rain of c...

  9. A Radio Census of Binary Supermassive Black Holes

    CERN Document Server

    Burke-Spolaor, Sarah

    2010-01-01

    Using archival VLBI data for 3114 radio-luminous active galactic nuclei, we searched for binary supermassive black holes using a radio spectral index mapping technique which targets spatially resolved, double radio-emitting nuclei. Only one source was detected as a double nucleus. This result is compared with a cosmological merger rate model and interpreted in terms of (1) implications for post-merger timescales for centralisation of the two black holes, (2) implications for the possibility of "stalled" systems, and (3) the relationship of radio activity in nuclei to mergers. Our analysis suggests that the binary evolution of paired supermassive black holes (both of masses >= 1e8 Msun) spends less than 500 Myr in progression from the merging of galactic stellar cores to within the purported stalling radius for supermassive black hole pairs. The data show no evidence for an excess of stalled binary systems at small separations. We see circumstantial evidence that the relative state of radio emission between pa...

  10. Modelling the Growth of Supermassive Black Holes in Cosmological Simulations

    CERN Document Server

    Muldrew, Stuart I; Power, Chris

    2013-01-01

    There is strong evidence that supermassive black holes reside in all galaxies that contain a stellar spheroid and their mass is tightly correlated with properties such as stellar bulge mass and velocity dispersion. There are also strong theoretical arguments that feedback from supermassive black holes plays an important role in shaping the high mass end of the galaxy mass function, hence to accurately model galaxies we also need to model the black holes. We present a comparison of two black hole growth models implemented within a large-scale, cosmological SPH simulation including star formation and feedback. One model is a modified Bondi-Hoyle prescription that grows black holes based on the smooth density of local gas, while the other is the recently proposed Accretion Disc Particle (ADP) method. This model swallows baryonic particles that pass within an accretion radius of the black hole and adds them to a subgrid accretion disc. Black holes are then grown by material from this disc. We find that both model...

  11. Astrophysics of Super-massive Black Hole Mergers

    OpenAIRE

    Schnittman, Jeremy D.

    2013-01-01

    We present here an overview of recent work in the subject of astrophysical manifestations of super-massive black hole (SMBH) mergers. This is a field that has been traditionally driven by theoretical work, but in recent years has also generated a great deal of interest and excitement in the observational astronomy community. In particular, the electromagnetic (EM) counterparts to SMBH mergers provide the means to detect and characterize these highly energetic events at cosmological distances,...

  12. The cosmological co-evolution of supermassive black holes, AGN and galaxies

    OpenAIRE

    Marulli, F.; Bonoli, S.; Branchini, E.; Moscardini, L.; Springel, V.

    2008-01-01

    We model the cosmological co-evolution of galaxies and their central supermassive black holes (BHs) within a semi-analytical framework developed on the outputs of the Millennium Simulation (Croton et al., 2006; De Lucia & Blaizot, 2007). In this work, we analyze the model BH scaling relations, fundamental plane and mass function, and compare them with the most recent observational data. Furthermore, we extend the original code developed by Croton et al. (2006) to follow the evolution of the B...

  13. Supermassive Black Holes and Their Host Galaxies - I. Bulge luminosities from dedicated near-infrared data

    OpenAIRE

    Läsker, Ronald; Ferrarese, Laura; 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 w...

  14. Dark Matter Accretion into Supermassive Black Holes

    CERN Document Server

    Peirani, Sébastien

    2008-01-01

    The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, $Q=\\rho_{\\infty}/\\sigma^3_{\\infty}$, remains constant during the inflow, the derived accretion rate can be higher up to five orders of magnitude than the classical accretion formula, valid for non-relativistic and non-interacting particles, when typical dark halo conditions are considered. For these typical conditions, the critical point of the flow is located at distances of about 30-150 times the horizon radius. Application of our results to black hole seeds hosted by halos issued from cosmological simulations indicate that dark matter contributes to no more than ~10% of the total accreted mass, confirming that the bolometric quasar luminosity is related to the baryonic accretion history of the black hole.

  15. Dark matter accretion into supermassive black holes

    International Nuclear Information System (INIS)

    The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, Q=ρ∞/σ∞3, remains constant during the inflow, the derived accretion rate can be higher up to 5 orders of magnitude than the classical accretion formula, valid for nonrelativistic and noninteracting particles, when typical dark halo conditions are considered. For these typical conditions, the critical point of the flow is located at distances of about 30-150 times the horizon radius. Application of our results to black hole seeds hosted by halos issued from cosmological simulations indicate that dark matter contributes to no more than ∼10% of the total accreted mass, confirming that the bolometric quasar luminosity is related to the baryonic accretion history of the black hole.

  16. Cold, clumpy accretion onto an active supermassive black hole

    Science.gov (United States)

    Tremblay, Grant R.; Oonk, J. B. Raymond; Combes, Françoise; Salomé, Philippe; O'Dea, Christopher P.; Baum, Stefi A.; Voit, G. Mark; Donahue, Megan; McNamara, Brian R.; Davis, Timothy A.; McDonald, Michael A.; Edge, Alastair C.; Clarke, Tracy E.; Galván-Madrid, Roberto; Bremer, Malcolm N.; Edwards, Louise O. V.; Fabian, Andrew C.; Hamer, Stephen; Li, Yuan; Maury, Anaëlle; Russell, Helen R.; Quillen, Alice C.; Urry, C. Megan; Sanders, Jeremy S.; Wise, Michael W.

    2016-06-01

    Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecular clouds—a departure from the ‘hot mode’ accretion model—although unambiguous observational support for this prediction remains elusive. Here we report observations that reveal a cold, clumpy accretion flow towards a supermassive black hole fuel reservoir in the nucleus of the Abell 2597 Brightest Cluster Galaxy (BCG), a nearby (redshift z = 0.0821) giant elliptical galaxy surrounded by a dense halo of hot plasma. Under the right conditions, thermal instabilities produce a rain of cold clouds that fall towards the galaxy’s centre, sustaining star formation amid a kiloparsec-scale molecular nebula that is found at its core. The observations show that these cold clouds also fuel black hole accretion, revealing ‘shadows’ cast by the molecular clouds as they move inward at about 300 kilometres per second towards the active supermassive black hole, which serves as a bright backlight. Corroborating evidence from prior observations of warmer atomic gas at extremely high spatial resolution, along with simple arguments based on geometry and probability, indicate that these clouds are within the innermost hundred parsecs of the black hole, and falling closer towards it.

  17. Cold, clumpy accretion onto an active supermassive black hole.

    Science.gov (United States)

    Tremblay, Grant R; Oonk, J B Raymond; Combes, Françoise; Salomé, Philippe; O'Dea, Christopher P; Baum, Stefi A; Voit, G Mark; Donahue, Megan; McNamara, Brian R; Davis, Timothy A; McDonald, Michael A; Edge, Alastair C; Clarke, Tracy E; Galván-Madrid, Roberto; Bremer, Malcolm N; Edwards, Louise O V; Fabian, Andrew C; Hamer, Stephen; Li, Yuan; Maury, Anaëlle; Russell, Helen R; Quillen, Alice C; Urry, C Megan; Sanders, Jeremy S; Wise, Michael W

    2016-06-01

    Supermassive black holes in galaxy centres can grow by the accretion of gas, liberating energy that might regulate star formation on galaxy-wide scales. The nature of the gaseous fuel reservoirs that power black hole growth is nevertheless largely unconstrained by observations, and is instead routinely simplified as a smooth, spherical inflow of very hot gas. Recent theory and simulations instead predict that accretion can be dominated by a stochastic, clumpy distribution of very cold molecular clouds--a departure from the 'hot mode' accretion model--although unambiguous observational support for this prediction remains elusive. Here we report observations that reveal a cold, clumpy accretion flow towards a supermassive black hole fuel reservoir in the nucleus of the Abell 2597 Brightest Cluster Galaxy (BCG), a nearby (redshift z = 0.0821) giant elliptical galaxy surrounded by a dense halo of hot plasma. Under the right conditions, thermal instabilities produce a rain of cold clouds that fall towards the galaxy's centre, sustaining star formation amid a kiloparsec-scale molecular nebula that is found at its core. The observations show that these cold clouds also fuel black hole accretion, revealing 'shadows' cast by the molecular clouds as they move inward at about 300 kilometres per second towards the active supermassive black hole, which serves as a bright backlight. Corroborating evidence from prior observations of warmer atomic gas at extremely high spatial resolution, along with simple arguments based on geometry and probability, indicate that these clouds are within the innermost hundred parsecs of the black hole, and falling closer towards it. PMID:27279215

  18. Theory of disk accretion onto supermassive black holes

    CERN Document Server

    Armitage, P J

    2004-01-01

    Accretion onto supermassive black holes produces both the dramatic phenomena associated with active galactic nuclei and the underwhelming displays seen in the Galactic Center and most other nearby galaxies. I review selected aspects of the current theoretical understanding of black hole accretion, emphasizing the role of magnetohydrodynamic turbulence and gravitational instabilities in driving the actual accretion and the importance of the efficacy of cooling in determining the structure and observational appearance of the accretion flow. Ongoing investigations into the dynamics of the plunging region, the origin of variability in the accretion process, and the evolution of warped, twisted, or eccentric disks are summarized.

  19. Dark Matter Accretion into Supermassive Black Holes

    OpenAIRE

    Peirani, Sébastien; De Freitas Pacheco, José Antonio

    2008-01-01

    The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, $Q=\\rho_{\\infty}/\\sigma^3_{\\infty}$, remains constant during the inflow, the derived accretion rate can be higher up to five orders of magnitude than the classical accretion formula, valid for non-relativistic and non-interacting particles, when typical dark halo conditions are considered. For these typical conditions, the critical point of the flow is loca...

  20. The shortest-known-period star orbiting our Galaxy's supermassive black hole.

    Science.gov (United States)

    Meyer, L; Ghez, A M; Schödel, R; Yelda, S; Boehle, A; Lu, J R; Do, T; Morris, M R; Becklin, E E; Matthews, K

    2012-10-01

    Stars with short orbital periods at the center of our Galaxy offer a powerful probe of a supermassive black hole. Over the past 17 years, the W. M. Keck Observatory has been used to image the galactic center at the highest angular resolution possible today. By adding to this data set and advancing methodologies, we have detected S0-102, a star orbiting our Galaxy's supermassive black hole with a period of just 11.5 years. S0-102 doubles the number of known stars with full phase coverage and periods of less than 20 years. It thereby provides the opportunity, with future measurements, to resolve degeneracies in the parameters describing the central gravitational potential and to test Einstein's theory of general relativity in an unexplored regime. PMID:23042888

  1. The Growth of the Stellar Seeds of Supermassive Black Holes

    CERN Document Server

    Johnson, Jarrett L; Whalen, Daniel J; Vecchia, Claudio Dalla; Fryer, Christopher L; Khochfar, Sadegh; Li, Hui; Livio, Mario

    2012-01-01

    One of the most promising explanations for the origin of the billion solar mass black holes (BHs) inferred to power quasars at redshifts z > 6 is that supermassive stars (SMSs) with masses > 10,000 solar masses collapse to form the seed BHs from which they grow. Here we review recent theoretical advances which provide support for this scenario. Firstly, given sufficiently high accretion rates of gas into the cores of primordial protogalaxies, it appears that neither the high energy radiation emitted from the stellar surface nor the limited lifetime of SMSs can prevent their growth to masses of up to > 100,000 solar masses. Secondly, recent cosmological simulations suggest that the high fluxes of molecule-dissociating radiation which may be required in order to achieve such high accretion rates may be more common in the early universe than previously thought. We conclude that the majority of supermassive BHs may originate from SMSs at high redshifts.

  2. Supermassive black holes in galactic nuclei

    Directory of Open Access Journals (Sweden)

    John Kormendy

    2001-01-01

    Full Text Available Mediante b usquedas din amicas se han descubierto objetos centrales oscuros | candidatos a hoyos negros (HN supermasivos | en 22 galaxias. Las siguientes conclusiones se desprenden de su demograf a: 1 la masa del HN es consistente con las predicciones basadas en la energ etica de los cuasares. (2 la masa del HN se correlaciona con la luminosidad del \\bulbo" , pero no con la componente del disco de la galaxia hu esped. (3 la masa del HN se correlaciona con la luminosidad de la componente central de alta densidad en las galaxias de disco independientemente de si es un bulbo real (mini{el ptica o un \\seudobulbo" (el que se cree se forma mediante transporte de material del disco hacia el interior. (4 los resultados del HN apoyan cada vez m as la hip otesis que el evento que forma una el ptica gigante y la fase principal de NAG de los HNs son el mismo evento. Los temas que necesitan m as estudio incluyen: (i las masas de los HNs de los mapas de reverberaci on son un factor de 5 menores que las de estudios din amicos detallados. Se han iden cado los factores que contribuyen y se sugiere que esta discrepancia puede no ser fundamental. (ii >Hay bulbos o el pticas a los que les falte HNs? >Hay HNs en galaxias de disco puras? (iii Necesitamos saber si la masa detectada en los estudios din amicos est a en c umulos oscuros de objetos y no en HNs.

  3. Dynamically important magnetic fields near accreting supermassive black holes.

    Science.gov (United States)

    Zamaninasab, M; Clausen-Brown, E; Savolainen, T; Tchekhovskoy, A

    2014-06-01

    Accreting supermassive black holes at the centres of active galaxies often produce 'jets'--collimated bipolar outflows of relativistic particles. Magnetic fields probably play a critical role in jet formation and in accretion disk physics. A dynamically important magnetic field was recently found near the Galactic Centre black hole. If this is common and if the field continues to near the black hole event horizon, disk structures will be affected, invalidating assumptions made in standard models. Here we report that jet magnetic field and accretion disk luminosity are tightly correlated over seven orders of magnitude for a sample of 76 radio-loud active galaxies. We conclude that the jet-launching regions of these radio-loud galaxies are threaded by dynamically important fields, which will affect the disk properties. These fields obstruct gas infall, compress the accretion disk vertically, slow down the disk rotation by carrying away its angular momentum in an outflow and determine the directionality of jets. PMID:24899311

  4. ASTRONOMICAL PLATE ARCHIVES AND SUPERMASSIVE BLACK HOLE BINARIES

    Directory of Open Access Journals (Sweden)

    René Hudec

    2013-12-01

    Full Text Available The recent extensive digitisation of astronomical photographic plate archives, the development of new dedicated software and the use of powerful computers have for the first time enabled effective data mining in extensive plate databases, with wide applications in various fields of recent astrophysics. As an example, analyses of supermassive binary black holes (binary blazars require very long time intervals (50 years and more, which cannot be provided by other data sources. Examples of data obtained from data mining in plate archives are presented and briefly discussed.

  5. Possible evolution of supermassive black holes from FRI quasars

    Science.gov (United States)

    Kim, Matthew I.; Christian, Damian J.; Garofalo, David; D'Avanzo, Jaclyn

    2016-08-01

    We explore the question of the rapid buildup of black hole mass in the early universe employing a growing black hole mass-based determination of both jet and disk powers predicted in recent theoretical work on black hole accretion and jet formation. Despite simplified, even artificial assumptions about accretion and mergers, we identify an interesting low probability channel for the growth of one billion solar mass black holes within hundreds of millions of years of the Big Bang without appealing to super Eddington accretion. This result is made more compelling by the recognition of a connection between this channel and an end product involving active galaxies with FRI radio morphology but weaker jet powers in mildly sub-Eddington accretion regimes. While FRI quasars have already been shown to occupy a small region of the available parameter space for black hole feedback in the paradigm, we further suggest that the observational dearth of FRI quasars is also related to their connection to the most massive black hole growth due to both these FRIs high redshifts and relative weakness. Our results also allow us to construct the AGN luminosity function at high redshift, that agree with recent studies. In short, we produce a connection between the unexplained paucity of a given family of active galactic nuclei and the rapid growth of supermassive black holes, two heretofore seemingly unrelated aspects of the physics of active galactic nuclei.

  6. Can Supermassive Black Holes alter Cold Dark Matter cusps through accretion?

    OpenAIRE

    Read, J. I.; Gilmore, G.

    2002-01-01

    We present some simple models to determine whether or not the accretion of cold dark matter by supermassive black holes is astrophysically important. Contrary to some claims in the literature, we show that supermassive black holes cannot significantly alter a power law density cusp via accretion, whether during mergers or in the steady state.

  7. Light or heavy supermassive black hole seeds: the role of internal rotation in the fate of supermassive stars

    OpenAIRE

    Fiacconi, Davide; Rossi, Elena M.

    2016-01-01

    Supermassive black holes are a key ingredient of galaxy evolution. However, their origin is still highly debated. In one of the leading formation scenarios, a black hole of $\\sim100$ M$_{\\odot}$ results from the collapse of the inner core of a supermassive star ($\\gtrsim 10^{4-5}$ M$_{\\odot}$), created by the rapid accumulation ($\\gtrsim 0.1 $ M$_{\\odot}$ yr$^{-1}$) of pristine gas at the centre of newly formed galaxies at $z\\sim 15$. The subsequent evolution is still speculative: the remaini...

  8. Evolution of Supermassive Black Holes from Cosmological Simulations

    CERN Document Server

    Filloux, Ch; Pacheco, J A de Freitas; Silk, J

    2009-01-01

    The correlations between the mass of supermassive black holes and properties of their host galaxies are investigated through cosmological simulations. Black holes grow from seeds of 100 solar masses inserted into density peaks present in the redshift range 12-15. Seeds grow essentially by accreting matter from a nuclear disk and also by coalescences resulting from merger episodes. At z=0, our simulations reproduce the black hole mass function and the correlations of the black hole mass both with stellar velocity dispersion and host dark halo mass. Moreover, the evolution of the black hole mass density derived from the present simulations agrees with that derived from the bolometric luminosity function of quasars, indicating that the average accretion history of seeds is adequately reproduced . However, our simulations are unable to form black holes with masses above $10^9 M_{\\odot}$ at $z\\sim 6$, whose existence is inferred from the bright quasars detected by the Sloan survey in this redshift range.

  9. Tidal disruption rate of stars by spinning supermassive black holes

    CERN Document Server

    Kesden, Michael

    2011-01-01

    A supermassive black hole can disrupt a star when its tidal field exceeds the star's self-gravity, and can directly capture stars that cross its event horizon. For black holes with mass M > 10^7 solar masses, tidal disruption of main-sequence stars occurs close enough to the event horizon that a Newtonian treatment of the tidal field is no longer valid. The fraction of stars that are directly captured is also no longer negligible. We calculate generically oriented stellar orbits in the Kerr metric, and evaluate the relativistic tidal tensor at pericenter for those stars not directly captured by the black hole. We combine this relativistic analysis with previous calculations of how these orbits are populated to determine tidal-disruption rates for spinning black holes. We find, consistent with previous results, that black-hole spin increases the upper limit on the mass of a black hole capable of tidally disrupting solar-like stars to ~7 x 10^8 solar masses. More quantitatively, we find that direct stellar capt...

  10. Interaction of Supermassive Black Holes with their Stellar and Dark Matter Environments

    OpenAIRE

    Merritt, David

    2004-01-01

    A review of recent theoretical work on the interactions of supermassive single and binary black holes with their nuclear environments, highlighting ways in which the observed structure of nuclei can be used to constrain the formation history of black holes.

  11. Measuring the Innermost Stable Circular Orbits of Supermassive Black Holes

    Science.gov (United States)

    Zalesky, L.; Chartas, G.

    2016-06-01

    We present a promising new technique (g-distribution method) for measuring the innermost stable circular orbit (ISCO), the inclination angle (i), and the spin of a supermassive black hole. The g-distribution method involves measurements of the distribution of the energy shifts of the relativistic iron line emitted from the accretion disk of a supermassive black hole that is microlensed by stars in a foreground galaxy and a comparison of the measured g-distribution with microlensing caustic simulations. The method has been applied to the gravitationally lensed quasars RX J1131-1231 (z_{s} = 0.658, z_{l} = 0.295), QJ 0158-4325 (z_{s} = 1.29, z_{l} = 0.317), and SDSS 1004+4112 (z_{s} = 1.73, z_{l} = 0.68). For RX J1131-1231 our initial results indicate an ISCO radius of < 5 gravitational radii and i < 65 degrees. Further monitoring of lensed quasars will provide tighter constraints on their inclination angles, ISCO radii, and spins.

  12. Supermassive black holes may be limited by the Holographic Bound

    CERN Document Server

    Custodio, P S; Custodio, Paulo Sergio

    2003-01-01

    Supermassive Black Holes are the most entropic objects found in the universe. The Holographic Bound (HB) to the entropy is used to constrain their formation time with initial masses $\\sim{10}^{6-8}M_{\\odot}$, as inferred from observations. We find that the entropy considerations are more limiting than causality for this "direct" formation. Later we analyze the possibility of SMBHs growing from seed black holes. The growth of the initial mass is studied in the case of accretion of pure radiation and quintessence fields, and we find that there is a class of models that may allow this metamorphosis. Our analysis generalizes recent work for some models of quintessence capable of producing a substantial growth in a short time, while simultaneously obeying the causal and Holographic Bound limits.

  13. Cosmological Evolution of Supermassive Black Holes: Mass Functions and Spins

    CERN Document Server

    Li, Yan-Rong; Ho, Luis C

    2012-01-01

    We derive the mass function of supermassive black holes (SMBHs) over the redshift range 0black hole spins up, then switching to a period of random, episodic accretion, governed by minor mergers and internal secular processes, during which the hole spins down. The transition epoch depends on mass, mirroring other evidence for "cosmic downsizing" in the AGN population.

  14. Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes

    CERN Document Server

    Hayasaki, Kimitake; Loeb, Abraham

    2015-01-01

    We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precurso...

  15. Multiple supermassive black hole systems: SKA's future leading role

    CERN Document Server

    Deane, Roger; Jarvis, Matt; Coriat, Mickäel; Bernardi, Gianni; Frey, Sandor; Heywood, Ian; Klöckner, Hans-Rainer

    2015-01-01

    Galaxies and supermassive black holes (SMBHs) are believed to evolve through a process of hierarchical merging and accretion. Through this paradigm, multiple SMBH systems are expected to be relatively common in the Universe. However, to date there are poor observational constraints on multiple SMBHs systems with separations comparable to a SMBH gravitational sphere of influence (<< 1 kpc). In this chapter, we discuss how deep continuum observations with the SKA will make leading contributions towards understanding how multiple black hole systems impact galaxy evolution. In addition, these observations will provide constraints on and an understanding of stochastic gravitational wave background detections in the pulsar timing array sensitivity band (nanoHz -microHz). We also discuss how targets for pointed gravitational wave experiments (that cannot be resolved by VLBI) could potentially be found using the large-scale radio-jet morphology, which can be modulated by the presence of a close-pair binary SMBH...

  16. The distribution of supermassive black holes in the nuclei of nearby galaxies

    OpenAIRE

    A. CATTANEO; Haehnelt, M. G.; Rees, M. J.

    1999-01-01

    The growth of supermassive black holes by merging and accretion in hierarchical models of galaxy formation is studied by means of Monte Carlo simulations. A tight linear relation between masses of black holes and masses of bulges arises if if the mass accreted by supermassive black holes scales linearly with the mass forming stars and if the redshift evolution of mass accretion tracks closely that of star formation. Differences in redshift evolution between black hole accretion and star forma...

  17. Direct Formation of Supermassive Black Holes via Multi-Scale Gas Inflows in Galaxy Mergers

    OpenAIRE

    Mayer, L; Kazantzidis, S.; Escala, A.; Callegari, S.

    2009-01-01

    Observations of distant quasars indicate that supermassive black holes of billions of solar masses already existed less than a billion years after the Big Bang. Models in which the `seeds' of such black holes form by the collapse of primordial metal-free stars cannot explain the rapid appearance of these supermassive black holes because gas accretion is not sufficiently efficient. Alternatively, these black holes may form by direct collapse of gas within isolated protogalaxies, but current mo...

  18. Growth of Accreting Supermassive Black Hole Seeds and Neutrino Radiation

    Directory of Open Access Journals (Sweden)

    Gagik Ter-Kazarian

    2015-01-01

    Full Text Available In the framework of microscopic theory of black hole (MTBH, which explores the most important processes of rearrangement of vacuum state and spontaneous breaking of gravitation gauge symmetry at huge energies, we have undertaken a large series of numerical simulations with the goal to trace an evolution of the mass assembly history of 377 plausible accreting supermassive black hole seeds in active galactic nuclei (AGNs to the present time and examine the observable signatures today. Given the redshifts, masses, and luminosities of these black holes at present time collected from the literature, we compute the initial redshifts and masses of the corresponding seed black holes. For the present masses MBH/M⊙≃1.1×106 to 1.3×1010 of 377 black holes, the computed intermediate seed masses are ranging from MBHSeed/M⊙≃26.4 to 2.9×105. We also compute the fluxes of ultrahigh energy (UHE neutrinos produced via simple or modified URCA processes in superdense protomatter nuclei. The AGNs are favored as promising pure UHE neutrino sources, because the computed neutrino fluxes are highly beamed along the plane of accretion disk, peaked at high energies, and collimated in smaller opening angle (θ≪1.

  19. Towards Precision Supermassive Black Hole Masses using Megamaser Disks

    CERN Document Server

    Bosch, Remco C E van den; Braatz, James A; Constantin, Anca; Kuo, Cheng-Yu

    2016-01-01

    Megamaser disks provide the most precise and accurate extragalactic supermassive black hole masses. Here we describe a search for megamasers in nearby galaxies using the Green Bank Telescope (GBT). We focus on galaxies where we believe that we can resolve the gravitational sphere of influence of the black hole and derive a stellar or gas dynamical measurement with optical or NIR observations. Since there are only a handful of super massive black holes (SMBH) that have direct black hole mass measurements from more than one method, even a single galaxy with a megamaser disk and a stellar dynamical black hole mass would provide necessary checks on the stellar dynamical methods. We targeted 87 objects from the Hobby-Eberly Telescope Massive Galaxy Survey, and detected no new maser disks. Most of the targeted objects are elliptical galaxies with typical stellar velocity dispersions of 250 km/s and distances within 130 Mpc. We discuss the implications of our non-detections, whether they imply a threshold X-ray lumi...

  20. Overlapping Inflow Events as Catalysts for Supermassive Black Hole Growth

    CERN Document Server

    Carmona-Loaiza, Juan Manuel; Dotti, Massimo; Valdarnini, Riccardo

    2013-01-01

    One of the greatest issues in modelling black hole fuelling is our lack of understanding of the processes by which gas loses angular momentum and falls from galactic scales down to the nuclear region where an accretion disc forms, subsequently guiding the inflow of gas down to the black hole horizon. It is feared that gas at larger scales might still retain enough angular momentum and settle into a larger scale disc with very low or no inflow to form or replenish the inner accretion disc (on ~0.01 pc scales). In this paper we report on hydrodynamical simulations of rotating infalling gas shells impacting at different angles onto a pre-existing, primitive large scale (~10 pc) disc around a super-massive black hole. The aim is to explore how the interaction between the shell and the disc redistributes the angular momentum on scales close to the black hole's sphere of influence. Angular momentum redistribution via hydrodynamical shocks leads to inflows of gas across the inner boundary, enhancing the inflow rate ...

  1. ALIGNMENT OF SUPERMASSIVE BLACK HOLE BINARY ORBITS AND SPINS

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M. Coleman [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742-2421 (United States); Krolik, Julian H., E-mail: miller@astro.umd.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2013-09-01

    Recent studies of accretion onto supermassive black hole binaries suggest that much, perhaps most, of the matter eventually accretes onto one hole or the other. If so, then for binaries whose inspiral from {approx}1 pc to {approx}10{sup -3}-10{sup -2} pc is driven by interaction with external gas, both the binary orbital axis and the individual black hole spins can be reoriented by angular momentum exchange with this gas. Here we show that, unless the binary mass ratio is far from unity, the spins of the individual holes align with the binary orbital axis in a time {approx}few-100 times shorter than the binary orbital axis aligns with the angular momentum direction of the incoming circumbinary gas; the spin of the secondary aligns more rapidly than that of the primary by a factor {approx}(m{sub 1}/m{sub 2}){sup 1/2} > 1. Thus the binary acts as a stabilizing agent, so that for gas-driven systems, the black hole spins are highly likely to be aligned (or counteraligned if retrograde accretion is common) with each other and with the binary orbital axis. This alignment can significantly reduce the recoil speed resulting from subsequent black hole merger.

  2. Rapidly Accreting Supergiant Protostars: Embryos of Supermassive Black Holes?

    CERN Document Server

    Hosokawa, Takashi; Yorke, Harold W

    2012-01-01

    Direct collapse of supermassive stars (SMSs) is a possible pathway for generating supermassive black holes in the early universe. It is expected that an SMS could form via very rapid mass accretion with Mdot ~ 0.1 - 1 Msun/yr during the gravitational collapse of an atomic-cooling primordial gas cloud. In this paper we study how stars would evolve under such extreme rapid mass accretion, focusing on the early evolution until the stellar mass reaches 1000 Msun. To this end we numerically calculate the detailed interior structure of accreting stars with primordial element abundances. Our results show that for accretion rates higher than 0.01 Msun/yr, stellar evolution is qualitatively different from that expected at lower rates. While accreting at these high rates the star always has a radius exceeding 100 Rsun, which increases monotonically with the stellar mass. The mass-radius relation for stellar masses exceeding ~ 100 Msun follows the same track with R_* \\propto M_*^0.5 in all cases with accretion rates > 0...

  3. Dark matter haloes determine the masses of supermassive black holes

    CERN Document Server

    Booth, C M

    2009-01-01

    The energy and momentum deposited by the radiation from accretion onto the supermassive black holes (BHs) that reside at the centres of virtually all galaxies can halt or even reverse gas inflow, providing a natural mechanism for supermassive BHs to regulate their growth and to couple their properties to those of their host galaxies. However, it remains unclear whether this self-regulation occurs on the scale at which the BH is gravitationally dominant, on that of the stellar bulge, the galaxy, or that of the entire dark matter halo. To answer this question, we use self-consistent simulations of the co-evolution of the BH and galaxy populations that reproduce the observed correlations between the masses of the BHs and the properties of their host galaxies. We first confirm unambiguously that the BHs regulate their growth: the amount of energy that the BHs inject into their surroundings remains unchanged when the fraction of the accreted rest mass energy that is injected, is varied by four orders of magnitude....

  4. To test dual supermassive black hole model for broad line AGN with double-peaked narrow [OIII] lines

    CERN Document Server

    XueGuang, Zhang

    2016-01-01

    In this manuscript, we proposed an interesting method to test the dual supermassive black hole model for AGN with double-peaked narrow \\oiii lines (double-peaked narrow emitters), through their broad optical Balmer line properties. Under the dual supermassive black hole model for double-peaked narrow emitters, we could expect statistically smaller virial black hole masses estimated by observed broad Balmer line properties than true black hole masses (total masses of central two black holes). Then, we compare the virial black hole masses between a sample of 37 double-peaked narrow emitters with broad Balmer lines and samples of SDSS selected normal broad line AGN with single-peaked \\oiii lines. However, we can find clearly statistically larger calculated virial black hole masses for the 37 broad line AGN with double-peaked \\oiii lines than for samples of normal broad line AGN. Therefore, we give our conclusion that the dual supermassive black hole model is probably not statistically preferred to the double-pea...

  5. Interim results from the ongoing hunt for supermassive black hole binaries

    Science.gov (United States)

    Runnoe, Jessie C.; Mathes, Gavin; Pennell, Alison; Brown, Stephanie Meghan; Eracleous, Michael; Boroson, Todd A.; Bogdanovic, Tamara; Sigurdsson, Steinn; Halpern, Jules P.; Liu, Jia

    2016-01-01

    Supermassive black hole binaries seem to be an inevitable product of the prevailing galaxy evolution scenarios in which most massive galaxies play host to a central black hole and undergo a history of mergers and accretion over the course of cosmic time. The early stages of this process have been observed in the form of interacting galaxy pairs as well dual active galactic nuclei with kilo-parsec separations, but detections of the close, bound binaries that are expected to follow have proven elusive. With this motivation, we have been conducting a systematic observational search for sub-parsec separation supermassive black hole binaries. Specifically, we test the hypothesis that the secondary black hole in the system is active and the resulting broad emission lines are doppler shifted due to orbital motion in the binary (analogous to a single-line spectroscopc binary star). Our sample includes 88 binary candidates selected from z1000 km/s) of their broad Hβ emission lines relative to their systemic redshifts. I will present the latest results from the spectroscopic monitoring campaign that we are conducting to constrain the nature of the binary candidates. These include the radial velocity curves, which now use observations made through 2015, and the constraints that can be placed on the physical properties of the binary based on the radial velocity curves and observed flux variability of the binaries.

  6. Tidal disruption events from supermassive black hole binaries

    CERN Document Server

    Coughlin, Eric R; Nixon, Chris; Begelman, Mitchell C

    2016-01-01

    We investigate the pre-disruption gravitational dynamics and post-disruption hydrodynamics of the tidal disruption of stars by supermassive black hole (SMBH) binaries. We focus on binaries with relatively low mass primaries ($10^6M_{\\odot}$), moderate mass ratios, and separations with reasonably long gravitational wave inspiral times (tens of Myr). First, we generate a large ensemble (between 1 and 10 million) of restricted three-body integrations to quantify the statistical properties of tidal disruptions by circular SMBH binaries of initially-unbound stars. Compared to the reference case of a disruption by a single SMBH, the binary potential induces significant variance into the specific energy and angular momentum of the star at the point of disruption. Second, we use Newtonian numerical hydrodynamics to study the detailed evolution of the fallback debris from 120 disruptions randomly selected from the three-body ensemble (excluding only the most deeply penetrating encounters). We find that the overall mor...

  7. Magnetic fields during the formation of supermassive black holes

    CERN Document Server

    Latif, M A; Schmidt, W

    2013-01-01

    Observations of quasars at $\\rm z> 6$ report the existence of a billion solar mass black holes. Comprehending their formation in such a short time scale is a matter of ongoing research. One of the most promising scenarios to assemble supermassive black holes is a monolithic collapse of protogalactic gas clouds in atomic cooling halos with $\\rm T_{vir} \\geq 10^{4} K$. In this article, we study the amplification and impact of magnetic fields during the formation of seed black holes in massive primordial halos. We perform high resolution cosmological magnetohydrodynamics simulations for four distinct halos and follow their collapse for a few free-fall times until the simulations reach a peak density of $\\rm 7 \\times 10^{-10} g/cm^{3}$. Our findings show that irrespective of the initial seed field, the magnetic field strength reaches a saturated state in the presence of strong accretion shocks. Under such conditions, the growth time becomes very short and amplification occurs rapidly within a small fraction of th...

  8. Overlapping inflow events as catalysts for supermassive black hole growth

    Science.gov (United States)

    Carmona-Loaiza, Juan M.; Colpi, Monica; Dotti, Massimo; Valdarnini, Riccardo

    2014-02-01

    One of the greatest issues in modelling black hole fuelling is our lack of understanding of the processes by which gas loses angular momentum and falls from galactic scales down to the nuclear region where an accretion disc forms, subsequently guiding the inflow of gas down to the black hole horizon. It is feared that gas at larger scales might still retain enough angular momentum and settle into a larger scale disc with very low or no inflow to form or replenish the inner accretion disc (on ˜0.01 pc scales). In this paper we report on hydrodynamical simulations of rotating infalling gas shells impacting at different angles on to a pre-existing, primitive large-scale (˜10 pc) disc around a supermassive black hole. The aim is to explore how the interaction between the shell and the disc redistributes the angular momentum on scales close to the black hole's sphere of influence. Angular momentum redistribution via hydrodynamical shocks leads to inflows of gas across the inner boundary, enhancing the inflow rate by more than 2-3 orders of magnitude. In all cases, the gas inflow rate across the inner parsec is higher than in the absence of the interaction, and the orientation of the angular momentum of the flow in the region changes with time due to gas mixing. Warped discs or nested misaligned rings form depending on the angular momentum content of the infalling shell relative to the disc. In the cases in which the shell falls in near counter-rotation, part of the resulting flows settle into an inner dense disc which becomes more susceptible to mass transfer.

  9. Collapse of differentially rotating supermassive stars: Post black hole formation

    International Nuclear Information System (INIS)

    We investigate the collapse of differentially rotating supermassive stars (SMSs) by means of 3+1 hydrodynamic simulations in general relativity. We particularly focus on the onset of collapse to understand the final outcome of collapsing SMSs. We find that the estimated ratio of the mass between the black hole and the surrounding disk from the equilibrium star is roughly the same as the results from numerical simulation. This suggests that the picture of axisymmetric collapse is adequate, in the absence of nonaxisymmetric instabilities, to illustrate the final state of the collapse. We also find that quasiperiodic gravitational waves continue to be emitted after the quasinormal mode frequency has decayed. We furthermore have found that when the newly formed black hole is almost extreme Kerr, the amplitude of the quasiperiodic oscillation is enhanced during the late stages of the evolution. Geometrical features, shock waves, and instabilities of the fluid are suggested as a cause of this amplification behavior. This alternative scenario for the collapse of differentially rotating SMSs might be observable by the Laser Interferometer Space Antenna.

  10. Modeling AGN outbursts from supermassive black hole binaries

    Directory of Open Access Journals (Sweden)

    Tanaka T.

    2012-12-01

    Full Text Available When galaxies merge to assemble more massive galaxies, their nuclear supermassive black holes (SMBHs should form bound binaries. As these interact with their stellar and gaseous environments, they will become increasingly compact, culminating in inspiral and coalescence through the emission of gravitational radiation. Because galaxy mergers and interactions are also thought to fuel star formation and nuclear black hole activity, it is plausible that such binaries would lie in gas-rich environments and power active galactic nuclei (AGN. The primary difference is that these binaries have gravitational potentials that vary – through their orbital motion as well as their orbital evolution – on humanly tractable timescales, and are thus excellent candidates to give rise to coherent AGN variability in the form of outbursts and recurrent transients. Although such electromagnetic signatures would be ideally observed concomitantly with the binary’s gravitational-wave signatures, they are also likely to be discovered serendipitously in wide-field, high-cadence surveys; some may even be confused for stellar tidal disruption events. I discuss several types of possible “smoking gun” AGN signatures caused by the peculiar geometry predicted for accretion disks around SMBH binaries.

  11. Migration Traps in Disks Around Supermassive Black Holes

    CERN Document Server

    Bellovary, Jillian; McKernan, Barry; Ford, K E Saavik

    2015-01-01

    Accretion disks around supermassive black holes (SMBHs) in active galactic nuclei contain stars, stellar mass black holes, and other stellar remnants, which perturb the disk gas gravitationally. The resulting density perturbations in turn exert torques on the embedded masses causing them to migrate through the disk in a manner analogous to the behavior of planets in protoplanetary disks. We determine the strength and direction of these torques using an empirical analytic description dependent on local disk gradients, applied to two different analytic, steady-state disk models of SMBH accretion disks. We find that there are radii in such disks where the gas torque changes sign, trapping migrating objects. Our analysis shows that major migration traps generally occur where the disk surface density gradient changes sign from positive to negative, around 20--300$R_{\\rm g}$, where $R_{\\rm g}=2GM/c^{2}$ is the Schwarzschild radius. At these traps, massive objects in the AGN disk can accumulate, collide, scatter, an...

  12. Self-gravitating warped discs around supermassive black holes

    CERN Document Server

    Ulubay-Siddiki, A; Arnaboldi, M

    2009-01-01

    We consider warped equilibrium configurations for stellar and gaseous disks in the Keplerian force-field of a supermassive black hole, assuming that the self-gravity of the disk provides the only acting torques. Modeling the disk as a collection of concentric circular rings, and computing the torques in the non-linear regime, we show that stable, strongly warped precessing equilibria are possible. These solutions exist for a wide range of disk-to-black hole mass ratios $M_d/M_{bh}$, can span large warp angles of up to $\\pm\\sim 120\\deg$, have inner and outer boundaries, and extend over a radial range of a factor of typically two to four. These equilibrium configurations obey a scaling relation such that in good approximation $\\phidot/\\Omega\\propto M_d/M_{bh}$ where $\\phidot$ is the (retrograde) precession frequency and $\\Omega$ is a characteristic orbital frequency in the disk. Stability was determined using linear perturbation theory and, in a few cases, confirmed by numerical integration of the equations of ...

  13. How well can we measure supermassive black hole spin?

    CERN Document Server

    Bonson, K

    2016-01-01

    Being one of only two fundamental properties black holes possess, the spin of supermassive black holes (SMBHs) is of great interest for understanding accretion processes and galaxy evolution. However, in these early days of spin measurements, consistency and reproducibility of spin constraints have been a challenge. Here we focus on X-ray spectral modelling of active galactic nuclei (AGN), examining how well we can truly return known reflection parameters such as spin under standard conditions. We have created and fit over 4000 simulated Seyfert 1 spectra each with 375$\\pm$1k counts. We assess the fits with reflection fraction of $R$ = 1 as well as reflection-dominated AGN with $R$ = 5. We also examine the consequence of permitting fits to search for retrograde spin. In general, we discover that most parameters are over-estimated when spectroscopy is restricted to the 2.5 - 10.0 keV regime and that models are insensitive to inner emissivity index and ionization. When the bandpass is extended out to 70keV, par...

  14. Forming supermassive black holes by accreting dark and baryon matter

    CERN Document Server

    Hu, J; Lou, Y Q; Zhang, S; Hu, Jian; Shen, Yue; Lou, Yu-Qing; Zhang, Shuangnan

    2006-01-01

    Given a large-scale mixture of self-interacting dark matter (SIDM) particles and baryon matter distributed in the early Universe, we advance here a two-phase accretion scenario for forming supermassive black holes (SMBHs) with masses around $\\sim 10^9 M_{\\odot}$ at high redshifts $z (\\gsim 6)$. The first phase is conceived to involve a rapid quasi-spherical and quasi-steady Bondi accretion of mainly SIDM particles embedded with baryon matter onto seed black holes (BHs) created at redshifts $z\\lsim 30$ by the first generation of massive Population III stars; this earlier phase rapidly gives birth to significantly enlarged seed BH masses of $M_{\\hbox{\\tiny BH},t_1}\\backsimeq 1.4\\times 10^6\\ M_\\odot \\sigma_0/(1\\hbox{cm}^2\\hbox{g}^{-1})(C_s/30\\hbox{km s}^{-1})^4$ during $z\\sim 20-15$, where $\\sigma_0$ is the cross section per unit mass of SIDM particles and $C_s$ is the velocity dispersion in the SIDM halo referred to as an effective "sound speed". The second phase of BH mass growth is envisaged to proceed primar...

  15. The Starburst in the Abell 1835 Cluster Central Galaxy: A Case Study of Galaxy Formation Regulated by an Outburst from a Supermassive Black Hole

    CERN Document Server

    McNamara, B R; Carilli, C L; Nulsen, P E J; Rafferty, D A; Ryan, R; Sharma, M; Steiner, J; Wise, M W

    2006-01-01

    We present an optical, X-ray, and radio analysis of the starburst in the Abell 1835 cluster's central cD galaxy. The dense gas surrounding the galaxy is radiating X-rays with a luminosity of ~1E45 erg/s consistent with a cooling rate of ~1000-2000 solar masses per year. However, new Chandra and XMM-Newton observations find less than 200 solar masses per year of gas cooling below ~2 keV, a level that is consistent with the cD's current star formation rate of 100-180 solar masses per year. One or more heating agents (feedback) must then be replenishing the remaining radiative losses. The heat fluxes from supernova explosions and thermal conduction alone are unable to do so. However, a pair of X-ray cavities from an AGN outburst has deposited ~1.7E60 erg into the surrounding gas over the past 40 Myr. The corresponding jet power 1.4E45 erg/sec is enough to offset most of the radiative losses from the cooling gas. The jet power exceeds the radio synchrotron power by ~4000 times, making this one of the most radiati...

  16. Supermassive binary black holes - possible observational effects in the x-ray emission

    Directory of Open Access Journals (Sweden)

    Jovanović Predrag

    2014-01-01

    Full Text Available Here we discuss the possible observational effects in the X-ray emission from two relativistic accretion disks in a supermassive binary black hole system. For that purpose we developed a model and performed numerical simulations of the X-ray radiation from a relativistic accretion disk around a supermassive black hole, based on the ray-tracing method in the Kerr metric, and applied it to the case of the close binary supermassive black holes. Our results indicate that the broad Fe Kα line is a powerful tool for detecting such systems and studying their properties. The most favorable candidates for observational studies are the supermassive binary black holes in the galactic mergers during the phase when the orbital velocities of their components are very large and exceed several thousand kms -1. [Projekat Ministarstva nauke Republike Srbije, br. 176003: Gravitation and the Large Scale Structure of the Universe i br. 176001: Astrophysical Spectroscopy of Extragalactic Objects

  17. A Highly Magnetized Twin-Jet Base Pinpoints a Supermassive Black Hole

    CERN Document Server

    Baczko, A -K; Kadler, M; Ros, E; Perucho, M; Krichbaum, T P; Böck, M; Bremer, M; Grossberger, C; Lindqvist, M; Lobanov, A P; Mannheim, K; Mart, I; Müller, C; Wilms, J; Zensus, J A

    2016-01-01

    Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical models based on Blandford & Znajek extract the rotational energy from a Kerr black hole, which could be the case for NGC1052, to launch these jets. This requires magnetic fields of the order of $10^3\\,$G to $10^4\\,$G. We imaged the vicinity of the SMBH of the AGN NGC1052 with the Global Millimetre VLBI Array and found a bright and compact central feature, smaller than 1.9 light days (100 Schwarzschild radii) in radius. Interpreting this as a blend of the unresolved jet bases, we derive the magnetic field at 1 Schwarzschild radius to lie between 200 G and ~80000 G consistent with Blandford & Znajek models.

  18. Formation of supermassive black holes in the center of galaxies. Importance of a multi-scale theoretical model

    International Nuclear Information System (INIS)

    It is now widely accepted that most of normal galaxies have their central supermassive black holes (SMBHs). However, the formation and evolution of SMBHs is still open question and a hot topic in astrophysics. In this article, we review recent theoretical studies on the formation of SMBHs in the center of galaxies, and mention the importance of constructing a multi-scale theoretical model. (author)

  19. X-ray constraints on the local supermassive black hole occupation fraction

    CERN Document Server

    Miller, Brendan P; Greene, Jenny E; Kelly, Brandon C; Treu, Tommaso; Woo, Jong-Hak; Baldassare, Vivienne

    2014-01-01

    Distinct seed formation mechanisms are imprinted upon the fraction of dwarf galaxies currently containing a central supermassive black hole. Seeding by Pop III remnants is expected to produce a higher occupation fraction than is generated with direct gas collapse precursors. Chandra observations of nearby early-type galaxies can directly detect even low-level supermassive black hole activity, and the active fraction immediately provides a firm lower limit to the occupation fraction. Here, we use the volume-limited AMUSE surveys of ~200 optically-selected early-type galaxies to characterize simultaneously, for the first time, the occupation fraction and the scaling of nuclear X-ray luminosity with stellar mass, accounting for intrinsic scatter, measurement uncertainties, and X-ray limits. For early-type galaxies with log(M_star/M_sun)20% (at 95% confidence), but full occupation cannot be excluded. The preferred dependence of log(L_X) upon log(M_star) has a slope of about 0.7-0.8, consistent with the "downsizin...

  20. X-RAY CONSTRAINTS ON THE LOCAL SUPERMASSIVE BLACK HOLE OCCUPATION FRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Brendan P.; Gallo, Elena; Baldassare, Vivienne [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Greene, Jenny E. [Department of Astrophysics, Princeton University, Princeton, NJ 08544 (United States); Kelly, Brandon C.; Treu, Tommaso [Physics Department, University of California, Santa Barbara, CA 93106 (United States); Woo, Jong-Hak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of)

    2015-01-20

    Distinct seed formation mechanisms are imprinted upon the fraction of dwarf galaxies currently containing a central supermassive black hole. Seeding by Population III remnants is expected to produce a higher occupation fraction than is generated with direct gas collapse precursors. Chandra observations of nearby early-type galaxies can directly detect even low-level supermassive black hole activity, and the active fraction immediately provides a firm lower limit to the occupation fraction. Here, we use the volume-limited AMUSE surveys of ∼200 optically selected early-type galaxies to characterize simultaneously, for the first time, the occupation fraction and the scaling of L {sub X} with M {sub star}, accounting for intrinsic scatter, measurement uncertainties, and X-ray limits. For early-type galaxies with M {sub star} < 10{sup 10} M {sub ☉}, we obtain a lower limit to the occupation fraction of >20% (at 95% confidence), but full occupation cannot be excluded. The preferred dependence of log L {sub X} upon log M {sub star} has a slope of ∼0.7-0.8, consistent with the ''downsizing'' trend previously identified from the AMUSE data set, and a uniform Eddington efficiency is disfavored at ∼2σ. We provide guidelines for the future precision with which these parameters may be refined with larger or more sensitive samples.

  1. Supermassive Black Holes in Galactic Nuclei with Tidal Disruption of Stars: Paper II - Axisymmetric Nuclei

    CERN Document Server

    Zhong, Shiyan; Spurzem, Rainer

    2015-01-01

    Tidal Disruption of stars by supermassive central black holes from dense rotating star clusters is modelled by high-accuracy direct N-body simulation. As in a previous paper on spherical star clusters we study the time evolution of the stellar tidal disruption rate and the origin of tidally disrupted stars, now according to several classes of orbits which only occur in axisymmetric systems (short axis tube and saucer). Compared with that in spherical systems, we found a higher TD rate in axisymmetric systems. The enhancement can be explained by an enlarged loss-cone in phase space which is raised from the fact that total angular momentum $\\bf J$ is not conserved. As in the case of spherical systems, the distribution of the last apocenter distance of tidally accreted stars peaks at the classical critical radius. However, the angular distribution of the origin of the accreted stars reveals interesting features. Inside the influence radius of the supermassive black hole the angular distribution of disrupted star...

  2. Cosmological growth and feedback from supermassive black holes

    CERN Document Server

    Mocz, P; Fabian, A C

    2013-01-01

    We develop a simple evolutionary scenario for the growth of supermassive black holes (BHs), assuming growth due to accretion only, to learn about the evolution of the BH mass function from $z=3$ to 0 and from it calculate the energy budgets of different modes of feedback. We tune the parameters of the model by matching the derived X-ray luminosity function (XLF) with the observed XLF of active galactic nuclei. We then calculate the amount of comoving kinetic and bolometric feedback as a function of redshift, derive a kinetic luminosity function and estimate the amount of kinetic feedback and $PdV$ work done by classical double Fanaroff-Riley II (FR II) radio sources. We also derive the radio luminosity function for FR IIs from our synthesized population and set constraints on jet duty cycles. Around 1/6 of the jet power from FR II sources goes into $PdV$ work done in the expanding lobes during the time the jet is on. Anti hierarchical growth of BHs is seen in our model due to addition of an amount of mass bei...

  3. Constraining the supermassive black holes evolution through continuity equation

    CERN Document Server

    Tucci, Marco

    2016-01-01

    The population of supermassive black holes (SMBHs) is composed by quiescent SMBHs, such as those seen in local galaxies including the Milky Way's, and active ones, resulting in quasars and active galactic nuclei (AGN). Outside our neighbourhood, all the information we have on SMBHs is derived from quasars and AGN, giving us a partial view. We study the evolution of the SMBH population, total and active, by the continuity equation, backwards in time from z=0 to z=4. Type-1 and type-2 AGN are differentiated in the model on the basis of the Eddington ratio distribution, chosen on the basis of observational estimates. The duty cycle is obtained by matching the luminosity function of quasars, and the average radiative efficiency is the only free parameter in the model. For higher radiative efficiencies (>~0.07) a large fraction of the SMBH population, most of them quiescent, must already be in place by z=4. For lower radiative efficiencies (~0.05), the duty cycle increases with the redshift and the SMBH population...

  4. 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...

  5. Misaligned accretion on to supermassive black hole binaries

    CERN Document Server

    Dunhill, Alex; Nixon, Chris; King, Andrew

    2014-01-01

    We present the results of high-resolution numerical simulations of gas clouds falling onto binary supermassive black holes to form circumbinary accretion discs, with both prograde and retrograde cloud orbits. We explore a range of clouds masses and cooling rates. We find that for low mass discs that cool fast enough to fragment, prograde discs are significantly shorter-lived than similar discs orbiting retrograde with respect to the binary. For fragmenting discs of all masses, we also find that prograde discs fragment across a narrower radial region. If the cooling is slow enough that the disc enters a self-regulating gravitoturbulent regime, we find that alignment between the disc and binary planes occurs on a timescale primarily dictated by the disc thickness. We estimate realistic cooling times for such discs, and find that in the majority of cases we expect fragmentation to occur. The longer lifetime of low-mass fragmenting retrograde discs allows them to drive significant binary evolution, and may provid...

  6. Physics of Coevolution of Galaxies and Supermassive Black Holes

    CERN Document Server

    Cen, Renyue

    2011-01-01

    A model for coevolution of galaxies and supermassive black holes (SMBH) is presented that is physically based. The starting point is a gas-rich major merger that triggers a starburst and the endpoint is a quiescent elliptical galaxy many gigayears later. There is an approximate coevolution between starburst galaxies and elliptical galaxies, although it is not exact in several important ways. Starburst precedes the onset of main SMBH growth with a gap of time equal to ~100Myr and is responsible for shutting down its own activities; AGN has little to do with it. While starburst occurs earlier and lasts for only about 100Myrs, the AGN accretion occurs later and lasts for ~1 Gyr or longer with a diminishing Eddington ratio. The main AGN growth in post-starburst phase is fueled by recycled gas from inner bulge stars and self-regulated. The predicted relation between SMBH mass and bulge mass/velocity dispersion is consistent with observations. A suite of testable and falsifiable predictions and implications with re...

  7. Supermassive black holes do not correlate with dark matter halos of galaxies

    OpenAIRE

    Kormendy, John; Bender, Ralf

    2011-01-01

    Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough so that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black hole growth and bulge formation regulate each other. That is, black holes and bulges "coevolve". Therefore, reports of a similar correlation between black holes and the dark matter halos in which visible galaxie...

  8. How well can we measure supermassive black hole spin?

    Science.gov (United States)

    Bonson, K.; Gallo, L. C.

    2016-05-01

    Being one of only two fundamental properties black holes possess, the spin of supermassive black holes (SMBHs) is of great interest for understanding accretion processes and galaxy evolution. However, in these early days of spin measurements, consistency and reproducibility of spin constraints have been a challenge. Here, we focus on X-ray spectral modelling of active galactic nuclei (AGN), examining how well we can truly return known reflection parameters such as spin under standard conditions. We have created and fit over 4000 simulated Seyfert 1 spectra each with 375±1k counts. We assess the fits with reflection fraction of R = 1 as well as reflection-dominated AGN with R = 5. We also examine the consequence of permitting fits to search for retrograde spin. In general, we discover that most parameters are overestimated when spectroscopy is restricted to the 2.5-10.0 keV regime and that models are insensitive to inner emissivity index and ionization. When the bandpass is extended out to 70 keV, parameters are more accurately estimated. Repeating the process for R = 5 reduces our ability to measure photon index (˜3 to 8 per cent error and overestimated), but increases precision in all other parameters - most notably ionization, which becomes better constrained (±45 erg cm s^{-1}) for low-ionization parameters (ξ 0.8 to about ±0.10) and that inner emissivity index is never well constrained. Allowing our model to search for retrograde spin did not improve the results.

  9. Circumnuclear Media and Accretion Rates of Quiescent Supermassive Black Holes

    CERN Document Server

    Generozov, Aleksey; Metzger, Brian D

    2015-01-01

    We calculate steady-state, one-dimensional hydrodynamic profiles of hot gas in slowly accreting ("quiescent") galactic nuclei for a range of central black hole masses, parameterized gas heating rates, and observationally-motivated stellar density profiles. Mass is supplied to the circumnuclear medium by stellar winds, while energy is injected primarily by stellar winds, supernovae, and black hole feedback. Analytic estimates are derived for the stagnation radius (where the radial velocity of the gas passes through zero) and the black hole accretion rate, as a function of the black hole mass and the gas heating efficiency, the latter being related to the star-formation history. We assess the conditions under which radiative instabilities develop in the hydrostatic region near the stagnation radius, both in the case of a single burst of star formation and for the average star formation history predicted by cosmological simulations. By combining a sample of measured nuclear X-ray luminosities from nearby quiesce...

  10. On the location of the supermassive black hole in CTA 102

    CERN Document Server

    Fromm, C M; Ros, E; Savolainen, T; Zensus, J A

    2014-01-01

    Relativistic jets in active galactic nuclei represent one of the most powerful phenomena in the Universe. They form in the surroundings of the supermassive black holes as a by-product of accretion onto the central black hole in active galaxies. The flow in the jets propagates at velocities close to the speed of light. The distance between the first part of the jet that is visible in radio images (core) and the black hole is still a matter of debate. Only very-long-baseline interferometry observations resolve the innermost compact regions of the radio jet. Those can access the jet base, and combining data at different wavelenghts, address the physical parameters of the outflow from its emission. We have performed an accurate analysis of the frequency-dependent shift of the VLBI core location for a multi-wavelength set of images of the blazar CTA 102 including data from 6 cm down to 3 mm. The measure of the position of the central black hole, with mass $\\sim 10^{8.93}\\,M_\\odot$, in the blazar CTA 102 reveals a ...

  11. To test dual supermassive black hole model for broad line active galactic nucleus with double-peaked narrow [O III] lines

    Science.gov (United States)

    Zhang, Xue-Guang; Feng, Long-Long

    2016-04-01

    In this paper, we proposed an interesting method to test the dual supermassive black hole model for active galactic nucleus (AGN) with double-peaked narrow [O III] lines (double-peaked narrow emitters) through their broad optical Balmer line properties. Under the dual supermassive black hole model for double-peaked narrow emitters, we could expect statistically smaller virial black hole masses estimated by observed broad Balmer line properties than true black hole masses (total masses of central two black holes). Then, we compare the virial black hole masses between a sample of 37 double-peaked narrow emitters with broad Balmer lines and samples of Sloan Digital Sky Survey selected normal broad line AGN with single-peaked [O III] lines. However, we can find clearly statistically larger calculated virial black hole masses for the 37 broad line AGN with double-peaked [O III] lines than for samples of normal broad line AGN. Therefore, we give our conclusion that the dual supermassive black hole model is probably not statistically preferred to the double-peaked narrow emitters, and more efforts should be necessary to carefully find candidates for dual supermassive black holes by observed double-peaked narrow emission lines.

  12. A Symbiotic Scenario for the Rapid Formation of Supermassive Black Holes

    OpenAIRE

    Richter, M. C.; Tupper, G. B.; Viollier, R. D.

    2006-01-01

    The most massive black holes, lurking at the centers of large galaxies, must have formed less than a billion years after the big bang, as they are visible today in the form of bright quasars at redshift larger than six. Their early appearance is mysterious, because the radiation pressure, generated by infalling ionized matter, inhibits the rapid growth of these black holes from stellar-mass black holes. Here we show that the supermassive black holes may form timeously through the accretion of...

  13. Very high energy emission from passive supermassive black holes

    International Nuclear Information System (INIS)

    The H.E.S.S. experiment, an array of four Imaging Cherenkov Telescopes, widened the horizon of Very High Energy (VHE) astronomy. Its unprecedented sensitivity is well suited for the study of new classes of expected VHE emitters, such as passive galactic nuclei that are the main focus of the work presented in this thesis. Acceleration of particles up to Ultra High Energies is expected in the magnetosphere of supermassive black holes (SMBH). The radiation losses of these accelerated particles are expected to reach the VHE regime in which H.E.S.S. operates. Predicted fluxes exceed the sensitivity of the array. However, strong photon fields in the surrounding of the acceleration region might absorb the produced radiation. Therefore observations focus on those galactic nuclei that are underluminous at lower photon energies. This work presents data collected by the H.E.S.S. telescopes on the test candidate NGC 1399 and their interpretation. While no detection has been achieved, important constraints can be derived from the obtained upper limits on the maximum energy attainable by the accelerated particles and on the magnetic field strength in the acceleration region. A limit on the magnetic field of B < 74 Gauss is given. The limit is model dependent and a scaling of the result with the assumptions is given. This is the tightest empirical constraint to date. Because of the lack of signal from the test candidate, a stacking analysis has been performed on similar sources in three cluster fields. A search for signal from classes of active galactic nuclei has also been made in the same three fields. None of the analyzed samples revealed a significant signal. Also presented are the expectations for the next generation of Cherenkov Telescopes and an outlook on the relativistic effects expected on the VHE emission close to SMBH. (orig.)

  14. Tidal stripping of stars near supermassive black holes

    Directory of Open Access Journals (Sweden)

    Blandford R.

    2012-12-01

    Full Text Available In a binary system composed of a supermassive black hole and a star orbiting the hole in an equatorial, circular orbit, the stellar orbit will shrink due to the action of gravitational radiation, until the star fills its Roche lobe outside the Innermost Stable Circular Orbit (ISCO of the hole or plunges into the hole. In the former case, gas will flow through the inner Lagrange point (L1 to the hole. If this tidal stripping process happens on a time scale faster than the thermal time scale but slower than the dynamical time scale, the entropy as a function of the interior mass is conserved. The star will evolve adiabatically, and, in most cases, will recede from the hole while filling its Roche lobe. We calculate how the stellar equilibrium properties change, which determines how the stellar orbital period and mass-transfer rate change through the “Roche evolution” for various types of stars in the relativistic regime. We envisage that the mass stream eventually hits the accretion disc, where it forms a hot spot orbiting the hole and may ultimately modulate the luminosity with the stellar orbital frequency. The ultimate goal is to probe the mass and spin of the hole and provide a test of general relativity in the strong-field regime from the resultant quasi-periodic signals. The observability of such a modulation is discussed along with a possible interpretation of an intermittent 1 hour period in the X-ray emission of RE J1034+ 396.

  15. Very high energy emission from passive supermassive black holes

    Energy Technology Data Exchange (ETDEWEB)

    Pedaletti, Giovanna

    2009-10-22

    The H.E.S.S. experiment, an array of four Imaging Cherenkov Telescopes, widened the horizon of Very High Energy (VHE) astronomy. Its unprecedented sensitivity is well suited for the study of new classes of expected VHE emitters, such as passive galactic nuclei that are the main focus of the work presented in this thesis. Acceleration of particles up to Ultra High Energies is expected in the magnetosphere of supermassive black holes (SMBH). The radiation losses of these accelerated particles are expected to reach the VHE regime in which H.E.S.S. operates. Predicted fluxes exceed the sensitivity of the array. However, strong photon fields in the surrounding of the acceleration region might absorb the produced radiation. Therefore observations focus on those galactic nuclei that are underluminous at lower photon energies. This work presents data collected by the H.E.S.S. telescopes on the test candidate NGC 1399 and their interpretation. While no detection has been achieved, important constraints can be derived from the obtained upper limits on the maximum energy attainable by the accelerated particles and on the magnetic field strength in the acceleration region. A limit on the magnetic field of B < 74 Gauss is given. The limit is model dependent and a scaling of the result with the assumptions is given. This is the tightest empirical constraint to date. Because of the lack of signal from the test candidate, a stacking analysis has been performed on similar sources in three cluster fields. A search for signal from classes of active galactic nuclei has also been made in the same three fields. None of the analyzed samples revealed a significant signal. Also presented are the expectations for the next generation of Cherenkov Telescopes and an outlook on the relativistic effects expected on the VHE emission close to SMBH. (orig.)

  16. Observing the dynamics of supermassive black hole binaries with pulsar timing arrays.

    Science.gov (United States)

    Mingarelli, C M F; Grover, K; Sidery, T; Smith, R J E; Vecchio, A

    2012-08-24

    Pulsar timing arrays are a prime tool to study unexplored astrophysical regimes with gravitational waves. Here, we show that the detection of gravitational radiation from individually resolvable supermassive black hole binary systems can yield direct information about the masses and spins of the black holes, provided that the gravitational-wave-induced timing fluctuations both at the pulsar and at Earth are detected. This in turn provides a map of the nonlinear dynamics of the gravitational field and a new avenue to tackle open problems in astrophysics connected to the formation and evolution of supermassive black holes. We discuss the potential, the challenges, and the limitations of these observations. PMID:23002736

  17. Linking the Supermassive Black Hole Growth with the Megamaser Emission

    CERN Document Server

    Constantin, Anca

    2012-01-01

    High-resolution observations of the central few 100 pc of the galactic nuclear environments remain prohibitive for large statistical samples, which are crucial for tracing the links between central black hole formation, galaxy formation and AGN activity over cosmic time. With this contribution, we present novel ways of connecting the physics of black hole accretion with its immediate environs via a new quantitative evaluation of the degree to which the strength and spatial configuration of the water maser emission is associated with the nuclear nebular galactic activity. We discuss possible evolutionary/causal connections between these two types of emission, together with criteria that could dramatically enhance our search for mega-maser systems in nearby galactic centers. These are timely results given the interest in combining high-resolution observations with extremely large optical telescopes and large arrays that start to conquer the sub-millimeter window.

  18. Major galaxy mergers and the growth of supermassive black holes in quasars.

    Science.gov (United States)

    Treister, Ezequiel; Natarajan, Priyamvada; Sanders, David B; Urry, C Megan; Schawinski, Kevin; Kartaltepe, Jeyhan

    2010-04-30

    Despite observed strong correlations between central supermassive black holes (SMBHs) and star formation in galactic nuclei, uncertainties exist in our understanding of their coupling. We present observations of the ratio of heavily obscured to unobscured quasars as a function of cosmic epoch up to z congruent with 3 and show that a simple physical model describing mergers of massive, gas-rich galaxies matches these observations. In the context of this model, every obscured and unobscured quasar represents two distinct phases that result from a massive galaxy merger event. Much of the mass growth of the SMBH occurs during the heavily obscured phase. These observations provide additional evidence for a causal link between gas-rich galaxy mergers, accretion onto the nuclear SMBH, and coeval star formation. PMID:20339033

  19. Multi-messenger approaches to binary supermassive black holes in the ‘continuous-wave’ regime

    International Nuclear Information System (INIS)

    Pulsar timing arrays are sensitive to gravitational waves from supermassive black hole (SMBH) binaries at orbital separations of ≪1 pc. There is currently an observational paucity of such systems, although they are central figures in studies of galaxy evolution, merger dynamics, and active nucleus formation. We review the prospects of detecting SMBH binaries through electromagnetic radiative processes thought to be associated with galaxy mergers and late-stage binary evolution. We then discuss the scientific goals of joint pulsar timing and electromagnetic studies of these systems, including the facilitation of binary parameter estimation, identifying galactic hosts of gravitational wave emitters, and relevant studies of merger dynamics and cosmology. The use of upcoming high-precision timing arrays with the International pulsar timing array and the square kilometre array, combined with ongoing electromagnetic observing campaigns to identify active SMBH binaries, provide generous possibilities for multi-messenger astrophysics in the near future. (paper)

  20. Suppressing star formation in quiescent galaxies with supermassive black hole winds.

    Science.gov (United States)

    Cheung, Edmond; Bundy, Kevin; Cappellari, Michele; Peirani, Sébastien; Rujopakarn, Wiphu; Westfall, Kyle; Yan, Renbin; Bershady, Matthew; Greene, Jenny E; Heckman, Timothy M; Drory, Niv; Law, David R; Masters, Karen L; Thomas, Daniel; Wake, David A; Weijmans, Anne-Marie; Rubin, Kate; Belfiore, Francesco; Vulcani, Benedetta; Chen, Yan-mei; Zhang, Kai; Gelfand, Joseph D; Bizyaev, Dmitry; Roman-Lopes, A; Schneider, Donald P

    2016-05-26

    Quiescent galaxies with little or no ongoing star formation dominate the population of galaxies with masses above 2 × 10(10) times that of the Sun; the number of quiescent galaxies has increased by a factor of about 25 over the past ten billion years (refs 1-4). Once star formation has been shut down, perhaps during the quasar phase of rapid accretion onto a supermassive black hole, an unknown mechanism must remove or heat the gas that is subsequently accreted from either stellar mass loss or mergers and that would otherwise cool to form stars. Energy output from a black hole accreting at a low rate has been proposed, but observational evidence for this in the form of expanding hot gas shells is indirect and limited to radio galaxies at the centres of clusters, which are too rare to explain the vast majority of the quiescent population. Here we report bisymmetric emission features co-aligned with strong ionized-gas velocity gradients from which we infer the presence of centrally driven winds in typical quiescent galaxies that host low-luminosity active nuclei. These galaxies are surprisingly common, accounting for as much as ten per cent of the quiescent population with masses around 2 × 10(10) times that of the Sun. In a prototypical example, we calculate that the energy input from the galaxy's low-level active supermassive black hole is capable of driving the observed wind, which contains sufficient mechanical energy to heat ambient, cooler gas (also detected) and thereby suppress star formation. PMID:27225122

  1. Warping and tearing of misaligned circumbinary disks around eccentric supermassive black hole binaries

    Science.gov (United States)

    Hayasaki, K.; Sohn, B. W.; Okazaki, A. T.; Jung, T.; Zhao, G.; Naito, T.

    2015-07-01

    We study the warping and tearing of a geometrically thin, non-self-gravitating disk surrounding binary supermassive black holes on an eccentric orbit. The circumbinary disk is significantly misaligned with the binary orbital plane, and is subject to the time-dependent tidal torques. In principle, such a disk is warped and precesses, and is torn into mutually misaligned rings in the region, where the tidal precession torques are stronger than the local viscous torques. We derive the tidal-warp and tearing radii of the misaligned circumbinary disks around eccentric SMBH binaries. We find that in disks with the viscosity parameter α larger than a critical value depending on the disk aspect ratio, the disk warping appears outside the tearing radius. This condition is expressed for small amplitude warps as α > √H/(3r) for H/rlesssim0.1, where H is the disk scale height. If α warp radius is inside the tearing radius, where most of disk material is likely to rapidly accrete onto SMBHs. In warped and torn disks, both the tidal-warp and the tearing radii most strongly depend on the binary semi-major axis, although they also mildly depend on the other orbital and disk parameters. This strong dependence enables us to estimate the semi-major axis, once the tidal warp or tearing radius is determined observationally: for the tidal warp radius of 0.1 pc, the semi-major axis is estimated to be ~10-2 pc for 107 Msolar black hole with typical orbital and disk parameters. We also briefly discuss the possibility that central objects of observed warped maser disks in active galactic nuclei are supermassive black hole binaries.

  2. Suppressing star formation in quiescent galaxies with supermassive black hole winds

    Science.gov (United States)

    Cheung, Edmond; Bundy, Kevin; Cappellari, Michele; Peirani, Sébastien; Rujopakarn, Wiphu; Westfall, Kyle; Yan, Renbin; Bershady, Matthew; Greene, Jenny E.; Heckman, Timothy M.; Drory, Niv; Law, David R.; Masters, Karen L.; Thomas, Daniel; Wake, David A.; Weijmans, Anne-Marie; Rubin, Kate; Belfiore, Francesco; Vulcani, Benedetta; Chen, Yan-Mei; Zhang, Kai; Gelfand, Joseph D.; Bizyaev, Dmitry; Roman-Lopes, A.; Schneider, Donald P.

    2016-05-01

    Quiescent galaxies with little or no ongoing star formation dominate the population of galaxies with masses above 2 × 1010 times that of the Sun; the number of quiescent galaxies has increased by a factor of about 25 over the past ten billion years (refs 1, 2, 3, 4). Once star formation has been shut down, perhaps during the quasar phase of rapid accretion onto a supermassive black hole, an unknown mechanism must remove or heat the gas that is subsequently accreted from either stellar mass loss or mergers and that would otherwise cool to form stars. Energy output from a black hole accreting at a low rate has been proposed, but observational evidence for this in the form of expanding hot gas shells is indirect and limited to radio galaxies at the centres of clusters, which are too rare to explain the vast majority of the quiescent population. Here we report bisymmetric emission features co-aligned with strong ionized-gas velocity gradients from which we infer the presence of centrally driven winds in typical quiescent galaxies that host low-luminosity active nuclei. These galaxies are surprisingly common, accounting for as much as ten per cent of the quiescent population with masses around 2 × 1010 times that of the Sun. In a prototypical example, we calculate that the energy input from the galaxy’s low-level active supermassive black hole is capable of driving the observed wind, which contains sufficient mechanical energy to heat ambient, cooler gas (also detected) and thereby suppress star formation.

  3. 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.

  4. Effects of gravitational-wave recoil on the dynamics and growth of supermassive black holes

    CERN Document Server

    Blecha, Laura

    2008-01-01

    Simulations of binary black hole mergers indicate that asymmetrical gravitational wave (GW) emission can cause black holes to recoil at speeds up to thousands of km/s. These GW recoil events can dramatically affect the coevolution of recoiling supermassive black holes (SMBHs) and their host galaxies. However, theoretical studies of SMBH-galaxy evolution almost always assume a stationary central black hole. In light of the numerical results on GW recoil velocities, we relax that assumption here and consider the consequences of recoil for SMBH evolution. We follow the trajectories of SMBHs ejected in a smooth background potential that includes both a stellar bulge and a multi-component gaseous disk. In addition, we calculate the accretion rate onto the SMBH as a function of time using a hybrid prescription of viscous (alpha-disk) and Bondi accretion. We find that recoil kicks between 100 km/s and the escape speed cause SMBHs to wander though the galaxy and halo for about 1 Myr - 1 Gyr before settling back to th...

  5. Line Shapes Emitted from Spiral Structures around Symmetric Orbits of Supermassive Binary Black Holes

    CERN Document Server

    Smailagić, Marijana

    2016-01-01

    Variability of active galactic nuclei is not well understood. One possible explanation is existence of supermassive binary black holes (SMBBH) in their centres. It is expected that major mergers are common in the Universe. It is expected that each supermassive black hole of every galaxy eventually finish as a SMBBH system in the core of newly formed galaxy. Here we model the emission line profiles of active galactic nuclei (AGN) assuming that the flux and emission line shapes variation are induced by supermassive binary black hole systems (SMBBH). We assume that accreting gas inside of circumbinary (CB) disk is photo ionized by mini accretion disk emission around each SMBBH. We calculate variations of emission line flux, shifts and shapes for different parameters of SMBBH orbits. We consider cases with different masses and inclinations for circular orbits and measure the effect to the shape of emission line profiles and flux variability.

  6. Line Shapes Emitted from Spiral Structures around Symmetric Orbits of Supermassive Binary Black Holes

    Indian Academy of Sciences (India)

    M. Smailagić; E. Bon

    2015-12-01

    Variability of active galactic nuclei is not well understood. One possible explanation is existence of supermassive binary black holes (SMBBH) in their centres. It is expected that major mergers are common in the Universe. It is expected that each supermassive black hole of every galaxy eventually finish as a SMBBH system in the core of newly formed galaxy. Here we model the emission line profiles of active galactic nuclei (AGN) assuming that the flux and emission line shape variations are induced by supermassive binary black hole systems (SMBBH). We assume that the accreting gas inside the circumbinary (CB) disk is photo ionized by mini accretion disk emission around each SMBBH. We calculate variations of emission line flux, shifts and shapes for different parameters of SMBBH orbits. We consider cases with different masses and inclinations for circular orbits and measure the effect to the shape of emission line profiles and flux variability.

  7. Suppression of star formation in early-type galaxies by feedback from supermassive black holes.

    Science.gov (United States)

    Schawinski, Kevin; Khochfar, Sadegh; Kaviraj, Sugata; Yi, Sukyoung K; Boselli, Alessandro; Barlow, Tom; Conrow, Tim; Forster, Karl; Friedman, Peter G; Martin, D Chris; Morrissey, Patrick; Neff, Susan; Schiminovich, David; Seibert, Mark; Small, Todd; Wyder, Ted K; Bianchi, Luciana; Donas, Jose; Heckman, Tim; Lee, Young-Wook; Madore, Barry; Milliard, Bruno; Rich, R Michael; Szalay, Alex

    2006-08-24

    Detailed high-resolution observations of the innermost regions of nearby galaxies have revealed the presence of supermassive black holes. These black holes may interact with their host galaxies by means of 'feedback' in the form of energy and material jets; this feedback affects the evolution of the host and gives rise to observed relations between the black hole and the host. Here we report observations of the ultraviolet emissions of massive early-type galaxies. We derive an empirical relation for a critical black-hole mass (as a function of velocity dispersion) above which the outflows from these black holes suppress star formation in their hosts by heating and expelling all available cold gas. Supermassive black holes are negligible in mass compared to their hosts but nevertheless seem to play a critical role in the star formation history of galaxies. PMID:16929291

  8. Dynamical Space: Supermassive Galactic Black Holes and Cosmic Filaments

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2011-10-01

    Full Text Available The unfolding revolution in observational astrophysics and cosmology has lead to nu- merous puzzles: “supermassive” galactic central black holes, galactic “dark matter” ha- los, relationships between these black hole “effective” masses and star dispersion speeds in galactic bulges, flat spiral galaxy rotation curves, cosmic filaments, and the need for “dark matter” and “dark energy” in fitting the Friedmann universe expansion equation to the supernovae and CMB data. Herein is reported the discovery of a dynamical the- ory for space which explains all these puzzles in terms of 3 constants; G , - which experimental data reveals to be the fine structure constant 1 = 137, and which is a small scale distance, perhaps a Planck length. It is suggested that the dynamics for space arises as a derivative expansion of a deeper quantum foam phenomenon. This discovery amounts to the emergence of a unification of space, gravity and the quantum.

  9. Supermassive Black Holes and their Host Spheroids III. The Mbh-nsph Correlation

    Science.gov (United States)

    Savorgnan, Giulia A. D.

    2016-04-01

    The Sérsic {R}1/n model is the best approximation known to date for describing the light distribution of stellar spheroidal and disk components, with the Sérsic index n providing a direct measure of the central radial concentration of stars. The Sérsic index of a galaxy’s spheroidal component, nsph, has been shown to tightly correlate with the mass of the central supermassive black hole, MBH. The {M}{BH}{--}{n}{sph} correlation is also expected from other two well known scaling relations involving the spheroid luminosity, Lsph: the {L}{sph}{--}{n}{sph} and the {M}{BH}{--}{L}{sph}. Obtaining an accurate estimate of the spheroid Sérsic index requires a careful modeling of a galaxy’s light distribution and some studies have failed to recover a statistically significant {M}{BH}{--}{n}{sph} correlation. With the aim of re-investigating the {M}{BH}{--}{n}{sph} and other black hole mass scaling relations, we performed a detailed (i.e., bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decomposition of 66 galaxies, with directly measured black hole masses, that had been imaged at 3.6 μm with Spitzer. In this paper, the third of this series, we present an analysis of the {L}{sph}{--}{n}{sph} and {M}{BH}{--}{n}{sph} diagrams. While early-type (elliptical+lenticular) and late-type (spiral) galaxies split into two separate relations in the {L}{sph}{--}{n}{sph} and {M}{BH}{--}{L}{sph} diagrams, they reunite into a single {M}{BH}\\propto {n}{sph}3.39+/- 0.15 sequence with relatively small intrinsic scatter (ε ≃ 0.25 {dex}). The black hole mass appears to be closely related to the spheroid central concentration of stars, which mirrors the inner gradient of the spheroid gravitational potential.

  10. Suppression of star formation in early-type galaxies by feedback from supermassive black holes

    OpenAIRE

    Schawinski, Kevin; Khochfar, Sadegh; Kaviraj, Sugata; Yi, Sukyoung K; Boselli, Alessandro; Barlow, Tom; Conrow, Tim; Forster, Karl; Friedman, Peter G.; Martin, D. Chris; Morrissey, Patrick; Neff, Susan; Schiminovich, David; Seibert, Mark; Small, Todd

    2006-01-01

    Detailed high-resolution observations of the innermost regions of nearby galaxies have revealed the presence of supermassive black holes1. These black holes may interact with their host galaxies by means of 'feedback' in the form of energy and material jets; this feedback affects the evolution of the host and gives rise to observed relations between the black hole and the host. Here we report observations of the ultraviolet emissions of massive early-type galaxies. We derive an empirical rela...

  11. Observational Constraints on the Self Interacting Dark Matter Scenario and the Growth of Supermassive Black Holes

    OpenAIRE

    Hennawi, Joseph F.; Ostriker, Jeremiah P.

    2001-01-01

    We consider the consequences of SIDM for a velocity dependent cross section per unit mass. Accretion of SIDM onto seed black holes can produce supermassive black holes that are too large for certain combinations of parameters,which is used to obtain a new constraint on the dark matter interaction. Constraints due to other considerations are presented and previous ones are generalized. The black hole constraint is extremely sensitive to the slope \\alpha, of the inner density profile of dark ha...

  12. The Role of Gravitational Instabilities in the Feeding of Supermassive Black Holes

    Directory of Open Access Journals (Sweden)

    Giuseppe Lodato

    2012-01-01

    Full Text Available I review the recent progresses that have been obtained, especially through the use of high-resolution numerical simulations, on the dynamics of self-gravitating accretion discs. A coherent picture is emerging, where the disc dynamics is controlled by a small number of parameters that determine whether the disc is stable or unstable, whether the instability saturates in a self-regulated state or runs away into fragmentation, and whether the dynamics is local or global. I then apply these concepts to the case of AGN discs, discussing the implications of such evolution on the feeding of supermassive black holes. Nonfragmenting, self-gravitating discs appear to play a fundamental role in the process of formation of massive black hole seeds at high redshift (∼ 10–15 through direct gas collapse. On the other hand, the different cooling properties of the interstellar gas at low redshifts determine a radically different behaviour for the outskirts of the accretion discs feeding typical AGNs. Here the situation is much less clear from a theoretical point of view, and while several observational clues point to the important role of massive discs at a distance of roughly a parsec from their central black hole, their dynamics is still under debate.

  13. The supermassive black hole mass - S\\'ersic index relations for bulges and elliptical galaxies

    CERN Document Server

    Savorgnan, Giulia; Marconi, Alessandro; Sani, Eleonora; Hunt, Leslie K; Vika, Marina; Driver, Simon P

    2013-01-01

    Scaling relations between supermassive black hole mass, M_BH, and host galaxy properties are a powerful instrument for studying their coevolution. A complete picture involving all of the black hole scaling relations, in which each relation is consistent with the others, is necessary to fully understand the black hole-galaxy connection. The relation between M_BH and the central light concentration of the surrounding bulge, quantified by the S\\'ersic index n, may be one of the simplest and strongest such relations, requiring only uncalibrated galaxy images. We have conducted a census of literature S\\'ersic index measurements for a sample of 54 local galaxies with directly measured M_BH values. We find a clear M_BH - n relation, despite an appreciable level of scatter due to the heterogeneity of the data. Given the current M_BH - L_sph and the L_sph - n relations, we have additionally derived the expected M_BH - n relations, which are marginally consistent at the 2 sigma level with the observed relations. Ellipt...

  14. Supermassive black holes and their host spheroids III. The $M_{BH} - n_{sph}$ correlation

    CERN Document Server

    Savorgnan, Giulia A D

    2016-01-01

    The S\\'ersic $R^{1/n}$ model is the best approximation known to date for describing the light distribution of stellar spheroidal and disk components, with the S\\'ersic index $n$ providing a direct measure of the central radial concentration of stars. The S\\'ersic index of a galaxy's spheroidal component, $n_{sph}$, has been shown to tightly correlate with the mass of the central supermassive black hole, $M_{BH}$. The $M_{BH}-n_{sph}$ correlation is also expected from other two well known scaling relations involving the spheroid luminosity, $L_{sph}$: the $L_{sph}-n_{sph}$ and the $M_{BH}-L_{sph}$. Obtaining an accurate estimate of the spheroid S\\'ersic index requires a careful modelling of a galaxy's light distribution and some studies have failed to recover a statistically significant $M_{BH}-n_{sph}$ correlation. With the aim of re-investigating the $M_{BH}-n_{sph}$ and other black hole mass scaling relations, we performed a detailed (i.e.~bulge, disks, bars, spiral arms, rings, halo, nucleus, etc.) decompo...

  15. Megaparsec relativistic jets launched from an accreting supermassive black hole in an extreme spiral galaxy

    International Nuclear Information System (INIS)

    The radio galaxy phenomenon is directly connected to mass-accreting, spinning supermassive black holes found in the active galactic nuclei. It is still unclear how the collimated jets of relativistic plasma on hundreds to thousands of kiloparsec scales form and why they are nearly always launched from the nuclei of bulge-dominated elliptical galaxies and not flat spirals. Here we present the discovery of the giant radio source J2345–0449 (z = 0.0755), a clear and extremely rare counterexample where relativistic jets are ejected from a luminous and massive spiral galaxy on a scale of ∼1.6 Mpc, the largest known so far. Extreme physical properties observed for this bulgeless spiral host, such as its high optical and infrared luminosity, large dynamical mass, rapid disk rotation, and episodic jet activity, are possibly the results of its unusual formation history, which has also assembled, via gas accretion from a disk, its central black hole of mass >2 × 108 M ☉. The very high mid-IR luminosity of the galaxy suggests that it is actively forming stars and still building a massive disk. We argue that the launch of these powerful jets is facilitated by an advection-dominated, magnetized accretion flow at a low Eddington rate onto this unusually massive (for a bulgeless disk galaxy) and possibly fast spinning central black hole. Therefore, J2345–0449 is an extremely rare, unusual galactic system whose properties challenge the standard paradigms for black hole growth and the formation of relativistic jets in disk galaxies. Thus, it provides fundamental insight into accretion disk-relativistic jet coupling processes.

  16. From horizon to torus: Uncovering supermassive black hole systems

    Science.gov (United States)

    Murphy, Kendrah

    2009-06-01

    The complexity of the structure and behavior of AGNs is often imprinted in the Fe K line emission in their X-ray spectra. We present a study of the Seyfert galaxy NGC 2992 with RXTE and Suzaku , which highlights this complexity, as we find evidence of both persistent emission from the accretion disk and from matter more distant from the central black hole (i.e., the putative obscuring torus), as well as short-term flaring emission from the accretion disk. Future X-ray instrumentation is expected to allow us to significantly improve the constraints derived from the Fe K lines in AGN, such as the black-hole angular momentum (spin) and the inclination angle of the putative accretion disk. However, significant model-dependence and degeneracy will persist with radially-integrated Fe K line profiles, so we have investigated the feasibility of utilizing Fe K line emission from localized orbiting flares ("hotspots") to provide a more robust measure of black-hole spin. In addition to affecting the persistent and transient Fe K line emission, the physical structure, geometry, and orientation of the central engine harboring the black hole furthermore effect the observed continuum in specific ways. It is therefore necessary to self-consistently model the continuum and emission lines in order to derive constraints on the physical parameters of the system. Improved X-ray spectral data quality has facilitated the ability to disentangle some of the spectral components, but the increased spectral complexity creates a need for more sophisticated models. Such a need has arisen with respect to the X-ray spectra of obscured AGN. To that end, we describe a new X-ray spectral model, based on Monte-Carlo simulations of the toroidal reprocessor, that will allow one to self-consistently fit for the line emission from distant matter as well as the associated Compton-scattered continuum. The model is valid for arbitrary incident spectra and can therefore be combined with models of

  17. Direct formation of supermassive black holes via multi-scale gas inflows in galaxy mergers.

    Science.gov (United States)

    Mayer, L; Kazantzidis, S; Escala, A; Callegari, S

    2010-08-26

    Observations of distant quasars indicate that supermassive black holes of billions of solar masses already existed less than a billion years after the Big Bang. Models in which the 'seeds' of such black holes form by the collapse of primordial metal-free stars cannot explain the rapid appearance of these supermassive black holes because gas accretion is not sufficiently efficient. Alternatively, these black holes may form by direct collapse of gas within isolated protogalaxies, but current models require idealized conditions, such as metal-free gas, to prevent cooling and star formation from consuming the gas reservoir. Here we report simulations showing that mergers between massive protogalaxies naturally produce the conditions for direct collapse into a supermassive black hole with no need to suppress cooling and star formation. Merger-driven gas inflows give rise to an unstable, massive nuclear gas disk of a few billion solar masses, which funnels more than 10(8) solar masses of gas to a sub-parsec-scale gas cloud in only 100,000 years. The cloud undergoes gravitational collapse, which eventually leads to the formation of a massive black hole. The black hole can subsequently grow to a billion solar masses on timescales of about 10(8) years by accreting gas from the surrounding disk. PMID:20740009

  18. Multi-messenger Efforts in the Search for Supermassive Black Hole Pairs

    Science.gov (United States)

    Spolaor, Sarah; LAZIO, J.; Pulsar Timing Array, Parkes

    2013-01-01

    A number of electromagnetic phenomena have been suggested to imply the presence of a supermassive black hole (SMBH) binary in the emission's host galaxy. No systems have been conclusively demonstrated to be a close binary (i.e. orbital periods Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  19. Toward the event horizon—the supermassive black hole in the Galactic Center

    NARCIS (Netherlands)

    H. Falcke; S. Markoff

    2013-01-01

    The center of our Galaxy hosts the best constrained supermassive black hole in the universe, Sagittarius A* (Sgr A*). Its mass and distance have been accurately determined from stellar orbits and proper motion studies, respectively, and its high-frequency radio, and highly variable near-infrared and

  20. Upper Limits on the Masses of 105 Supermassive Black Holes from HST/STIS Archival Data

    CERN Document Server

    Beifiori, A; Corsini, E M; Bonta, E Dalla; Pizzella, A; Coccato, L; Bertola, F

    2008-01-01

    Based on the modeling of the central emission-line width measured over sub-arcsecond apertures with the Hubble Space Telescope, we present stringent upper bounds on the mass of the central supermassive black hole, MBH, for a sample of 105 nearby galaxies (D<100Mpc) spanning a wide range of Hubble types (E-Sc) and values of the central stellar velocity dispersion, sigma (58-419km/s). For the vast majority of the objects the derived MBH upper limits run parallel and above the well-known MBH-sigma relation independently of the galaxy distance, suggesting that our nebular line-width measurements trace rather well the nuclear gravitational potential. For values of sigma between 90 and 220km/s the 68% of our upper limits falls immediately above the MBH-sigma relation without exceeding the expected MBH values by more than a factor 4.1. No systematic trends or offsets are observed in this sigma range as a function of the galaxy Hubble type or with respect to the presence of a bar. For 6 of our 12 MBH upper limits ...

  1. Supermassive black holes do not correlate with dark matter halos of galaxies

    CERN Document Server

    Kormendy, John

    2011-01-01

    Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough so that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black hole growth and bulge formation regulate each other. That is, black holes and bulges "coevolve". Therefore, reports of a similar correlation between black holes and the dark matter halos in which visible galaxies are embedded have profound implications. Dark matter is likely to be nonbaryonic, so these reports suggest that unknown, exotic physics controls black hole growth. Here we show - based in part on recent measurements of bulgeless galaxies - that there is almost no correlation between dark matter and parameters that measure black holes unless the galaxy also contains a bulge. We conclude that black holes do not correlate directly with dark matter. They do not correlate with galaxy disks, either. Therefore black holes coev...

  2. The role of galactic cold gas in low-level supermassive black hole activity

    CERN Document Server

    Alfvin, Erik D; Haynes, Martha P; Gallo, Elena; Giovanelli, Riccardo; Koopmann, Rebecca A; Hodges-Kluck, Edmund; Cannon, John M

    2016-01-01

    The nature of the relationship between low-level supermassive black hole (SMBH) activity and galactic cold gas, if any, is currently unclear. Here, we test whether central black holes may feed at higher rates in gas-rich galaxies, probing SMBH activity well below the active regime down to Eddington ratios of ~1e-7. We use a combination of radio data from the ALFALFA survey and from the literature, along with archival X-ray flux measurements from the Chandra X-ray observatory, to investigate this potential relationship. We construct a sample of 129 late-type galaxies, with MB<-18 out to 50 Mpc, that have both HI masses and sensitive X-ray coverage. Of these, 75 host a nuclear X-ray source, a 58% detection fraction. There is a highly significant correlation between nuclear X-ray luminosity LX and galaxy stellar mass Mstar with a slope of 1.7+/-0.3, and a tentative correlation (significant at the 2.8 sigma level) between LX and HI gas mass MHI. However, a joint fit to LX as a function of both Mstar and MHI fi...

  3. Suppressing star formation in quiescent galaxies with supermassive black hole winds

    CERN Document Server

    Cheung, Edmond; Cappellari, Michele; Peirani, Sébastien; Rujopakarn, Wiphu; Westfall, Kyle; Yan, Renbin; Bershady, Matthew; Greene, Jenny E; Heckman, Timothy M; Drory, Niv; Law, David R; Masters, Karen L; Thomas, Daniel; Wake, David A; Weijmans, Anne-Marie; Rubin, Kate; Belfiore, Francesco; Vulcani, Benedetta; Chen, Yan-mei; Zhang, Kai; Gelfand, Joseph D; Bizyaev, Dmitry; Roman-Lopes, A; Schneider, Donald P

    2016-01-01

    Quiescent galaxies with little or no ongoing star formation dominate the galaxy population above $M_{*}\\sim 2 \\times 10^{10}~M_{\\odot}$, where their numbers have increased by a factor of $\\sim25$ since $z\\sim2$. Once star formation is initially shut down, perhaps during the quasar phase of rapid accretion onto a supermassive black hole, an unknown mechanism must remove or heat subsequently accreted gas from stellar mass loss or mergers that would otherwise cool to form stars. Energy output from a black hole accreting at a low rate has been proposed, but observational evidence for this in the form of expanding hot gas shells is indirect and limited to radio galaxies at the centers of clusters, which are too rare to explain the vast majority of the quiescent population. Here we report bisymmetric emission features co-aligned with strong ionized gas velocity gradients from which we infer the presence of centrally-driven winds in typical quiescent galaxies that host low-luminosity active nuclei. These galaxies ar...

  4. Evidence of a Supermassive Black Hole in the Galaxy NGC 1023 from the Nuclear Stellar Dynamics

    CERN Document Server

    Bower, G A; Bender, R; Gebhardt, K; Lauer, T R; Magorrian, J; Richstone, D O; Danks, A C; Gull, T R; Hutchings, J B; Joseph, C L; Kaiser, M E; Weistrop, D; Woodgate, B; Nelson, C; Malumuth, E M

    2001-01-01

    We analyze the nuclear stellar dynamics of the SB0 galaxy NGC 1023, utilizing observational data both from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope and from the ground. The stellar kinematics measured from these long-slit spectra show rapid rotation (V = 70 km/s at a distance of 0.1 arcsec = 4.9 pc from the nucleus) and increasing velocity dispersion toward the nucleus (where sigma = 295 +/- 30 km/s). We model the observed stellar kinematics assuming an axisymmetric mass distribution with both two and three integrals of motion. Both modeling techniques point to the presence of a central dark compact mass (which presumably is a supermassive black hole) with confidence > 99%. The isotropic two-integral models yield a best-fitting black hole mass of (6.0 +/- 1.4) x 10^7 M_sun and mass-to-light ratio (M/L_V) of 5.38 +/- 0.08, and the goodness-of-fit (chi^2) is insensitive to reasonable values for the galaxy's inclination. The three-integral models, which non-parametrically fit th...

  5. Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way

    CERN Document Server

    Schödel, R; Genzel, R; Hofmann, R; Lehnert, M; Eckart, A; Mouawad, N; Alexander, T; Reid, M J; Lenzen, R; Hartung, M; Lacombe, F; Rouan, D; Gendron, E; Rousset, G; Lagrange, A M; Brandner, W; Ageorges, N; Lidman, C E; Moorwood, A F M; Spyromilio, J; Hubin, N; Menten, K M

    2002-01-01

    Measurements of stellar velocities and variable X-ray emission near the centre of the Milky Way have provided the strongest evidence so far that the dark mass concentrations seen in many galactic nuclei are likely supermassive black holes, but have not yet excluded several alternative configurations. Here we report ten years of high resolution astrometric imaging that allow us to trace two thirds of the orbit of the star currently closest to the compact radio source and massive black hole candidate SgrA*. In particular, we have observed both peri- and apocentre passages. Our observations show that the star is on a bound, highly elliptical Keplerian orbit around SgrA*, with an orbital period of 15.2 years and a peri-centre distance of only 17 light hours. The orbital elements require an enclosed point mass of 3.7+-1.5x10^6 solar masses. The data exclude with high confidence that the central dark mass consists of a cluster of astrophysical objects or massive, degenerate fermions, and strongly constrain the cent...

  6. Formation of dark matter tori around supermassive black holes via the eccentric Kozai-Lidov mechanism

    International Nuclear Information System (INIS)

    We explore the effects of long-term secular perturbations on the distribution of dark matter particles around supermassive black hole (BH) binaries. We show that in the hierarchical (in separation) three-body problem, one of the BHs and a dark matter particle form an inner binary. Gravitational perturbations from the BH companion, on a much wider orbit, can cause the dark matter particle to reach extremely high eccentricities and even get accreted onto the BH by what is known as the eccentric Kozai-Lidov (EKL) mechanism. We show that this may produce a torus-like configuration for the dark matter distribution around the less massive member of the BH binary. We first consider an intermediate BH (IMBH) in the vicinity of our galactic center, which may be a relic of a past minor merger. We show that if the IMBH is close enough (i.e., near the stellar disk) the EKL mechanism is very efficient in exciting the eccentricity of dark matter particles in near-polar configurations to extremely high values where they are accreted by the IMBH. We show that this mechanism is even more effective if the central BH grows in mass, where we have assumed adiabatic growth. Because near-polar configurations are disrupted, a torus-like shape is formed. We also show that this behavior is also likely to be relevant for supermassive BH binaries. We suggest that if the BHs are spinning, the accreted dark matter particles may linger in the ergosphere, and thereby generate self-annihilations and produce an indirect signature of potential interest.

  7. Formation of dark matter tori around supermassive black holes via the eccentric Kozai-Lidov mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Naoz, Smadar [Harvard Smithsonian Center for Astrophysics, Institute for Theory and Computation, 60 Garden St., Cambridge, MA 02138 (United States); Silk, Joseph, E-mail: snaoz@astro.ucla.edu [Institut d' Astrophysique de Paris, CNRS, UPMC Univ Paris 06, UMR7095, 98 bis, boulevard Arago, F-75014, Paris (France)

    2014-11-10

    We explore the effects of long-term secular perturbations on the distribution of dark matter particles around supermassive black hole (BH) binaries. We show that in the hierarchical (in separation) three-body problem, one of the BHs and a dark matter particle form an inner binary. Gravitational perturbations from the BH companion, on a much wider orbit, can cause the dark matter particle to reach extremely high eccentricities and even get accreted onto the BH by what is known as the eccentric Kozai-Lidov (EKL) mechanism. We show that this may produce a torus-like configuration for the dark matter distribution around the less massive member of the BH binary. We first consider an intermediate BH (IMBH) in the vicinity of our galactic center, which may be a relic of a past minor merger. We show that if the IMBH is close enough (i.e., near the stellar disk) the EKL mechanism is very efficient in exciting the eccentricity of dark matter particles in near-polar configurations to extremely high values where they are accreted by the IMBH. We show that this mechanism is even more effective if the central BH grows in mass, where we have assumed adiabatic growth. Because near-polar configurations are disrupted, a torus-like shape is formed. We also show that this behavior is also likely to be relevant for supermassive BH binaries. We suggest that if the BHs are spinning, the accreted dark matter particles may linger in the ergosphere, and thereby generate self-annihilations and produce an indirect signature of potential interest.

  8. Constraints on individual supermassive black hole binaries from pulsar timing array limits on continuous gravitational waves

    Science.gov (United States)

    Schutz, Katelin; Ma, Chung-Pei

    2016-06-01

    Pulsar timing arrays (PTAs) are placing increasingly stringent constraints on the strain amplitude of continuous gravitational waves emitted by supermassive black hole binaries on subparsec scales. In this paper, we incorporate independent information about the dynamical masses Mbh of supermassive black holes in specific galaxies at known distances and use this additional information to further constrain whether or not those galaxies could host a detectable supermassive black hole binary. We estimate the strain amplitudes from individual binaries as a function of binary mass ratio for two samples of nearby galaxies: (1) those with direct dynamical measurements of Mbh in the literature, and (2) the 116 most massive early-type galaxies (and thus likely hosts of the most massive black holes) within 108 Mpc from the MASSIVE Survey. Our exploratory analysis shows that the current PTA upper limits on continuous waves (as a function of angular position in the sky) can already constrain the mass ratios of hypothetical black hole binaries in many galaxies in our samples. The constraints are stronger for galaxies with larger Mbh and at smaller distances. For the black holes with Mbh ≳ 5 × 109 M⊙ at the centres of NGC 1600, NGC 4889, NGC 4486 (M87), and NGC 4649 (M60), any binary companion in orbit within the PTA frequency bands would have to have a mass ratio of a few per cent or less.

  9. A close-pair binary in a distant triple supermassive black-hole system

    OpenAIRE

    Deane, R. P.; Paragi, Z.; Jarvis, M. J.; Coriat, M.; Bernardi, G; Fender, R. P.; S. Frey; Heywood, I.; Klöckner, H. -R.; Grainge, K.; Rumsey, C.

    2014-01-01

    Galaxies are believed to evolve through merging, which should lead to multiple supermassive black holes in some. There are four known triple black hole systems, with the closest pair being 2.4 kiloparsecs apart (the third component is more distant at 3 kiloparsecs), which is far from the gravitational sphere of influence of a black hole with mass $\\sim$10$^9$ M$_\\odot$ (about 100 parsecs). Previous searches for compact black hole systems concluded that they were rare, with the tightest binary...

  10. Music from the heavens - Gravitational waves from supermassive black hole mergers in the EAGLE simulations

    Science.gov (United States)

    Salcido, Jaime; Bower, Richard G.; Theuns, Tom; McAlpine, Stuart; Schaller, Matthieu; Crain, Robert A.; Schaye, Joop; Regan, John

    2016-08-01

    We estimate the expected event rate of gravitational wave signals from mergers of supermassive black holes that could be resolved by a space-based interferometer, such as the Evolved Laser Interferometer Space Antenna (eLISA), utilising the reference cosmological hydrodynamical simulation from the EAGLE suite. These simulations assume a ΛCDM cosmogony with state-of-the-art subgrid models for radiative cooling, star formation, stellar mass loss, and feedback from stars and accreting black holes. They have been shown to reproduce the observed galaxy population with unprecedented fidelity. We combine the merger rates of supermassive black holes in EAGLE with the latest phenomenological waveform models to calculate the gravitational waves signals from the intrinsic parameters of the merging black holes. The EAGLE models predict ˜2 detections per year by a gravitational wave detector such as eLISA. We find that these signals are largely dominated by mergers between seed mass black holes merging at redshifts between z ˜ 2 and z ˜ 1. In order to investigate the dependence on the assumed black hole seed mass, we introduce an additional model with a black hole seed mass an order of magnitude smaller than in our reference model. We also consider a variation of the reference model where a prescription for the expected delays in the black hole merger timescale has been included after their host galaxies merge. We find that the merger rate is similar in all models, but that the initial black hole seed mass could be distinguished through their detected gravitational waveforms. Hence, the characteristic gravitational wave signals detected by eLISA will provide profound insight into the origin of supermassive black holes and the initial mass distribution of black hole seeds.

  11. Possible Evolution of Supermassive Black Holes from FRI quasars

    OpenAIRE

    Kim, Matthew I; Christian, Damian J.; Garofalo, David; D'Avanzo, Jaclyn

    2016-01-01

    We explore the question of the rapid buildup of black hole mass in the early universe employing a growing black hole mass-based determination of both jet and disk powers predicted in recent theoretical work on black hole accretion and jet formation. Despite simplified, even artificial assumptions about accretion and mergers, we identify an interesting low probability channel for the growth of one billion solar mass black holes within hundreds of millions of years of the Big Bang without appea...

  12. Supermassive Black Holes, AGN Feedback, and Hot X-ray Coronae in Early Type Galaxies

    Science.gov (United States)

    Forman, William R.; Anderson, Michael E.; Churazov, Eugene; Nulsen, Paul; Jones, Christine; Kraft, Ralph P.

    2016-06-01

    We present the analysis of a sample of more than 200 nearby, early type galaxies observed with the Chandra X-ray Observatory. We exclude resolved point sources, and model the emission from both unresolved X-ray binaries and CVs and ABs to derive the residual thermal emission from the hot atmosphere around each galaxy. We compute the X-ray luminosity of the central supermassive black hole (SMBH). Using galaxy velocity dispersion (or stellar mass) as a proxy for SMBH mass, we derive the Eddington ratios for these low luminosity AGN. We present the X-ray luminosity and gas temperature of the hot coronae as a function of stellar mass (a proxy for dark matter halo mass) and central velocity dispersion to look for anomalously X-ray bright gaseous coronae and to determine the stellar (or halo) mass, below which galactic winds may be important. For hot coronae with X-ray cavities, we derive the "mechanical" power of SMBHs and compare these to their radiative luminosities.

  13. Correlations Between Supermassive Black Holes, Velocity Dispersions, and Mass Deficits in Elliptical Galaxies with Cores

    CERN Document Server

    Kormendy, John; 10.1088/0004-637X/691/2/L142

    2009-01-01

    High-dynamic-range surface photometry in a companion paper makes possible accurate measurement of the stellar light deficits L_def and mass deficits M_def associated with the cores of elliptical galaxies. We show that L_def correlates with the velocity dispersion sigma of the host galaxy bulge averaged outside the central region that may be affected by a supermassive black hole (BH). We confirm that L_def correlates with BH mass MBH. Also, the fractional light deficit L_def/L correlates with MBH/M, the ratio of BH mass to the galaxy stellar mass. All three correlations have scatter similar to or smaller than the scatter in the well known correlation between MBH and sigma. The new correlations are remarkable in view of the dichotomy between ellipticals with cores and those with central extra light. Core light deficit correlates closely with MBH and sigma, but extra light does not. This supports the suggestion that extra light Es are made in wet mergers with starbursts whereas core Es are made in dry mergers. A...

  14. Supermassive Black Hole Formation at High Redshifts via Direct Collapse: Physical Processes in the Early Stage

    CERN Document Server

    Choi, Jun-Hwan; Begelman, Mitchell C

    2013-01-01

    We use numerical simulations to explore whether direct collapse can lead to the formation of supermassive black hole (SMBH) seeds at high redshifts. We follow the evolution of gas within slowly tumbling DM halos of 2 x 10^8 Mo and 1 kpc. We adopt cosmologically motivated density profiles and j-distributions. Our goal is to understand how the collapsing flow overcomes the centrifugal barrier and whether it is subject to fragmentation. We find that the collapse leads either to a central runaway or to off-center fragmentation. A disk-like configuration is formed inside the centrifugal barrier. For more cuspy DM distribution, the gas collapses more and experiences a bar-like perturbation and a central runaway. We have followed this inflow down to ~10^{-4} pc. The flow remains isothermal and the specific angular momentum is efficiently transferred by gravitational torques in a cascade of nested bars. This cascade supports a self-similar, disk-like collapse. In the collapsing phase, virial supersonic turbulence dev...

  15. Gravitational Wave Driven Mergers and Coalescence Time of Supermassive Black Holes

    Science.gov (United States)

    Khan, Fazeel Mahmood; Berczik, Peter; Just, Andreas

    2016-07-01

    The evolution of Supermassive Black Holes (SMBHs) initially embedded in the centers of merging galaxies is studied from the onset of galaxy mergers till coalescence. We performed direct N-body simulations using the highly efficient and massively parallel phi-GPU code capable to run on GPU supported high performance computer clusters. Post-Newtonian terms up to order 3.5 are used to drive the SMBH binary evolution in the relativistic regime. We find that SMBH binaries coalesce well within one billion year when our models are scaled to dense cuspy galaxies at low redshift. Here higher central densities provide larger supply of stars to efficiently extract energy from the SMBH binary orbit and shrink it to the phase where gravitational wave (GW) emission becomes dominant leading to the coalescence of the SMBHs. On the other hand, mergers of models that are representative of giant elliptical galaxies having central cores result in less efficient extraction of binary's orbit energy due to the lower stellar densities in the center. However, high value of eccentricities witnessed for SMBH binaries in such galaxy mergers ensure that the GW emission dominated phase sets in at larger values of the semi-major axis. This helps to compensate for the less efficient energy extraction during the phase dominated by stellar encounters resulting in mergers of SMBHs in about one billion years after the formation of binary.

  16. Double-double radio galaxies: remnants of merger of supermassive binary black holes

    CERN Document Server

    Liu, F K; Cao, S L; Wu, Xue-Bing

    2003-01-01

    The activity of active galaxy may be triggered by the merge of galaxies and present-day galaxies are probably the product of successive minor mergers. The frequent galactic merges at high redshift imply that active galaxy harbors supermassive unequal-mass binary black holes in its center at least once during its life time. In this paper, we showed that the recently discovered double-lobed FR II radio galaxies are the remnants of such supermassive binary black holes. The inspiraling secondary black hole opens a gap in the accretion disk and removes the inner accretion disk when it merges into the primary black hole, leaving a big hole of about several hundreds of Schwarzschild radius in the vicinity of the post-merged supermassive black hole and leading to an interruption of jet formation. When the outer accretion disk slowly refills the big hole on a viscous time scale, the jet formation restarts and the interaction of the recurrent jets and the inter-galactic medium forms a secondary pair of lobes. We applie...

  17. Supermassive black hole seed formation at high redshifts: long-term evolution of the direct collapse

    Science.gov (United States)

    Shlosman, Isaac; Choi, Jun-Hwan; Begelman, Mitchell C.; Nagamine, Kentaro

    2016-02-01

    We use cosmological adaptive mesh refinement code ENZO zoom-in simulations to study the long-term evolution of the collapsing gas within dark matter haloes at z. This direct collapse process is a leading candidate for rapid formation of supermassive black hole (SMBH) seeds. To circumvent the Courant condition at small radii, we apply the sink particle method, focusing on evolution on scales ˜0.01-10 pc. The collapse proceeds in two stages, with the secondary runaway happening within the central 10 pc. The sink particles form when the collapsing gas requires additional refinement of the grid size at the highest refinement level. Their growth is negligible with the sole exception of the central seed which grows dramatically to Mseed ˜ 2 × 106 M⊙ in ˜2 Myr, confirming the feasibility of this path to the SMBH. The variability of angular momentum in the accreted gas results in the formation of two misaligned discs. Both discs lie within the Roche limit of the central seed. While the inner disc is geometrically thin and weakly asymmetric, the outer disc flares due to turbulent motions as a result of the massive inflow along a pair of penetrating filaments. The filamentary inflow determines the dominant Fourier modes in this disc - these modes have a non-self-gravitational origin. We do not confirm that m = 1 is a dominant mode that drives the inflow in the presence of a central massive object. The overall configuration appears to be generic, and is expected to form when the central seed becomes sufficiently massive.

  18. Strong Gravitational Lensing as a Probe of Gravity, Dark-Matter and Super-Massive Black Holes

    CERN Document Server

    Koopmans, L V E; Barnabe, M; Bolton, A; Bradac, M; Ciotti, L; Congdon, A; Czoske, O; Dye, S; Dutton, A; Elliasdottir, A; Evans, E; Fassnacht, C D; Jackson, N; Keeton, C; Lazio, J; Marshall, P; Meneghetti, M; McKean, J; Moustakas, L; Myers, S; Nipoti, C; Suyu, S; van de Ven, G; Vegetti, S; Wambsganss, J; Webster, R; Wucknitz, O; Zhao, H-S

    2009-01-01

    Whereas considerable effort has been afforded in understanding the properties of galaxies, a full physical picture, connecting their baryonic and dark-matter content, super-massive black holes, and (metric) theories of gravity, is still ill-defined. Strong gravitational lensing furnishes a powerful method to probe gravity in the central regions of galaxies. It can (1) provide a unique detection-channel of dark-matter substructure beyond the local galaxy group, (2) constrain dark-matter physics, complementary to direct-detection experiments, as well as metric theories of gravity, (3) probe central super-massive black holes, and (4) provide crucial insight into galaxy formation processes from the dark matter point of view, independently of the nature and state of dark matter. To seriously address the above questions, a considerable increase in the number of strong gravitational-lens systems is required. In the timeframe 2010-2020, a staged approach with radio (e.g. EVLA, e-MERLIN, LOFAR, SKA phase-I) and optica...

  19. 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.

  20. 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...

  1. A candidate supermassive binary black hole system in the brightest cluster galaxy of RBS 797

    CERN Document Server

    Gitti, M; Giovannini, G; Feretti, L; Liuzzo, E

    2013-01-01

    The radio source at the center of the cool core galaxy cluster RBS 797 (z=0.35) is known to exhibit a misalignment of its radio jets and lobes observed at different VLA-scale, with the innermost kpc-scale jets being almost orthogonal to the radio emission which extends for tens of kpc filling the X-ray cavities. Gitti et al. suggested that this peculiar radio morphology may indicate a recurrent activity of the central radio source, where the jet orientation is changing between the different outbursts due to the effects of supermassive binary black holes (SMBBHs). We aim at unveiling the nuclear radio properties of the brightest cluster galaxy (BCG) in RBS 797 and at investigating the presence of a SMBBH system in its center. We have performed new high-resolution observations at 5 GHz with the European VLBI Network (EVN), reaching an angular resolution of 9x5 mas^2 and a sensitivity of 36 microJy/beam. We report the EVN detection of two compact components in the BCG of RBS 797, with a projected separation of ~...

  2. Prospects for gravitational-wave detection and supermassive black hole astrophysics with pulsar timing arrays

    CERN Document Server

    Ravi, V; Shannon, R M; Hobbs, G

    2014-01-01

    [Abridged] Large-area sky surveys show that massive galaxies undergo at least one major merger in a Hubble time. If all massive galaxies host central supermassive black holes (SMBHs), as is inferred from observations in the local Universe, it is likely that there is a population of binary SMBHs at the centres of galaxy merger remnants. Numerous authors have proposed pulsar timing array (PTA) experiments to measure the gravitational wave (GW) emission from binary SMBHs. In this paper, using the latest observational estimates for a range of galaxy properties and scaling relations, we predict the amplitude of the GW background generated by the binary SMBH population. We also predict counts of individual binary SMBH GW sources. We assume that all binary SMBHs are in circular orbits evolving under GW emission alone, which is likely to be correct for binaries emitting GWs at frequencies >~10^-8 Hz. Our fiducial model results in a characteristic strain amplitude of the GW background of A_yr=1.2(+0.6-0.3)*10^-15 at a...

  3. Did supermassive black holes form by direct collapse?

    OpenAIRE

    Begelman, Mitchell C.

    2007-01-01

    Rapid infall of gas in the nuclei of galaxies could lead to the formation of black holes by direct collapse, without first forming stars. Black holes formed in this way would have initial masses of a few solar masses, but would be embedded in massive envelopes that would allow them to grow at a highly super-Eddington rate. Thus, seed black holes as large as 10^3-10^4 solar masses could form very rapidly. I will sketch the basic physics of the direct collapse process and the properties of the ...

  4. Very long term observations of blazars candidates for supermassive black hole binaries

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Bašta, Milan

    Trieste: Proceedings of Science, 2008, s. 1-7. ISSN 1824-8039. [Workshop on Blazar Variability across the Electromagnetic Spectrum. Palaiseau (FR), 22.04.2008-25.04.2008] R&D Projects: GA ČR GA205/08/1207; GA ČR GA205/05/2167 Institutional research plan: CEZ:AV0Z10030501 Keywords : cosmic sources * supermassive black holes * high-energy sources Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics http://pos.sissa.it

  5. Diffuse Gamma Ray Background from Annihilating Dark Matter in Density Spikes around Supermassive Black Holes

    OpenAIRE

    Belikov, Alexander; Silk, Joseph

    2013-01-01

    Dark matter annihilation is proportional to the square of the density and is especially efficient in places of highest concentration of dark matter, such as dark matter spikes. The spikes are formed as a result of contraction of the dark matter density profile caused by adiabatic growth of a supermassive black hole at the center of the dark matter halo or subhalo. We revisit the relation between the properties and mass functions of dark matter halos and spikes, and propose alternative models ...

  6. Seeding supermassive black holes with a non-vortical dark-matter subcomponent

    OpenAIRE

    Sawicki, Ignacy; Marra, Valerio; Valkenburg, Wessel

    2013-01-01

    A perfect irrotational fluid with the equation of state of dust, Irrotational Dark Matter (IDM), is incapable of virializing and instead forms a cosmoskeleton of filaments with supermassive black holes at the joints. This stark difference from the standard cold dark matter (CDM) scenario arises because IDM must exhibit potential flow at all times, preventing shell-crossing from occurring. This scenario is applicable to general non-oscillating scalar-field theories with a small sound speed. Ou...

  7. Modeling the cosmological co-evolution of supermassive black holes and galaxies: I. BH scaling relations and the AGN luminosity function

    OpenAIRE

    Marulli, Federico; Bonoli, Silvia; Branchini, Enzo; Moscardini, Lauro; Springel, Volker

    2007-01-01

    We model the cosmological co-evolution of galaxies and their central supermassive black holes (BHs) within a semi-analytical framework developed on the outputs of the Millennium Simulation. This model, described in detail in Croton et al. (2006) and De Lucia & Blaizot (2007), introduces a `radio mode' feedback from Active Galactic Nuclei (AGN) at the centre of X-ray emitting atmospheres in galaxy groups and clusters. Thanks to this mechanism, the model can simultaneously explain: (i) the low ...

  8. Possible Evolution of Supermassive Black Holes from FRI quasars

    CERN Document Server

    Kim, Matthew I; Garofalo, David; D'Avanzo, Jaclyn

    2016-01-01

    We explore the question of the rapid buildup of black hole mass in the early universe employing a growing black hole mass-based determination of both jet and disk powers predicted in recent theoretical work on black hole accretion and jet formation. Despite simplified, even artificial assumptions about accretion and mergers, we identify an interesting low probability channel for the growth of one billion solar mass black holes within hundreds of millions of years of the Big Bang without appealing to super Eddington accretion. This result is made more compelling by the recognition of a connection between this channel and an end product involving active galaxies with FRI radio morphology but weaker jet powers in mildly sub-Eddington accretion regimes. While FRI quasars have already been shown to occupy a small region of the available parameter space for black hole feedback in the paradigm, we further suggest that the observational dearth of FRI quasars is also related to their connection to the most massive bla...

  9. Evolution of supermassive stars as a pathway to black hole formation

    CERN Document Server

    Begelman, Mitchell C

    2009-01-01

    Supermassive stars, with masses greater than a million solar masses, are possible progenitors of supermassive black holes in galactic nuclei. Because of their short nuclear burning timescales, such objects can be formed only when matter is able to accumulate at a rate exceeding ~ 1 solar mass/yr. Here we revisit the structure and evolution of rotationally-stabilized supermassive stars, taking into account their continuous accumulation of mass and their thermal relaxation. We show that the outer layers of supermassive stars are not thermally relaxed during much of the star's main sequence lifetime. As a result, they do not resemble n=3 polytropes, as assumed in previous literature, but rather consist of convective (polytropic) cores surrounded by convectively stable envelopes that contain most of the mass. We compute the structures of these envelopes, in which the specific entropy is proportional to the enclosed mass M(R) to the 2/3-power. By matching the envelope solutions to convective cores, we calculate th...

  10. Implications of primordial black holes on the first stars and the origin of the super--massive black holes

    CERN Document Server

    Bambi, Cosimo; Dolgov, Alexander D; Freese, Katherine; Volonteri, Marta

    2008-01-01

    If the cosmological dark matter has a component made of small primordial black holes, they may have a significant impact on the physics of the first stars and on the subsequent formation of massive black holes. Primordial black holes would be adiabatically contracted into these stars and then would sink to the stellar center by dynamical friction, creating a larger black hole which may quickly swallow the whole star. The first stars would thus live only for a very short time and would not contribute much to reionization of the universe. They would instead become $10 - 10^3 M_\\odot$ black holes which (depending on subsequent accretion) could serve as seeds for the super--massive black holes seen at high redshifts as well as those inside galaxies today.

  11. A strong magnetic field in the jet base of a supermassive black hole

    OpenAIRE

    Marti-Vidal, Ivan; Muller, Sebastien; Vlemmings, Wouter; Horellou, Cathy; Aalto, Susanne

    2016-01-01

    Active galactic nuclei (AGN) host some of the most energetic phenomena in the Universe. AGN are thought to be powered by accretion of matter onto a rotating disk that surrounds a supermassive black hole. Jet streams can be boosted in energy near the event horizon of the black hole and then flow outward along the rotation axis of the disk. The mechanism that forms such a jet and guides it over scales from a few light-days up to millions of light-years remains uncertain, but magnetic fields are...

  12. Music from the heavens - Gravitational waves from supermassive black hole mergers in the EAGLE simulations

    CERN Document Server

    Salcido, Jaime; Theuns, Tom; McAlpine, Stuart; Schaller, Matthieu; Crain, Robert A; Schaye, Joop; Regan, John

    2016-01-01

    We estimate the expected event rate of gravitational wave signals from mergers of supermassive black holes that could be resolved by a space-based interferometer, such as the Evolved Laser Interferometer Space Antenna (eLISA), utilising cosmological hydrodynamical simulations from the EAGLE suite. These simulations assume a $\\Lambda$CDM cosmogony with state-of-the-art subgrid models for radiative cooling, star formation, stellar mass loss, and feedback from stars and accreting black holes. They have been shown to reproduce the observed galaxy population with unprecedented fidelity. We combine the merger rates of supermassive black holes in EAGLE with a model to calculate the gravitational waves signals from the intrinsic parameters of the black holes. The EAGLE models predict $\\sim2$ detections per year by a gravitational wave detector such as eLISA. We find that these signals are largely dominated by mergers between $10^5 \\textrm{M}_{\\odot} h^{-1}$ seed mass black holes merging at redshifts between $z\\sim2.5...

  13. Super-massive black hole mass scaling relations

    CERN Document Server

    Graham, Alister W; Schombert, James

    2014-01-01

    Using black hole masses which span 10^5 to 10^(10) solar masses, the distribution of galaxies in the (host spheroid stellar mass)-(black hole mass) diagram is shown to be strongly bent. While the core-Sersic galaxies follow a near-linear relation, having a mean M_(bh)/M_(sph) mass ratio of ~0.5%, the Sersic galaxies follow a near-quadratic relation: M_bh~M_sph^(2.22+\\-0.58). This is not due to offset pseudobulges, but is instead an expected result arising from the long-known bend in the M_(sph)-sigma relation and the log-linear M_(bh)-sigma relation.

  14. Supermassive Black Holes and Their Relationships with Their Host Galaxies

    International Nuclear Information System (INIS)

    We review how the masses of black holes in active galactic nuclei are measured and outline the current limitations and uncertainties. Masses have been measured directly by emission-line reverberation for nearly 50 relatively nearby AGNs, but uncertainties due to the unknown geometry and projection effects limit the accuracy of these masses to ∼ 0.3 dex. Reverberation studies show that there is a very tight relationship between the broad-line region radius and the AGN luminosity, with an intrinsic scatter of ∼ 0.1 dex, which shows (1) that the largest source of systematic uncertainty in the black hole mass determinations is how the velocity field of the broad-line region is characterized, not the size of the broad-line region, and (2) that the size of the broad-line region can be estimated to fairly high accuracy from the AGN luminosity alone, thus providing a powerful indirect method of estimating black hole masses in even distant AGNs.

  15. A normal supermassive black hole in NGC 1277

    CERN Document Server

    Graham, Alister W; Savorgnan, Giulia A D; Medling, Anne M; Batcheldor, D; Scott, Nicholas; Watson, Beverly; Marconi, A

    2016-01-01

    The identification of galaxies with `overly massive' black holes requires two measurements: a black hole mass (M_bh) and a host spheroid mass (M_sph,*). Here we provide our measurements for NGC 1277. Our structural decomposition reveals that NGC 1277 is dominated by a `classical' spheroid with a Sersic index n=5.3, a half-light radius R_e=2.1 kpc, and a stellar mass of 2.7x10^{11} M_sun (using M_*/L_V=11.65, Martin-Navarro et al.). This mass is an order of magnitude greater than originally reported. Using the latest (M_bh)-n, (M_bh)-(M_sph,*) and (M_bh)-sigma relations, the expected black hole mass is respectively (0.57^{+1.29}_{-0.40})x10^9 M_sun, (1.58^{+4.04}_{-1.13})x10^9 M_sun, and (2.27^{+4.04}_{-1.44})x10^9 M_sun (using sigma=300 km/s) for which the `sphere-of-influence' is 0".31. Our new kinematical maps obtained from laser guide star assisted, adaptive optics on the Keck I Telescope reaffirm the presence of the inner, nearly edge-on, disk seen and modelled in the galaxy image. This disk produces a la...

  16. 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...

  17. The Galactic Tango: The Elegant Dance of Galaxies and their Supermassive Black Holes

    Science.gov (United States)

    Sherman, Sydney; Li, Yuexing; Zhu, Qirong

    2015-01-01

    For well over a decade, it has been known that a supermassive black hole resides in the center of almost every galaxy, and that these black holes strongly correlate with the stellar velocity dispersion (the MBH-σ correlation) and stellar mass (the MBH-Mhost correlation) of their hosts. The origins of these correlations, however, have yet to be determined. To explore the interplay between black holes and galaxies, we have utilized a sample of nearby spiral and elliptical galaxies as well as a sample of AGN in the redshift range z = 0-3. By examining galaxy properties such as mass, kinematics, and growth history, we have determined that these two correlations have distinct origins: the MBH-σ relation may be the result of virial equilibrium, whereas the MBH-Mhost relation may be the result of self-regulated black hole growth and star formation in galaxies. These results confirm the predictions of our previous theoretical model.

  18. Supermassive Black Holes and Their Host Spheroids. I. Disassembling Galaxies

    Science.gov (United States)

    Savorgnan, G. A. D.; Graham, A. W.

    2016-01-01

    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 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.

  19. Accretion in Strong Gravity: From Galactic to Supermassive Black Holes

    OpenAIRE

    Done, Chris; Gierlinski, Marek

    2005-01-01

    The galactic black hole binary systems give an observational template showing how the accretion flow changes as a function of increasing mass accretion rate, or L/L_Edd. These data can be synthetised with theoretical models of the accretion flow to give a coherent picture of accretion in strong gravity, in which the major hard-soft spectral transition is triggered by a change in the nature and geometry of the inner accretion flow from a hot, optically thin plasma to a cool, optically thick ac...

  20. Supermassive Black Hole Formation at High Redshifts via Direct Collapse: Physical Processes in the Early Stage

    Science.gov (United States)

    Choi, Jun-Hwan; Shlosman, Isaac; Begelman, Mitchell C.

    2013-09-01

    We use numerical simulations to explore whether direct collapse can lead to the formation of supermassive black hole (SMBH) seeds at high redshifts. Using the adaptive mesh refinement code ENZO, we follow the evolution of gas within slowly tumbling dark matter (DM) halos of M vir ~ 2 × 108 M ⊙ and R vir ~ 1 kpc. For our idealized simulations, we adopt cosmologically motivated DM and baryon density profiles and angular momentum distributions. Our principal goal is to understand how the collapsing flow overcomes the centrifugal barrier and whether it is subject to fragmentation which can potentially lead to star formation, decreasing the seed SMBH mass. We find that the collapse proceeds from inside out and leads either to a central runaway or to off-center fragmentation. A disk-like configuration is formed inside the centrifugal barrier, growing via accretion. For models with a more cuspy DM distribution, the gas collapses more and experiences a bar-like perturbation and a central runaway on scales of damped. Models with progressively larger initial DM cores evolve similarly, but the timescales become longer. In models with more organized initial rotation—when the rotation of spherical shells is constrained to be coplanar—a torus forms on scales ~20-50 pc outside the disk, and appears to be supported by turbulent motions driven by accretion from the outside. The overall evolution of the models depends on the competition between two timescales, corresponding to the onset of the central runaway and of off-center fragmentation. In models with less organized rotation—when the rotation of spherical shells is randomized (but the total angular momentum remains unchanged)—the torus is greatly weakened, the central accretion timescale is shortened, and off-center fragmentation is suppressed—triggering the central runaway even in previously "stable" models. The resulting seed SMBH masses is found in the range M • ~ 2 × 104 M ⊙-2 × 106 M ⊙, substantially

  1. Supermassive black holes do not correlate with dark matter haloes of galaxies.

    Science.gov (United States)

    Kormendy, John; Bender, Ralf

    2011-01-20

    Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black-hole growth and bulge formation regulate each other. That is, black holes and bulges coevolve. Therefore, reports of a similar correlation between black holes and the dark matter haloes in which visible galaxies are embedded have profound implications. Dark matter is likely to be non-baryonic, so these reports suggest that unknown, exotic physics controls black-hole growth. Here we show, in part on the basis of recent measurements of bulgeless galaxies, that there is almost no correlation between dark matter and parameters that measure black holes unless the galaxy also contains a bulge. We conclude that black holes do not correlate directly with dark matter. They do not correlate with galaxy disks, either. Therefore, black holes coevolve only with bulges. This simplifies the puzzle of their coevolution by focusing attention on purely baryonic processes in the galaxy mergers that make bulges. PMID:21248846

  2. New observational constraints on the growth of the first supermassive black holes

    International Nuclear Information System (INIS)

    We constrain the total accreted mass density in supermassive black holes at z > 6, inferred via the upper limit derived from the integrated X-ray emission from a sample of photometrically selected galaxy candidates. Studying galaxies obtained from the deepest Hubble Space Telescope images combined with the Chandra 4 Ms observations of the Chandra Deep Field-South, we achieve the most restrictive constraints on total black hole growth in the early universe. We estimate an accreted mass density <1000 M ☉ Mpc–3 at z ∼ 6, significantly lower than the previous predictions from some existing models of early black hole growth and earlier prior observations. These results place interesting constraints on early black hole growth and mass assembly by accretion and imply one or more of the following: (1) only a fraction of the luminous galaxies at this epoch contain active black holes; (2) most black hole growth at early epochs happens in dusty and/or less massive—as yet undetected—host galaxies; (3) there is a significant fraction of low-z interlopers in the galaxy sample; (4) early black hole growth is radiatively inefficient, heavily obscured, and/or due to black hole mergers as opposed to accretion; or (5) the bulk of the black hole growth occurs at late times. All of these possibilities have important implications for our understanding of high-redshift seed formation models.

  3. Flares from stars tidally disrupted by supermassive black holes

    Science.gov (United States)

    Komossa, St.

    2016-04-01

    Stellar tidal disruption events are unique probes of accretion physics and disk winds under extreme conditions. Their luminous flares of radiation are signposts of intermediate-mass black holes (BHs) and recoiling BHs. In X-rays, they have the potential to probe GR effects near the last stable orbit. Some of the events launch relativistic jets, and provide us with a powerful new method of understanding the physics of jet formation and evolution in a quiescent environment. About 30-40 candidate events have been identified by now, mostly in the X-rays and the optical. Events will be detected in the thousands in upcoming sky surveys, enabling statistical studies and rapid multi-wavelength follow-ups. Here, I provide a review of the field, including most recent results.

  4. Editorial: Understanding the Growth of the First Supermassive Black Holes

    Science.gov (United States)

    Valiante, Rosa; Schneider, Raffaella; Volonteri, Marta

    2016-08-01

    The formation, assembly history, and environmental impact of the massive black holes (BH) that are ubiquitous in the nuclei of luminous galaxies today remain some of the main unsolved problems in cosmic structure formation. In the last several years, it has become clear that quasars are not just tracers of early and recent structure formation, but that they seem to have actively influenced galaxies and clusters through feedback mechanisms that are still not well understood. The discovery of more and more numerous quasars at redshift above 6, powered by BHs with masses similar to that of their local counterparts, further complicates this scenario. This emphasises the urgent need to better understand how and when such massive objects form and grow, what is the strength and scale of their impact on the evolution of their host galaxies, and what are the main physical processes driving and regulating this co-evolution.

  5. Hunting a wandering supermassive black hole in the M31 halo hermitage

    International Nuclear Information System (INIS)

    In the hierarchical structure formation scenario, galaxies enlarge through multiple merging events with less massive galaxies. In addition, the Magorrian relation indicates that almost all galaxies are occupied by a central supermassive black hole (SMBH) of mass 10–3 times the mass of its spheroidal component. Consequently, SMBHs are expected to wander in the halos of their host galaxies following a galaxy collision, although evidence of this activity is currently lacking. We investigate a current plausible location of an SMBH wandering in the halo of the Andromeda galaxy (M31). According to theoretical studies of N-body simulations, some of the many substructures in the M31 halo are remnants of a minor merger occurring about 1 Gyr ago. First, to evaluate the possible parameter space of the infalling orbit of the progenitor, we perform numerous parameter studies using a graphics processing unit cluster. To reduce uncertainties in the predicted position of the expected SMBH, we then calculate the time evolution of the SMBH in the progenitor dwarf galaxy from N-body simulations using the plausible parameter sets. Our results show that the SMBH lies within the halo (∼20-50 kpc from the M31 center), closer to the Milky Way than the M31 disk. Furthermore, the predicted current positions of the SMBH were restricted to an observational field of 0.°6 × 0.°7 in the northeast region of the M31 halo. We also discuss the origin of the infalling orbit of the satellite galaxy and its relationships with the recently discovered vast thin disk plane of satellite galaxies around M31.

  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. Bose-Einstein condensed supermassive black holes: A case of renormalized quantum field theory in curved space-time

    NARCIS (Netherlands)

    T.M. Nieuwenhuizen; V. Špička

    2008-01-01

    This paper investigates the question whether a realistic black hole can be in principal similar to a star, having a large but finite redshift at its horizon. If matter spreads throughout the interior of a supermassive black hole with mass M similar to 10⁹M_{⊙}, it has an average density comparable t

  8. Spin properties of supermassive black holes with powerful outflows

    Science.gov (United States)

    Daly, Ruth. A.

    2016-05-01

    Relationships between beam power and accretion disc luminosity are studied for a sample of 55 high excitation radio galaxies (HERG), 13 low excitation radio galaxies (LERG), and 29 radio loud quasars (RLQ) with powerful outflows. The ratio of beam power to disc luminosity tends to be high for LERG, low for RLQ, and spans the full range of values for HERG. Writing general expressions for the disc luminosity and beam power and applying the empirically determined relationships allows a function that parametrizes the spins of the holes to be estimated. Interestingly, one of the solutions that is consistent with the data has a functional form that is remarkably similar to that expected in the generalized Blandford-Znajek model with a magnetic field that is similar in form to that expected in magnetically arrested disk (MAD) and advection-dominated accretion flow (ADAF) models. Values of the spin function, obtained independent of specific outflow models, suggest that spin and active galactic nucleus type are not related for these types of sources. The spin function can be used to solve for black hole spin in the context of particular outflow models, and one example is provided.

  9. Ubiquitous seeding of supermassive black holes by direct collapse

    CERN Document Server

    Agarwal, Bhaskar; Johnson, Jarrett L; Neistein, Eyal; Vecchia, Claudio Dalla; Livio, Mario

    2012-01-01

    We study for the first time the environment of massive black hole (BH) seeds (~10^4-5 Msun) formed via the direct collapse of pristine gas clouds in massive haloes (>10^7 Msun) at z>6. Our model is based on the evolution of dark matter haloes within a cosmological N-body simulation, combined with prescriptions for the formation of BH along with both Pop III and Pop II stars. We calculate the spatially-varying intensity of Lyman Werner (LW) radiation from stars and identify the massive pristine haloes in which it is high enough to shut down molecular hydrogen cooling. In contrast to previous BH seeding models with a spatially constant LW background, we find that the intensity of LW radiation due to local sources, J_local, can be up to 10^6 times the spatially averaged background in the simulated volume and exceeds the critical value, J_crit, for the complete suppression of molecular cooling, in some cases by 4 orders of magnitude. Even after accounting for possible metal pollution in a halo from previous episo...

  10. The Co-Evolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe

    CERN Document Server

    Heckman, Timothy

    2014-01-01

    We summarize what large surveys of the contemporary universe have taught us about the physics and phenomenology of the processes that link the formation and evolution of galaxies and their central supermassive black holes. We present a picture in which the population of AGN can be divided into two distinct populations. The Radiative-Mode AGN are associated with black holes that produce radiant energy powered by accretion at rates in excess of ~1% of the Eddington Limit. They are primarily associated with less massive black holes growing in high-density pseudo-bulges at a rate sufficient to produce the total mass budget in these black holes in ~10 Gyr. The circum-nuclear environment contains high density cold gas and associated star-formation. Major mergers are not the primary mechanism for transporting this gas inward; secular processes appear dominant. Stellar feedback will be generic in these objects and strong AGN feedback is seen only in the most powerful AGN. In Jet-Mode AGN the bulk of energetic output ...

  11. Observing Supermassive Black Holes across cosmic time: from phenomenology to physics

    CERN Document Server

    Merloni, A

    2015-01-01

    In the last decade, a combination of high sensitivity, high spatial resolution observations and of coordinated multi-wavelength surveys has revolutionized our view of extra-galactic black hole (BH) astrophysics. We now know that supermassive black holes reside in the nuclei of almost every galaxy, grow over cosmological times by accreting matter, interact and merge with each other, and in the process liberate enormous amounts of energy that influence dramatically the evolution of the surrounding gas and stars, providing a powerful self-regulatory mechanism for galaxy formation. The different energetic phenomena associated to growing black holes and Active Galactic Nuclei (AGN), their cosmological evolution and the observational techniques used to unveil them, are the subject of this chapter. In particular, I will focus my attention on the connection between the theory of high-energy astrophysical processes giving rise to the observed emission in AGN, the observable imprints they leave at different wavelengths...

  12. Seeding supermassive black holes with a non-vortical dark-matter subcomponent

    CERN Document Server

    Sawicki, Ignacy; Valkenburg, Wessel

    2013-01-01

    A perfect irrotational fluid with the equation of state of dust, Irrotational Dark Matter (IDM), is incapable of virializing and instead forms a cosmoskeleton of filaments with supermassive black holes at the joints. This stark difference from the standard cold dark matter (CDM) scenario arises because IDM must exhibit potential flow at all times, preventing shell-crossing from occurring. This scenario is applicable to general non-oscillating scalar-field theories with a small sound speed. Our model of combined IDM and CDM components thereby provides a solution to the problem of forming the observed billion-solar-mass black holes at redshifts of six and higher. In particular, as a result of the reduced vortical flow, the growth of the black holes is expected to be more rapid at later times as compared to the standard scenario.

  13. THE SUPERNOVA THAT DESTROYED A PROTOGALAXY: PROMPT CHEMICAL ENRICHMENT AND SUPERMASSIVE BLACK HOLE GROWTH

    International Nuclear Information System (INIS)

    The first primitive galaxies formed from accretion and mergers by z ∼ 15, and were primarily responsible for cosmological reionization and the chemical enrichment of the early cosmos. But a few of these galaxies may have formed in the presence of strong Lyman-Werner UV fluxes that sterilized them of H2, preventing them from forming stars or expelling heavy elements into the intergalactic medium prior to assembly. At masses of 108 M☉ and virial temperatures of 104 K, these halos began to rapidly cool by atomic lines, perhaps forming 104-106 M☉ Pop III stars and, later, the seeds of supermassive black holes. We have modeled the explosion of a supermassive Pop III star in the dense core of a line-cooled protogalaxy with the ZEUS-MP code. We find that the supernova (SN) expands to a radius of ∼1 kpc, briefly engulfing the entire galaxy, but then collapses back into the potential well of the dark matter. Fallback fully mixes the interior of the protogalaxy with metals, igniting a violent starburst and fueling the rapid growth of a massive black hole at its center. The starburst would populate the protogalaxy with stars in greater numbers and at higher metallicities than in more slowly evolving, nearby halos. The SN remnant becomes a strong synchrotron source that can be observed with eVLA and eMERLIN and has a unique signature that easily distinguishes it from less energetic SN remnants. Such explosions, and their attendant starbursts, may well have marked the birthplaces of supermassive black holes on the sky

  14. INTERACTION OF RECOILING SUPERMASSIVE BLACK HOLES WITH STARS IN GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Supermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. The coalescence of the SMBHBs is a distinct source of gravitational wave (GW) radiation. The detections of the strong GW radiation and their possible electromagnetic counterparts are essential. Numerical relativity suggests that the post-merger supermassive black hole (SMBH) gets a kick velocity up to 4000 km s–1 due to the anisotropic GW radiations. Here, we investigate the dynamical coevolution and interaction of the recoiling SMBHs and their galactic stellar environments with one million direct N-body simulations including the stellar tidal disruption by the recoiling SMBHs. Our results show that the accretion of disrupted stars does not significantly affect the SMBH dynamical evolution. We investigate the stellar tidal disruption rates as a function of the dynamical evolution of oscillating SMBHs in the galactic nuclei. Our simulations show that most stellar tidal disruptions are contributed by the unbound stars and occur when the oscillating SMBHs pass through the galactic center. The averaged disruption rate is ∼10–6 M☉ yr–1, which is about an order of magnitude lower than that by a stationary SMBH at similar galactic nuclei. Our results also show that a bound star cluster is around the oscillating SMBH of about ∼0.7% the black hole mass. In addition, we discover a massive cloud of unbound stars following the oscillating SMBH. We also investigate the dependence of the results on the SMBH masses and density slopes of the galactic nuclei.

  15. Tidal disruption of stars by supermassive black holes: The X-ray view

    Directory of Open Access Journals (Sweden)

    Komossa S.

    2012-12-01

    Full Text Available The tidal disruption of stars by supermassive black holes produces luminous soft X-ray accretion flares in otherwise inactive galaxies. First events have been discovered in X-rays with the ROSAT observatory, and have more recently been detected with XMM-Newton, Chandra and Swift, and at other wavelengths. In X-rays, they typically appear as very soft, exceptionally luminous outbursts of radiation, which decline consistent with L ∝ t−5/3 on the timescale of months to years. They reach total amplitudes of decline up to factors 1000–6000 more than a decade after their initial high-states, and in low-state, their host galaxies are essentially X-ray inactive, optically inactive, and radio inactive. X-ray luminous tidal disruption events (TDEs represent a powerful new probe of accretion physics near the event horizon, and of relativistic effects. TDEs offer a new way of estimating black hole spin, and they are signposts of supermassive binary black holes and recoiling black holes. Once discovered in the thousands in upcoming sky surveys, their rates will probe stellar dynamics in distant galaxies, and they will uncover the – so far elusive – population of intermediate mass black holes in the universe, if they do exist. Further, the reprocessing of the flare into IR, optical and UV emission lines provides us with multiple new diagnostics of the properties of any gaseous material in the vicinity of the black hole (including the disrupted star itself and in the host galaxy. First candidate events of this kind have been reported recently.

  16. Gravitational-wave limits from pulsar timing constrain supermassive black hole evolution.

    Science.gov (United States)

    Shannon, R M; Ravi, V; Coles, W A; Hobbs, G; Keith, M J; Manchester, R N; Wyithe, J S B; Bailes, M; Bhat, N D R; Burke-Spolaor, S; Khoo, J; Levin, Y; Osłowski, S; Sarkissian, J M; van Straten, W; Verbiest, J P W; Wang, J-B

    2013-10-18

    The formation and growth processes of supermassive black holes (SMBHs) are not well constrained. SMBH population models, however, provide specific predictions for the properties of the gravitational-wave background (GWB) from binary SMBHs in merging galaxies throughout the universe. Using observations from the Parkes Pulsar Timing Array, we constrain the fractional GWB energy density (Ω(GW)) with 95% confidence to be Ω(GW)(H0/73 kilometers per second per megaparsec)(2) formation model implemented in the Millennium Simulation Project is inconsistent with our limit with 50% probability. PMID:24136962

  17. Seeking for the leading actor on the cosmic stage: Galaxies versus Supermassive Black Holes

    CERN Document Server

    Bongiorno, Angela; Civano, Francesca; Gavignaud, Isabelle; Georgakakis, Antonis

    2012-01-01

    We present a Special Issue on the interplay of galaxies and Supermassive Black Holes (SMBHs) recently published in Advances in Astronomy. This is the introductory paper containing the motivation for this Special Issue together with a brief description of the articles which are part of the manuscript and the link to the entire book (http://www.hindawi.com/journals/aa/si/610485/). We hope this Special Issue will be useful for many astronomers who want to get an update on the current status of the AGN-Galaxy coevolution topic.

  18. Using Pulsar Timing observations to understand the formation and evolution of supermassive black hole binaries

    Science.gov (United States)

    Cornish, Neil; Sampson, Laura; McWilliams, Sean

    2015-04-01

    The astrophysical processes that form and harden supermassive black hole binaries impart distinct features that may be observed in the gravitational-wave spectrum within the sensitive frequency range of Pulsar Timing Arrays (PTA). We investigate how well the various formation and hardening mechanisms can be constrained by applying Bayesian inference to simulated PTA data sets. We find that even without strong priors on the merger rate, any detection of the signal will place interesting constraints on the astrophysical models. Folding in priors on the merger rate allows us to place interesting constraints on the astrophysical models even before a detection is made.

  19. Hydrodynamics of galaxy mergers with supermassive black holes: is there a last parsec problem ?

    OpenAIRE

    Chapon, D.; Mayer, L.; Teyssier, R.

    2011-01-01

    We study the formation of a supermassive black hole (SMBH) binary and the shrinking of the separation of the two holes to sub-parsec scales starting from a realistic major merger between two gas-rich spiral galaxies with mass comparable to our Milky Way. The simulations, carried out with the adaptive mesh refinement (AMR) code RAMSES, are capable of resolving separations as small as 0.1 pc. The collision of the two galaxies produces a gravoturbulent rotating nuclear disc with mass (˜109 M⊙) a...

  20. Dark matter halos and the M-\\sigma relation for supermassive black holes

    OpenAIRE

    Larkin, Adam C; McLaughlin, Dean E.

    2016-01-01

    We develop models of two-component spherical galaxies to establish scaling relations linking the properties of spheroids at $z=0$ (total stellar masses, effective radii $R_e$ and velocity dispersions within $R_e$) to the properties of their dark-matter halos at both $z=0$ and higher redshifts. . Our main motivation is the widely accepted idea that the accretion-driven growth of supermassive black holes (SMBHs) in protogalaxies is limited by quasar-mode feedback and gas blow-out. The SMBH mass...

  1. Blindly detecting orbital modulations of jets from merging supermassive black holes

    OpenAIRE

    O'Shaughnessy, R.; D. Kaplan; Sesana, A.; Kamble, A.

    2011-01-01

    In the last few years before merger, supermassive black hole binaries will rapidly inspiral and precess in a magnetic field imposed by a surrounding circumbinary disk. Multiple simulations suggest this relative motion will convert some of the local energy to a Poynting-dominated outflow, with a luminosity 10^{43} erg/s * (B/10^4 G)^2(M/10^8 Msun)^2 (v/0.4 c)^2, some of which may emerge as synchrotron emission at frequencies near 1 GHz where current and planned wide-field radio surveys will op...

  2. The Megamaser Cosmology Project. III. Accurate Masses of Seven Supermassive Black Holes in Active Galaxies with Circumnuclear Megamaser Disks

    CERN Document Server

    Kuo, C Y; Condon, J J; Impellizzeri, C M V; Lo, K Y; Zaw, I; Schenker, M; Henkel, C; Reid, M J; Greene, J E

    2010-01-01

    Observations of H$_2$O masers from circumnuclear disks in active galaxies for the Megamaser Cosmology Project allow accurate measurement of the mass of supermassive black holes (BH) in these galaxies. We present the Very Long Baseline Interferometry (VLBI) images and kinematics of water maser emission in six active galaxies: NGC~1194, NGC~2273, NGC~2960 (Mrk~1419), NGC~4388, NGC~6264 and NGC~6323. We use the Keplerian rotation curves of these six megamaser galaxies, plus a seventh previously published, to determine accurate enclosed masses within the central $\\sim0.3$ pc of these galaxies, smaller than the radius of the sphere of influence of the central mass in all cases. We also set lower limits to the central mass densities of between 0.12 and 60 $\\times 10^{10} M_{\\odot}$~pc$^{-3}$. For six of the seven disks, the high central densities rule out clusters of stars or stellar remnants as the central objects, and this result further supports our assumption that the enclosed mass can be attributed predominant...

  3. A close-pair binary in a distant triple supermassive black hole system.

    Science.gov (United States)

    Deane, R P; Paragi, Z; Jarvis, M J; Coriat, M; Bernardi, G; Fender, R P; Frey, S; Heywood, I; Klöckner, H-R; Grainge, K; Rumsey, C

    2014-07-01

    Galaxies are believed to evolve through merging, which should lead to some hosting multiple supermassive black holes. There are four known triple black hole systems, with the closest black hole pair being 2.4 kiloparsecs apart (the third component in this system is at 3 kiloparsecs), which is far from the gravitational sphere of influence (about 100 parsecs for a black hole with mass one billion times that of the Sun). Previous searches for compact black hole systems concluded that they were rare, with the tightest binary system having a separation of 7 parsecs (ref. 10). Here we report observations of a triple black hole system at redshift z = 0.39, with the closest pair separated by about 140 parsecs and significantly more distant from Earth than any other known binary of comparable orbital separation. The effect of the tight pair is to introduce a rotationally symmetric helical modulation on the structure of the large-scale radio jets, which provides a useful way to search for other tight pairs without needing extremely high resolution observations. As we found this tight pair after searching only six galaxies, we conclude that tight pairs are more common than hitherto believed, which is an important observational constraint for low-frequency gravitational wave experiments. PMID:24990745

  4. Searching for GW signals from eccentric supermassive black-hole binaries with pulsar-timing arrays

    Science.gov (United States)

    Taylor, Stephen; Gair, Jonathan; Huerta, Eliu; McWilliams, Sean

    2015-04-01

    The mergers of massive galaxies leads to the formation of supermassive black-hole binaries in the common merger remnants. Various mechanisms have been proposed to harden these binaries into the adiabatic GW inspiral regime, from interactions with circumbinary disks to stellar scattering. It may be the case that these mechanisms leave the binary with a residual eccentricity, such that the deviation to the time-of-arrival of pulsar signals induced by the emitted GW passing between the Earth and a pulsar will contain a signature of this eccentricity. Current pulsar-timing search pipelines only probe circular binary systems, but much effort is now being devoted to considering the influence of the binary environment on GW signals. We will detail our efforts in constructing a generalised GW search pipeline to constrain the eccentricity of single systems with arrays of precisely-timed pulsars, which may shed light on the influence of various supermassive black-hole binary hardening mechanisms and illuminate the importance of environmental couplings.

  5. Detecting eccentric supermassive black hole binaries with pulsar timing arrays: Resolvable source strategies

    CERN Document Server

    Taylor, S R; Gair, J R; McWilliams, S T

    2015-01-01

    The couplings between supermassive black-hole binaries and their environments within galactic nuclei have been well studied as part of the search for solutions to the final parsec problem. The scattering of stars by the binary or the interaction with a circumbinary disk may efficiently drive the system to sub-parsec separations, allowing the binary to enter a regime where the emission of gravitational-waves can drive it to merger within a Hubble time. However, these interactions can also affect the orbital parameters of the binary. In particular, they may drive an increase in binary eccentricity which survives until the system's gravitational-wave signal enters the pulsar-timing array band. Therefore, if we can measure the eccentricity from observed signals, we can potentially deduce some of the properties of the binary environment. To this end, we build on previous techniques to present a general Bayesian pipeline with which we can detect and estimate the parameters of an eccentric supermassive black-hole bi...

  6. The impact of reionization on the formation of supermassive black hole seeds

    CERN Document Server

    Johnson, Jarrett L; Agarwal, Bhaskar; Paardekooper, Jan-Pieter; Khochfar, Sadegh

    2014-01-01

    Black holes (BHs) formed from the direct collapse of primordial gas in the early Universe are strong candidates for the seeds of supermassive BHs residing in the centers of massive galaxies today and powering quasars at z > 6. These direct collapse black holes (DCBHs) are thought to form from pristine primordial gas collapsing in atomic cooling haloes in the presence of a strong molecule-dissociating, Lyman-Werner (LW) radiation field, which prevents the cooling of the gas to temperatures below ~ 10^4 K. The runaway gravitational collapse of this hot gas leads to the formation of a supermassive star which collapses to form a 10^4 - 10^6 M_Sun BH. Given that star forming galaxies are likely to be the source of the LW radiation in this scenario, it is likely that some ionizing radiation from these galaxies accompanies the LW radiation. We present cosmological simulations resolving the collapse of primordial gas into an atomic cooling halo, including the effects of both LW and ionizing radiation. We find that in...

  7. The formation of galaxy stellar cores by the hierarchical merging of supermassive black holes

    CERN Document Server

    Volonteri, M; Haardt, F; Volonteri, Marta; Madau, Piero

    2003-01-01

    We investigate a hierarchical structure formation scenario in which galaxy stellar cores are created from the binding energy liberated by shrinking supermassive black hole (SMBH) binaries. The binary orbital decay heats the surrounding stars, eroding a preexisting 1/r^2 stellar cusp. We follow the merger history of dark matter halos and associated SMBHs via cosmological Monte Carlo realizations of the merger hierarchy from early times to the present in a LCDM cosmology. Massive black holes get incorporated through a series of mergers into larger and larger halos, sink to the center owing to dynamical friction, accrete a fraction of the gas in the merger remnant to become supermassive, and form a binary system. Stellar dynamical processes drive the binary to harden and eventually coalesce. A simple scheme is applied in which the loss cone is constantly refilled and a constant density core forms due to the ejection of stellar mass. We find that a model in which the effect of the hierarchy of SMBH interactions i...

  8. INTERRUPTION OF TIDAL-DISRUPTION FLARES BY SUPERMASSIVE BLACK HOLE BINARIES

    International Nuclear Information System (INIS)

    Supermassive black hole binaries (SMBHBs) are products of galaxy mergers, and are important in testing Λ cold dark matter cosmology and locating gravitational-wave-radiation sources. A unique electromagnetic signature of SMBHBs in galactic nuclei is essential in identifying the binaries in observations from the IR band through optical to X-ray. Recently, the flares in optical, UV, and X-ray caused by supermassive black holes (SMBHs) tidally disrupting nearby stars have been successfully used to observationally probe single SMBHs in normal galaxies. In this Letter, we investigate the accretion of the gaseous debris of a tidally disrupted star by a SMBHB. Using both stability analysis of three-body systems and numerical scattering experiments, we show that the accretion of stellar debris gas, which initially decays with time ∝t -5/3, would stop at a time Ttr ≅ ηTb. Here, η ∼ 0.25 and Tb is the orbital period of the SMBHB. After a period of interruption, the accretion recurs discretely at time Tr ≅ ξb, where ξ ∼ 1. Both η and ξ sensitively depend on the orbital parameters of the tidally disrupted star at the tidal radius and the orbit eccentricity of SMBHB. The interrupted accretion of the stellar debris gas gives rise to an interrupted tidal flare, which could be used to identify SMBHBs in non-active galaxies in the upcoming transient surveys.

  9. Populating the galaxy velocity dispersion - supermassive black hole mass diagram: A catalogue of (M_bh, sigma) values

    CERN Document Server

    Graham, Alister W

    2008-01-01

    An updated catalogue of 76 galaxies with direct supermassive black hole mass measurements (M_bh) plus, when available, their host bulge's central velocity dispersion (sigma_0) is provided. Fifty of these mass measurements are considered reliable, while the others remain somewhat uncertain at this time. An additional eight stellar systems, including one stellar cluster and three globular clusters, are listed as hosting potential intermediate mass black holes < 10^6 M_solar. With this larger data set, the demographics within the M_bh-sigma_0 diagram are briefly explored. Many barred galaxies are shown to be offset from the M_bh-sigma_0 relation defined by the non-barred galaxies, in the sense that their velocity dispersions are too high. Furthermore, including 88 AGN with black hole mass estimates from reverberation mapping studies, we speculate that barred AGN may follow this same general trend. We also show that some AGN with sigma_0 < 100 km/s tend to reside up to 0.6 dex above the "barless" M_bh-sigma...

  10. Rapid formation of supermassive black hole binaries in galaxy mergers with gas.

    Science.gov (United States)

    Mayer, L; Kazantzidis, S; Madau, P; Colpi, M; Quinn, T; Wadsley, J

    2007-06-29

    Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that after the merger of two massive galaxies, a SMBH binary will form, shrink because of stellar or gas dynamical processes, and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas because of the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years after the collision between two spiral galaxies. A massive, turbulent, nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than 1 million years as a result of the gravitational drag from the gas rather than from the stars. PMID:17556550

  11. Cosmological evolution of supermassive black holes in galactic centers unveiled by hard X-ray observations.

    Science.gov (United States)

    Ueda, Yoshihiro

    2015-01-01

    We review the current understanding of the cosmological evolution of supermassive black holes in galactic centers elucidated by X-ray surveys of active galactic nuclei (AGNs). Hard X-ray observations at energies above 2 keV are the most efficient and complete tools to find "obscured" AGNs, which are dominant populations among all AGNs. Combinations of surveys with various flux limits and survey area have enabled us to determine the space number density and obscuration properties of AGNs as a function of luminosity and redshift. The results have essentially solved the origin of the X-ray background in the energy band below ∼10 keV. The downsizing (or anti-hierarchical) evolution that more luminous AGNs have the space-density peak at higher redshifts has been discovered, challenging theories of galaxy and black hole formation. Finally, we summarize unresolved issues on AGN evolution and prospects for future X-ray missions. PMID:25971656

  12. Cosmological evolution of supermassive black holes in galactic centers unveiled by hand X-ray observations

    International Nuclear Information System (INIS)

    We review the current understanding of the cosmological evolution of supermassive black holes in galactic centers elucidated by X-ray surveys of active galactic nuclei (AGNs). Hard X-ray observations at energies above 2 keV are the most efficient and complete tools to find “obscured” AGNs, which are dominant populations among all AGNs. Combinations of surveys with various flux limits and survey area have enabled us to determine the space number density and obscuration properties of AGNs as a function of luminosity and redshift. The results have essentially solved the origin of the X-ray background in the energy band below ∼10 keV. The downsizing (or anti-hierarchical) evolution that more luminous AGNs have the space-density peak at higher redshifts has been discovered, challenging theories of galaxy and black hole formation. Finally, we summarize unresolved issues on AGN evolution and prospects for future X-ray missions. (author)

  13. Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, L.; /Zurich U. /Zurich, ETH; Kazantzidis, S.; /KIPAC, Menlo Park; Madau, P.; /UC, Santa Cruz /Garching, Max Planck Inst.; Colpi, M.; /Milan Bicocca U.; Quinn, T.; /Washington U., Seattle; Wadsley, J.; /McMaster U.

    2008-03-24

    Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that, following the merger of two massive galaxies, a SMBH binary will form, shrink due to stellar or gas dynamical processes and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas due to the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years following the collision between two spiral galaxies. A massive, turbulent nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than a million years as a result of the gravitational drag from the gas rather than from the stars.

  14. SUPERMASSIVE BLACK HOLE FORMATION AT HIGH REDSHIFTS VIA DIRECT COLLAPSE: PHYSICAL PROCESSES IN THE EARLY STAGE

    International Nuclear Information System (INIS)

    We use numerical simulations to explore whether direct collapse can lead to the formation of supermassive black hole (SMBH) seeds at high redshifts. Using the adaptive mesh refinement code ENZO, we follow the evolution of gas within slowly tumbling dark matter (DM) halos of Mvir ∼ 2 × 108 M☉ and Rvir ∼ 1 kpc. For our idealized simulations, we adopt cosmologically motivated DM and baryon density profiles and angular momentum distributions. Our principal goal is to understand how the collapsing flow overcomes the centrifugal barrier and whether it is subject to fragmentation which can potentially lead to star formation, decreasing the seed SMBH mass. We find that the collapse proceeds from inside out and leads either to a central runaway or to off-center fragmentation. A disk-like configuration is formed inside the centrifugal barrier, growing via accretion. For models with a more cuspy DM distribution, the gas collapses more and experiences a bar-like perturbation and a central runaway on scales of ∼–4 pc (∼10 AU), where it is estimated to become optically thick. The flow remains isothermal and the specific angular momentum, j, is efficiently transferred by gravitational torques in a cascade of nested bars. This cascade is triggered by finite perturbations from the large-scale mass distribution and by gas self-gravity, and supports a self-similar, disk-like collapse where the axial ratios remain constant. The mass accretion rate shows a global minimum on scales of ∼1-10 pc at the time of the central runaway. In the collapsing phase, virial supersonic turbulence develops and fragmentation is damped. Models with progressively larger initial DM cores evolve similarly, but the timescales become longer. In models with more organized initial rotation—when the rotation of spherical shells is constrained to be coplanar—a torus forms on scales ∼20-50 pc outside the disk, and appears to be supported by turbulent motions driven by accretion from the

  15. A close-pair binary in a distant triple supermassive black-hole system

    CERN Document Server

    Deane, R P; Jarvis, M J; Coriat, M; Bernardi, G; Fender, R P; Frey, S; Heywood, I; Klöckner, H -R; Grainge, K; Rumsey, C

    2014-01-01

    Galaxies are believed to evolve through merging, which should lead to multiple supermassive black holes in some. There are four known triple black hole systems, with the closest pair being 2.4 kiloparsecs apart (the third component is more distant at 3 kiloparsecs), which is far from the gravitational sphere of influence of a black hole with mass $\\sim$10$^9$ M$_\\odot$ (about 100 parsecs). Previous searches for compact black hole systems concluded that they were rare, with the tightest binary system having a separation of 7 parsecs. Here we report observations of a triple black hole system at redshift z=0.39, with the closest pair separated by $\\sim$140 parsecs. The presence of the tight pair is imprinted onto the properties of the large-scale radio jets, as a rotationally-symmetric helical modulation, which provides a useful way to search for other tight pairs without needing extremely high resolution observations. As we found this tight pair after searching only six galaxies, we conclude that tight pairs ar...

  16. Spin and mass of the supermassive black hole in the Galactic Center

    International Nuclear Information System (INIS)

    A new method for exact determination of the masses and spins of black holes from the observations of quasi-periodic oscillations is discussed. The detected signal from the hot clumps in the accretion plasma must contain modulations with two characteristic frequencies: the frequency of rotation of the black hole event horizon and the frequency of the latitudinal precession of the clump’s orbit. Application of the method of two characteristic frequencies for interpretation of the observed quasi-periodic oscillations from the supermassive black hole in the Galactic center in the X-rays and in the near IR region yields the most exact, for the present, values of the mass and the spin (Kerr parameter) of the Sgr A* black hole: M = (4.2 ± 0.2) × 106M⊙ and a = 0.65 ± 0.05. The observed quasi-periodic oscillations with a period of about 11.5 min are identified as the black hole event horizon rotation period and those with a period of about 19 min are identified as the latitudinal oscillation period of the hot spot orbits in the accretion disk

  17. Spin and mass of the supermassive black hole in the Galactic Center

    Energy Technology Data Exchange (ETDEWEB)

    Dokuchaev, V. I., E-mail: dokuchaev@inr.ac.ru [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2015-12-15

    A new method for exact determination of the masses and spins of black holes from the observations of quasi-periodic oscillations is discussed. The detected signal from the hot clumps in the accretion plasma must contain modulations with two characteristic frequencies: the frequency of rotation of the black hole event horizon and the frequency of the latitudinal precession of the clump’s orbit. Application of the method of two characteristic frequencies for interpretation of the observed quasi-periodic oscillations from the supermassive black hole in the Galactic center in the X-rays and in the near IR region yields the most exact, for the present, values of the mass and the spin (Kerr parameter) of the Sgr A* black hole: M = (4.2 ± 0.2) × 10{sup 6}M{sub ⊙} and a = 0.65 ± 0.05. The observed quasi-periodic oscillations with a period of about 11.5 min are identified as the black hole event horizon rotation period and those with a period of about 19 min are identified as the latitudinal oscillation period of the hot spot orbits in the accretion disk.

  18. A LARGE SYSTEMATIC SEARCH FOR CLOSE SUPERMASSIVE BINARY AND RAPIDLY RECOILING BLACK HOLES

    Energy Technology Data Exchange (ETDEWEB)

    Eracleous, Michael [Department of Astronomy and Astrophysics and Center for Gravitational Wave Physics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16803 (United States); Boroson, Todd A. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Halpern, Jules P.; Liu Jia [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027-6601 (United States)

    2012-08-01

    We have carried out a systematic search for subparsec supermassive black hole (BH) binaries among z {approx}< 0.7 Sloan Digital Sky Survey quasars. These are predicted by models of supermassive BH and host galaxy coevolution, therefore their census and population properties constitute an important test of these models. In our working hypothesis, one of the two BHs accretes at a much higher rate than the other and carries with it the only broad emission line region of the system, making the system analogous to a single-lined spectroscopic binary star. Accordingly, we used spectroscopic principal component analysis to search for broad H{beta} emission lines that are displaced from the quasar rest frame by |{Delta} v| {approx}> 1000 km s{sup -1}. This method also yields candidates for rapidly recoiling BHs. Of the 88 candidates, several were previously reported in the literature. We found a correlation between the peak offset and skewness of the broad H{beta} profiles, suggesting a common physical explanation for these profiles. We carried out follow-up spectroscopic observations of 68 objects to search for changes in the peak velocities of the H{beta} lines. We measured statistically significant changes in 14 objects, with implied accelerations between -120 and +120 km s{sup -1} yr{sup -1}. Interpreting the offset broad emission lines as signatures of supermassive binaries is subject to many caveats. Many more follow-up observations over a long temporal baseline are needed to characterize the variability pattern of the broad lines and test that it is consistent with orbital motion. The possibility that some of the objects in this sample are rapidly recoiling BHs remains open.

  19. INTERACTION OF RECOILING SUPERMASSIVE BLACK HOLES WITH STARS IN GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Li Shuo; Liu, F. K. [Astronomy Department, Peking University, 100871 Beijing (China); Berczik, Peter; Spurzem, Rainer [Astronomisches Rechen-Institut, Zentrum fuer Astronomie, Universitaet Heidelberg, Moenchhofstr. 12-14, D-69120 Heidelberg (Germany); Chen Xian, E-mail: lis@bac.pku.edu.cn, E-mail: fkliu@bac.pku.edu.cn, E-mail: chenx@bac.pku.edu.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China)

    2012-03-20

    Supermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. The coalescence of the SMBHBs is a distinct source of gravitational wave (GW) radiation. The detections of the strong GW radiation and their possible electromagnetic counterparts are essential. Numerical relativity suggests that the post-merger supermassive black hole (SMBH) gets a kick velocity up to 4000 km s{sup -1} due to the anisotropic GW radiations. Here, we investigate the dynamical coevolution and interaction of the recoiling SMBHs and their galactic stellar environments with one million direct N-body simulations including the stellar tidal disruption by the recoiling SMBHs. Our results show that the accretion of disrupted stars does not significantly affect the SMBH dynamical evolution. We investigate the stellar tidal disruption rates as a function of the dynamical evolution of oscillating SMBHs in the galactic nuclei. Our simulations show that most stellar tidal disruptions are contributed by the unbound stars and occur when the oscillating SMBHs pass through the galactic center. The averaged disruption rate is {approx}10{sup -6} M{sub Sun} yr{sup -1}, which is about an order of magnitude lower than that by a stationary SMBH at similar galactic nuclei. Our results also show that a bound star cluster is around the oscillating SMBH of about {approx}0.7% the black hole mass. In addition, we discover a massive cloud of unbound stars following the oscillating SMBH. We also investigate the dependence of the results on the SMBH masses and density slopes of the galactic nuclei.

  20. Subaru and e-Merlin observations of NGC 3718. Diaries of a supermassive black hole recoil?

    Science.gov (United States)

    Markakis, K.; Dierkes, J.; Eckart, A.; Nishiyama, S.; Britzen, S.; García-Marín, M.; Horrobin, M.; Muxlow, T.; Zensus, J. A.

    2015-08-01

    NGC 3718 is a low-ionization nuclear emission line region (LINER) L1.9 galaxy, lying at a distance of about ~17.4 Mpc from the Earth; its similarities with NGC 5128 often award it the name northern Centaurus A. The presence of a compact radio source with a candidate jet structure, a prominent dust lane, and a strongly warped molecular and atomic gas disk are indications that NGC 3718 has undergone some sort of a large-scale gravitational interaction sometime in the recent past, which channeled gas towards the center, feeding the black hole and igniting the central engine. One proposed scenario involves an encounter with the close neighboring galaxy NGC 3729, while other authors favor a merging event with mass ratio ≥(3-4):1 as the origin of NGC3718. We use high angular resolution (~100 mas) e-Merlin radio and Subaru near-IR (NIR) (~170 mas) data to take a detailed view of the processes taking place in its central region. In order to preserve some objectivity in our interpretation, we combine our results with literature values and findings from previous studies. Our NIR maps suggest, on the one hand, that towards the stellar bulge there are no large-scale absorption phenomena caused by the apparent dust lane and, on the other, that there is a significant (local) contribution from hot (~1000 K) dust to the nuclear NIR emission. The position where this takes place appears to be closer to the offset compact radio emission from our e-Merlin 6 cm map and is offset by ~4.25 pc from the center of the underlying stellar bulge. The shape of the radio map suggests the presence of one (or possibly two, forming an X-shape) bipolar structure(s) ~1 (~0.6) arcsec across, which combined with the balance between the gas and the stellar velocity dispersions and the presence of hard X-ray emission, point towards effects expected by AGN feedback. We also argue that NGC 3718 has a core in its surface brightness profile, although it is a gas-rich galaxy and we discuss its mixed

  1. CONNECTING STAR FORMATION QUENCHING WITH GALAXY STRUCTURE AND SUPERMASSIVE BLACK HOLES THROUGH GRAVITATIONAL HEATING OF COOLING FLOWS

    International Nuclear Information System (INIS)

    Recent observations suggested that star formation quenching in galaxies is related to galaxy structure. Here we propose a new mechanism to explain the physical origin of this correlation. We assume that while quenching is maintained in quiescent galaxies by a feedback mechanism, cooling flows in the hot halo gas can still develop intermittently. We study cooling flows in a large suite of around 90 hydrodynamic simulations of an isolated galaxy group, and find that the flow development depends significantly on the gravitational potential well in the central galaxy. If the galaxy's gravity is not strong enough, cooling flows result in a central cooling catastrophe, supplying cold gas and feeding star formation to galactic bulges. When the bulge grows prominent enough, compressional heating starts to offset radiative cooling and maintains cooling flows in a long-term hot mode without producing a cooling catastrophe. Our model thus describes a self-limited growth channel for galaxy bulges and naturally explains the connection between quenching and bulge prominence. In particular, we explicitly demonstrate that M∗/Reff1.5 is a good structural predictor of quenching. We further find that the gravity from the central supermassive black hole also affects the bimodal fate of cooling flows, and we predict a more general quenching predictor to be Mbh1.6M∗/Reff1.5, which may be tested in future observational studies

  2. Prospects for measuring supermassive black hole masses with future extremely large telescopes

    CERN Document Server

    Do, Tuan; Barth, Aaron J; Barton, Elizabeth J; Simard, Luc; Larkin, James E; Moore, Anna M; Wang, Lianqi; Ellerbroek, Brent

    2014-01-01

    The next generation of giant-segmented mirror telescopes ($>$ 20 m) will enable us to observe galactic nuclei at much higher angular resolution and sensitivity than ever before. These capabilities will introduce a revolutionary shift in our understanding of the origin and evolution of supermassive black holes by enabling more precise black hole mass measurements in a mass range that is unreachable today. We present simulations and predictions of the observations of nuclei that will be made with the Thirty Meter Telescope (TMT) and the adaptive optics assisted integral-field spectrograph IRIS, which is capable of diffraction-limited spectroscopy from $Z$ band (0.9 $\\mu$m) to $K$ band (2.2 $\\mu$m). These simulations, for the first time, use realistic values for the sky, telescope, adaptive optics system, and instrument, to determine the expected signal-to-noise ratio of a range of possible targets spanning intermediate mass black holes of $\\sim10^4$ \\msun to the most massive black holes known today of $>10^{10}...

  3. A LARGE SYSTEMATIC SEARCH FOR CLOSE SUPERMASSIVE BINARY AND RAPIDLY RECOILING BLACK HOLES

    International Nuclear Information System (INIS)

    We have carried out a systematic search for subparsec supermassive black hole (BH) binaries among z ∼ 1000 km s–1. This method also yields candidates for rapidly recoiling BHs. Of the 88 candidates, several were previously reported in the literature. We found a correlation between the peak offset and skewness of the broad Hβ profiles, suggesting a common physical explanation for these profiles. We carried out follow-up spectroscopic observations of 68 objects to search for changes in the peak velocities of the Hβ lines. We measured statistically significant changes in 14 objects, with implied accelerations between –120 and +120 km s–1 yr–1. Interpreting the offset broad emission lines as signatures of supermassive binaries is subject to many caveats. Many more follow-up observations over a long temporal baseline are needed to characterize the variability pattern of the broad lines and test that it is consistent with orbital motion. The possibility that some of the objects in this sample are rapidly recoiling BHs remains open.

  4. Prospects for measuring supermassive black hole masses with future extremely large telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Do, Tuan; Wright, Shelley A. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto M5S 3H4, ON (Canada); Barth, Aaron J.; Barton, Elizabeth J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Simard, Luc [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC, V9E 2E7 (Canada); Larkin, James E. [Physics and Astronomy Department, University of California, Los Angeles, CA 90095-1547 (United States); Moore, Anna M. [Caltech Optical Observatories, California Institute of Technology, Pasadena, CA (United States); Wang, Lianqi; Ellerbroek, Brent [TMT Observatory Corporation Instrumentation Department, Pasadena, CA (United States)

    2014-04-01

    The next generation of giant-segmented mirror telescopes (>20 m) will enable us to observe galactic nuclei at much higher angular resolution and sensitivity than ever before. These capabilities will introduce a revolutionary shift in our understanding of the origin and evolution of supermassive black holes by enabling more precise black hole mass measurements in a mass range that is unreachable today. We present simulations and predictions of the observations of nuclei that will be made with the Thirty Meter Telescope (TMT) and the adaptive optics assisted integral-field spectrograph IRIS, which is capable of diffraction-limited spectroscopy from Z band (0.9 μm) to K band (2.2 μm). These simulations, for the first time, use realistic values for the sky, telescope, adaptive optics system, and instrument to determine the expected signal-to-noise ratio of a range of possible targets spanning intermediate mass black holes of ∼10{sup 4} M {sub ☉} to the most massive black holes known today of >10{sup 10} M {sub ☉}. We find that IRIS will be able to observe Milky Way mass black holes out the distance of the Virgo Cluster, and will allow us to observe many more of the brightest cluster galaxies where the most massive black holes are thought to reside. We also evaluate how well the kinematic moments of the velocity distributions can be constrained at the different spectral resolutions and plate scales designed for IRIS. We find that a spectral resolution of ∼8000 will be necessary to measure the masses of intermediate mass black holes. By simulating the observations of galaxies found in Sloan Digital Sky Survey DR7, we find that over 10{sup 5} massive black holes will be observable at distances between 0.005 < z < 0.18 with the estimated sensitivity and angular resolution provided by access to Z-band (0.9 μm) spectroscopy from IRIS and the TMT adaptive optics system. These observations will provide the most accurate dynamical measurements of black hole masses to

  5. Prospects for measuring supermassive black hole masses with future extremely large telescopes

    International Nuclear Information System (INIS)

    The next generation of giant-segmented mirror telescopes (>20 m) will enable us to observe galactic nuclei at much higher angular resolution and sensitivity than ever before. These capabilities will introduce a revolutionary shift in our understanding of the origin and evolution of supermassive black holes by enabling more precise black hole mass measurements in a mass range that is unreachable today. We present simulations and predictions of the observations of nuclei that will be made with the Thirty Meter Telescope (TMT) and the adaptive optics assisted integral-field spectrograph IRIS, which is capable of diffraction-limited spectroscopy from Z band (0.9 μm) to K band (2.2 μm). These simulations, for the first time, use realistic values for the sky, telescope, adaptive optics system, and instrument to determine the expected signal-to-noise ratio of a range of possible targets spanning intermediate mass black holes of ∼104 M ☉ to the most massive black holes known today of >1010 M ☉. We find that IRIS will be able to observe Milky Way mass black holes out the distance of the Virgo Cluster, and will allow us to observe many more of the brightest cluster galaxies where the most massive black holes are thought to reside. We also evaluate how well the kinematic moments of the velocity distributions can be constrained at the different spectral resolutions and plate scales designed for IRIS. We find that a spectral resolution of ∼8000 will be necessary to measure the masses of intermediate mass black holes. By simulating the observations of galaxies found in Sloan Digital Sky Survey DR7, we find that over 105 massive black holes will be observable at distances between 0.005 < z < 0.18 with the estimated sensitivity and angular resolution provided by access to Z-band (0.9 μm) spectroscopy from IRIS and the TMT adaptive optics system. These observations will provide the most accurate dynamical measurements of black hole masses to enable the study of the

  6. Insights into the astrophysics of supermassive black hole binaries from pulsar timing observations

    International Nuclear Information System (INIS)

    Pulsar timing arrays (PTAs) are designed to detect the predicted gravitational wave (GW) background produced by a cosmological population of supermassive black hole (SMBH) binaries. In this contribution, I review the physics of such GW background, highlighting its dependence on the overall binary population, the relation between SMBHs and their hosts, and their coupling with the stellar and gaseous environment. The latter is particularly relevant when it drives the binaries to extreme eccentricities (e > 0.9), which might be the case for stellar-driven systems. This causes a substantial suppression of the low-frequency signal, potentially posing a serious threat to the effectiveness of PTA observations. A future PTA detection will allow us to directly observe for the first time subparsec SMBH binaries on their way to the GW-driven coalescence, providing important answers of the outstanding questions related to the physics underlying the formation and evolution of these spectacular sources. (paper)

  7. A fast and long-lived outflow from the supermassive black hole in NGC 5548

    Science.gov (United States)

    Kaastra, J. S.; Kriss, G. A.; Cappi, M.; Mehdipour, M.; Petrucci, P.-O.; Steenbrugge, K. C.; Arav, N.; Behar, E.; Bianchi, S.; Boissay, R.; Branduardi-Raymont, G.; Chamberlain, C.; Costantini, E.; Ely, J. C.; Ebrero, J.; Di Gesu, L.; Harrison, F. A.; Kaspi, S.; Malzac, J.; De Marco, B.; Matt, G.; Nandra, K.; Paltani, S.; Person, R.; Peterson, B. M.; Pinto, C.; Ponti, G.; Nuñez, F. Pozo; De Rosa, A.; Seta, H.; Ursini, F.; de Vries, C. P.; Walton, D. J.; Whewell, M.

    2014-07-01

    Supermassive black holes in the nuclei of active galaxies expel large amounts of matter through powerful winds of ionized gas. The archetypal active galaxy NGC 5548 has been studied for decades, and high-resolution x-ray and ultraviolet (UV) observations have previously shown a persistent ionized outflow. An observing campaign in 2013 with six space observatories shows the nucleus to be obscured by a long-lasting, clumpy stream of ionized gas not seen before. It blocks 90% of the soft x-ray emission and causes simultaneous deep, broad UV absorption troughs. The outflow velocities of this gas are up to five times faster than those in the persistent outflow, and, at a distance of only a few light days from the nucleus, it may likely originate from the accretion disk.

  8. Signature of Plausible Accreting Supermassive Black Holes in Mrk 261/262 and Mrk 266

    Directory of Open Access Journals (Sweden)

    Gagik Ter-Kazarian

    2013-01-01

    Full Text Available We address the neutrino radiation of plausible accreting supermassive black holes closely linking to the 5 nuclear components of galaxy samples of Mrk 261/262 and Mrk 266. We predict a time delay before neutrino emission of the same scale as the age of the Universe. The ultrahigh energy neutrinos are produced in superdense protomatter medium via simple (quark or pionic reactions or modified URCA processes (G. Gamow was inspired to name the process URCA after the name of a casino in Rio de Janeiro. The resulting neutrino fluxes for quark reactions are ranging from to , where is the opening parameter. For pionic and modified URCA reactions, the fluxes are and , respectively. These fluxes are highly beamed along the plane of accretion disk, peaked at ultrahigh energies, and collimated in smaller opening angle .

  9. Gravitational waves from binary supermassive black holes missing in pulsar observations.

    Science.gov (United States)

    Shannon, R M; Ravi, V; Lentati, L T; Lasky, P D; Hobbs, G; Kerr, M; Manchester, R N; Coles, W A; Levin, Y; Bailes, M; Bhat, N D R; Burke-Spolaor, S; Dai, S; Keith, M J; Osłowski, S; Reardon, D J; van Straten, W; Toomey, L; Wang, J-B; Wen, L; Wyithe, J S B; Zhu, X-J

    2015-09-25

    Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems would modulate the arrival times of pulses from radio pulsars. Using observations of millisecond pulsars obtained with the Parkes radio telescope, we constrained the characteristic amplitude of this background, A(c,yr), to be <1.0 × 10(-15) with 95% confidence. This limit excludes predicted ranges for A(c,yr) from current models with 91 to 99.7% probability. We conclude that binary evolution is either stalled or dramatically accelerated by galactic-center environments and that higher-cadence and shorter-wavelength observations would be more sensitive to gravitational waves. PMID:26404832

  10. The variability timescales and brightness temperatures of radio flares from stars to supermassive black holes

    CERN Document Server

    Pietka, M; Keane, E F

    2014-01-01

    In this paper we compile the analysis of ~ 200 synchrotron flare events from ~ 90 distinct objects/events for which the distance is well established, and hence the peak luminosity can be accurately estimated. For each event we measure this peak and compare it to the rise and decay timescales, as fit by exponential functions, which allows us in turn to estimate a minimum brightness temperature for all the events. The astrophysical objects from which the flares originate vary from flare stars to supermassive black holes in active galactic nuclei, and include both repeating phenomena and single cataclysmic events (such as supernovae and gamma ray burst afterglows). The measured timescales vary from minutes to longer than years, and the peak radio luminosities range over 22 orders of magnitude. Despite very different underlying phenomena, including relativistic and non-relativistic regimes, and highly collimated versus isotropic phenomena, we find a broad correlation between peak radio luminosity and rise/decay t...

  11. A fast and long-lived outflow from the supermassive black hole in NGC 5548

    CERN Document Server

    Kaastra, J S; Cappi, M; Mehdipour, M; Petrucci, P -O; Steenbrugge, K C; Arav, N; Behar, E; Bianchi, S; Boissay, R; Branduardi-Raymont, G; Chamberlain, C; Costantini, E; Ely, J C; Ebrero, J; Di Gesu, L; Harrison, F A; Kaspi, S; Malzac, J; De Marco, B; Matt, G; Nandra, K; Paltani, S; Person, R; Peterson, B M; Pinto, C; Ponti, G; Nuñez, F Pozo; De Rosa, A; Seta, H; Ursini, F; de Vries, C P; Walton, D J; Whewell, M

    2014-01-01

    Supermassive black holes in the nuclei of active galaxies expel large amounts of matter through powerful winds of ionized gas. The archetypal active galaxy NGC 5548 has been studied for decades, and high-resolution X-ray and UV observations have previously shown a persistent ionized outflow. An observing campaign in 2013 with six space observatories shows the nucleus to be obscured by a long-lasting, clumpy stream of ionized gas never seen before. It blocks 90% of the soft X-ray emission and causes simultaneous deep, broad UV absorption troughs. The outflow velocities of this gas are up to five times faster than those in the persistent outflow, and at a distance of only a few light days from the nucleus, it may likely originate from the accretion disk.

  12. Identifying Decaying Supermassive Black Hole Binaries from their Variable Electromagnetic Emission

    CERN Document Server

    Haiman, Zoltán; Menou, Kristen; Lippai, Zoltán; Frei, Zsolt

    2008-01-01

    Supermassive black hole binaries (SMBHBs) with masses in the range 10^4-10^7 M_sun/(1+z), produced in galaxy mergers, are thought to complete their coalescence due to the emission of gravitational waves (GWs). The anticipated detection of the GWs by the LISA will constitute a milestone for fundamental physics and astrophysics. While the GW signatures themselves will provide a treasure trove of information, if the source can be securely identified in electromagnetic (EM) bands, this would open up entirely new scientific opportunities, to probe fundamental physics, astrophysics, and cosmology. We discuss several ideas, involving wide-field telescopes, that may be useful in locating electromagnetic counterparts to SMBHBs detected by LISA. In particular, the binary may produce a variable electromagnetic flux, such as a roughly periodic signal due to the orbital motion prior to coalescence, or a prompt transient signal caused by shocks in the circumbinary disk when the SMBHB recoils and "shakes" the disk. We discu...

  13. Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole

    Energy Technology Data Exchange (ETDEWEB)

    Trap, G.; Goldwurm, A.; Ferrando, P. [Service d' Astrophysique - SAp, /IRFU/DSM/CEA Saclay, Bat. 709, 91191 Gif-sur-Yvette Cedex (France); AstroParticule and Cosmologie - APC, Universite Paris VII/CNRS/CEA/Observatoire de Paris, Bat. Condorcet, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (FR); Terrier, R. [AstroParticule and Cosmologie - APC, Universite Paris VII/CNRS/CEA/Observatoire de Paris, Bat. Condorcet, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (FR); Dodds-Eden, K.; Gillessen, S.; Genzel, R. [Max Planck Institut fuer Extraterretrische Physik - MPE, 85748 Garching (Germany); Pantin, E.; Lagage, P.O. [Service d' Astrophysique - SAp, /IRFU/DSM/CEA Saclay, Bat. 709, 91191 Gif-sur-Yvette Cedex (FR); Astrophysique Interactions Multi-echelles - AIM/Universite Paris VII/CEA/CNRS, Bat. 709, 91191 Gif-sur-Yvette Cedex (FR); Belanger, G. [European Space Agency - ESA/ESAC, P.O. Box 78, Villanueva de la Canada, 28691 Madrid (Spain); Porquet, D.; Grosso, N. [Observatoire astronomique de Strasbourg/Universite de Strasbourg/CNRS, 11, rue de l' Universite, 67000 Strasbourg (FR); Yusef-Zadeh, F. [Department of Physics and Astronomy/Northwestern University, Evanston, IL 60208 (US); Melia, F. [Department of Physics and Steward Observatory/The University of Arizona, Tucson, AZ 85721 (US)

    2010-07-01

    Sagittarius A* (SgrA*) is the supermassive black hole residing at the center of the Milky Way. It has been the main target of an extensive multiwavelength campaign we carried out in April 2007. Herein, we report the detection of a bright flare from the vicinity of the horizon, observed simultaneously in X-rays (XMM-Newton/EPIC) and near infrared (VLT/NACO) on April 4 for 1-2 h. For the first time, such an event also benefited from a soft gamma-rays (INTEGRAL/ISGRI) and mid infrared (VLT/VISIR) coverage, which enabled us to derive upper limits at both ends of the flare spectral energy distribution (SED). We discuss the physical implications of the contemporaneous light curves as well as the SED, in terms of synchrotron, synchrotron self-Compton and external Compton emission processes. (authors)

  14. Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole

    CERN Document Server

    Trap, G; Terrier, R; Dodds-Eden, K; Gillessen, S; Genzel, R; Pantin, E; Lagage, P O; Ferrando, P; Bélanger, G; Porquet, D; Grosso, N; Yusef-Zadeh, F; Melia, F

    2009-01-01

    Sagittarius A* (Sgr A*) is the supermassive black hole residing at the center of the Milky Way. It has been the main target of an extensive multiwavelength campaign we carried out in April 2007. Herein, we report the detection of a bright flare from the vicinity of the horizon, observed simultaneously in X-rays (XMM/EPIC) and near infrared (VLT/NACO) on April 4th for 1-2 h. For the first time, such an event also benefitted from a soft gamma-rays (INTEGRAL/ISGRI) and mid infrared (VLT/VISIR) coverage, which enabled us to derive upper limits at both ends of the flare spectral energy distribution (SED). We discuss the physical implications of the contemporaneous light curves as well as the SED, in terms of synchrotron, synchrotron self-Compton and external Compton emission processes.

  15. Soft gamma-ray constraints on a bright flare from the Galactic Center supermassive black hole

    International Nuclear Information System (INIS)

    Sagittarius A* (SgrA*) is the supermassive black hole residing at the center of the Milky Way. It has been the main target of an extensive multiwavelength campaign we carried out in April 2007. Herein, we report the detection of a bright flare from the vicinity of the horizon, observed simultaneously in X-rays (XMM-Newton/EPIC) and near infrared (VLT/NACO) on April 4 for 1-2 h. For the first time, such an event also benefited from a soft gamma-rays (INTEGRAL/ISGRI) and mid infrared (VLT/VISIR) coverage, which enabled us to derive upper limits at both ends of the flare spectral energy distribution (SED). We discuss the physical implications of the contemporaneous light curves as well as the SED, in terms of synchrotron, synchrotron self-Compton and external Compton emission processes. (authors)

  16. Compact symmetric objects and supermassive binary black holes in the VLBA Imaging and Polarimetry Survey

    Science.gov (United States)

    Tremblay, S. E.; Taylor, G. B.; Ortiz, A. A.; Tremblay, C. D.; Helmboldt, J. F.; Romani, R. W.

    2016-06-01

    We present multifrequency Very Long Baseline Array (VLBA) follow-up observations of VLBA Imaging and Polarimetry Survey sources identified as likely compact symmetric objects (CSOs) or supermassive binary black holes (SBBHs). We also present new spectroscopic redshifts for 11 sources observed with the Hobby-Eberly Telescope. While no new SBBHs can be confirmed from these observations, we have identified 24 CSOs in the sample, 15 of which are newly designated, and refuted 52 candidates leaving 33 unconfirmed candidates. This is the first large uniform sample of CSOs which can be used to elicit some of the general properties of these sources, including morphological evolution and environmental interaction. We have detected polarized emission from two of these CSOs the properties of which are consistent with active galactic nuclei unification schemes.

  17. On the detection of eccentric supermassive black hole binaries with pulsar timing arrays

    Science.gov (United States)

    Huerta, Eliu; McWilliams, Sean; Gair, Jonathan; Taylor, Stephen

    2015-04-01

    It is believed that supermassive black holes (SMBHs) with masses between a million up to a few billion solar masses are ubiquitous in nearby galactic nuclei. Hence, the merger of a pair of galaxies hosting these compact objects may result in the formation of a compact binary that decays to small orbital separations via interactions with its stellar and gaseous environments. Recent studies suggest that these formation channels imply that SMBH binaries may have large orbital eccentricities when they become dominated by gravitational wave emission. In light of these considerations, we present a novel and comprehensive framework that we put at work to carry out an end-to-end analysis of the effect of eccentricity on the amplitude and spectrum of a stochastic, isotropic gravitational wave background from SMBH binaries and single resolvable sources that may be detected with Pulsar Timing Arrays.

  18. Compact Symmetric Objects and Supermassive Binary Black Holes in the VLBA Imaging and Polarimetry Survey

    CERN Document Server

    Tremblay, S E; Ortiz, A A; Tremblay, C D; Helmboldt, J F; Romani, R W

    2016-01-01

    We present multi-frequency Very Long Baseline Array (VLBA) follow-up observations of VLBA Imaging and Polarimetry Survey sources identified as likely compact symmetric objects (CSOs) or super-massive binary black holes (SBBHs). We also present new spectroscopic redshifts for 11 sources observed with the Hobby-Eberly Telescope. While no new SBBHs can be confirmed from these observations, we have identified 24 CSOs in the sample, 15 of which are newly designated, and refuted 52 candidates leaving 33 unconfirmed candidates. This is the first large uniform sample of CSOs which can be used to elicit some of the general properties of these sources, including morphological evolution and environmental interaction. We have detected polarised emission from two of these CSOs the properties of which are consistent with Active Galactic Nuclei unification schemes.

  19. The Tidal Disruption of Giant Stars and Their Contribution to the Flaring Supermassive Black Hole Population

    CERN Document Server

    MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2012-01-01

    Sun-like stars are thought to be regularly disrupted by supermassive black holes (SMBHs) within galactic nuclei. Yet, as stars evolve off the main sequence their vulnerability to tidal disruption increases drastically as they develop a bifurcated structure consisting of a dense core and a tenuous envelope. Here we present the first hydrodynamic simulations of the tidal disruption of giant stars and show that the core has a substantial influence on the star's ability to survive the encounter. Stars with more massive cores retain large fractions of their envelope mass, even in deep encounters. Accretion flares resulting from the disruption of giant stars should last for tens to hundreds of years. Their characteristic signature in transient searches would not be the $t^{-5/3}$ decay typically associated with tidal disruption events, but a correlated rise over many orders of magnitude in brightness on months to years timescales. We calculate the relative disruption rates of stars of varying evolutionary stages in...

  20. Accretion and Orbital Inspiral in Gas-Assisted Supermassive Black Hole Binary Mergers

    CERN Document Server

    Rafikov, Roman R

    2016-01-01

    Many galaxies are expected to harbor binary supermassive black holes (SMBHs) in their centers. Their interaction with the surrounding gas results in accretion and exchange of angular momentum via tidal torques, facilitating binary inspiral. Here we explore the non-trivial coupling between these two processes and analyze how the global properties of externally supplied circumbinary disks depend on the binary accretion rate. By formulating our results in terms of the angular momentum flux driven by internal stresses, we come up with a very simple classification of the possible global disk structures, which differ from the standard constant $\\dot M$ accretion disk solution. Suppression of accretion by the binary tides, leading to a significant mass accumulation in the inner disk, accelerates binary inspiral. We show that once the disk region strongly perturbed by the viscously transmitted tidal torque exceeds the binary semi-major axis, the binary can merge in less than its mass-doubling time due to accretion. T...

  1. A Population of Short-Period Variable Quasars from PTF as Supermassive Black Hole Binary Candidates

    CERN Document Server

    Charisi, M; Haiman, Z; Price-Whelan, A M; Graham, M J; Bellm, E C; Laher, R R; Marka, S

    2016-01-01

    Supermassive black hole binaries (SMBHBs) at sub-parsec separations should be common in galactic nuclei, as a result of frequent galaxy mergers. Hydrodynamical simulations of circumbinary discs predict strong periodic modulation of the mass accretion rate on time-scales comparable to the orbital period of the binary. As a result, SMBHBs may be recognized by the periodic modulation of their brightness. We conducted a statistical search for periodic variability in a sample of 35,383 spectroscopically confirmed quasars in the photometric database of the Palomar Transient Factory (PTF). We analysed Lomb-Scargle periodograms and assessed the significance of our findings by modeling each individual quasar's variability as a damped random walk (DRW). We identified 50 quasars with significant periodicity beyond the DRW model, typically with short periods of a few hundred days. We find 33 of these to remain significant after a re-analysis of their periodograms including additional optical data from the intermediate-PT...

  2. Compact object mergers: Observations of supermassive binary black holes and stellar tidal disruption events

    CERN Document Server

    Komossa, S

    2015-01-01

    The capture and disruption of stars by supermassive black holes (SMBHs), and the formation and coalescence of binaries, are inevitable consequences of the presence of SMBHs at the cores of galaxies. Pairs of active galactic nuclei (AGN) and binary SMBHs are important stages in the evolution of galaxy mergers, and an intense search for these systems is currently ongoing. In the early and advanced stages of galaxy merging, observations of the triggering of accretion onto one or both BHs inform us about feedback processes and BH growth. Identification of the compact binary SMBHs at parsec and sub-parsec scales provides us with important constraints on the interaction processes that govern the shrinkage of the binary beyond the "final parsec". Coalescing binary SMBHs are among the most powerful sources of gravitational waves (GWs) in the universe. Stellar tidal disruption events (TDEs) appear as luminous, transient, accretion flares when part of the stellar material is accreted by the SMBH. About 30 events have b...

  3. 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...

  4. Precessing supermassive black hole binaries and dark energy measurements with LISA

    International Nuclear Information System (INIS)

    Spin induced precessional modulations of gravitational wave signals from supermassive black hole binaries can improve the estimation of luminosity distance to the source by space based gravitational wave missions like the Laser Interferometer Space Antenna (LISA). We study how this impacts the ability of LISA to do cosmology, specifically, to measure the dark energy equation of state (EOS) parameter w. Using the ΛCDM model of cosmology, we show that observations of precessing binaries with mass ratio 10 ratio 1 by LISA, combined with a redshift measurement, can improve the determination of w up to an order of magnitude with respect to the nonprecessing case depending on the total mass and the redshift.

  5. COSMOLOGICAL EVOLUTION OF SUPERMASSIVE BLACK HOLES. II. EVIDENCE FOR DOWNSIZING OF SPIN EVOLUTION

    International Nuclear Information System (INIS)

    The spin is an important but poorly constrained parameter for describing supermassive black holes (SMBHs). Using the continuity equation of SMBH number density, we explicitly obtain the mass-dependent cosmological evolution of the radiative efficiency for accretion, which serves as a proxy for SMBH spin. Our calculations make use of the SMBH mass function of active and inactive galaxies (derived in the first paper of this series), the bolometric luminosity function of active galactic nuclei (AGNs), corrected for the contribution from Compton-thick sources, and the observed Eddington ratio distribution. We find that the radiative efficiency generally increases with increasing black hole mass at high redshifts (z ∼> 1), roughly as η∝M0.5., while the trend reverses at lower redshifts, such that the highest efficiencies are attained by the lowest mass black holes. Black holes with M. ∼> 108.5 M☉ maintain radiative efficiencies as high as η ≈ 0.3-0.4 at high redshifts, near the maximum for rapidly spinning systems, but their efficiencies drop dramatically (by an order of magnitude) by z ≈ 0. The pattern for lower mass holes is somewhat more complicated but qualitatively similar. Assuming that the standard accretion disk model applies, we suggest that the accretion history of SMBHs and their accompanying spins evolves in two distinct regimes: an early phase of prolonged accretion, plausibly driven by major mergers, during which the black hole spins up, then switching to a period of random, episodic accretion, governed by minor mergers and internal secular processes, during which the hole spins down. The transition epoch depends on mass, mirroring other evidence for 'cosmic downsizing' in the AGN population; it occurs at z ≈ 2 for high-mass black holes and somewhat later, at z ≈ 1, for lower mass systems.

  6. Unbound Debris Streams and Remnants Resulting From the Tidal Disruptions of Stars by Supermassive Black Holes

    CERN Document Server

    Guillochon, James; Chen, Xian; Johnson, Michael D; Berger, Edo

    2015-01-01

    The kinetic energy of a star in orbit about a supermassive black hole is a significant fraction of its rest mass energy when its periapse is comparable to its tidal radius. Upon its destruction, a fraction of this energy is extracted and injected into the stellar debris, half of which becomes unbound from the black hole, with the fastest material moving at $\\sim 0.03 c$. In this paper, we present a formalism for determining the fate of these unbound debris streams (UDSs) as they depart from the black hole and interact with the surrounding gas. As the density and velocity varies along the length of a UDS, we find that hydrodynamical drag quickly shapes UDSs into loop-like structures, with the densest portions of the streams leading portions of lower density. As UDSs travel outwards, their drag against the ISM increases quadratically with distance, which causes UDSs to deposit their momentum and energy into the ambient medium before the surrounding shocked ISM has a chance to cool. This sudden injection of $\\si...

  7. Tidal disruption rate of stars by supermassive black holes obtained by direct N-body simulations

    CERN Document Server

    Brockamp, M; Kroupa, P

    2011-01-01

    The disruption rate of stars by supermassive black holes (SMBHs) is calculated numerically with a modified version of Aarseth's NBODY6 code. The initial stellar distribution around the SMBH follows a S\\'{e}rsic n=4 profile representing bulges and early type galaxies. In order to infer relaxation driven effects and to increase the statistical significance, a very large set of N-body integrations with different particle numbers N, ranging from 10^{3} to 0.5 \\cdot 10^{6} particles, is performed. Three different black hole capture radii are taken into account, enabling us to scale these results to a broad range of astrophysical systems with relaxation times shorter than one Hubble time, i.e. for SMBHs up to M_bh \\approx 10^{7} M_sun. The computed number of disrupted stars are driven by diffusion in angular momentum space into the loss cone of the black hole and the rate scales with the total number of particles as dN/dt \\propto N^{b}, where b is as large as 0.83. This is significantly steeper than the expected sc...

  8. Gas squeezing during the merger of a supermassive black hole binary

    CERN Document Server

    Cerioli, Alice; Price, Daniel J

    2016-01-01

    We study accretion rates during the gravitational wave-driven merger of a binary supermassive black hole embedded in an accretion disc, formed by gas driven to the centre of the galaxy. We use 3D simulations performed with PHANTOM, a Smoothed Particle Hydrodynamics code. Contrary to previous investigations, we show that there is evidence of a "squeezing phenomenon", caused by the compression of the inner disc gas when the secondary black hole spirals towards the primary. This causes an increase in the accretion rates that always exceed the Eddington rate. We have studied the main features of the phenomenon for a mass ratio $q = 10^{-3}$ between the black holes, including the effects of numerical resolution, the secondary accretion radius and the disc thickness. With our disc model with a low aspect ratio, we show that the mass expelled from the orbit of the secondary is negligible ($< 5\\%$ of the initial disc mass), different to the findings of previous 2D simulations with thicker discs. The increase in th...

  9. Supermassive black holes in the EAGLE Universe. Revealing the observables of their growth

    CERN Document Server

    Bower, Rosas-Guevara Y M; Schaye, Joop; McAlpine, Stuart; Dalla-Vecchia, Claudio; Frenk, S Carlos; Schaller, Matthieu; Theuns, Tom

    2016-01-01

    We investigate the evolution of supermassive black holes in the `Evolution and Assembly of GaLaxies and their Environments' (EAGLE) cosmological hydrodynamic simulations. The largest of the EAGLE volumes covers a $(100 \\,\\rm cMpc)^3$ and includes state-of-the-art physical models for star formation and black hole growth that depend only on local gas properties. We focus on the black hole mass function, Eddington ratio distribution and the implied duty cycle of nuclear activity. The simulation is broadly consistent with observational constraints on these quantities. In order to make a more direct comparison with observational data, we calculate the soft and hard X-ray luminosity functions of the active galactic nuclei (AGN). Between redshifts $0$ and $1$, the simulation is in agreement with data. At higher redshifts, the simulation tends to underpredict the luminosities of the brightest observed AGN. This may be due to the limited volume of the simulation, or a fundamental deficiency of the underlying model. It...

  10. Unbound Debris Streams and Remnants Resulting from the Tidal Disruptions of Stars by Supermassive Black Holes

    Science.gov (United States)

    Guillochon, James; McCourt, Michael; Chen, Xian; Johnson, Michael D.; Berger, Edo

    2016-05-01

    The kinetic energy of a star in orbit about a supermassive black hole is a significant fraction of its rest mass energy when its periapse is comparable to its tidal radius. Upon its destruction, a fraction of this energy is extracted and injected into the stellar debris, half of which becomes unbound from the black hole, with the fastest material moving at ∼ 0.03c. In this paper, we present a formalism for determining the fate of these unbound debris streams (UDSs) as they depart from the black hole and interact with the surrounding gas. As the density and velocity varies along the length of a UDS, we find that hydrodynamical drag quickly shapes UDSs into loop-like structures, with the densest portions of the streams leading portions of lower density. As UDSs travel outwards, their drag against the ISM increases quadratically with distance, which causes UDSs to deposit their momentum and energy into the ambient medium before the surrounding shocked ISM has a chance to cool. This sudden injection of ∼ {10}50 erg into the ambient medium generates a Sedov-like unbound debris remnant (UDR) that mimics supernova remnants (SNRs) in energetics and appearance, accelerates particles which will produce cosmic rays and synchrotron emission, and provides momentum feedback into the molecular clouds surrounding a black hole. We estimate that a few of these UDRs might be present within a couple degrees of the Galactic Center masquerading as SNRs, and that the UDR scenario is a plausible explanation for Sgr A east.

  11. Long-Term Evolution of and X-ray Emission from a Recoiling Supermassive Black Hole in a Disk Galaxy

    OpenAIRE

    Fujita, Yutaka

    2008-01-01

    Recent numerical relativity simulations have shown that the emission of gravitational waves at the merger of two black holes gives a recoil kick to the final black hole. We follow the orbits of a recoiling supermassive black hole (SMBH) in a fixed background potential of a disk galaxy including the effect of dynamical friction. If the recoil velocity of the SMBH is smaller than the escape velocity of the galaxy, the SMBH moves around in the potential along a complex trajectory before it spira...

  12. SUPERMASSIVE BLACK HOLE FORMATION AT HIGH REDSHIFTS THROUGH A PRIMORDIAL MAGNETIC FIELD

    International Nuclear Information System (INIS)

    It has been proposed that primordial gas in early dark matter halos, with virial temperatures Tvir ∼> 104 K, can avoid fragmentation and undergo rapid collapse, possibly resulting in a supermassive black hole. This requires the gas to avoid cooling and to remain at temperatures near T ∼ 104 K. We show that this condition can be satisfied in the presence of a sufficiently strong primordial magnetic field, which heats the collapsing gas via ambipolar diffusion. If the field has a strength above |B | ∼>3.6 (comoving) nG, the collapsing gas is kept warm (T ∼ 104 K) until it reaches the critical density ncrit ∼ 103 cm-3 at which the rotovibrational states of H2 approach local thermodynamic equilibrium. H2 cooling then remains inefficient and the gas temperature stays near ∼104 K, even as it continues to collapse at higher densities. The critical magnetic field strength required to permanently suppress H2 cooling is somewhat higher than the upper limit of ∼2 nG from the cosmic microwave background. However, it can be realized in the rare ∼>(2-3)σ regions of the spatially fluctuating B field; these regions contain a sufficient number of halos to account for z ∼ 6 quasar black holes.

  13. THE FORMATION OF SUPERMASSIVE BLACK HOLES FROM LOW-MASS POP III SEEDS

    International Nuclear Information System (INIS)

    The existence of 109 M☉ black holes (BHs) in massive galaxies by z ∼ 7 is one of the great unsolved mysteries in cosmological structure formation. One theory argues that they originate from the BHs of Pop III stars at z ∼ 20 and then accrete at the Eddington limit down to the epoch of reionization, which requires that they have constant access to rich supplies of fuel. Because early numerical simulations suggested that Pop III stars were ∼>100 M☉, the supermassive black hole (SMBH) seeds considered up to now were 100-300 M☉. However, there is a growing numerical and observational consensus that some Pop III stars were tens of solar masses, not hundreds, and that 20-40 M☉ BHs may have been much more plentiful at high redshift. However, we find that natal kicks imparted to 20-40 M☉ Pop III BHs during formation eject them from their halos and hence their fuel supply, precluding them from Eddington-limit growth. Consequently, SMBHs are far less likely to form from low-mass Pop III stars than from very massive ones.

  14. Impact of baryonic streaming velocities on the formation of supermassive black holes via direct collapse

    CERN Document Server

    Latif, M A; Schleicher, D R G

    2013-01-01

    Baryonic streaming motions produced prior to the epoch of recombination became supersonic during the cosmic dark ages. Various studies suggest that such streaming velocities change the halo statistics and also influence the formation of Population III stars. In this study, we aim to explore the impact of streaming velocities on the formation of supermassive black holes at $z>10$ via the direct collapse scenario. To accomplish this goal, we perform cosmological large eddy simulations for two halos of a few times $\\rm 10^{7} M_{\\odot}$ with initial streaming velocities of 3, 6 and 9 $\\rm km/s$. These massive primordial halos illuminated by the strong Lyman Werner flux are the potential cradles for the formation of direct collapse seed black holes. To study the evolution for longer times, we employ sink particles and track the accretion for 10,000 years. Our findings show that higher streaming velocities increase the circular velocities from about 14 $\\rm km/s$ to 16 $\\rm km/s$. They also delay the collapse of h...

  15. Kinematically Identified Recoiling Supermassive Black Hole Candidates in SDSS QSOs with z $<$ 0.25

    CERN Document Server

    Kim, D -C; Stierwalt, S; Privon, G C

    2016-01-01

    We have performed a spectral decomposition to search for recoiling supermassive black holes (rSMBH) in the SDSS QSOs with $z<0.25$. Out of 1271 QSOs, we have identified 26 rSMBH candidates that are recoiling toward us. The projected recoil velocities range from $-76\\ \\kms$ to $-307\\ \\kms$ with a mean of $-149\\pm58\\ \\kms$. Most of the rSMBH candidates are hosted by gas-rich LIRGs/ULIRGs, but only 23\\% of them shows signs of tidal features suggesting majority of them are advanced mergers. We find that the black hole masses $M_{BH}$ of the rSMBH candidates are on average $\\sim$5 times smaller than that of their stationary counterparts and cause a scatter in $M_{BH}-\\sigma_*$ relation. The Eddington ratios of all of the rSMBH candidates are larger than 0.1, with mean of 0.52$\\pm$0.27, suggesting they are actively accreting mass. Velocity shifts in high-excitation coronal lines suggest that the rSMBH candidates are recoiling with an average velocity of about $-265\\ \\kms$. Electron density in the narrow line reg...

  16. A Hybrid Two Component Accretion Flow Surrounding Supermassive Black Holes in AGN

    CERN Document Server

    Liu, B F; Qiao, E; Yuan, W

    2015-01-01

    It is commonly believed that the optical/UV and X-ray emissions in luminous AGN are produced in an accretion disk and an embedded hot corona respectively. The inverse Compton scattering of disk photons by hot electrons in the corona can effectively cool the coronal gas if the mass supply is predominantly via a cool disk like flow as in BHXRBs. Thus, the application of such a model to AGNs fails to produce their observed X-ray emission. As a consequence, a fraction of disk accretion energy is usually assumed to be transferred to the corona. To avoid this assumption, we propose that gas in a vertically extended distribution is supplied to a supermassive black hole by the gravitational capture of interstellar medium or stellar wind material. In this picture, the gas partially condenses to an underlying cool disk as it flows toward the black hole, releasing accretion energy as X-ray emission and supplying mass for the disk accretion. Detailed numerical calculations reveal that the X-ray luminosity can reach a few...

  17. A strong magnetic field in the jet base of a supermassive black hole

    CERN Document Server

    Marti-Vidal, Ivan; Vlemmings, Wouter; Horellou, Cathy; Aalto, Susanne

    2016-01-01

    Active galactic nuclei (AGN) host some of the most energetic phenomena in the Universe. AGN are thought to be powered by accretion of matter onto a rotating disk that surrounds a supermassive black hole. Jet streams can be boosted in energy near the event horizon of the black hole and then flow outward along the rotation axis of the disk. The mechanism that forms such a jet and guides it over scales from a few light-days up to millions of light-years remains uncertain, but magnetic fields are thought to play a critical role. Using the Atacama large mm/submm array (ALMA), we have detected a polarization signal (Faraday rotation) related to the strong magnetic field at the jet base of a distant AGN, PKS1830-211. The amount of Faraday rotation (rotation measure) is proportional to the magnetic field strength along the line of sight times the density of electrons. Although it is impossible to precisely infer the magnetic fields in the region of Faraday rotation, the high rotation measures derived suggest magnetic...

  18. A three-stage search for supermassive black-hole binaries in LISA data

    Science.gov (United States)

    Brown, Duncan A.; Crowder, Jeff; Cutler, Curt; Mandel, Ilya; Vallisneri, Michele

    2007-10-01

    Gravitational waves from the inspiral and coalescence of supermassive black-hole (SMBH) binaries with masses m1 ~ m2 ~ 106Modot are likely to be among the strongest sources for the Laser Interferometer Space Antenna (LISA). We describe a three-stage data-analysis pipeline designed to search for and measure the parameters of SMBH binaries in LISA data. The first stage uses a time frequency track-search method to search for inspiral signals and provide a coarse estimate of the black-hole masses m1, m2 and the coalescence time of the binary tc. The second stage uses a sequence of matched-filter template banks, seeded by the first stage, to improve the measurement accuracy of the masses and coalescence time. Finally, a Markov chain Monte Carlo search is used to estimate all nine physical parameters of the binary (masses, coalescence time, distance, initial phase, sky position and orientation). Using results from the second stage substantially shortens the Markov chain burn-in time and allows us to determine the number of SMBH-binary signals in the data before starting parameter estimation. We demonstrate our analysis pipeline using simulated data from the first Mock LISA Data Challenge. We discuss our plan for improving this pipeline and the challenges that will be faced in real LISA data analysis.

  19. A Three-Stage Search for Supermassive Black Hole Binaries in LISA Data

    CERN Document Server

    Brown, Duncan A; Cutler, Curt; Mandel, Ilya; Vallisneri, Michele

    2007-01-01

    Gravitational waves from the inspiral and coalescence of supermassive black-hole (SMBH) binaries with masses ~10^6 Msun are likely to be among the strongest sources for the Laser Interferometer Space Antenna (LISA). We describe a three-stage data-analysis pipeline designed to search for and measure the parameters of SMBH binaries in LISA data. The first stage uses a time-frequency track-search method to search for inspiral signals and provide a coarse estimate of the black-hole masses m_1, m_2 and of the coalescence time of the binary t_c. The second stage uses a sequence of matched-filter template banks, seeded by the first stage, to improve the measurement accuracy of the masses and coalescence time. Finally, a Markov Chain Monte Carlo search is used to estimate all nine physical parameters of the binary. Using results from the second stage substantially shortens the Markov Chain burn-in time and allows us to determine the number of SMBH-binary signals in the data before starting parameter estimation. We de...

  20. SUPERMASSIVE BLACK HOLE BINARY EVOLUTION IN AXISYMMETRIC GALAXIES: THE FINAL PARSEC PROBLEM IS NOT A PROBLEM

    International Nuclear Information System (INIS)

    During a galaxy merger, the supermassive black hole (SMBH) in each galaxy is thought to sink to the center of the potential and form an SMBH binary; this binary can eject stars via three-body scattering, bringing the SMBHs ever closer. In a static spherical galaxy model, the binary stalls at a separation of about a parsec after ejecting all the stars in its loss cone—this is the well-known final parsec problem. Earlier work has shown that the centrophilic orbits in triaxial galaxy models are key in refilling the loss cone at a high enough rate to prevent the black holes from stalling. However, the evolution of binary SMBHs has never been explored in axisymmetric galaxies, so it is not clear if the final parsec problem persists in these systems. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in galaxy models with a range of ellipticity. For the first time, we show that mere axisymmetry can solve the final parsec problem; we find the SMBH evolution is independent of N for an axis ratio of c/a = 0.8, and that the SMBH binary separation reaches the gravitational radiation regime for c/a = 0.75

  1. A probable Milli-Parsec Supermassive Binary Black Hole in the Nearest Quasar Mrk 231

    CERN Document Server

    Yan, Chang-Shuo; Dai, Xinyu; Yu, Qingjuan

    2015-01-01

    Supermassive binary black holes (BBHs) are unavoidable products of galaxy mergers and are expected to exist in the cores of many quasars. Great effort has been made during the past several decades to search for BBHs among quasars; however, observational evidence for BBHs remains elusive and ambiguous, which is difficult to reconcile with theoretical expectations. In this paper, we show that the distinct optical-to-UV spectrum of Mrk 231 can be well interpreted as emission from accretion flows onto a BBH, with a semimajor axis of ~590AU and an orbital period of ~1.2 year. The flat optical and UV continua are mainly emitted from a circumbinary disk and a mini-disk around the secondary black hole (BH), respectively; and the observed sharp drop off and flux deficit at wavelength lambda ~ 4000-2500 Angstrom is due to a gap (or hole) opened by the secondary BH migrating within the circumbinary disk. If confirmed by future observations, this BBH will provide a unique laboratory to study the interplay between BBHs an...

  2. Constraints on supermassive black hole spins from observations of active galaxy jets

    CERN Document Server

    Kun, E; Gergely, L Á; Keresztes, Z; Gopal-Krishna,; Biermann, P L

    2013-01-01

    We discuss the origin of the low-energy cutoff, or LEC, seen in the radio spectra of many extragalactic jets and relate this to the spin of the supermassive black holes that presumably power them. Pion decay via proton-proton collisions is a possible mechanism to supply a secondary positron population with a low energy limit. We expect that pion production would occur in advection dominated accretion flows or ADAFs. In radiatively inefficient ADAFs the heat energy of the accreting gas is unable to radiate in less than the accretion time and the particle temperature could be high enough so that thermal protons can yield such pion production. Strong starbursts are another option for the injection of a truncated particle population into the jet. The role of both mechanisms is discussed with respect to the black hole spin estimate. The energy demanded to produce the pion decay process involves a minimum threshold for kinetic energy of the interacting protons. Therefore the mean proton speed in the flow can determ...

  3. Blindly detecting orbital modulations of jets from merging supermassive black holes

    CERN Document Server

    O'Shaughnessy, R; Sesana, A; Kamble, A

    2011-01-01

    In the last few years before merger, supermassive black hole binaries will rapidly inspiral and precess in a magnetic field imposed by a surrounding circumbinary disk. Multiple simulations suggest this relative motion will convert some of the local energy to a Poynting-dominated outflow, with a luminosity 10^{43} erg/s * (B/10^4 G)^2(M/10^8 Msun)^2 (v/0.4 c)^2, some of which may emerge as synchrotron emission at frequencies near 1 GHz where current and planned wide-field radio surveys will operate. On top of a secular increase in power on the gravitational wave inspiral timescale, orbital motion will produce significant, detectable modulations, both on orbital periods and (if black hole spins are not aligned with the binary's total angular momenta) spin-orbit precession timescales. Because the gravitational wave merger time increases rapidly with separation, we find vast numbers of these transients are ubiquitously predicted, unless explicitly ruled out (by low efficiency $\\epsilon$) or obscured (by accretion...

  4. Understanding the build-up of supermassive black holes and galaxies

    Science.gov (United States)

    Carrera, Francisco; Ueda, Yoshihiro; Georgakakis, Antonis

    2016-07-01

    One of the main open questions in modern Astrophysics is understanding the coupled growth of supermassive black holes by accretion and their host galaxies via star formation, from their peak at redshifts z~ 1-4 to the present time. The generic scenario proposed involves an early phase of intense black hole growth that takes place behind large obscuring columns of inflowing dust and gas clouds. It is postulated that this is followed by a blow-out stage during which some form of AGN feedback controls the fate of the interstellar medium and hence, the evolution of the galaxy. X-rays are essential for testing this scenario as they uniquely probe AGN at both the early heavily obscured stage and the later blow-out phase. X-ray spectral analysis can identify the smoking gun evidence of heavily obscured black hole growth (e.g. intense iron Kalpha line). It therefore provides the most robust method for compiling clean samples of deeply shrouded AGN with well-defined selection functions and unbiased determinations of their intrinsic properties (accretion luminosity, obscuring column). X-rays are also the best window for studying in detail AGN feedback. This process ultimately originates in the innermost regions close to the supermassive black hole and is dominated, in terms of energy and mass flux, by highly ionisedmaterial that remains invisible at other wavelengths. The most important epoch for investigating the relation between AGN and galaxies is the redshift range z~1-4, when most black holes and stars we see in the present-day Universe were put in place. Unfortunately, exhaustive efforts with current high-energy telescopes only scrape the tip of the iceberg of the most obscured AGN population. Moreover, Xray studies of the incidence, nature and energetics of AGN feedback are limited to the local Universe. The Athena observatory will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe

  5. Inflow Generated X-ray Corona Around Supermassive Black Holes and Unified Model for X-ray Emission

    CERN Document Server

    Wang, Lile

    2015-01-01

    Three-dimensional hydrodynamic simulations, covering the spatial domain from hundreds of Schwarzschild radii to $2\\ \\mathrm{pc}$ around the central supermassive black hole of mass $10^8 M_\\odot$, with detailed radiative cooling processes, are performed. Generically found is the existence of a significant amount of shock heated, high temperature ($\\geq 10^8\\ \\mathrm{K}$) coronal gas in the inner ($\\leq 10^4 r_\\mathrm{sch}$) region. It is shown that the composite bremsstrahlung emission spectrum due to coronal gas of various temperatures are in reasonable agreement with the overall ensemble spectrum of AGNs and hard X-ray background. Taking into account inverse Compton processes, in the context of the simulation-produced coronal gas, our model can readily account for the wide variety of AGN spectral shape, which can now be understood physically. The distinguishing feature of our model is that X-ray coronal gas is, for the first time, an integral part of the inflow gas and its observable characteristics are phys...

  6. Physics of the Galactic Center Cloud G2, on its Way towards the Super-Massive Black Hole

    CERN Document Server

    Burkert, Andreas; Alig, Christian; Gillessen, Stefan; Genzel, Reinhard; Fritz, Tobias; Eisenhauer, Frank

    2012-01-01

    The origin, structure and evolution of the small gas cloud, G2, is investigated, that is on an orbit almost straight into the Galactic central supermassive black hole (SMBH). G2 is a sensitive probe of the hot accretion zone of Sgr A*, requiring gas temperatures and densities that agree well with models of captured shock-heated stellar winds. Its mass is equal to the critical mass below which cold clumps would be destroyed quickly by evaporation. Its mass is also constrained by the fact that at apocenter its sound crossing timescale was equal to its orbital timescale. Our numerical simulations show that the observed structure and evolution of G2 can be well reproduced if it formed in pressure equilibrium with the surrounding in 1995 at a distance from the SMBH of 7.6e16 cm. If the cloud would have formed at apocenter in the 'clockwise' stellar disk as expected from its orbit, it would be torn into a very elongated spaghetti-like filament by 2011 which is not observed. This problem can be solved if G2 is the h...

  7. Spectroastrometry of rotating gas disks for the detection of supermassive black holes in galactic nuclei. I. Method and simulations

    CERN Document Server

    Gnerucci, A; Capetti, A; Axon, D; Robinson, A

    2010-01-01

    This is the first in a series of papers in which we study the application of spectroastrometry in the context of gas kinematical studies aimed at measuring the mass of supermassive black holes. The spectroastrometrical method consists in measuring the photocenter of light emission in different wavelength or velocity channels. In particular we explore the potential of spectroastrometry of gas emission lines in galaxy nuclei to constrain the kinematics of rotating gas disks and to measure the mass of putative supermassive black holes. By means of detailed simulations and test cases, we show that the fundamental advantage of spectroastrometry is that it can provide information on the gravitational potential of a galaxy on scales significantly smaller (~ 1/10) than the limit imposed by the spatial resolution of the observations. We then describe a simple method to infer detailed kinematical informations from spectroastrometry in longslit spectra and to measure the mass of nuclear mass concentrations. Such method ...

  8. MEASURING GAS ACCRETION AND ANGULAR MOMENTUM NEAR SIMULATED SUPERMASSIVE BLACK HOLES

    International Nuclear Information System (INIS)

    Using cosmological simulations with a dynamic range in excess of 107, we study the transport of gas mass and angular momentum through the circumnuclear region of a disk galaxy containing a supermassive black hole (SMBH). The simulations follow fueling over relatively quiescent phases of the galaxy's evolution (no mergers) and without feedback from active galactic nuclei (AGNs), as part of the first stage of using state-of-the-art, high-resolution cosmological simulations to model galaxy and black hole co-evolution. We present results from simulations at different redshifts (z = 6, 4, and 3) and three different black hole masses (3 x 107, 9 x 107, and 3 x 108 Msun; at z = 4), as well as a simulation including a prescription that approximates optically thick cooling in the densest regions. The interior gas mass throughout the circumnuclear disk shows transient and chaotic behavior as a function of time. The Fourier transform of the interior gas mass follows a power law with slope -1 throughout the region, indicating that, in the absence of the effects of galaxy mergers and AGN feedback, mass fluctuations are stochastic with no preferred timescale for accretion over the duration of each simulation (∼1-2 Myr). The angular momentum of the gas disk changes direction relative to the disk on kiloparsec scales over timescales less than 1 Myr, reflecting the chaotic and transient gas dynamics of the circumnuclear region. Infalling clumps of gas, which are driven inward as a result of the dynamical state of the circumnuclear disk, may play an important role in determining the spin evolution of an SMBH, as has been suggested in stochastic accretion scenarios.

  9. High-redshift quasars and the supermassive black hole mass budget: constraints on quasar formation models

    Science.gov (United States)

    Bromley, J. M.; Somerville, R. S.; Fabian, A. C.

    2004-05-01

    We investigate the constraints on models of supermassive black hole (SMBH) and quasar formation obtainable from two recent observational developments: the discovery of luminous quasars at z~ 6, and estimates of the local mass density of SMBHs. If ~90 per cent of this mass was accreted at redshifts zjoint constraints pose a challenge for models, which must account for the observed luminous quasar population at z~ 6 within a very limited `mass budget'. We investigate a class of models based within the hierarchical structure formation scenario, in which major mergers lead to black hole formation and fuelling, and the resulting quasars shine at their Eddington-limited rate until their fuel is exhausted. We show that the simplest such model, in which a constant fraction of the gas within the halo is accreted in each major merger, cannot satisfy both constraints simultaneously. When this model is normalized to reproduce the number density of luminous quasars at z~ 6, the mass budget is grossly exceeded owing to an overabundance of lower-mass SMBHs. We explore a range of modifications to the simple model designed to overcome this problem. We show that both constraints can be satisfied if the gas accretion fraction scales as a function of the halo virial velocity. Similar scalings have been proposed in order to reproduce the local M•-σ relation. Successful models can also be constructed by restricting the formation of seed black holes to redshifts above zcrit~ 11.5 or to haloes above a velocity threshold vcrit~ 55 km s-1, or assuming that only a fraction of major mergers result in formation of a seed SMBH. We also briefly discuss the issue of trying to assume a `universal M•-σ relation' within the framework of simple Press-Schechter models, and further show that a fixed universal relation between SMBH mass and host halo mass is unlikely.

  10. Black Holes: Physics and Astrophysics - Stellar-mass, supermassive and primordial black holes

    OpenAIRE

    Bekenstein, Jacob D.

    2004-01-01

    I present an elementary primer of black hole physics, including its general relativity basis, all peppered with astrophysical illustrations. Following a brief review of the process stellar collapse to a black hole, I discuss the gravitational redshift, particle trajectories in gravitational fields, the Schwarzschild and Kerr solutions to Einstein's equations, orbits in Schwarzschild and in Kerr geometry, and the dragging of inertial frames. I follow with a brief review of galactic X-ray binar...

  11. Bose-Einstein condensed supermassive black holes: a case of renormalized quantum field theory in curved space-time

    Czech Academy of Sciences Publication Activity Database

    Nieuwenhuizen, T.M.; Špička, Václav

    2010-01-01

    Roč. 42, č. 3 (2010), s. 256-268. ISSN 1386-9477. [International Conference on Frontiers of Quantum and Mesoscopic Thermodynamics (FQMT '08). Praha, 28.07.2008-02.08.2008] Institutional research plan: CEZ:AV0Z10100521 Keywords : supermassive black hole * quantum held theory * Bose-Einstein condensation * renormalization Subject RIV: BE - Theoretical Physics Impact factor: 1.304, year: 2010

  12. A Radiation-Hydrodynamical Model for Supermassive Black Hole-to-Bulge Mass Relation and Quasar Formation

    OpenAIRE

    Umemura, Masayuki

    2001-01-01

    As a potential mechanism to build up supermassive black holes (BHs) in a spheroidal system, we consider the radiation drag effect by bulge stars, which extracts angular momentum from interstellar gas and thus allows the gas to accrete onto the galactic center. With incorporating radiation hydrodynamical equation with simple stellar evolution, it is shown that the BH-to-bulge mass ratio, $f_{BH}$, is basically determined by a fundamental constant, that is, the energy conversion efficiency for ...

  13. Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes

    OpenAIRE

    Brandt, W.N.; Alexander, D. M.

    2015-01-01

    We review results from cosmic X-ray surveys of active galactic nuclei (AGNs) over the past ≈15 years that have dramatically improved our understanding of growing supermassive black holes in the distant universe. First, we discuss the utility of such surveys for AGN investigations and the capabilities of the missions making these surveys, emphasizing Chandra, XMM-Newton, and NuSTAR. Second, we briefly describe the main cosmic X-ray surveys, the essential roles of complementary multiwavelength ...

  14. ACCRETION ONTO THE SUPERMASSIVE BLACK HOLE IN THE HIGH-REDSHIFT RADIO-LOUD AGN 0957+561

    International Nuclear Information System (INIS)

    We present the results of our X-ray, UV, and optical monitoring campaign of the first gravitationally lensed active galactic nucleus (AGN) from late 2009 to mid-2010. The trailing (B) image of the AGN 0957+561 shows the intrinsic continuum variations that were predicted in advance based on observations of the leading (A) image in the gr optical bands. This multiwavelength variability of the B image allows us to carry out a reverberation mapping analysis in the radio-loud AGN 0957+561 at redshift z = 1.41. We find that the U-band and r-band light curves are highly correlated with the g-band record, leading and trailing it by 3 ± 1 days (U band) and 4 ± 1 days (r band). These 1σ measurements are consistent with a scenario in which flares originated in the immediate vicinity of the supermassive black hole are thermally reprocessed in a standard accretion disk at ∼10-20 Schwarzschild radii from the central dark object. We also report that the light curve for the X-ray emission with power-law spectrum is delayed with respect to those in the Ugr bands by ∼32 days. Hence, the central driving source cannot be a standard corona emitting the observed power-law X-rays. This result is also supported by X-ray reprocessing simulations and the absence of X-ray reflection features in the spectrum of 0957+561. We plausibly interpret the lack of reflection and the 32 day delay as evidence for a power-law X-ray source in the base of the jet at a typical height of ∼200 Schwarzschild radii. A central EUV source would drive the variability of 0957+561.

  15. ENHANCED ACCRETION RATES OF STARS ON SUPERMASSIVE BLACK HOLES BY STAR-DISK INTERACTIONS IN GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    We investigate the dynamical interaction of a central star cluster surrounding a supermassive black hole (SMBH) and a central accretion disk (AD). The dissipative force acting on stars in the disk leads to an enhanced mass flow toward the SMBH and to an asymmetry in the phase space distribution due to the rotating AD. The AD is considered as a stationary Keplerian rotating disk, which is vertically extended in order to employ a fully self-consistent treatment of stellar dynamics including the dissipative force originating from star-gas ram pressure effects. The stellar system is treated with a direct high-accuracy N-body integration code. A star-by-star representation, desirable in N-body simulations, cannot be extended to real particle numbers yet. Hence, we carefully discuss the scaling behavior of our model with regard to particle number and tidal accretion radius. The main idea is to find a family of models for which the ratio of two-body relaxation time and dissipation time (for kinetic energy of stellar orbits) is constant, which then allows us to extrapolate our results to real parameters of galactic nuclei. Our model is derived from basic physical principles and as such it provides insight into the role of physical processes in galactic nuclei, but it should be regarded as a first step toward more realistic and more comprehensive simulations. Nevertheless, the following conclusions appear to be robust: the star accretion rate onto the AD and subsequently onto the SMBH is enhanced by a significant factor compared to purely stellar dynamical systems neglecting the disk. This process leads to enhanced fueling of central disks in active galactic nuclei (AGNs) and to an enhanced rate of tidal stellar disruptions. Such disruptions may produce electromagnetic counterparts in the form of observable X-ray flares. Our models improve predictions for their rates in quiescent galactic nuclei. We do not yet model direct stellar collisions in the gravitational potential

  16. A possible close supermassive black-hole binary in a quasar with optical periodicity.

    Science.gov (United States)

    Graham, Matthew J; Djorgovski, S G; Stern, Daniel; Glikman, Eilat; Drake, Andrew J; Mahabal, Ashish A; Donalek, Ciro; Larson, Steve; Christensen, Eric

    2015-02-01

    Quasars have long been known to be variable sources at all wavelengths. Their optical variability is stochastic and can be due to a variety of physical mechanisms; it is also well-described statistically in terms of a damped random walk model. The recent availability of large collections of astronomical time series of flux measurements (light curves) offers new data sets for a systematic exploration of quasar variability. Here we report the detection of a strong, smooth periodic signal in the optical variability of the quasar PG 1302-102 with a mean observed period of 1,884 ± 88 days. It was identified in a search for periodic variability in a data set of light curves for 247,000 known, spectroscopically confirmed quasars with a temporal baseline of about 9 years. Although the interpretation of this phenomenon is still uncertain, the most plausible mechanisms involve a binary system of two supermassive black holes with a subparsec separation. Such systems are an expected consequence of galaxy mergers and can provide important constraints on models of galaxy formation and evolution. PMID:25561176

  17. DUAL SUPERMASSIVE BLACK HOLE CANDIDATES IN THE AGN AND GALAXY EVOLUTION SURVEY

    International Nuclear Information System (INIS)

    Dual supermassive black holes (SMBHs) with kiloparsec-scale separations in merger-remnant galaxies are informative tracers of galaxy evolution, but the avenue for identifying them in large numbers for such studies is not yet clear. One promising approach is to target spectroscopic signatures of systems where both SMBHs are fueled as dual active galactic nuclei (AGNs), or where one SMBH is fueled as an offset AGN. Dual AGNs may produce double-peaked narrow AGN emission lines, while offset AGNs may produce single-peaked narrow AGN emission lines with line-of-sight velocity offsets relative to the host galaxy. We search for such dual and offset systems among 173 Type 2 AGNs at z +3.6-1.9% to 18+5-5%). This may be associated with the rise in the galaxy merger fraction over the same cosmic time. As further evidence for a link with galaxy mergers, the AGES offset and dual AGN candidates are tentatively ∼3 times more likely than the overall AGN population to reside in a host galaxy that has a companion galaxy (from 16/173 to 2/7, or 9+3-2% to 29-19+26%). Follow-up observations of the seven offset and dual AGN candidates in AGES will definitively distinguish velocity offsets produced by dual SMBHs from those produced by narrow-line region kinematics, and will help sharpen our observational approach to detecting dual SMBHs

  18. The Formation of Supermassive Black Holes from Population III Seeds. I. Cosmic Formation Histories

    CERN Document Server

    Banik, Nilanjan; Monaco, Pierluigi

    2016-01-01

    We model the cosmic distributions in space and time of the formation sites of the first stars that may be the progenitors of supermassive black holes (SMBHs). Pop III.1 stars are defined to form in dark matter minihalos (i.e., with masses $\\sim10^6\\:M_\\odot$) that are isolated from neighboring astrophysical sources by a given isolation distance, $d_{\\rm iso}$. We assume these sources are the seeds for the cosmic population of SMBHs, based on a model of protostellar support by dark matter annihilation heating that allows these objects to accrete most of the baryonic content of their minihalos, i.e., $\\gtrsim10^5\\:M_\\odot$. Exploring a range of $d_{\\rm iso}$ from 10 to 100~kpc (proper distances), we predict the evolution with redshift of the number density of these Pop III.1 sources and their SMBH remnants. In the context of this model, the local, $z=0$ density of SMBHs constrains $d_{\\rm iso}\\gtrsim100$~kpc (i.e., a comoving distance of 3~Mpc at $z\\simeq30$). In our simulated ($\\sim$40.96 $h^{-1}$~Mpc)$^3$ com...

  19. European Pulsar Timing Array Limits on Continuous Gravitational Waves from Individual Supermassive Black Hole Binaries

    CERN Document Server

    Babak, Stanislav; Sesana, Alberto; Brem, Patrick; Rosado, Pablo A; Taylor, Stephen R; Lassus, Antoine; Hessels, Jason W T; Bassa, Cees G; Burgay, Marta; Caballero, R Nicolas; Champion, David J; Cognard, Ismael; Desvignes, Gregory; Gair, Jonathan R; Guillemot, Lucas; Janssen, Gemma H; Karuppusamy, Ramesh; Kramer, Michael; Lazarus, Patrick; Lee, K J; Lentati, Lindley; Liu, Kuo; Mingarelli, Chiara M F; Oslowsky, Stefan; Perrodin, Delphine; Possenti, Andrea; Purver, Mark B; Sanidas, Sotiris; Smits, Roy; Stappers, Ben; Theureau, Gilles; Tiburzi, Caterina; van Haasteren, Rutger; Vecchio, Alberto; Verbiest, Joris P W

    2015-01-01

    We have searched for continuous gravitational wave (CGW) signals produced by individually resolvable, circular supermassive black hole binaries (SMBHBs) in the latest EPTA dataset, which consists of ultra-precise timing data on 41 millisecond pulsars. We develop frequentist and Bayesian detection algorithms to search both for monochromatic and frequency-evolving systems. None of the adopted algorithms show evidence for the presence of such a CGW signal, indicating that the data are best described by pulsar and radiometer noise only. Depending on the adopted detection algorithm, the 95\\% upper limit on the sky-averaged strain amplitude lies in the range $6\\times 10^{-15}10^9$M$_\\odot$ out to a distance of about 25Mpc, and with $\\cal{M}_c>10^{10}$M$_\\odot$ out to a distance of about 1Gpc ($z\\approx0.2$). We show that state-of-the-art SMBHB population models predict $<1\\%$ probability of detecting a CGW with the current EPTA dataset, consistent with the reported non-detection. We stress, however, that PTA lim...

  20. Swift Coalescence of Supermassive Black Holes in Cosmological Mergers of Massive Galaxies

    Science.gov (United States)

    Khan, Fazeel Mahmood; Fiacconi, Davide; Mayer, Lucio; Berczik, Peter; Just, Andreas

    2016-09-01

    Supermassive black holes (SMBHs) are ubiquitous in galaxies with a sizable mass. It is expected that a pair of SMBHs originally in the nuclei of two merging galaxies would form a binary and eventually coalesce via a burst of gravitational waves. So far, theoretical models and simulations, focusing only on limited phases of the orbital decay of SMBHs under idealized conditions of the galaxy hosts, have been unable to directly predict the SMBH merger timescale from ab-initio galaxy formation theory. The predicted SMBH merger timescales are long, of order Gyrs, which could be problematic for future gravitational wave (GW) searches. Here, we present the first multi-scale ΛCDM cosmological simulation that follows the orbital decay of a pair of SMBHs in a merger of two typical massive galaxies at z∼ 3, all the way to the final coalescence driven by GW emission. The two SMBHs, with masses ∼ {10}8 {M}ȯ , settle quickly in the nucleus of the merger remnant. The remnant is triaxial and extremely dense due to the dissipative nature of the merger and the intrinsic compactness of galaxies at high redshift. Such properties naturally allow a very efficient hardening of the SMBH binary. The SMBH merger occurs in only ∼10 Myr after the galactic cores have merged, which is two orders of magnitude smaller than the Hubble time.

  1. Super-massive binary black holes and emission lines in active galactic nuclei

    CERN Document Server

    Popovic, Luka C

    2011-01-01

    The broad emission spectral lines emitted from AGNs are our main probe of the geometry and physics of the broad line region (BLR) close to the SMBH. There is a group of AGNs that emits very broad and complex line profiles, showing two displaced peaks, one blueshifted and one redshifted from the systemic velocity defined by the narrow lines, or a single such peak. It has been proposed that such line shapes could indicate a supermassive binary black hole (SMB) system. We discuss here how the presence of an SMB will affect the BLRs of AGNs and what the observational consequences might be. We review previous claims of SMBs based on broad line profiles and find that they may have non-SMB explanations as a consequence of a complex BLR structure. Because of these effects it is very hard to put limits on the number of SMBs from broad line profiles. It is still possible, however, that unusual broad line profiles in combination with other observational effects (line ratios, quasi-periodical oscillations, spectropolarim...

  2. The Role of Nuclear Star Clusters in Enhancing Supermassive Black Hole Feeding Rates During Galaxy Mergers

    CERN Document Server

    Naiman, J P; Debuhr, J; Ma, C -P

    2014-01-01

    During galaxy mergers the gas falls to the center, triggers star formation, and feeds the rapid growth of supermassive black holes (SMBHs). SMBHs respond to this fueling by supplying energy back to the ambient gas. Numerical studies suggest that this feedback is necessary to explain why the properties of SMBHs and the formation of bulges are closely related. This intimate link between the SMBH's mass and the large scale dynamics and luminosity of the host has proven to be a difficult issue to tackle with simulations due to the inability to resolve all the relevant length scales simultaneously. In this paper we simulate SMBH growth at high-resolution with {\\it FLASH}, accounting for the gravitational focusing effects of nuclear star clusters (NSCs), which appear to be ubiquitous in galactic nuclei. In the simulations, the NSC core is resolved by a minimum cell size of about 0.001 pc or approximately $10^{-3}$ of the cluster's radius. We discuss the conditions required for effective gas funneling to occur, whic...

  3. The imprint of the cosmic supermassive black hole growth history on the 21 cm background radiation

    CERN Document Server

    Tanaka, Takamitsu L; Perna, Rosalba

    2015-01-01

    The redshifted 21 cm transition line of hydrogen tracks the thermal evolution of the neutral intergalactic medium (IGM) at "cosmic dawn," during the emergence of the first luminous astrophysical objects (~100 Myr after the Big Bang) but before these objects ionized the IGM (~400-800 Myr after the Big Bang). Because X-rays, in particular, are likely to be the chief energy courier for heating the IGM, measurements of the 21 cm signature can be used to infer knowledge about the first astrophysical X-ray sources. Using analytic arguments and a numerical population synthesis algorithm, we argue that the progenitors of supermassive black holes (SMBHs) should be the dominant source of hard astrophysical X-rays---and thus the primary driver of IGM heating and the 21 cm signature---at redshifts $z 20$. An absence of such a signature in the forthcoming observational data would imply that SMBH formation occurred later (e.g. via so-called direct collapse scenarios), that it was not a common occurrence in early galaxies ...

  4. A statistical method to search for recoiling supermassive black holes in active galactic nuclei

    Science.gov (United States)

    Raffai, P.; Haiman, Z.; Frei, Z.

    2016-01-01

    We propose an observational test for gravitationally recoiling supermassive black holes (BHs) in active galactic nuclei, based on a correlation between the velocities of BHs relative to their host galaxies, |Δv|, and their obscuring dust column densities, Σdust (both measured along the line of sight). We use toy models for the distribution of recoil velocities, BH trajectories, and the geometry of obscuring dust tori in galactic centres, to simulate 2.5 × 105 random observations of recoiling quasars. BHs with recoil velocities comparable to the escape velocity from the galactic centre remain bound to the nucleus, and do not fully settle back to the centre of the torus due to dynamical friction in a typical quasar lifetime. We find that |Δv| and Σdust for these BHs are positively correlated. For obscured (Σdust > 0) and for partially obscured (0 103 km s-1) ≲ 0.4. This predicted trend can be compared to the observed fraction of type II quasars, and can further test combinations of recoil, trajectory, and dust torus models.

  5. 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 ...

  6. The effect of baryonic streaming motions on the formation of the first supermassive black holes

    CERN Document Server

    Tanaka, Takamitsu L; Haiman, Zoltán

    2013-01-01

    Observations of quasars at redshifts z > 6 reveal that 10^9 Msol supermassive black holes (SMBHs) had already formed when the Universe was 20. This is the regime where baryonic streaming motions--the relative velocities of baryons with respect to dark matter in the early Universe--most strongly inhibit star formation by suppressing gas infall and cooling. We investigate the impact of this effect on the growth of the first SMBHs using a suite of high-fidelity, ellipsoidal-collapse Monte Carlo merger-tree simulations. We find that the suppression of seed BH formation by the streaming motions significantly reduces the number density of the most massive BHs at z > 15, but the residual effect at lower redshifts is essentially negligible. The streaming motions can reduce by a factor of few the number density of the most luminous quasars at z ~ 10-11, where such objects could be detected by the James Webb Space Telescope. We conclude, with minor theoretical caveats, that baryonic streaming motions are unlikely to p...

  7. The Coevolution of Supermassive Black Holes and Massive Galaxies at High Redshift

    CERN Document Server

    Lapi, A; Aversa, R; Cai, Z -Y; Negrello, M; Celotti, A; De Zotti, G; Danese, L

    2013-01-01

    We exploit the recent, wide samples of far-infrared (FIR) selected galaxies followed-up in X rays and of X-ray/optically selected active galactic nuclei (AGNs) followed-up in the FIR band, along with the classic data on AGN and stellar luminosity functions at high redshift z>1.5, to probe different stages in the coevolution of supermassive black holes (BHs) and host galaxies. The results of our analysis indicate the following scenario: (i) the star formation in the host galaxy proceeds within a heavily dust-enshrouded medium at an almost constant rate over a timescale ~0.5-1 Gyr, and then abruptly declines due to quasar feedback; over the same timescale, (ii) part of the interstellar medium loses angular momentum, reaches the circum-nuclear regions at a rate proportional to the star formation and is temporarily stored into a massive reservoir/proto-torus wherefrom it can be promptly accreted; (iii) the BH grows by accretion in a self-regulated regime with radiative power that can slightly exceed the Eddington...

  8. Sensitive Spitzer Photometry of Supermassive Black Holes at the Final Stage of Adolescence

    Science.gov (United States)

    Shemmer, Ohad; Netzer, Hagai; Mor, Rivay; Trakhtenbrot, Benny

    2011-05-01

    We propose to obtain sensitive Spitzer snapshot observations of a unique sample of 35 Sloan Digital Sky Survey quasars at redshift 4.8 for which we obtained reliable, Mg II-based determinations of the supermassive black hole (SMBH) mass and normalized accretion rate (L/L_Edd). These quasars appear to mark the final stage of SMBH `adolescence' in the history of the Universe as their SMBHs are significantly less massive and their L/L_Edd values are significantly higher with respect to their counterparts at lower redshifts. Our observations will provide both 1) deep coverage of the fields around these quasars which will be utilized as crucial priors for our approved Herschel/SPIRE observations of these sources, and 2) coverage of the rest-frame optical SEDs of these fast accreting quasars. The results will maximize our ability to measure the star-formation rate in the host galaxies of these quasars using Herschel. We will thus be able to investigate correlations between SMBH growth and star-forming activity in the early Universe. The Spitzer photometry will also provide invaluable information about the shape of the rest-frame optical continuum in these quasars which will be used to search for extreme disk properties that may be signatures of the remarkably high accretion rates in these sources.

  9. The co-evolution of galaxies and supermassive black holes in the near Universe

    CERN Document Server

    Storchi-Bergmann, Thaisa

    2014-01-01

    A fundamental role is attributed to supermassive black holes (SMBH), and the feedback they generate, in the evolution of galaxies. But theoretical models trying to reproduce the relation between the SMBH mass and stellar velocity dispersion of the galaxy bulge make broad assumptions about the physical processes involved. These assumptions are needed due to the scarcity of observational constraints on the relevant physical processes which occur when the SMBH is being fed via mass accretion in Active Galactic Nuclei (AGN). In search for these constraints, our group -- AGN Integral Field Spectroscopy (AGNIFS) -- has been mapping the gas kinematics as well as the stellar population properties of the inner few hundred parsecs of a sample of nearby AGN hosts. In this contribution, I report results obtained so far which show gas inflows along nuclear spirals and compact disks in the inner tens to hundreds of pc in nearby AGN hosts which seem to be the sources of fuel to the AGN. As the inflow rates are much larger t...

  10. 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.

  11. Detecting Eccentric Supermassive Black Hole Binaries with Pulsar Timing Arrays: Resolvable Source Strategies

    Science.gov (United States)

    Taylor, S. R.; Huerta, E. A.; Gair, J. R.; McWilliams, S. T.

    2016-01-01

    The couplings between supermassive black hole binaries (SMBHBs) and their environments within galactic nuclei have been well studied as part of the search for solutions to the final parsec problem. The scattering of stars by the binary or the interaction with a circumbinary disk may efficiently drive the system to sub-parsec separations, allowing the binary to enter a regime where the emission of gravitational waves can drive it to merger within a Hubble time. However, these interactions can also affect the orbital parameters of the binary. In particular, they may drive an increase in binary eccentricity which survives until the system’s gravitational-wave (GW) signal enters the pulsar-timing array (PTA) band. Therefore, if we can measure the eccentricity from observed signals, we can potentially deduce some of the properties of the binary environment. To this end, we build on previous techniques to present a general Bayesian pipeline with which we can detect and estimate the parameters of an eccentric SMBHB system with PTAs. Additionally, we generalize the PTA {{ F }}{{e}}-statistic to eccentric systems, and show that both this statistic and the Bayesian pipeline are robust when studying circular or arbitrarily eccentric systems. We explore how eccentricity influences the detection prospects of single GW sources, as well as the detection penalty incurred by employing a circular waveform template to search for eccentric signals, and conclude by identifying important avenues for future study.

  12. A CHANDRA SURVEY OF SUPERMASSIVE BLACK HOLES WITH DYNAMICAL MASS MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Gueltekin, Kayhan; Miller, Jon M.; Richstone, Douglas O. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Cackett, Edward M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Di Matteo, Tiziana [Physics Department, McWilliams Center for Cosmology, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Markoff, Sera, E-mail: kayhan@umich.edu [Astronomical Institute ' Anton Pannekoek' , Science Park 904, 1098XH Amsterdam (Netherlands)

    2012-04-20

    We present Chandra observations of 12 galaxies that contain supermassive black holes (SMBHs) with dynamical mass measurements. Each galaxy was observed for 30 ks and resulted in a total of 68 point-source detections in the target galaxies including SMBH sources, ultraluminous X-ray sources (ULXs), and extragalactic X-ray binaries. Based on our fits of the X-ray spectra, we report fluxes, luminosities, Eddington ratios, and slope of the power-law spectrum. Normalized to the Eddington luminosity, the 2-10 keV band X-ray luminosities of the SMBH sources range from 10{sup -8} to 10{sup -6}, and the power-law slopes are centered at {approx}2 with a slight trend toward steeper (softer) slopes at smaller Eddington fractions, implying a change in the physical processes responsible for their emission at low accretion rates. We find 20 ULX candidates, of which 6 are likely (>90% chance) to be true ULXs. The most promising ULX candidate has an isotropic luminosity in the 0.3-10 keV band of 1.0{sup +0.6}{sub -0.3} Multiplication-Sign 10{sup 40} erg s{sup -1}.

  13. A Statistical Method to Search for Recoiling Supermassive Black Holes in Active Galactic Nuclei

    CERN Document Server

    Raffai, Peter; Frei, Zsolt

    2015-01-01

    We propose an observational test for gravitationally recoiling supermassive black holes (BHs) in active galactic nuclei, based on a correlation between the velocities of BHs relative to their host galaxies, |\\Delta v|, and their obscuring dust column densities, \\Sigma_{dust} (both measured along the line of sight). Proxies for both quantities can be derived from spectral features of individual quasars. We use toy models for the distribution of recoil velocities, BH trajectories, and the geometry of obscuring dust tori in galactic centres, to simulate 2.5x10^5 random observations of recoiling quasars. BHs with recoil velocities comparable to the escape velocity from the galactic centre remain bound to the nucleus, and do not fully settle back to the centre of the torus due to dynamical friction in a typical quasar lifetime. We find that |\\Delta v| and \\Sigma_ {dust} for these BHs are positively correlated. For obscured (\\Sigma_{dust}>0) and for partially obscured (0=45 km/s, the sample correlation coefficient ...

  14. Swift coalescence of supermassive black holes in cosmological mergers of massive galaxies

    CERN Document Server

    Khan, Fazeel M; Mayer, Lucio; Berczik, Peter; Just, Andreas

    2016-01-01

    Supermassive black holes (SMBHs) are ubiquitous in galaxies with a sizable mass. It is expected that a pair of SMBHs originally in the nuclei of two merging galaxies would form a binary and eventually coalesce via a burst of gravitational waves. So far theoretical models and simulations have been unable to predict directly the SMBH merger timescale from ab-initio galaxy formation theory, focusing only on limited phases of the orbital decay of SMBHs under idealized conditions of the galaxy hosts. The predicted SMBH merger timescales are long, of order Gyrs, which could be problematic for future gravitational wave searches. Here we present the first multi-scale $\\Lambda$CDM cosmological simulation that follows the orbital decay of a pair of SMBHs in a merger of two typical massive galaxies at $z\\sim3$, all the way to the final coalescence driven by gravitational wave emission. The two SMBHs, with masses $\\sim10^{8}$ M$_{\\odot}$, settle quickly in the nucleus of the merger remnant. The remnant is triaxial and ex...

  15. Direct Collapse to Supermassive Black Hole Seeds: Comparing the AMR and SPH Approaches

    CERN Document Server

    Luo, Yang; Shlosman, Isaac

    2015-01-01

    We provide detailed comparison between the AMR code Enzo-2.4 and the SPH code GADGET-3 in the context of direct baryonic collapse within DM halos to form supermassive black hole (SMBH) seeds, in isolated and cosmological frameworks, at z ~ 10-20. We find that both codes show an overall agreement in the general features of the collapse, however, many subtle differences exist. For isolated models, we find that the codes increase their spatial and mass resolutions at different pace, leading to substantially earlier collapse times in SPH due to higher gravitational resolution in GADGET-3. In fully cosmological runs, starting from z = 200, the AMR develops a slightly higher baryonic resolution than SPH during DM halo growth via cold accretion permeated by mergers. Still, both numerical schemes agree in the buildup of DM and baryonic structures. However, with the onset of direct collapse, this difference in mass and spatial resolution is amplified, so the evolution of SPH models begins to lag behind the AMR by ~10-...

  16. Effects of high-energy particles on accretion flows onto a supermassive black hole

    International Nuclear Information System (INIS)

    We study the effects of high-energy particles (HEPs) on the accretion flows onto a supermassive black hole and luminosities of escaping particles such as protons, neutrons, gamma rays, and neutrinos. We formulate a one-dimensional model of the two-component accretion flow consisting of thermal particles and HEPs, supposing that some fraction of the released energy is converted to the acceleration of HEPs. The thermal component is governed by fluid dynamics while the HEPs obey the moment equations of the diffusion-convection equation. By solving the time evolution of these equations, we obtain advection-dominated flows as the steady state solutions. The effects of the HEPs on the flow structures turn out to be small even if the pressure of the HEPs dominates over the thermal pressure. For a model in which the escaping protons take away almost all the energy released, the HEPs have a large enough influence to make the flow have a Keplerian angular velocity at the inner region. We calculate the luminosities of the escaping particles for these steady solutions. The escaping particles can extract the energy from about 10−4 M-dot c2 to 10−2 M-dot c2, where M-dot is the mass accretion rate. The luminosities of the escaping particles depend on parameters such as the injection Lorentz factors, the mass accretion rates, and the diffusion coefficients. We also discuss some implications on the relativistic jet production by the escaping particles.

  17. NANOGrav Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries in Circular Orbits

    CERN Document Server

    Arzoumanian, Z; Burke-Spolaor, S; Chamberlin, S J; Chatterjee, S; Cordes, J M; Demorest, P B; Deng, X; Dolch, T; Ellis, J A; Ferdman, R D; Finn, L S; Garver-Daniels, N; Jenet, F; Jones, G; Kaspi, V M; Koop, M; Lam, M; Lazio, T J W; Lommen, A N; Lorimer, D R; Luo, J; Lynch, R S; Madison, D R; McLaughlin, M; McWilliams, S T; Nice, D J; Palliyaguru, N; Pennucci, T T; Ransom, S M; Sesana, A; Siemens, X; Stairs, I H; Stinebring, D R; Stovall, K; Swiggum, J; Vallisneri, M; van Haasteren, R; Wang, Y; Zhu, W W

    2014-01-01

    The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project currently observes 43 pulsars using the Green Bank and Arecibo radio telescopes. In this work we use a subset of 17 pulsars timed for a span of roughly five years (2005--2010). We analyze these data using standard pulsar timing models, with the addition of time-variable dispersion measure and frequency-variable pulse shape terms. Within the timing data, we perform a search for continuous gravitational waves from individual supermassive black hole binaries in circular orbits using robust frequentist and Bayesian techniques. We find that there is no evidence for the presence of a detectable continuous gravitational wave; however, we can use these data to place the most constraining upper limits to date on the strength of such gravitational waves. Using the full 17 pulsar dataset we place a 95% upper limit on the sky-averaged strain amplitude of $h_0\\lesssim 3.8\\times 10^{-14}$ at a frequency of 10 nHz. Furthermore, we place 95% ...

  18. Offset Active Galactic Nuclei as Tracers of Galaxy Mergers and Supermassive Black Hole Growth

    CERN Document Server

    Comerford, Julia M

    2014-01-01

    Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search for offset AGNs in the Sloan Digital Sky Survey, by selecting AGN emission lines that exhibit statistically significant line-of-sight velocity offsets relative to systemic. From a parent sample of 18314 Type 2 AGNs at z<0.21, we identify 351 offset AGN candidates with velocity offsets of 50 km/s < |v| < 410 km/s. When we account for projection effects in the observed velocities, we estimate that 4% - 8% of AGNs are offset AGNs. We designed our selection criteria to bypass velocity offsets produced by rotating gas disks, AGN outflows, and gravitational recoil of supermassive black holes, but follow-up observations are still required to confirm our candidates as offset AGNs. We find that the fraction of AGNs that are offset candidates increases with AGN bolometric l...

  19. Dark matter halos and the M-\\sigma relation for supermassive black holes

    CERN Document Server

    Larkin, Adam C

    2016-01-01

    We develop models of two-component spherical galaxies to establish scaling relations linking the properties of spheroids at $z=0$ (total stellar masses, effective radii $R_e$ and velocity dispersions within $R_e$) to the properties of their dark-matter halos at both $z=0$ and higher redshifts. . Our main motivation is the widely accepted idea that the accretion-driven growth of supermassive black holes (SMBHs) in protogalaxies is limited by quasar-mode feedback and gas blow-out. The SMBH masses, $M_{\\rm{BH}}$, should then be connected to the dark-matter potential wells at the redshift $z_{\\rm{qso}}$ of the blow-out. We specifically consider the example of a power-law dependence on the maximum circular speed in a protogalactic dark-matter halo: $M_{\\rm{BH}}\\propto V^4_{\\rm{d,pk}}$, as could be expected if quasar-mode feedback were momentum-driven. For halos with a given $V_{\\rm{d,pk}}$ at a given $z_{\\rm{qso}}\\ge 0$, our model scaling relations give a typical stellar velocity dispersion $\\sigma_{\\rm{ap}}(R_e)$...

  20. A Hamiltonian Monte–Carlo method for Bayesian inference of supermassive black hole binaries

    International Nuclear Information System (INIS)

    We investigate the use of a Hamiltonian Monte–Carlo to map out the posterior density function for supermassive black hole binaries. While previous Markov Chain Monte–Carlo (MCMC) methods, such as Metropolis–Hastings MCMC, have been successfully employed for a number of different gravitational wave sources, these methods are essentially random walk algorithms. The Hamiltonian Monte–Carlo treats the inverse likelihood surface as a ‘gravitational potential’ and by introducing canonical positions and momenta, dynamically evolves the Markov chain by solving Hamilton's equations of motion. This method is not as widely used as other MCMC algorithms due to the necessity of calculating gradients of the log-likelihood, which for most applications results in a bottleneck that makes the algorithm computationally prohibitive. We circumvent this problem by using accepted initial phase-space trajectory points to analytically fit for each of the individual gradients. Eliminating the waveform generation needed for the numerical derivatives reduces the total number of required templates for a 106 iteration chain from ∼109 to ∼106. The result is in an implementation of the Hamiltonian Monte–Carlo that is faster, and more efficient by a factor of approximately the dimension of the parameter space, than a Hessian MCMC. (paper)

  1. 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...

  2. H_2 Suppression with Shocking Inflows: Testing a Pathway for Supermassive Black Hole Formation

    CERN Document Server

    Fernandez, Ricardo; Haiman, Zoltan; Li, Miao

    2014-01-01

    The presence of quasars at redshifts z > 6 indicates the existence of supermassive black holes (SMBHs) as massive as a few times 10^9 Msun, challenging models for SMBH formation. One pathway is through the direct collapse of gas in T_{vir} > 10^4 K halos; however, this requires the suppression of H_2 cooling to prevent fragmentation. In this paper, we examine a proposed new mechanism for this suppression which relies on cold-mode accretion flows leading to shocks at high densities (n > 10^4 cm^{-3}) and temperatures (T > 10^4 K). In such gas, H_2 is efficiently collisionally dissociated. We use high-resolution numerical simulations to test this idea, demonstrating that such halos typically have lower temperature progenitors, in which cooling is efficient. Those halos do show filamentary flows; however, the gas shocks at or near the virial radius (at low densities), thus preventing the proposed collisional mechanism from operating. We do find that, if we artificially suppress H_2 formation with a high UV backg...

  3. Disk Assembly and the M_BH-sigma Relation of Supermassive Black Holes

    CERN Document Server

    Debattista, Victor P; Bosch, Frank C van den

    2013-01-01

    Recent Hubble Space Telescope (HST) observations have revealed that a majority of active galactic nuclei (AGN) at z ~ 1-3 are resident in isolated disk galaxies, contrary to the usual expectation that AGN are triggered by mergers. Here we develop a new test of the cosmic evolution of supermassive black holes (SMBHs) in disk galaxies by considering the local population of SMBHs. We show that substantial SMBH growth in spiral galaxies is required as disks assemble. SMBHs exhibit a tight relation between their mass and the velocity dispersion of the spheroid within which they reside, the M_BH-sigma relation. In disk galaxies the bulge is the spheroid of interest. We explore the evolution of the M_BH-sigma relation when bulges form together with SMBHs on the M_BH-sigma relation and then slowly reform a disk around them. The formation of the disk compresses the bulge raising its sigma. We present evidence for such compression in the form of larger velocity dispersion of classical bulges compared with elliptical ga...

  4. The Population of Viscosity- and Gravitational Wave-Driven Supermassive Black Hole Binaries Among Luminous AGN

    CERN Document Server

    Haiman, Zoltán; Menou, Kristen

    2009-01-01

    Supermassive black hole binaries (SMBHBs) in galactic nuclei are thought to be a common by-product of major galaxy mergers. We use simple disk models for the circumbinary gas and for the binary-disk interaction to follow the orbital decay of SMBHBs with a range of total masses (M) and mass ratios (q), through physically distinct regions of the disk, until gravitational waves (GWs) take over their evolution. Prior to the GW-driven phase, the viscous decay is in the stalled "secondary-dominated" regime. SMBHBs spend a non-negligible fraction of 10^7 years at orbital periods t_var between a day and a year. A dedicated optical or X-ray survey could identify coalescing SMBHBs statistically, as a population of periodically variable quasars, whose abundance N_var is proportional to t_var^alpha, in a range of periods t_var around tens of weeks. SMBHBs with M < 10^7 M_sun, with 0.5 < alpha < 1.5, would probe the physics of viscous orbital decay, whereas the detection of a population of higher-mass binaries, w...

  5. SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY SPECTROSCOPIC SAMPLE

    International Nuclear Information System (INIS)

    Supermassive black hole (SMBH) binaries are expected in a ΛCDM cosmology given that most (if not all) massive galaxies contain a massive black hole (BH) at their center. So far, however, direct evidence for such binaries has been elusive. We use cross-correlation to search for temporal velocity shifts in the Mg II broad emission lines of 0.36 9 M☉ BHs in SMBH binaries, we are sensitive to velocity drifts for binary separations of ∼0.1 pc with orbital periods of ∼100 yr. We find seven candidate sub-parsec-scale binaries with velocity shifts >3.4σ ∼ 280 km s–1, where σ is our systematic error. Comparing the detectability of SMBH binaries with the number of candidates (N ≤ 7), we can rule out that most 109 M☉ BHs exist in ∼0.03-0.2 pc scale binaries, in a scenario where binaries stall at sub-parsec scales for a Hubble time. We further constrain that ≤16% (one-third) of quasars host SMBH binaries after considering gas-assisted sub-parsec evolution of SMBH binaries, although this result is very sensitive to the assumed size of the broad line region. We estimate the detectability of SMBH binaries with ongoing or next-generation surveys (e.g., Baryon Oscillation Spectroscopic Survey, Subaru Prime Focus Spectrograph), taking into account the evolution of the sub-parsec binary in circumbinary gas disks. These future observations will provide longer time baselines for searches similar to ours and may in turn constrain the evolutionary scenarios of SMBH binaries

  6. Quasars in the Time Domain: Supermassive Black Hole Binaries and Extreme Objects

    Science.gov (United States)

    Graham, Matthew; Djorgovski, Stanislav G.; Stern, Daniel; Drake, Andrew J.; Mahabal, Ashish A.; Glikman, Eilat

    2016-01-01

    Quasar variability can offer insights into the physics of AGN, as it is driven by the variations in the accretion rate, changes in obscuration, and/or instabilities and propagation effects of the relativistic jets. Large synoptic sky surveys such as CRTS (crts.caltech.edu) offer new possibilities in this domain.We use the data set of CRTS light curves of ~335,000 known, spectroscopically confirmed quasars. They have up to a few hundred data points each, with baselines of up to 10 years. This is an unprecedented data set for the studies of quasar variability.We have previously identified a characteristic time scale of stochastic quasar variability, ~54 days (restframe), which anticorrelates with luminosity and black hole mass. While the origin of this phenomenon is not yet understood, it may lead to new insights into the physics of AGN accretion disks and quasars in general. While most quasars show such a characteristic time scale and trends, a subset exhibit a time scale that is significantly different than expected given their physical parameters. We have also found a number of other objects that show extreme variability (in RMS amplitude, or other measures). For a number of these objects we have now detected significant spectroscopic changes that correlate with the photometric variability. We will describe some of the more interesting cases.An even more interesting is the recent detection of periodically variable quasars, which are interpreted as a signature of close (milliparsec scale) supermassive black hole binaries (SMBH) en route to a merger. This population may offer new insights into the assembly of SMBH and their physics in the gravitational wave regime. We have initiate a spectroscopic monitoring program of these objects, and have already detected some spectroscopic changes for some of them. We will describe these results and their possible interpretations.

  7. DISCOVERY OF AN ACTIVE SUPERMASSIVE BLACK HOLE IN THE BULGELESS GALAXY NGC 4561

    Energy Technology Data Exchange (ETDEWEB)

    Salvo, C. Araya; Mathur, S. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Ghosh, H. [CNRS/CEA-Saclay, F-91911 Gif-sur-Yvette (France); Fiore, F. [Osservatorio Astronomico di Roma, Via Frascati 33, I-100040 Monteporzio Catone (Italy); Ferrarese, L., E-mail: araya@astronomy.ohio-state.edu [Hertzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)

    2012-10-01

    We present XMM-Newton observations of the Chandra-detected nuclear X-ray source in NGC 4561. The hard X-ray spectrum can be described by a model composed of an absorbed power law with {Gamma} = 2.5{sup +0.4}{sub -0.3} and column density N{sub H} = 1.9{sup +0.1}{sub -0.2} Multiplication-Sign 10{sup 22} atoms cm{sup -2}. The absorption-corrected luminosity of the source is L(0.2-10.0 keV) =2.5 Multiplication-Sign 10{sup 41} erg s{sup -1}, with bolometric luminosity over 3 Multiplication-Sign 10{sup 42} erg s{sup -1}. Based on the spectrum and the luminosity, we identify the nuclear X-ray source in NGC 4561 to be an active galactic nucleus (AGN), with a black hole (BH) of mass M{sub BH} >2 Multiplication-Sign 10{sup 4} M{sub Sun }. The presence of a supermassive black hole at the center of this bulgeless galaxy shows that BH masses are not necessarily related to bulge properties, contrary to general belief. Observations such as these call into question several theoretical models of BH-galaxy coevolution that are based on merger-driven BH growth; secular processes clearly play an important role. Several emission lines are detected in the soft X-ray spectrum of the source which can be well parameterized by an absorbed diffuse thermal plasma with non-solar abundances of some heavy elements. Similar soft X-ray emission is observed in spectra of Seyfert 2 galaxies and low-luminosity AGNs, suggesting an origin in the circumnuclear plasma.

  8. The Formation of Galaxies and Supermassive Black Holes: Insights and Puzzles

    Science.gov (United States)

    Somerville, Rachel S.

    2014-01-01

    Galaxies exist at a nexus of physical scales, molded by physics ranging from the “small” scales of star formation and accretion onto nuclear black holes, up to the very large scales of the cosmic web. It is this special property that makes galaxies so fascinating and so challenging to study, both observationally and theoretically. The past two decades have seen enormous progress in our understanding of how galaxies form and evolve. We have surveyed slices of the sky at many wavelengths, and built sophisticated models and simulations that attempt to capture the complex array of physics that influences galaxy evolution. We are only now coming into possession of large samples of galaxies for which we can study the internal structure as well as the large scale environment in detail, from the epoch of ‘cosmic high noon’ ( 2) to the present. At the same time, numerical simulations set within a cosmological framework have only recently succeeded in building galaxies with realistic internal structures. It has been known for several years that galaxies are growing in mass and radius, experiencing morphological transformation, and ‘downsizing’ their star formation activity over cosmic time. Now, new observations are painting a picture in which the internal structure of galaxies (size and morphology) is intimately linked with their star formation activity and formation history. There are hints that the co-evolution of supermassive black holes with their host galaxies may be the driving force behind these correlations - but this remains controversial. While cosmological simulations set within the hierarchical formation scenario of Cold Dark Matter currently offer a plausible story for interpreting these observations, many puzzles remain. I will review recent insights gleaned from deep multi-wavelength surveys and state-of-the-art theoretical models and simulations, as well as highlight the open questions and challenges for the future.

  9. Constraints on the Nature of CID-42: Recoil Kick or Supermassive Black Hole Pair?

    Science.gov (United States)

    Blecha, Laura; Civano, Francesca; Elvis, Martin; Loeb, Abraham

    2012-01-01

    The galaxy CXOC J100043.1+020637, also known as CID-42, is a highly unusual object. An apparent galaxy merger remnant, it displays signatures of both an inspiraling, kiloparsecscale active galactic nucleus (AGN) pair and of a recoiling AGN with a kick velocity approximately greater than 1300 km s(exp -1). Among recoiling AGN candidates, CID-42 alone has both spatial offsets (in optical and X-ray bands) and spectroscopic offsets. In order to constrain the relative likelihood of both scenarios, we develop models using hydrodynamic galaxy merger simulations coupled with radiative transfer calculations. Our gas-rich, major merger models are generally well matched to the galactic morphology and to the inferred stellar mass and star formation rate. We show that a recoiling supermassive black hole (SMBH) in CID-42 should be observable as an AGN at the time of observation. However, in order for the recoiling AGN to produce narrow-line emission, it must be observed shortly after the kick while it still inhabits a dense gaseous region, implying a large total kick velocity (vk approximately greater than 2000 km s(exp -1)). For the dual AGN scenario, an unusually large broad-line offset is required, and the best match to the observed morphology requires a galaxy that is less luminous than CID-42. Further, the lack of X-ray emission from one of the two optical nuclei is not easily attributed to an intrinsically quiescent SMBH or to a Compton-thick galactic environment. While the current data do not allow either the recoiling or the dual AGN scenario for CID-42 to be excluded, our models highlight the most relevant parameters for distinguishing these possibilities with future observations. In particular, high-quality, spatially-resolved spectra that can pinpoint the origin of the broad and narrow line features will be critical for determining the nature of this unique source.

  10. 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)

  11. Accretion and Orbital Inspiral in Gas-assisted Supermassive Black Hole Binary Mergers

    Science.gov (United States)

    Rafikov, Roman R.

    2016-08-01

    Many galaxies are expected to harbor binary supermassive black holes (SMBHs) in their centers. Their interaction with the surrounding gas results in the accretion and exchange of angular momentum via tidal torques, facilitating binary inspiral. Here, we explore the non-trivial coupling between these two processes and analyze how the global properties of externally supplied circumbinary disks depend on the binary accretion rate. By formulating our results in terms of the angular momentum flux driven by internal stresses, we come up with a very simple classification of the possible global disk structures, which differ from the standard constant \\dot{M} accretion disk solution. The suppression of accretion by the binary tides, leading to a significant mass accumulation in the inner disk, accelerates binary inspiral. We show that once the disk region strongly perturbed by the viscously transmitted tidal torque exceeds the binary semimajor axis, the binary can merge in less than its mass-doubling time due to accretion. Thus, unlike the inspirals driven by stellar scattering, the gas-assisted merger can occur even if the binary is embedded in a relatively low-mass disk (lower than its own mass). This is important for resolving the “last parsec” problem for SMBH binaries and understanding powerful gravitational wave sources in the universe. We argue that the enhancement of accretion by the binary found in some recent simulations cannot persist for a long time and should not affect the long-term orbital inspiral. We also review existing simulations of SMBH binary–disk coupling and propose a numerical setup which is particularly well suited to verifying our theoretical predictions.

  12. The coevolution of supermassive black holes and massive galaxies at high redshift

    International Nuclear Information System (INIS)

    We exploit the recent, wide samples of far-infrared (FIR) selected galaxies followed up in X-rays and of X-ray/optically selected active galactic nuclei (AGNs) followed up in the FIR band, along with the classic data on AGNs and stellar luminosity functions at high redshift z ≳ 1.5, to probe different stages in the coevolution of supermassive black holes (BHs) and host galaxies. The results of our analysis indicate the following scenario: (1) the star formation in the host galaxy proceeds within a heavily dust-enshrouded medium at an almost constant rate over a timescale ≲ 0.5-1 Gyr and then abruptly declines due to quasar feedback, over the same timescale; (2) part of the interstellar medium loses angular momentum, reaches the circum-nuclear regions at a rate proportional to the star formation, and is temporarily stored in a massive reservoir/proto-torus wherefrom it can be promptly accreted; (3) the BH grows by accretion in a self-regulated regime with radiative power that can slightly exceed the Eddington limit L/L Edd ≲ 4, particularly at the highest redshifts; (4) for massive BHs, the ensuing energy feedback at its maximum exceeds the stellar one and removes the interstellar gas, thus stopping the star formation and the fueling of the reservoir; (5) afterward, if the latter has retained enough gas, a phase of supply-limited accretion follows, exponentially declining with a timescale of about two e-folding times. We also discuss how the detailed properties and the specific evolution of the reservoir can be investigated via coordinated, high-resolution observations of star-forming, strongly lensed galaxies in the (sub-)mm band with ALMA and in the X-ray band with Chandra and the next-generation X-ray instruments.

  13. The coevolution of supermassive black holes and massive galaxies at high redshift

    Energy Technology Data Exchange (ETDEWEB)

    Lapi, A.; Raimundo, S.; Aversa, R.; Cai, Z.-Y.; Celotti, A.; De Zotti, G.; Danese, L. [SISSA, Via Bonomea 265, I-34136 Trieste (Italy); Negrello, M. [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy)

    2014-02-20

    We exploit the recent, wide samples of far-infrared (FIR) selected galaxies followed up in X-rays and of X-ray/optically selected active galactic nuclei (AGNs) followed up in the FIR band, along with the classic data on AGNs and stellar luminosity functions at high redshift z ≳ 1.5, to probe different stages in the coevolution of supermassive black holes (BHs) and host galaxies. The results of our analysis indicate the following scenario: (1) the star formation in the host galaxy proceeds within a heavily dust-enshrouded medium at an almost constant rate over a timescale ≲ 0.5-1 Gyr and then abruptly declines due to quasar feedback, over the same timescale; (2) part of the interstellar medium loses angular momentum, reaches the circum-nuclear regions at a rate proportional to the star formation, and is temporarily stored in a massive reservoir/proto-torus wherefrom it can be promptly accreted; (3) the BH grows by accretion in a self-regulated regime with radiative power that can slightly exceed the Eddington limit L/L {sub Edd} ≲ 4, particularly at the highest redshifts; (4) for massive BHs, the ensuing energy feedback at its maximum exceeds the stellar one and removes the interstellar gas, thus stopping the star formation and the fueling of the reservoir; (5) afterward, if the latter has retained enough gas, a phase of supply-limited accretion follows, exponentially declining with a timescale of about two e-folding times. We also discuss how the detailed properties and the specific evolution of the reservoir can be investigated via coordinated, high-resolution observations of star-forming, strongly lensed galaxies in the (sub-)mm band with ALMA and in the X-ray band with Chandra and the next-generation X-ray instruments.

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

    International Nuclear Information System (INIS)

    We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M •, and their host galaxies' K-band bulge (L bul) and total (L 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 •, 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 •-L bul and M •-L tot relations have consistent intrinsic scatter, suggesting that M • 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 •-L bul and M •-L tot relations are 0.75 ± 0.10 and 0.92 ± 0.14, respectively. However, while the slope of the M •-L bul relation depends on the detail of the image decomposition, the characterization of M •-L tot does not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L tot is more suitable as a tracer of SMBH mass than L bul, and that the M •-L tot relation should be used when studying the co-evolution of SMBHs and galaxies.

  15. 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.

  16. Identifying decaying supermassive black hole binaries from their variable electromagnetic emission

    Energy Technology Data Exchange (ETDEWEB)

    Haiman, Zoltan; Menou, Kristen [Department of Astronomy, Columbia University, New York, NY (United States); Kocsis, Bence [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Lippai, Zoltan; Frei, Zsolt [Institute of Physics, Eoetvoes University, Budapest (Hungary)

    2009-05-07

    Supermassive black hole binaries (SMBHBs) with masses in the mass range approx(10{sup 4}-10{sup 7}) M{sub o-dot}/(1 + z), produced in galaxy mergers, are thought to complete their coalescence due to the emission of gravitational waves (GWs). The anticipated detection of the GWs by the future Laser Interferometric Space Antenna (LISA) will constitute a milestone for fundamental physics and astrophysics. While the GW signatures themselves will provide a treasure trove of information, if the source can be securely identified in electromagnetic (EM) bands, this would open up entirely new scientific opportunities, to probe fundamental physics, astrophysics and cosmology. We discuss several ideas, involving wide-field telescopes, that may be useful in locating electromagnetic counterparts to SMBHBs detected by LISA. In particular, the binary may produce a variable electromagnetic flux, such as a roughly periodic signal due to the orbital motion prior to coalescence, or a prompt transient signal caused by shocks in the circumbinary disc when the SMBHB recoils and 'shakes' the disc. We discuss whether these time-variable EM signatures may be detectable, and how they can help in identifying a unique counterpart within the localization errors provided by LISA. We also discuss a possibility of identifying a population of coalescing SMBHBs statistically, in a deep optical survey for periodically variable sources, before LISA detects the GWs directly. The discovery of such sources would confirm that gas is present in the vicinity and is being perturbed by the SMBHB-serving as a proof of concept for eventually finding actual LISA counterparts.

  17. GROWTH OF EARLY SUPERMASSIVE BLACK HOLES AND THE HIGH-REDSHIFT EDDINGTON RATIO DISTRIBUTION

    Energy Technology Data Exchange (ETDEWEB)

    DeGraf, C.; Di Matteo, T.; Khandai, N.; Croft, R. [McWilliams Center for Cosmology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)

    2012-08-10

    Using a new large-scale ({approx} 0.75 Gpc){sup 3} hydrodynamic cosmological simulation, we investigate the growth rate of supermassive black holes (BHs) in the early universe (z {approx}> 4.75). Remarkably we find a clear peak in the typical Eddington ratio ({lambda}) at BH masses of (4-8) Multiplication-Sign 10{sup 7} M{sub Sun} (typically in halos of {approx}7 Multiplication-Sign 10{sup 11} to 1 Multiplication-Sign 10{sup 12} M{sub Sun }, close to their shock heating scale), independent of redshift and indicative that most BH growth occurs in the cold-flow-dominated regime. BH growth is enhanced at high-z and by and large regulated by the cosmological evolution of gas density, with {lambda} scaling simply as (1 + z){sup 3}. The peak in {lambda} is caused by the competition between increased gas density available in more massive hosts, and a decrease due to active galactic nucleus feedback that becomes effective above the shock heating halo mass scale and at high BH masses. We show that the distribution of {lambda} among both mass-selected and luminosity-selected samples is approximately lognormal. We combine these findings into a single lognormal fitting formula for the distribution of Eddington ratios as a function of (M{sub BH}, z). This formula can be used in analytic and semianalytic models for evolving BH populations, predicting BH masses of observed quasars, and, in conjunction with the observed distribution of Eddington ratios, can be used to constrain the BH mass function.

  18. ENHANCED OFF-CENTER STELLAR TIDAL DISRUPTIONS BY SUPERMASSIVE BLACK HOLES IN MERGING GALAXIES

    International Nuclear Information System (INIS)

    Off-center stellar tidal disruption flares have been suggested to be a powerful probe of recoiling supermassive black holes (SMBHs) out of galactic centers due to anisotropic gravitational wave radiations. However, off-center tidal flares can also be produced by SMBHs in merging galaxies. In this paper, we computed the tidal flare rates by dual SMBHs in two merging galaxies before the SMBHs become self-gravitationally bounded. We employ an analytical model to calculate the tidal loss-cone feeding rates for both SMBHs, taking into account two-body relaxation of stars, tidal perturbations by the companion galaxy, and chaotic stellar orbits in triaxial gravitational potential. We show that for typical SMBHs with masses 107 M☉, the loss-cone feeding rates are enhanced by mergers up to Γ ∼ 10–2 yr–1, about two orders of magnitude higher than those by single SMBHs in isolated galaxies and about four orders of magnitude higher than those by recoiling SMBHs. The enhancements are mainly due to tidal perturbations by the companion galaxy. We suggest that off-center tidal flares are overwhelmed by those from merging galaxies, making the identification of recoiling SMBHs challenging. Based on the calculated rates, we estimate the relative contributions of tidal flare events by single, binary, and dual SMBH systems during cosmic time. Our calculations show that the off-center tidal disruption flares by un-bound SMBHs in merging galaxies contribute a fraction comparable to that by single SMBHs in isolated galaxies. We conclude that off-center tidal disruptions are powerful tracers of the merging history of galaxies and SMBHs.

  19. Direct Collapse to Supermassive Black Hole Seeds: Comparing the AMR and SPH Approaches

    Science.gov (United States)

    Luo, Yang; Nagamine, Kentaro; Shlosman, Isaac

    2016-03-01

    We provide detailed comparison between the AMR code Enzo-2.4 and the SPH/N-body code GADGET-3 in the context of isolated or cosmological direct baryonic collapse within dark matter (DM) halos to form supermassive black holes. Gas flow is examined by following evolution of basic parameters of accretion flows. Both codes show an overall agreement in the general features of the collapse, however, many subtle differences exist. For isolated models, the codes increase their spatial and mass resolutions at different pace, which leads to substantially earlier collapse in SPH than in AMR cases due to higher gravitational resolution in GADGET-3. In cosmological runs, the AMR develops a slightly higher baryonic resolution than SPH during halo growth via cold accretion permeated by mergers. Still, both codes agree in the buildup of DM and baryonic structures. However, with the onset of collapse, this difference in mass and spatial resolution is amplified, so evolution of SPH models begins to lag behind. Such a delay can have effect on formation/destruction rate of H2 due to UV background, and on basic properties of host halos. Finally, isolated non-cosmological models in spinning halos, with spin parameter λ ˜ 0.01 - 0.07, show delayed collapse for greater λ, but pace of this increase is faster for AMR. Within our simulation setup, GADGET-3 requires significantly larger computational resources than Enzo-2.4 during collapse, and needs similar resources, during the pre-collapse, cosmological structure formation phase. Yet it benefits from substantially higher gravitational force and hydrodynamic resolutions, except at the end of collapse.

  20. Direct collapse to supermassive black hole seeds: comparing the AMR and SPH approaches

    Science.gov (United States)

    Luo, Yang; Nagamine, Kentaro; Shlosman, Isaac

    2016-07-01

    We provide detailed comparison between the adaptive mesh refinement (AMR) code ENZO-2.4 and the smoothed particle hydrodynamics (SPH)/N-body code GADGET-3 in the context of isolated or cosmological direct baryonic collapse within dark matter (DM) haloes to form supermassive black holes. Gas flow is examined by following evolution of basic parameters of accretion flows. Both codes show an overall agreement in the general features of the collapse; however, many subtle differences exist. For isolated models, the codes increase their spatial and mass resolutions at different pace, which leads to substantially earlier collapse in SPH than in AMR cases due to higher gravitational resolution in GADGET-3. In cosmological runs, the AMR develops a slightly higher baryonic resolution than SPH during halo growth via cold accretion permeated by mergers. Still, both codes agree in the build-up of DM and baryonic structures. However, with the onset of collapse, this difference in mass and spatial resolution is amplified, so evolution of SPH models begins to lag behind. Such a delay can have effect on formation/destruction rate of H2 due to UV background, and on basic properties of host haloes. Finally, isolated non-cosmological models in spinning haloes, with spin parameter λ ˜ 0.01-0.07, show delayed collapse for greater λ, but pace of this increase is faster for AMR. Within our simulation set-up, GADGET-3 requires significantly larger computational resources than ENZO-2.4 during collapse, and needs similar resources, during the pre-collapse, cosmological structure formation phase. Yet it benefits from substantially higher gravitational force and hydrodynamic resolutions, except at the end of collapse.

  1. HIGH-FREQUENCY GRAVITATIONAL WAVES FROM SUPERMASSIVE BLACK HOLES: PROSPECTS FOR LIGO-VIRGO DETECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kocsis, Bence, E-mail: bkocsis@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-02-15

    It is commonly assumed that ground-based gravitational wave (GW) instruments will not be sensitive to supermassive black holes (SMBHs) because the characteristic GW frequencies are far below the {approx}10-1000 Hz sensitivity bands of terrestrial detectors. Here, however, we explore the possibility of SMBH GWs to leak to higher frequencies. In particular, if the high-frequency spectral tail asymptotes to h-tilde (f){proportional_to}f{sup -{alpha}}, where {alpha} {<=} 2, then the spectral amplitude is a constant or increasing function of the mass M at a fixed frequency f >> c {sup 3}/GM. This will happen if the time-domain waveform or its derivative exhibits a discontinuity. Ground-based instruments could search for these universal spectral tails to detect or rule out such features irrespective of their origin. We identify the following processes which may generate high-frequency signals: (1) gravitational bremsstrahlung of ultrarelativistic objects in the vicinity of an SMBH, (2) ringdown modes excited by an external process that has a high-frequency component or terminates abruptly, and (3) gravitational lensing echoes and diffraction. We estimate the order of magnitude of the detection signal-to-noise ratio for each mechanism (1, 2, and 3) as a function of the waveform parameters. In particular for (3), SMBHs produce GW echoes of inspiraling stellar mass binaries in galactic nuclei with a delay of a few minutes to hours. The lensed primary signal and GW echo are both amplified if the binary is within a {approx}10 deg (r/100M){sup -1/2} cone behind the SMBH relative to the line of sight at a distance r from the SMBH. For the rest of the binaries near SMBHs, the amplitude of the GW echo is {approx}0.1(r/100M){sup -1} of the primary signal on average.

  2. The imprint of the cosmic supermassive black hole growth history on the 21 cm background radiation

    Science.gov (United States)

    Tanaka, Takamitsu L.; O'Leary, Ryan M.; Perna, Rosalba

    2016-01-01

    The redshifted 21 cm transition line of hydrogen tracks the thermal evolution of the neutral intergalactic medium (IGM) at `cosmic dawn', during the emergence of the first luminous astrophysical objects (˜100 Myr after the big bang) but before these objects ionized the IGM (˜400-800 Myr after the big bang). Because X-rays, in particular, are likely to be the chief energy courier for heating the IGM, measurements of the 21 cm signature can be used to infer knowledge about the first astrophysical X-ray sources. Using analytic arguments and a numerical population synthesis algorithm, we argue that the progenitors of supermassive black holes (SMBHs) should be the dominant source of hard astrophysical X-rays - and thus the primary driver of IGM heating and the 21 cm signature - at redshifts z ≳ 20, if (i) they grow readily from the remnants of Population III stars and (ii) produce X-rays in quantities comparable to what is observed from active galactic nuclei and high-mass X-ray binaries. We show that models satisfying these assumptions dominate over contributions to IGM heating from stellar populations, and cause the 21 cm brightness temperature to rise at z ≳ 20. An absence of such a signature in the forthcoming observational data would imply that SMBH formation occurred later (e.g. via so-called direct collapse scenarios), that it was not a common occurrence in early galaxies and protogalaxies, or that it produced far fewer X-rays than empirical trends at lower redshifts, either due to intrinsic dimness (radiative inefficiency) or Compton-thick obscuration close to the source.

  3. THE SUPERMASSIVE BLACK HOLE AND DARK MATTER HALO OF NGC 4649 (M60)

    International Nuclear Information System (INIS)

    We apply the axisymmetric orbit superposition modeling to estimate the mass of the supermassive black hole (BH) and dark matter (DM) halo profile of NGC 4649. We have included data sets from the Hubble Space Telescope (HST), stellar, and globular cluster (GC) observations. Our modeling gives M. = (4.5 ± 1.0) x 109 Msun and M/LV,obs = 8.7 ± 1.0 (or M/LV = 8.0 ± 0.9 after foreground Galactic extinction is corrected). We confirm the presence of a DM halo, but the stellar mass dominates inside the effective radius. The parameters of the dark halo are less constrained due to the sparse GC data at large radii. We find that in NGC 4649 the dynamical mass profile from our modeling is consistently larger than that derived from the X-ray data over most of the radial range by roughly 60%-80%. It implies that either some forms of non-thermal pressure need to be included, the assumed hydrostatic equilibrium may not be a good approximation in the X-ray modelings of NGC 4649, or our assumptions used in the dynamical models are biased. Our new M. is about 2 times larger than the previous published value; the earlier model did not adequately sample the orbits required to match the large tangential anisotropy in the galaxy center. If we assume that there is no DM, the results on the BH mass and M/LV,obs do not change significantly, which we attribute to the inclusion of HST spectra, the sparse GC kinematics, and a diffuse DM halo. Without the HST data, the significance of the BH detection is greatly reduced.

  4. SUPERMASSIVE BLACK HOLE FORMATION VIA GAS ACCRETION IN NUCLEAR STELLAR CLUSTERS

    International Nuclear Information System (INIS)

    Black holes exceeding a billion solar masses have been detected at redshifts greater than six. The rapid formation of these objects may suggest a massive early seed or a period of growth faster than Eddington. Here we suggest a new mechanism along these lines. We propose that in the process of hierarchical structure assembly, dense star clusters can be contracted on dynamical timescales due to the nearly free-fall inflow of self-gravitating gas with a mass comparable to or larger than that of the clusters. This process increases the velocity dispersion to the point where the few remaining hard binaries can no longer effectively heat the cluster, and the cluster goes into a period of homologous core collapse. The cluster core can then reach a central density high enough for fast mergers of stellar-mass black holes and hence the rapid production of a black hole seed that could be 105 Msun or larger.

  5. UNLEASHING POSITIVE FEEDBACK: LINKING THE RATES OF STAR FORMATION, SUPERMASSIVE BLACK HOLE ACCRETION, AND OUTFLOWS IN DISTANT GALAXIES

    International Nuclear Information System (INIS)

    Pressure-regulated star formation is a simple variant on the usual supernova-regulated star formation efficiency that controls the global star formation rate as a function of cold gas content in star-forming galaxies, and accounts for the Schmidt-Kennicutt law in both nearby and distant galaxies. Inclusion of active galactic nucleus (AGN) induced pressure, by jets and/or winds that flow back onto a gas-rich disk, can lead, under some circumstances, to significantly enhanced star formation rates, especially at high redshift and most likely followed by the more widely accepted phase of star formation quenching. Simple expressions are derived that relate supermassive black hole growth, star formation, and outflow rates. The ratios of black hole to spheroid mass and of both black hole accretion and outflow rates to star formation rate are predicted as a function of time. I suggest various tests of the AGN-triggered star formation hypothesis

  6. Formation of Supermassive Black Holes in Galactic Bulges: A Rotating Collapse Model Consistent with the M(sub BH-sigma) Relation

    Science.gov (United States)

    Adams, Fred C.; Graff, David S.; Mbonye, Manasse; Richstone, Douglas O.

    2003-01-01

    Motivated by the observed correlation between black hole masses M(sub BH) and the velocity dispersion sigma of host galaxies, we develop a theoretical model of black hole formation in galactic bulges (this paper generalizes an earlier ApJ Letter). The model assumes an initial state specified by a uniform rotation rate OMEGA and a density distribution of the form rho = a(sup 2)(sub eff)per2piGR(sup 2)(so that a(sub eff)is an effective transport speed). The black hole mass is determined when the centrifugal radius of the collapse flow exceeds the capture radius of the central black hole (for Schwarzschild geometry). This model reproduces the observed correlation between the estimated black hole masses and the velocity dispersions of galactic bulges, i.e., M(sub BH) approximately equal to 10(sup 8) solar mass(sigma per 200 kilometers per second)(sup 4) where sigma = the square root of 2a(sub eff). To obtain this normalization, the rotation rate OMEGA approximately equal to 2 x 10(exp -15) rad per second. The model also defines a bulge mass scale M(sub B). If we identify the scale M(sub B) with the bulge mass, the model determines the ratio mu(sub B) of black hole mass to the host mass: mu(sub B) approximately equal to 0.0024(sigma per 200 kilometer per second), again in reasonable agreement with observed values. In this scenario, supermassive black holes form quickly (in approximately 10(exp 5) yr) and are born rapidly rotating (with a per M approximately 0.9). This paper also shown how these results depend on the assumed initial conditions; the most important quantity is the initial distribution of specific angular momentum in the precollapse state.

  7. Pulsar Timing Residuals Induced by Gravitational Waves from Single Non-evolving Supermassive Black Hole Binaries with Elliptical Orbits

    International Nuclear Information System (INIS)

    The pulsar timing residuals induced by gravitational waves from non-evolving single binary sources with general elliptical orbits are analyzed. For different orbital eccentricities, the timing residuals present different properties. The standard deviations of the timing residuals induced by a fixed gravitational wave source are calculated for different values of the eccentricity. We also analyze the timing residuals of PSR J0437-4715 induced by one of the best known single gravitational wave sources, the supermassive black hole binary in the blazar OJ287

  8. Hunting for Supermassive Black Holes in Nearby Galaxies with the Hobby-Eberly Telescope

    CERN Document Server

    Bosch, Remco van den; Gültekin, Kayhan; Yıldırım, Akin; Walsh, Jonelle

    2015-01-01

    We have conducted an optical long-slit spectroscopic survey of 1022 galaxies using the 10m Hobby-Eberly Telescope (HET) at McDonald Observatory. The main goal of the HET Massive Galaxy Survey (HETMGS) is to find nearby galaxies that are suitable for black hole mass measurements. In order to measure accurately the black hole mass, one should kinematically resolve the region where the black hole dominates the gravitational potential. For most galaxies, this region is much less than an arcsecond. Thus, black hole masses are best measured in nearby galaxies with telescopes that obtain high-spatial resolution. The HETMGS focuses on those galaxies predicted to have the largest sphere-of-influence, based on published stellar velocity dispersions or the galaxy fundamental plane. To ensure coverage over galaxy types, the survey targets those galaxies across a face-on projection of the fundamental plane. We present the sample selection and resulting data products from the long-slit observations, including central stell...

  9. Connecting galaxy and supermassive black hole growth during the last 8 billion years

    Science.gov (United States)

    Juneau, Stephanie

    It has become increasingly clear that a complete picture of galaxy evolution requires a better understanding of the role of Active Galactic Nuclei (AGN). In particular, they could be responsible for regulating star formation and galaxy growth via feedback processes. There are also competing views about the main modes of stellar growth and supermassive black hole growth in galaxies that need to be resolved. With high infrared luminosities (thus star formation rates) and a frequent occurrence of AGN, galaxies selected in the far-infrared wavebands form an ideal sample to search for a connection between AGN and star formation. The first part of this thesis contains a detailed analysis of the molecular gas properties of nearby infrared luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs). We find that the enhanced molecular gas density in the most IR-luminous systems can be explained by major galaxy mergers, and that AGN are more likely to reside in higher-density systems. While the frequent concurrence of AGN and galaxy mergers in ULIRGs was already established, this work provides a coherent framework that explains trends observed with five molecular gas tracers with a broad range of critical densities, and a comparison with simulations that reproduce observed molecular line ratios without invoking AGN-induced chemistry. The second part of the thesis presents an analysis of the AGN content of intermediate redshift galaxies (0.3 < z < 1). However, identifying complete AGN samples at these redshift is challenging because it is difficult to find X-ray weak or absorbed AGN. To alleviate this problem, we developed the Mass-Excitation (MEx) diagram, which is applicable out to redshift of ˜ 1 with existing optical spectra. It improves the overall AGN census by detecting AGN that are missed in even the most sensitive X-ray surveys. The new diagnostic was used to study the concurrence of star formation and AGN in 70 micron-selected galaxies from the Far

  10. Properties of galaxies around AGNs with the most massive supermassive black holes revealed by clustering analysis

    Science.gov (United States)

    Shirasaki, Yuji; Komiya, Yutaka; Ohishi, Masatoshi; Mizumoto, Yoshihiko

    2016-04-01

    We present results of the clustering analysis between active galactic nuclei (AGNs) and galaxies at redshift 0.1-1.0, which was performed to investigate the properties of galaxies associated with the AGNs and reveal the nature of the fueling mechanism of supermassive black holes (SMBHs). We used 8059 AGNs/quasi-stellar objects (QSOs) for which virial masses of individual SMBHs were measured, and divided them into four mass groups.Cross-correlation analysis was performed to reconfirm our previous result that cross-correlation length increases with SMBH mass MBH; we obtained consistent results. A linear bias of AGN for each mass group was measured as 1.47 for MBH = 107.5-108.2 M⊙ and 3.08 for MBH = 109-1010 M⊙. The averaged color and luminosity distributions of galaxies around the AGNs/QSOs were also derived for each mass group. The galaxy color Dopt-IR was estimated from a spectral energy distribution (SED) constructed from a catalog derived by merging the Sloan Digital Sky Survey (SDSS) and the UKIRT Infrared Deep Sky Survey (UKIDSS) catalogs. The distributions of color and luminosity were derived by a subtraction method, which does not require redshift information of galaxies. The main results of this work are as follows. (1) A linear bias increases by a factor of two from the lower-mass group to the highest-mass group. (2) The environment around AGNs with the most massive SMBHs (MBH > 109 M⊙) is dominated by red sequence galaxies. (3) Marginal indication of decline in luminosity function at dimmer side of MIR > -19.5 is found for galaxies around AGNs with MBH = 108.2-109 M⊙ and nearest redshift group (z = 0.1-0.3). These results indicate that AGNs with the most massive SMBHs reside in haloes where a large fraction of galaxies have been transited to the red sequence. The accretion of hot halo gas as well as recycled gas from evolving stars can be one of the plausible mechanisms to fuel the SMBHs above ˜ 109 M⊙.

  11. The role of relativistic jets in the heaviest and most active supermassive black holes at high redshift

    CERN Document Server

    Ghisellini, G; Della Ceca, R; Volonteri, M; Sbarrato, T

    2013-01-01

    In powerful radio-quiet active galactic nuclei (AGN), black holes heavier than one billion solar masses form at a redshift ~1.5-2. Supermassive black holes in jetted radio-loud AGN seems to form earlier, at a redshift close to 4. The ratio of active radio-loud to radio-quiet AGN hosting heavy black holes is therefore a rather a strong function of redshift. We report on some recent evidence supporting this conclusion, gathered from the Burst Alert Telescope (BAT, onboard Swift) and by the Large Area Telescope (LAT, onboard Fermi). We suggest that the more frequent occurrence of relativistic jets in the most massive black holes at high redshifts, compared to later times, could be due to the average black hole spin being greater in the distant past, or else to the jet helping a fast accretion rate (or some combination of the two scenarios). We emphasize that the large total accretion efficiency of rapidly spinning black holes inhibits a fast growth, unless a large fraction of the available gravitational energy o...

  12. Radio continuum observations of the candidate supermassive black hole in the dwarf elliptical VCC128

    CERN Document Server

    Buyle, Pieter; Debattista, Victor P; Ferreras, Ignacio; Pasquali, Anna; Seth, Anil; Morelli, Lorenzo

    2008-01-01

    The presence of black holes (BHs) at the centers of dwarf elliptical galaxies (dEs) has been argued both theoretically and observationally. Using archival HST/WFPC2 data, we found the Virgo cluster dwarf elliptical galaxy VCC128 to harbor a binary nucleus, a feature that is usually interpreted as the observable signature of a stellar disk orbiting a central massive black hole. Debattista et al. 2006 estimated its mass M sim 6 10^6 - 5 10^7 Msun. One of the most robust means of verifying the existence of a BH is radio continuum and/or X-ray emission, however because of the deficiency of gas in dEs, radio continuum emission forms the best option here. We have tried to detect the X-band radio emission coming from the putative black hole in VCC128 when it accretes gas from the surrounding ISM. While we made a positive 4 sigma detection of a point source 4.63'' south-west of the binary nucleus, no statistically significant evidence for emission associated with the nuclei themselves was detected. This implies eithe...

  13. Simulating the Growth of a Disk Galaxy and its Supermassive Black Hole in a Cosmological Simulating the Growth of a Disk Galaxy and its Supermassive Black Hole in a Cosmological Context

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Robyn Deborah; /JILA, Boulder

    2008-07-01

    Supermassive black holes (SMBHs) are ubiquitous in the centers of galaxies. Their formation and subsequent evolution is inextricably linked to that of their host galaxies, and the study of galaxy formation is incomplete without the inclusion of SMBHs. The present work seeks to understand the growth and evolution of SMBHs through their interaction with the host galaxy and its environment. In the first part of the thesis (Chap. 2 and 3), we combine a simple semi-analytic model of outflows from active galactic nuclei (AGN) with a simulated dark matter density distribution to study the impact of SMBH feedback on cosmological scales. We find that constraints can be placed on the kinetic efficiency of such feedback using observations of the filling fraction of the Ly{alpha} forest. We also find that AGN feedback is energetic enough to redistribute baryons over cosmological distances, having potentially significant effects on the interpretation of cosmological data which are sensitive to the total matter density distribution (e.g. weak lensing). However, truly assessing the impact of AGN feedback in the universe necessitates large-dynamic range simulations with extensive treatment of baryonic physics to first model the fueling of SMBHs. In the second part of the thesis (Chap. 4-6) we use a hydrodynamic adaptive mesh refinement simulation to follow the growth and evolution of a typical disk galaxy hosting a SMBH, in a cosmological context. The simulation covers a dynamical range of 10 million allowing us to study the transport of matter and angular momentum from super-galactic scales all the way down to the outer edge of the accretion disk around the SMBH. Focusing our attention on the central few hundred parsecs of the galaxy, we find the presence of a cold, self-gravitating, molecular gas disk which is globally unstable. The global instabilities drive super-sonic turbulence, which maintains local stability and allows gas to fuel a SMBH without first fragmenting

  14. NuSTAR reveals the extreme properties of the super-Eddington accreting supermassive black hole in PG 1247+267

    DEFF Research Database (Denmark)

    Lanzuisi, G.; Perna, M.; Comastri, A.;

    2016-01-01

    PG1247+267 is one of the most luminous known quasars at z similar to 2 and is a strongly super-Eddington accreting supermassive black hole (SMBH) candidate. We obtained NuSTAR data of this intriguing source in December 2014 with the aim of studying its high-energy emission, leveraging the broad...

  15. Axisymmetric nonstationary model of the central engine in an active galactic nucleus. I. Black hole electrodynamics

    International Nuclear Information System (INIS)

    In a previous paper the authors analyzed an axisymmetric, nonstationary model of the central engine of an active galactic nucleus, consisting of a supermassive black hole surrounded by a magnetized accretion disk. The equations used were the equations of power output and angular momentum loss given by Macdonald and Thorne (1982), in which an axisymmetric, stationary model is described. In this paper, all the fundamental equations in a fully time-dependent manner and the electrodynamics of a black hole and its magnetosphere is investigated. Under the assumption that the mass accretion is confined to the equatorial plane of the black hole, the results suggest that, at the equatorial zone of the black hole, the angular velocity of the magnetic field lines anchored on the accreting matter must be close to that of the black hole. 21 references

  16. Can emission line profiles from perturbed accretion disks mimic those from the broad line region of a black hole in a supermassive binary?

    Science.gov (United States)

    Brown, Stephanie Meghan; Eracleous, Michael; Runnoe, Jessie C.; Bogdanovic, Tamara; Sigurdsson, Steinn; Boroson, Todd A.; Halpern, Jules P.

    2016-01-01

    Both observations and simulations from the last decade suggest a link between the evolution of galaxies and their central supermassive black holes. An important ingredient in these evolutionary models is galactic interaction and mergers. Consequently, we expect to see dual active galactic nuclei at the early stages of an interaction and close, bound binary black holes after the parent galaxies have merged. While binary active galactic nuclei have been detected at large separations, it has proven difficult to detect close, bound binaries. Our team has been carrying out an observing campaign to find binary black holes with sub-parsec separations. Thus, we have been studying a sample of 88 quasars from the Sloan Digital Sky Survey whose broad Hβ lines are offset from their nominal wavelength by a few thousand km/s. These offsets suggest orbital motion of one of the black holes and the gas that is bound to it. In this work, we play devil's advocate by exploring an alternative interpretation of the broad emission lines. We ask whether lines formed in a perturbed, non-axisymmetric disks can have profiles similar to those observed. Two categories of non-axisymmetric disks are explored - one with a prominent spiral arm and one that is elliptical. To make the model as general as possible, the radial emissivity of the disk was allowed to have a broken power-law profile. For certain combinations of model parameters, these models can match the observed profile shapes. A subset of these model parameters can mimic the sinusoidal procession of the peak velocity we would expect to see in a binary system on an observable time scale. However, the predominate, observed statistical trend between the Pearson Skewness and the peak position is not reproduced; instead, other trends are predicted by the models that we do not observe.

  17. Selection bias in dynamically-measured super-massive black hole samples: consequences for pulsar timing arrays

    CERN Document Server

    Sesana, A; Bernardi, M; Sheth, R K

    2016-01-01

    Supermassive black hole -- host galaxy relations are key to the computation of the expected gravitational wave background (GWB) in the pulsar timing array (PTA) frequency band. It has been recently pointed out that standard relations adopted in GWB computations are in fact biased-high. We show that when this selection bias is taken into account, the expected GWB in the PTA band is a factor of about three smaller than previously estimated. Compared to other scaling relations recently published in the literature, the median amplitude of the signal at $f=1$yr$^{-1}$ drops from $1.3\\times10^{-15}$ to $4\\times10^{-16}$. Although this solves any potential tension between theoretical predictions and recent PTA limits without invoking other dynamical effects (such as stalling, eccentricity or strong coupling with the galactic environment), it also makes the GWB detection more challenging.

  18. Supermassive Black Hole Binary Environments: Effects on the Scaling Laws and Time to Detection for the Stochastic Background

    CERN Document Server

    Vigeland, Sarah J

    2016-01-01

    One of the primary gravitational wave (GW) sources for pulsar timing arrays (PTAs) is the stochastic background formed by supermassive black holes binaries (SMBHBs). In this paper, we investigate how the environments of SMBHBs will effect the sensitivity of PTAs by deriving scaling laws for the signal-to-noise ratio (SNR) of the optimal cross-correlation statistic. The presence of gas and stars around SMBHBs will accelerate the merger at large distances, depleting the GW stochastic background at low frequencies. We show that environmental interactions may delay detection by a few years or more, depending on the PTA configuration and the frequency at which the dynamical evolution transitions from being dominated by environmental effects to GW-dominated.

  19. The possibility of formation of Supermassive Black Holes from Bose-Einstein Condensation of Bosonic Dark Matter

    CERN Document Server

    Gupta, Patrick Das

    2015-01-01

    Observed active galactic nuclei at redshifts of about 6 strongly suggest that supermassive black holes (SMBHs) had formed early on. Accretion of matter onto remnants of Population III stars leading to SMBHs is a very slow process, and therefore the model faces difficulties in explaining quasars detected at $ z \\gtrsim 6$. In this paper we invoke Bose-Einstein condensation of dark bosons to demonstrate that existence of very light ($m \\sim 10^{-23} \\ \\mbox{eV}$) spinless dark matter particles can not only lead to SMBHs of mass $\\gtrsim 10^{10} \\ M_\\odot$ at $ z \\gtrsim 6$ but also such particles can masquerade as dark matter as well as dark energy.

  20. A systematic search for close supermassive black hole binaries in the Catalina Real-Time Transient Survey

    CERN Document Server

    Graham, Matthew J; Stern, Daniel; Drake, Andrew J; Mahabal, Ashish A; Donalek, Ciro; Glikman, Eilat; Larsen, Steve; Christensen, Eric

    2015-01-01

    Hierarchical assembly models predict a population of supermassive black hole (SMBH) binaries. These are not resolvable by direct imaging but may be detectable via periodic variability (or nanohertz frequency gravitational waves). Following our detection of a 5.2 year periodic signal in the quasar PG 1302-102 (Graham et al. 2015), we present a novel analysis of the optical variability of 243,500 known spectroscopically confirmed quasars using data from the Catalina Real-time Transient Survey (CRTS) to look for close (< 0.1 pc) SMBH systems. Looking for a strong Keplerian periodic signal with at least 1.5 cycles over a baseline of nine years, we find a sample of 111 candidate objects. This is in conservative agreement with theoretical predictions from models of binary SMBH populations. Simulated data sets, assuming stochastic variability, also produce no equivalent candidates implying a low likelihood of spurious detections. The periodicity seen is likely attributable to either jet precession, warped accreti...

  1. On the detection of eccentric supermassive black hole binaries with pulsar timing arrays: Signal-to-noise ratio calculations

    CERN Document Server

    Huerta, E A; Gair, Jonathan R; Taylor, Stephen R

    2015-01-01

    We present a detailed analysis of the expected signal-to-noise ratios of supermassive black hole binaries on eccentric orbits observed by pulsar timing arrays. We derive several analytical relations that extend the results of Peters and Mathews [Phys. Rev. D 131, 435 (1963)] to facilitate this analysis. We show that eccentricity enhances the signal-to-noise ratio of single resolvable sources whose dominant harmonic is located in the low-frequency sensitivity regime of pulsar timing arrays for continuous wave sources, whereas the expected signal-to-noise ratio of single resolvable sources emitting in the high frequency sensitivity regime of pulsar timing arrays will be attenuated. We also show that the strain of a stochastic, isotropic gravitational wave background generated by a cosmological population of eccentric binaries will be suppressed in the frequency band of pulsar timing arrays relative to a population of circular binaries, which may pose a potential problem for their detection.

  2. A Radiation-Hydrodynamical Model for Supermassive Black Hole-to-Bulge Mass Relation and Quasar Formation

    CERN Document Server

    Umemura, M

    2001-01-01

    As a potential mechanism to build up supermassive black holes (BHs) in a spheroidal system, we consider the radiation drag effect by bulge stars, which extracts angular momentum from interstellar gas and thus allows the gas to accrete onto the galactic center. With incorporating radiation hydrodynamical equation with simple stellar evolution, it is shown that the BH-to-bulge mass ratio, $f_{BH}$, is basically determined by a fundamental constant, that is, the energy conversion efficiency for nuclear fusion of hydrogen to helium, $\\epsilon=0.007$. More specifically, $f_{BH}$ is predicted to be $0.3\\epsilon -0.5\\epsilon$. Based on the present model for BH growth, a scenario for quasar formation is addressed in relation to ultraluminous infrared galaxies.

  3. Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes

    CERN Document Server

    Brandt, W N

    2015-01-01

    We review results from cosmic X-ray surveys of active galactic nuclei (AGNs) over the past ~ 15 yr that have dramatically improved our understanding of growing supermassive black holes (SMBHs) in the distant universe. First, we discuss the utility of such surveys for AGN investigations and the capabilities of the missions making these surveys, emphasizing Chandra, XMM-Newton, and NuSTAR. Second, we briefly describe the main cosmic X-ray surveys, the essential roles of complementary multiwavelength data, and how AGNs are selected from these surveys. We then review key results from these surveys on the AGN population and its evolution ("demographics"), the physical processes operating in AGNs ("physics"), and the interactions between AGNs and their environments ("ecology"). We conclude by describing some significant unresolved questions and prospects for advancing the field.

  4. Accretion of gaseous clumps from the Galactic Centre Mini-spiral onto Milky Way's supermassive black hole

    Science.gov (United States)

    Karas, Vladimir; Kunneriath, Devaky; Czerny, Bozena; Rozanska, Agata; Adhikari, Tek P.

    2016-07-01

    Evidence for reflection of X-rays on molecular clouds in the vicinity of Sagittarius A* super-massive black hole (Sgr A* SMBH) suggests that the center of Galaxy was active in its recent history. We investigate the idea of gaseous Mini-spiral pattern as the origin of material triggering this enhanced activity. Collisions between clumps of gas in the Mini-spiral can reduce their angular momentum and set some of the clumps on a plunging trajectory towards Sgr A* SMBH. It turns out that the amount of material in the Mini-spiral region is sufficient to sustain the required level of luminosity. We examine a possibility of Thermal Instability onset to describe the mechanism for elevated accretion during the past period. Our contribution extends a recent paper by including the effect of the Nuclear Star Cluster, which provides additional important contribution to the energy balance of the inter-stellar medium.

  5. Central black hole masses of galaxies

    Institute of Scientific and Technical Information of China (English)

    樊军辉

    2003-01-01

    In this paper, the stellar velocity dispersions in the host galaxies are used to estimate the central black hole masses for a sample of elliptical galaxies. We find that the central black hole masses are in the range of 10(5.5-9.5) M(○). Based on the estimated masses in this paper and those by Woo & Urry (2002) and the measured host galaxy absolute magnitude,a relation, log(MBH/M(○)) = -(0.25 ± 4.3 × 10-3)MR + (2.98 4 0.208) is found for central black hole mass and the host galaxy magnitude. Some discussions are presented.

  6. Long-Term Evolution of and X-ray Emission from a Recoiling Supermassive Black Hole in a Disk Galaxy

    CERN Document Server

    Fujita, Yutaka

    2008-01-01

    Recent numerical relativity simulations have shown that the emission of gravitational waves at the merger of two black holes gives a recoil kick to the final black hole. We follow the orbits of a recoiling supermassive black hole (SMBH) in a fixed background potential of a disk galaxy including the effect of dynamical friction. If the recoil velocity of the SMBH is smaller than the escape velocity of the galaxy, the SMBH moves around in the potential along a complex trajectory before it spirals into the galactic center through dynamical friction. We consider the accretion of gas onto the SMBH from the surrounding ISM and estimate the X-ray luminosity of the SMBH. We find that it can be larger than 3x 10^39 erg^-1 or the typical X-ray luminosity of ultra-luminous X-ray sources, when the SMBH passes the galactic disk. In particular, the luminosity could exceed ~10^46 erg s^-1, if the SMBH is ejected into the galactic disk. The average luminosity gradually increases as the SMBH spirals into the galactic center. ...

  7. A gas cloud on its way towards the super-massive black hole in the Galactic Centre

    CERN Document Server

    Gillessen, S; Fritz, T K; Quataert, E; Alig, C; Burkert, A; Cuadra, J; Eisenhauer, F; Pfuhl, O; Dodds-Eden, K; Gammie, C F; Ott, T

    2011-01-01

    Measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a black hole four million times the mass of the Sun. With the exception of modest X-ray and infrared flares, Sgr A* is surprisingly faint, suggesting that the accretion rate and radiation efficiency near the event horizon are currently very low. Here we report the presence of a dense gas cloud approximately three times the mass of Earth that is falling into the accretion zone of Sgr A*. Our observations tightly constrain the cloud's orbit to be highly eccentric, with an innermost radius of approach of only ~3,100 times the event horizon that will be reached in 2013. Over the past three years the cloud has begun to disrupt, probably mainly through tidal shearing arising from the black hole's gravitational force. The cloud's dynamic evolution and radiation in the next few years will probe the properties of the accretion flow and the feeding processes of the super-massive black hole. ...

  8. Imaging the supermassive black hole shadow and jet base of M87 with the event horizon telescope

    International Nuclear Information System (INIS)

    The Event Horizon Telescope (EHT) is a project to assemble a Very Long Baseline Interferometry (VLBI) network of millimeter wavelength dishes that can resolve strong field general relativistic signatures near a supermassive black hole. As planned, the EHT will include enough dishes to enable imaging of the predicted black hole 'shadow', a feature caused by severe light bending at the black hole boundary. The center of M87, a giant elliptical galaxy, presents one of the most interesting EHT targets as it exhibits a relativistic jet, offering the additional possibility of studying jet genesis on Schwarzschild radius scales. Fully relativistic models of the M87 jet that fit all existing observational constraints now allow horizon-scale images to be generated. We perform realistic VLBI simulations of M87 model images to examine the detectability of the black shadow with the EHT, focusing on a sequence of model images with a changing jet mass load radius. When the jet is launched close to the black hole, the shadow is clearly visible both at 230 and 345 GHz. The EHT array with a resolution of 20-30 μas resolution (∼2-4 Schwarzschild radii) is able to image this feature independent of any theoretical models and we show that imaging methods used to process data from optical interferometers are applicable and effective for EHT data sets. We demonstrate that the EHT is also capable of tracing real-time structural changes on a few Schwarzschild radii scales, such as those implicated by very high-energy flaring activity of M87. While inclusion of ALMA in the EHT is critical for shadow imaging, the array is generally robust against loss of a station.

  9. The role of the supermassive black hole spin in the estimation of the EMRI event rate

    CERN Document Server

    Amaro-Seoane, Pau; Freitag, Marc Dewi

    2012-01-01

    One of the main channels of interactions in galactic nuclei between stars and the central massive black hole (MBH) is the gradual inspiral of compact remnants into the MBH due to the emission of gravitational radiation. Previous works about the estimation of how many events space observatories such as LISA will be able to observe during its operational time differ in orders of magnitude, due to the complexity of the problem. Nevertheless, a common result to all investigations is that a plunge is much more likely than a slow adiabatic inspiral, an EMRI. The event rates for plunges are orders of magnitude larger than slow inspirals. On the other hand, nature MBH's are most likely Kerr and the magnitude of the spin has been sized up to be high. We calculate the number of periapsis passages that a compact object set on to an extremely radial orbit goes through before being actually swallowed by the Kerr MBH and we then translate it into an event rate for a LISA-like observatory. We prove that a "plunging" compact...

  10. The Stellar-Dynamical Search for Supermassive Black Holes in Galactic Nuclei

    CERN Document Server

    Kormendy, J

    2003-01-01

    The robustness of stellar-dynamical black hole (BH) mass measurements is illustrated using 7 galaxies that have results from independent groups. Derived masses have remained constant to a factor of about 2 as spatial resolution has improved by factors of 2 - 330 and as the analysis has improved from spherical, isotropic models to axisymmetric, three-integral models. This gives us confidence that the masses are reliable and that the galaxies do not indulge in a wide variety of perverse orbital structures. Constraints on BH alternatives are also improving. In M31, Hubble Space Telescope (HST) spectroscopy shows that the central massive dark object (MDO) is in a tiny cluster of blue stars embedded in the P2 nucleus of the galaxy. The MDO must be less than about 0.06 arcsec in radius. M31 becomes the third galaxy in which dark clusters of brown dwarf stars or stellar remnants can be excluded. In our Galaxy, observations of almost-complete stellar orbits show that the MDO radius is less than about 0.0006 pc. Among...

  11. Hot versus cold: The dichotomy in spherical accretion of cooling flows onto supermassive black holes in elliptical galaxies, galaxy groups, and clusters

    International Nuclear Information System (INIS)

    Feedback heating from active galactic nuclei (AGNs) has been commonly invoked to suppress cooling flows predicted in hot gas in elliptical galaxies, galaxy groups, and clusters. Previous studies have focused on if and how AGN feedback heats the gas but have little paid attention to its triggering mechanism. Using spherically symmetric simulations, we investigate how large-scale cooling flows are accreted by central supermassive black holes (SMBHs) in eight well-observed systems and find an interesting dichotomy. In massive clusters, the gas develops a central cooling catastrophe within about the cooling time (typically ∼100-300 Myr), resulting in cold-mode accretion onto SMBHs. However, in our four simulated systems on group and galaxy scales at a low metallicity Z = 0.3 Z ☉, the gas quickly settles into a long-term state that has a cuspy central temperature profile extending to several tens to about 100 pc. At the more realistic solar metallicity, two groups (with R e ∼ 4 kpc) still host the long-term, hot-mode accretion. Both accretion modes naturally appear in our idealized calculations where only cooling, gas inflow, and compressional heating are considered. The long-term, hot-mode accretion is maintained by the quickly established closeness between the timescales of these processes, preferably in systems with low gas densities, low gas metallicities, and importantly, compact central galaxies, which result in strong gravitational acceleration and compressional heating at the intermediate radii. Our calculations predict that central cuspy temperature profiles appear more often in smaller systems than galaxy clusters, which instead often host significant cold gas and star formation.

  12. Extracting X rays, gamma rays, and electron-positron pairs from supermassive Kerr black holes using the Penrose mechanism

    Science.gov (United States)

    Williams, Reva Kay D.

    Monte Carlo computer simulations are presented of Compton scattering and electron-positron (e-e+) pair production processes in the ergosphere of a supermassive rotating black hole. Particles from an accretion disk surrounding the black hole fall into the ergosphere and scatter off particles that are in bound orbits. The equations that govern the orbital trajectory of a particle about a Kerr (rotating) black hole (KBH) are solved to determine the conserved energy and angular momentum of materials and massless particles that have orbits not confined to the equatorial plane. The escape conditions to determine whether or not a particle escapes from the potential well of the KBH are applied to the scatter particles. The Penrose mechanism allows rotational energy of a KBH to be extracted by scattered particles escaping from the ergosphere to large distances from the black hole. The results of these model calculations show that the Penrose mechanism is capable of producing the astronomically observed high energy particles emitted by quasars and other active galactic nuclei (AGN's). This mechanism, as applied in the models, can extract hard X ray/gamma ray photons from the inverse Compton scatterings of initially low energy UV/soft X ray photons by target orbiting electrons in the ergosphere. Such low energy infalling photons are consistent with photons emitted by of a classical thin accretion disk. These model calculations also allow relativistic e-e+ pairs to be produced by infalling low energy photons interacting with target photons in bound orbits inside the ergosphere. This process may be the origin of the relativistic electrons inferred from observations to emerge from the cores of AGN's.

  13. Coalescence Rate of Supermassive Black Hole Binaries Derived from Cosmological Simulations: Detection Rates for LISA and ET

    CERN Document Server

    Filloux, Ch; Durier, F; de Araujo, J C N

    2011-01-01

    The coalescence history of massive black holes has been derived from cosmological simulations, in which the evolution of those objects and that of the host galaxies are followed in a consistent way. The present study indicates that supermassive black holes having masses greater than $\\sim 10^{9} M_{\\odot}$ underwent up to 500 merger events along their history. The derived coalescence rate per comoving volume and per mass interval permitted to obtain an estimate of the expected detection rate distribution of gravitational wave signals ("ring-down") along frequencies accessible by the planned interferometers either in space (LISA) or in the ground (Einstein). For LISA, in its original configuration, a total detection rate of about $15 yr^{-1}$ is predicted for events having a signal-to-noise ratio equal to 10, expected to occur mainly in the frequency range $4-9 mHz$. For the Einstein gravitational wave telescope, one event each 14 months down to one event each 4 years is expected with a signal-to-noise ratio o...

  14. The Properties of Hypervelocity Stars and S-stars Originating from an Eccentric Disk around a Supermassive Black Hole

    Science.gov (United States)

    Šubr, Ladislav; Haas, Jaroslav

    2016-09-01

    Hypervelocity stars (HVSs), which are observed in the Galactic halo, are believed to be accelerated to large velocities by a process of tidal disruption of binary stars passing close to the supermassive black hole (SMBH) which resides in the center of the Galaxy. It is, however, still unclear where these relatively young stars were born and what dynamical process pushed them to nearly radial orbits around the SMBH. In this paper we investigate the possibility that the young binaries originated from a thin eccentric disk, similar to the one currently observed in the Galactic center. By means of direct N-body simulations, we follow the dynamical evolution of an initially thin and eccentric disk of stars with a 100% binary fraction orbiting around the SMBH. Such a configuration leads to Kozai–Lidov oscillations of orbital elements, bringing a considerable number of binaries to the close vicinity of the black hole. Subsequent tidal disruption of these binaries accelerates one of their components to velocities well above the escape velocity from the SMBH, while the second component becomes tightly bound to the SMBH. We describe the main kinematic properties of the escaping and tightly bound stars within our model, and compare them qualitatively to the properties of the observed HVSs and S-stars, respectively. The most prominent feature is strong anisotropy in the directions of the escaping stars, which is observed for Galactic HVSs but has not yet been explained.

  15. Emission Signatures from Sub-parsec Binary Supermassive Black Holes I: Diagnostic Power of Broad Emission Lines

    CERN Document Server

    Nguyen, Khai

    2016-01-01

    Motivated by advances in observational searches for sub-parsec supermassive black hole binaries (SBHBs) made in the past few years we develop a semi-analytic model to describe spectral emission line signatures of these systems. The goal of this study is to aid the interpretation of spectroscopic searches for binaries and help test one of the leading models of binary accretion flows in the literature: SBHB in a circumbinary disk. In this work we present the methodology and a comparison of the preliminary model with the data. We model SBHB accretion flows as a set of three accretion disks: two mini-disks that are gravitationally bound to the individual black holes and a circumbinary disk. Given a physically motivated parameter space occupied by sub-parsec SBHBs, we calculate a synthetic database of nearly 15 million broad optical emission line profiles and explore the dependence of the profile shapes on characteristic properties of SBHBs. We find that the modeled profiles show distinct statistical properties as...

  16. A systematic search for close supermassive black hole binaries in the Catalina Real-time Transient Survey

    Science.gov (United States)

    Graham, Matthew J.; Djorgovski, S. G.; Stern, Daniel; Drake, Andrew J.; Mahabal, Ashish A.; Donalek, Ciro; Glikman, Eilat; Larson, Steve; Christensen, Eric

    2015-10-01

    Hierarchical assembly models predict a population of supermassive black hole (SMBH) binaries. These are not resolvable by direct imaging but may be detectable via periodic variability (or nanohertz frequency gravitational waves). Following our detection of a 5.2-year periodic signal in the quasar PG 1302-102, we present a novel analysis of the optical variability of 243 500 known spectroscopically confirmed quasars using data from the Catalina Real-time Transient Survey (CRTS) to look for close (warped accretion discs or periodic accretion associated with a close SMBH binary system. We also consider how other SMBH binary candidates in the literature appear in CRTS data and show that none of these are equivalent to the identified objects. Finally, the distribution of objects found is consistent with that expected from a gravitational-wave-driven population. This implies that circumbinary gas is present at small orbital radii and is being perturbed by the black holes. None of the sources is expected to merge within at least the next century. This study opens a new unique window to study a population of close SMBH binaries that must exist according to our current understanding of galaxy and SMBH evolution.

  17. Dust-enshrouded star near supermassive black hole: predictions for high-eccentricity passages near low-luminosity galactic nuclei

    CERN Document Server

    Zajacek, Michal; Eckart, Andreas

    2014-01-01

    Supermassive black holes reside in cores of galaxies, where they are often surrounded by a nuclear cluster and a clumpy torus of gas and dust. Mutual interactions can set some stars on a plunging trajectory towards the black hole. We model the pericentre passage of a dust-enshrouded star during which the dusty envelope becomes stretched by tidal forces and is affected by the interaction with the surrounding medium. In particular, we explore under which conditions these encounters can lead to periods of enhanced accretion activity. We discuss different scenarios for such a dusty source. To this end, we employed a modification of the Swift integration package. Elements of the cloud were modelled as numerical particles that represent the dust component that interacts with the optically thin gaseous environment. We determine the fraction of the total mass of the dust component that is diverted from the original path during the passages through the pericentre at $\\sim 10^3$ Schwarzschild radii and find that the ma...

  18. Matter of Life & Death: The impact of environmental conditions on the origins of stars and supermassive black holes

    CERN Document Server

    Van Borm, Caroline

    2016-01-01

    Observational evidence suggests that some very large supermassive black holes (SMBHs) already existed less than 1 Gyr after the Big Bang. Explaining the formation and growth of the 'seeds' of these SMBHs is quite challenging. We explore the formation of such seeds in the direct collapse scenario. Using 3D hydrodynamical simulations, we investigate the impact of turbulence and rotation on the fragmentation behavior of collapsing primordial gas in the presence of a strong UV radiation background, which keeps the gas hot. Additionally, we explore different ways in which the collapsing gas may be able to stay hot, and thus limit fragmentation. Using a one-zone model, we examine the interplay between magnetic fields, turbulence, and a UV radiation background. Feedback processes from stars and black holes shape the interstellar medium (ISM) out of which new generations of luminous objects form. To understand the properties of these objects, e.g. the stellar initial mass function, it is vital to have knowledge of th...

  19. Disruption of a Red Giant Star by a Supermassive Black Hole and the Case of PS1-10jh

    CERN Document Server

    Bogdanovic, Tamara; Amaro-Seoane, Pau

    2013-01-01

    The development of a new generation of theoretical models for tidal disruptions is timely, as increasingly diverse events are being captured in surveys of the transient sky. Recently, Gezari et al. (2012) reported a discovery of a new class of tidal disruption events: the disruption of a helium-rich stellar core, thought to be a remnant of a red giant (RG) star. Motivated by this discovery and in anticipation of others, we consider tidal interaction of a RG star with a supermassive black hole (SMBH) which leads to the stripping of the stellar envelope and subsequent inspiral of the compact core towards the black hole. Once the stellar envelope is removed the inspiral of the core is driven by tidal heating as well as the emission of gravitational radiation until the core either falls into the SMBH or is tidally disrupted. In the case of tidal disruption candidate PS1-10jh we find that there is a set of orbital solutions at high eccentricities in which the tidally stripped hydrogen envelope is accreted by the S...

  20. The properties of hypervelocity stars and S-stars originating from an eccentric disc around a supermassive black hole

    CERN Document Server

    Subr, Ladislav

    2016-01-01

    Hypervelocity stars (HVSs) that are observed in the Galactic halo, are believed to be accelerated to large velocities by a process of tidal disruption of binary stars passing close to a supermassive black hole (SMBH) which resides in the center of the Galaxy. It is, however, still unclear, where these relatively young stars were born and which dynamical process pushed them to nearly radial orbits around the SMBH. In this paper we investigate the possibility that the young binaries originated from a thin eccentric disc, similar to the one observed in the Galactic center nowadays. By means of direct N-body simulations, we follow the dynamical evolution of an initially thin and eccentric disc of stars with a 100% binary fraction orbiting around the SMBH. Such a configuration leads to Kozai-Lidov oscillations of orbital elements, bringing considerable amount of binaries to close vicinity of the black hole. Subsequent tidal disruption of these binaries accelerates one of their component to velocities well above th...

  1. SDSS J0159+0105: A Radio-Quiet Quasar with a Centi-Parsec Supermassive Black Hole Binary Candidate

    CERN Document Server

    Zheng, Zhen-Ya; Shen, Yue; Jiang, Linhua; Wang, Jun-Xian; Chen, Xian; Cuadra, Jorge

    2015-01-01

    We report a candidate centi-parsec supermassive black hole binary (SMBHB) in the radio-quiet quasar SDSS J0159+0105 at z=0.217. The 8.1-year Catalina V-band light curve for this quasar reveals two significant (at P>99%) periodic signals at ~741 day and ~1500 day. The period ratio, which is close to 1:2, is typical of a black-hole binary system with a mass ratio of 0.05

  2. Detecting supermassive binary black holes with VLBI - discovery of a ring-structure in 3C454.3

    International Nuclear Information System (INIS)

    We report the detection of the first VLBI ring-structure around the core of an AGN - around the core of the quasar 3C454.3. This ring-structure starts being visible in VLBI maps around 1996. It expands with an apparent velocity between 0.11±0.01mas/yr and 0.18±0.01mas/yr and dominates the pc-scale structure for at least 14 years. This is the result of a re-analysis of 41 VLBA data sets at six different radio frequencies observed between 1995.57 and 2011.48. We observe a correlation between radio flaring, flux-density variability, a ring-structure and kinematic properties of the jet. Taken together, it is tempting to see a causal connection and to explain all of this geometrically. The kinematic changes as well as the changes in the flaring characteristics might be caused by a change of the angle to the line of sight towards the observer. This behaviour resembles our findings for 0735+178 - with 3C454.3 being the second AGN to reveal kinematic mode changes. These mode changes could be explained by the presence of a supermassive binary black hole. 3C454.3 had been modelled as a binary black hole before.

  3. Extracting x rays, γ rays, and relativistic e-e+ pairs from supermassive Kerr black holes using the Penrose mechanism

    Science.gov (United States)

    Williams, Reva Kay

    1995-05-01

    Monte Carlo computer simulations of Compton scattering and e-e+ pair production processes, in the ergosphere of a supermassive (~108Msolar) rotating black hole, are presented. Particles from an accretion disk surrounding the black hole fall into the ergosphere and scatter off particles that are in bound orbits. In this paper, the equations that govern the orbital trajectory of a particle about a Kerr black hole (KBH) are used to derive analytical expressions for the conserved energy and angular momentum of material and massless particles that have orbits not confined to the equatorial plane. The escape conditions to determine whether or not a particle escapes from the potential well of the KBH are applied to the scattered particles. The Penrose mechanism, in general, allows rotational energy of a KBH to be extracted by scattered particles escaping from the ergosphere to large distances from the black hole. The results of these model calculations, presented in this paper, show that the Penrose mechanism is capable of producing the astronomically observed high energy particles (~ GeV) emitted by quasars and other active galactic nuclei (AGN). This mechanism can extract hard x-ray and γ-ray photons, from Penrose Compton scatterings of initially low energy UV and soft x-ray photons by target orbiting electrons in the ergosphere; such low energy infalling photons, and high energy scattered escaping photons, are consistent with observations and popular theoretical accretion disk, black hole models. The Penrose pair production processes (γγ-->e+e-), presented here, allow relativistic e-e+ pairs to escape with energies up to ~2 GeV; these pairs are produced when infalling low energy photons collide with bound target, highly blueshifted photons at the photon orbit. This process may very well be the origin of the relativistic electrons inferred, from observations, to emerge from the cores of AGN. Overall, these Penrose processes can apply to any mass size black hole, more

  4. Implications of primordial black holes on the first stars and the origin of the super--massive black holes

    OpenAIRE

    Bambi, Cosimo; Spolyar, Douglas; Dolgov, Alexander D.; Freese, Katherine; Volonteri, Marta

    2008-01-01

    If the cosmological dark matter has a component made of small primordial black holes, they may have a significant impact on the physics of the first stars and on the subsequent formation of massive black holes. Primordial black holes would be adiabatically contracted into these stars and then would sink to the stellar center by dynamical friction, creating a larger black hole which may quickly swallow the whole star. If these primordial black holes are heavier than $\\sim 10^{22} {\\rm g}$, the...

  5. Supermassive black hole formation by the cold accretion shocks in the first galaxies

    CERN Document Server

    Inayoshi, Kohei

    2012-01-01

    We propose a new scenario for supermassive star (SMS;>10^5Msun) formation in shocked regions of colliding cold accretion flows near the centers of first galaxies. Recent numerical simulations indicate that assembly of a typical first galaxy with virial temperature (~10^4K) proceeds via cold and dense flows penetrating deep to the center, where the supersonic streams collide each other to develop a hot and dense (~10^4K, ~10^3/cc) shocked gas. The post-shock layer first cools by efficient Ly alpha emission and contracts isobarically until 8000K. Whether the layer continues the isobaric contraction depends on the density at this moment: if the density is high enough for collisionally exciting H2 rovibrational levels (>10^4/cc), enhanced H2 collisional dissociation suppresses the gas to cool further. In this case, the layer fragments into massive (>10^5Msun) clouds, which collapse isothermally (~8000K) by the Ly alpha cooling without subsequent fragmentation. As an outcome, SMSs are expected to form and evolve e...

  6. CO-EVOLUTION OF SUPERMASSIVE BLACK HOLE AND HOST GALAXY FROM z ∼ 1 TO z = 0

    International Nuclear Information System (INIS)

    Stellar masses of bulges in hosts of active galactic nuclei (AGNs) and black hole masses in the AGNs are derived at z = 0.5-1.15 to study evolution of the black hole-to-bulge mass relation. In order to derive bulge stellar masses, we use a sample of type-2 AGNs to avoid the bright nuclear light. 34 type-2 AGNs are selected from the spectroscopically identified X-ray sources in the Chandra Deep Field South. We use optical images from the Hubble Space Telescope, and near- and mid-infrared photometry from the Very Large Telescope and the Spitzer Space Telescope. The bulge components are derived by fitting the two-dimensional surface brightness model consisting of a bulge and a disk component to the optical images. We derive stellar masses (M bulge) and star formation rates (SFRs) of the bulge components by spectral energy distribution fitting. The derived M bulge ranges over 109-1011 M sun, and the estimated SFR is 0.01-100 M sun yr-1. Masses of supermassive black holes (SMBHs; M .) and black hole accretion rates (BHARs) are estimated with the absorption-corrected X-ray luminosities in the 2-10 keV band under an assumption of the constant Eddington ratio of 0.1 and the constant energy conversion factor of 0.1. Resulting black hole masses and BHARs range over 105.5-108 M sun and 0.001-1 M sun yr-1, respectively. For luminous AGNs, the estimated M ./M bulge ratio is ∼4 x 10-4 in the median, which is lower than that for local galaxies and for type-2 AGNs at z ∼ 0.2. However, these differences are within uncertainty and are not significant. This can imply that SMBHs and their host galaxies are evolving almost holding the constant M ./M bulge ratio from z ∼ 1.0 to 0 in a cosmological timescale. Meanwhile, the estimated BHAR/SFR ratio is about 60 times larger than the M ./M bulge ratio in the median value. This indicates that growths of SMBHs and their host bulges do not proceed simultaneously in a shorter timescale such as an AGN phase.

  7. Supermassive recoil velocities for binary black-hole mergers with antialigned spins.

    Science.gov (United States)

    González, José A; Hannam, Mark; Sperhake, Ulrich; Brügmann, Bernd; Husa, Sascha

    2007-06-01

    Recent calculations of the recoil velocity in binary black-hole mergers have found the kick velocity to be of the order of a few hundred km/s in the case of nonspinning binaries and about 500 km/s in the case of spinning configurations, and have lead to predictions of a maximum kick of up to 1300 km/s. We test these predictions and demonstrate that kick velocities of at least 2500 km/s are possible for equal-mass binaries with antialigned spins in the orbital plane. Kicks of that magnitude are likely to have significant repercussions for models of black-hole formation, the population of intergalactic black holes, and the structure of host galaxies. PMID:17677893

  8. A rapidly spinning supermassive black hole at the centre of NGC 1365

    DEFF Research Database (Denmark)

    Risaliti, G.; Harrison, F. A.; Madsen, K. K.;

    2013-01-01

    and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims...... that the black hole (2 × 10(6) solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe-line emission...... and an associated Compton scattering excess of 10-30 kiloelectronvolts. Using temporal and spectral analyses, we disentangle continuum changes due to time-variable absorption from reflection, which we find arises from a region within 2.5 gravitational radii of the rapidly spinning black hole. Absorption...

  9. A new way to measure supermassive black hole spin in accretion disc-dominated active galaxies

    OpenAIRE

    Done, C.; Jin, C; Middleton, M; Ward, M.

    2013-01-01

    We show that disc continuum fitting can be used to constrain black hole spin in a subclass of narrow-line Seyfert 1 (NLS1) active galactic nuclei as their low mass and high mass accretion rate means that the disc peaks at energies just below the soft X-ray bandpass. We apply the technique to the NLS1 PG1244+026, where the optical/UV/X-ray spectrum is consistent with being dominated by a standard disc component. This gives a best estimate for black hole spin which is low, with a firm upper lim...

  10. A new way to measure supermassive black hole spin in accretion disc dominated Active Galaxies

    OpenAIRE

    Done, C.; Jin, C; Middleton, M; Ward, M.

    2013-01-01

    We show that disc continuum fitting can be used to constrain black hole spin in a subclass of narrow-line Seyfert 1 (NLS1) active galactic nuclei as their low mass and high mass accretion rate means that the disc peaks at energies just below the soft X-ray bandpass. We apply the technique to the NLS1 PG1244+026, where the optical/UV/X-ray spectrum is consistent with being dominated by a standard disc component. This gives a best estimate for black hole spin which is low, with a firm upper lim...

  11. EXTREME STAR FORMATION IN THE HOST GALAXIES OF THE FASTEST GROWING SUPERMASSIVE BLACK HOLES AT z = 4.8

    International Nuclear Information System (INIS)

    We report new Herschel observations of 25 z ≅ 4.8 extremely luminous optically selected active galactic nuclei (AGNs). Five of the sources have extremely large star-forming (SF) luminosities, LSF, corresponding to SF rates (SFRs) of 2800-5600 M☉ yr–1 assuming a Salpeter initial mass function. The remaining sources have only upper limits on their SFRs, but stacking their Herschel images results in a mean SFR of 700 ± 150 M☉ yr–1. The higher SFRs in our sample are comparable to the highest observed values so far at any redshift. Our sample does not contain obscured AGNs, which enables us to investigate several evolutionary scenarios connecting supermassive black holes and SF activity in the early universe. The most probable scenario is that we are witnessing the peak of SF activity in some sources and the beginning of the post-starburst decline in others. We suggest that all 25 sources, which are at their peak AGN activity, are in large mergers. AGN feedback may be responsible for diminishing the SF activity in 20 of them, but is not operating efficiently in 5 others.

  12. The contribution of young core-collapse supernova remnants to the X-ray emission near quiescent supermassive black holes

    CERN Document Server

    Rimoldi, Alex; Costantini, Elisa; Zwart, Simon Portegies

    2015-01-01

    Appreciable star formation, and, therefore, numerous massive stars, are frequently found near supermassive black holes (SMBHs). As a result, core-collapse supernovae in these regions should also be expected. In this paper, we consider the observational consequences of predicting the fate of supernova remnants (SNRs) in the sphere of influence of quiescent SMBHs. We present these results in the context of `autarkic' nuclei, a model that describes quiescent nuclei as steady-state and self-sufficient environments where the SMBH accretes stellar winds with no appreciable inflow of material from beyond the sphere of influence. These regions have properties such as gas density that scale with the mass of the SMBH. Using predictions of the X-ray lifetimes of SNRs originating in the sphere of influence, we make estimates of the number of core collapse SNRs present at a given time. With the knowledge of lifetimes of SNRs and their association with young stars, we predict a number of core-collapse SNRs that grows from ...

  13. Hierarchical Assembly of Supermassive Black Holes: Adaptive Optics Imaging of Double-Peaked [O III] Active Galactic Nuclei

    CERN Document Server

    Fu, Hai; Djorgovski, S G; Yan, Lin

    2010-01-01

    Hierarchical galaxy assembly models predict the ubiquity of binary supermassive black holes (SMBHs). Nevertheless, observational confirmations of binary SMBHs are rare. We have obtained high-resolution near-infrared images of 50 double-peaked [O III] active galactic nuclei (AGNs) with Keck II laser guide star adaptive optics. The sample is compiled from the literature and consists of 17 type-1 and 33 type-2 AGNs over 0.03 < z < 0.56. Eight type-1 and eight type-2 sources are apparently undergoing mergers with multiple components of comparable luminosities, separated between 0.6 and 12 kpc. Disturbed morphologies are evident in most cases. The merger fractions of type-1s and type-2s differ because the fraction increases with redshift, f_merger \\propto (1+z)^4, which is consistent with the evolution of major merger fraction of L* galaxies at z < 1. We show that type-1 AGNs in compact merging systems are outliers of the M_BH-sigma relation since stellar velocity dispersions could be over-estimated becau...

  14. RADIO ACTIVE GALAXY NUCLEI IN GALAXY CLUSTERS: HEATING HOT ATMOSPHERES AND DRIVING SUPERMASSIVE BLACK HOLE GROWTH OVER COSMIC TIME

    International Nuclear Information System (INIS)

    We estimate the average radio active galactic nucleus (AGN, mechanical) power deposited into the hot atmospheres of galaxy clusters over more than three quarters of the age of the Universe. Our sample was drawn from eight major X-ray cluster surveys and includes 685 clusters in the redshift range 0.1 44 erg s–1 exceeds the X-ray luminosity of 44% of the clusters, indicating that the accumulation of radio-AGN energy is significant in these clusters. Integrating the AGN mechanical power to redshift z = 2.0, using simple models for its evolution and disregarding the hierarchical growth of clusters, we find that the AGN energy accumulated per particle in low luminosity X-ray clusters exceeds 1 keV per particle. This result represents a conservative lower limit to the accumulated thermal energy. The estimate is comparable to the level of energy needed to 'preheat' clusters, indicating that continual outbursts from radio-AGN are a significant source of gas energy in hot atmospheres. Assuming an average mass conversion efficiency of η = 0.1, our result implies that the supermassive black holes that released this energy did so by accreting an average of ∼109 M ☉ over time, which is comparable to the level of growth expected during the quasar era.

  15. The Supermassive Black Hole Mass - Spheroid Stellar Mass Relation for S\\'ersic and Core-S\\'ersic Galaxies

    CERN Document Server

    Scott, Nicholas; Schombert, James

    2013-01-01

    We have examined the relationship between supermassive black hole mass (M_BH) and the stellar mass of the host spheroid (M_sph,*) for a sample of 75 nearby galaxies. To derive the spheroid stellar masses we used improved 2MASS K_s-band photometry from the ARCHANGEL photometry pipeline. Dividing our sample into core-S\\'ersic and S\\'ersic galaxies, we find that they are described by very different M_BH-M_sph,* relations. For core-S\\'ersic galaxies - which are typically massive and luminous, with M_BH \\gtrsim 2x10^8 M_solar - we find M_BH \\propto M_sph,*^(0.97 \\pm 0.14), consistent with other literature relations. However, for the S\\'ersic galaxies - with typically lower masses, M_sph,* \\lesssim 3x10^10 M_solar - we find M_BH \\propto M_sph,*^(2.22 \\pm 0.58), a dramatically steeper slope that differs by more than 2 standard deviations. This relation confirms that, for S\\'ersic galaxies, M_BH is not a constant fraction of M_sph,*. S\\'ersic galaxies can grow via the accretion of gas which fuels both star formation ...

  16. A reduced orbital period for the supermassive black hole binary candidate in the quasar PG 1302-102?

    CERN Document Server

    D'Orazio, Daniel J; Duffell, Paul; Farris, Brian D; MacFadyen, Andrew I

    2015-01-01

    Graham et al. (2015) have detected a 5.2 year periodic optical variability of the quasar PG 1302-102 at redshift $z=0.3$, which they interpret as the redshifted orbital period $(1+z)t_{\\rm bin}$ of a putative supermassive black hole binary (SMBHB). Here we consider the implications of a $3-8$ times shorter orbital period, suggested by hydrodynamical simulations of circumbinary discs (CBDs) with nearly equal--mass SMBHBs ($q\\equiv M_2/M_1\\gtrsim 0.3$). With the corresponding $2-4$ times tighter binary separation, PG 1302 would be undergoing gravitational wave dominated inspiral, and serve as a proof that the BHs can be fueled and produce bright emission even in this late stage of the merger. The expected fraction of binaries with the shorter $t_{\\rm bin}$, among bright quasars, would be reduced by 1-2 orders of magnitude, compared to the 5.2 year period, in better agreement with the rarity of candidates reported by Graham et al. (2015). Finally, shorter periods would imply higher binary speeds, possibly imprin...

  17. Near-Infrared Spectroscopy of Quasars at z~3 and Estimates of Their Supermassive Black Hole Masses

    CERN Document Server

    Saito, Yuriko; Minowa, Yosuke; Morokuma, Tomoki; Kawaguchi, Toshihiro; Sameshima, Hiroaki; Minezaki, Takeo; Oi, Nagisa; Nagao, Tohru; Kawatatu, Nozomu; Matsuoka, Kenta

    2015-01-01

    We present the results of new infrared spectroscopic observations of 37 quasars at z~3, selected based on the optical r'-band magnitude and the availability of nearby bright stars for future imaging follow-up with Adaptive Optics system. The supermassive black hole (SMBH) masses (M_BH) were successfully estimated in 28 out of 37 observed objects from the combination of the H_beta emission linewidth and continuum luminosity at rest-frame 5100A. Comparing these results with those from previous studies of quasars with similar redshift, our sample exhibited slightly lower (~ -0.11 dex in median) Eddington ratios; and, the SMBH masses are slightly (~ 0.38 dex in median) higher. The SMBH growth time, t_grow, was calculated by dividing the estimated SMBH mass by the mass accretion rate measured using optical luminosity. We found, given reasonable assumptions, that t_grow was smaller than the age of the universe at the redshift of individual quasars for a large fraction of observed sources, suggesting that the SMBHs ...

  18. Infalling clouds onto super-massive black hole binaries - I. Formation of discs, accretion and gas dynamics

    CERN Document Server

    Goicovic, F G; Sesana, A; Stasyszyn, F; Amaro-Seoane, P; Tanaka, T L

    2015-01-01

    There is compelling evidence that most -if not all- galaxies harbour a super-massive black hole (SMBH) at their nucleus, hence binaries of these massive objects are an inevitable product of the hierarchical evolution of structures in the universe, and represent an important but thus-far elusive phase of galaxy evolution. Gas accretion via a circumbinary disc is thought to be important for the dynamical evolution of SMBH binaries, as well as in producing luminous emission that can be used to infer their properties. One plausible source of the gaseous fuel is clumps of gas formed due to turbulence and gravitational instabilities in the interstellar medium, that later fall toward and interact with the binary. In this context, we model numerically the evolution of turbulent clouds in near-radial infall onto equal-mass SMBH binaries, using a modified version of the SPH code GADGET-3. We present a total of 12 simulations that explore different possible pericentre distances and relative inclinations, and show that t...

  19. Spectroscopic Indication of a Centi-parsec Supermassive Black Hole Binary in the Galactic Center of NGC 5548

    Science.gov (United States)

    Li, Yan-Rong; Wang, Jian-Min; Ho, Luis C.; Lu, Kai-Xing; Qiu, Jie; Du, Pu; Hu, Chen; Huang, Ying-Ke; Zhang, Zhi-Xiang; Wang, Kai; Bai, Jin-Ming

    2016-05-01

    As a natural consequence of cosmological hierarchical structure formation, sub-parsec supermassive black hole binaries (SMBHBs) should be common in galaxies but thus far have eluded spectroscopic identification. Based on four decades of optical spectroscopic monitoring, we report that the nucleus of NGC 5548, a nearby Seyfert galaxy long suspected to have experienced a major merger about 1 billion yr ago, exhibits long-term variability with a period of ∼14 yr in the optical continuum and broad Hβ emission line. Remarkably, the double-peaked profile of Hβ shows systematic velocity changes with a similar period. These pieces of observations plausibly indicate that an SMBHB resides in the center of NGC 5548. The complex, secular variations in the line profiles can be explained by orbital motion of a binary with equal mass and a semimajor axis of ∼22 light-days (corresponding to ∼18 milli-parsec). At a distance of 75 Mpc, NGC 5548 is one of the nearest sub-parsec SMBHB candidates that offers an ideal laboratory for gravitational wave detection.

  20. Supermassive black holes pairs in clumpy galaxies at high redshift: delayed binary formation and concurrent mass growth

    CERN Document Server

    Tamburello, Valentina; Mayer, Lucio; Bellovary, Jillian M; Wadsley, James

    2016-01-01

    Massive gas-rich galaxy discs at $z \\sim 1-3$ host massive star-forming clumps with typical baryonic masses in the range $10^7-10^8$ M$_{\\odot}$ which can affect the orbital decay and concurrent growth of supermassive black hole (BH) pairs. We use a set of high-resolution simulations of isolated clumpy galaxies hosting a pair of unequal-mass BHs, in order to study the interaction between massive clumps and a BH pair at kpc scales, during the early phase of the orbital decay, before the formation of a bound BH binary. We find that both the interaction with massive clumps and the heating of the cold gas layer of the disc by BH feedback tend to delay significantly the orbital decay of the secondary, which in many cases is ejected and then hovers for a whole Gyr around a separation of 1-2 kpc. In the envelope, dynamical friction is weak and there is no contribution of disc torques: these lead to the fastest decay once the orbit of the secondary BH has circularised in the disc midplane. In runs with larger eccentr...

  1. Detection of eccentric supermassive black hole binaries with pulsar timing arrays: Signal-to-noise ratio calculations

    Science.gov (United States)

    Huerta, E. A.; McWilliams, Sean T.; Gair, Jonathan R.; Taylor, Stephen R.

    2015-09-01

    We present a detailed analysis of the expected signal-to-noise ratios of supermassive black hole binaries on eccentric orbits observed by pulsar timing arrays. We derive several analytical relations that extend the results of Peters and Mathews [Phys. Rev. D 131, 435 (1963)] to quantify the impact of eccentricity in the detection of single resolvable binaries in the pulsar timing array band. We present ready-to-use expressions to compute the increase/loss in signal-to-noise ratio of eccentric single resolvable sources whose dominant harmonic is located in the low/high frequency sensitivity regime of pulsar timing arrays. Building upon the work of Phinney (arXiv:astro-ph/0108028) and Enoki and Nagashima [Prog. Theor. Phys. 117, 241 (2007)], we present an analytical framework that enables the construction of rapid spectra for a stochastic gravitational-wave background generated by a cosmological population of eccentric sources. We confirm previous findings which indicate that, relative to a population of quasicircular binaries, the strain of a stochastic, isotropic gravitational-wave background generated by a cosmological population of eccentric binaries will be suppressed in the frequency band of pulsar timing arrays. We quantify this effect in terms of signal-to-noise ratios in a pulsar timing array.

  2. Rich Kozai-Lidov Dynamics in an Initially Thin and Eccentric Stellar Disc Around a Supermassive Black Hole

    CERN Document Server

    Haas, Jaroslav

    2016-01-01

    There is growing evidence of star formation in the vicinity of supermassive black holes (SMBH) in galactic nuclei. A viable scenario for this process assumes infall of a massive gas cloud towards the SMBH and subsequent formation of a dense accretion disc which gives birth to the young stars. Numerical hydrodynamical models indicate that this star formation process is rather fast and it precedes full circularization of the accretion flow, i.e. the new stars are born on elliptic orbits. By means of direct numerical N-body modeling, we show in this paper that the non-zero eccentricity of the stellar discs around the SMBH leads to an onset of various types of the Kozai-Lidov oscillations of a non-negligible subset of individual orbits in the disc, showing a remarkable robustness of this classical mechanism. Among others, we demonstrate that under certain circumstances, presence of an additional spherical cluster (which is generally known to damp Kozai-Lidov oscillations) may trigger such oscillations due to affe...

  3. Rich Kozai–Lidov Dynamics in an Initially Thin and Eccentric Stellar Disk around a Supermassive Black Hole

    Science.gov (United States)

    Haas, Jaroslav; Šubr, Ladislav

    2016-05-01

    There is growing evidence of star formation in the vicinity of supermassive black holes (SMBHs) in galactic nuclei. A viable scenario for this process assumes infall of a massive gas cloud toward the SMBH and subsequent formation of a dense accretion disk, which gives birth to the young stars. Numerical hydrodynamical models indicate that this star formation process is rather fast and precedes full circularization of the accretion flow, i.e., the new stars are born on elliptic orbits. By means of direct numerical N-body modeling, we show in this paper that the nonzero eccentricity of the stellar disks around the SMBH leads to an onset of various types of the Kozai–Lidov oscillations of a non-negligible subset of individual orbits in the disk, showing a remarkable robustness of this classical mechanism. Among others, we demonstrate that under certain circumstances, the presence of an additional spherical cluster (which is generally known to damp Kozai–Lidov oscillations) may trigger such oscillations as a result of affecting the internal flow of the angular momentum through the disk. We conclude that the Kozai–Lidov oscillations are capable of substantially modifying the initial structure of the disk (its thickness and distribution of eccentricities, in particular).

  4. Multiple periods in the variability of the supermassive black hole binary candidate quasar PG1302-102?

    CERN Document Server

    Charisi, Maria; Haiman, Zoltán; Price-Whelan, Adrian M; Márka, Szabolcs

    2015-01-01

    Graham et al. (2015) discovered a supermassive black hole binary (SMBHB) candidate and identified the detected 5.2 yr period of the optical variability as the orbital period of the binary. Hydrodynamical simulations predict multiple periodic components for the variability of SMBHBs, thus raising the possibility that the true period of the binary is different from 5.2 yr. We analyse the periodogram of PG1302 and find no compelling evidence for additional peaks. We derive upper limits on any additional periodic modulations in the available data, by modeling the light-curve as the sum of red noise and the known 5.2 yr periodic component, and injecting additional sinusoidal signals. We find that, with the current data, we would be able to detect with high significance (false alarm probability <1%) secondary periodic terms with periods in the range predicted by the simulations, if the amplitude of the variability was at least ~0.07 mag (compared to 0.14 mag for the main peak). A three-year follow-up monitoring ...

  5. Near-infrared polarimetry as a tool for testing properties of accreting supermassive black holes

    Czech Academy of Sciences Publication Activity Database

    Zamaninasab, M.; Eckart, A.; Dovčiak, Michal; Karas, Vladimír; Schoedel, R.; Witzel, G.; Sabha, N.; García-Marín, M.; Kunneriath, D.; Muzic, K.; Straubmeier, C.; Valencia-S, M.; Zensus, J. A.

    2011-01-01

    Roč. 413, č. 1 (2011), s. 322-332. ISSN 0035-8711 R&D Projects: GA ČR GA205/07/0052 Institutional research plan: CEZ:AV0Z10030501 Keywords : polarimetry * black holes * relativity * galactic centre Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.900, year: 2011

  6. The XMM-Newton spectrum of a candidate recoiling supermassive black hole: An elusive inverted P-Cygni profile

    International Nuclear Information System (INIS)

    We present a detailed spectral analysis of new XMM-Newton data of the source CXOC J100043.1+020637, also known as CID-42, detected in the COSMOS survey at z = 0.359. Previous works suggested that CID-42 is a candidate recoiling supermassive black hole (SMBH) showing also an inverted P-Cygni profile in the X-ray spectra at ∼6 keV (rest) with an iron emission line plus a redshifted absorption line (detected at 3σ in previous XMM-Newton and Chandra observations). Detailed analysis of the absorption line suggested the presence of ionized material flowing into the black hole at high velocity. In the new long XMM-Newton observation, while the overall spectral shape remains constant, the continuum 2-10 keV flux decrease of ∼20% with respect to previous observation and the absorption line is undetected. The upper limit on the intensity of the absorption line is EW < 162 eV. Extensive Monte Carlo simulations show that the nondetection of the line is solely due to variation in the properties of the inflowing material, in agreement with the transient nature of these features, and that the intensity of the line is lower than the previously measured with a probability of 98.8%. In the scenario of CID-42 as a recoiling SMBH, the absorption line can be interpreted as being due to an inflow of gas with variable density that is located in the proximity of the SMBH and recoiling with it. New monitoring observations will be requested to further characterize this line.

  7. Emission Signatures from Sub-parsec Binary Supermassive Black Holes. I. Diagnostic Power of Broad Emission Lines

    Science.gov (United States)

    Nguyen, Khai; Bogdanović, Tamara

    2016-09-01

    Motivated by advances in observational searches for sub-parsec supermassive black hole binaries (SBHBs) made in the past few years, we develop a semi-analytic model to describe spectral emission-line signatures of these systems. The goal of this study is to aid the interpretation of spectroscopic searches for binaries and to help test one of the leading models of binary accretion flows in the literature: SBHB in a circumbinary disk. In this work, we present the methodology and a comparison of the preliminary model with the data. We model SBHB accretion flows as a set of three accretion disks: two mini-disks that are gravitationally bound to the individual black holes and a circumbinary disk. Given a physically motivated parameter space occupied by sub-parsec SBHBs, we calculate a synthetic database of nearly 15 million broad optical emission-line profiles and explore the dependence of the profile shapes on characteristic properties of SBHBs. We find that the modeled profiles show distinct statistical properties as a function of the semimajor axis, mass ratio, eccentricity of the binary, and the degree of alignment of the triple disk system. This suggests that the broad emission-line profiles from SBHB systems can in principle be used to infer the distribution of these parameters and as such merit further investigation. Calculated profiles are more morphologically heterogeneous than the broad emission lines in observed SBHB candidates and we discuss improved treatment of radiative transfer effects, which will allow a direct statistical comparison of the two groups.

  8. Direct Formation of Supermassive Black Holes in Metal-enriched Gas at the Heart of High-redshift Galaxy Mergers

    Science.gov (United States)

    Mayer, Lucio; Fiacconi, Davide; Bonoli, Silvia; Quinn, Thomas; Roškar, Rok; Shen, Sijing; Wadsley, James

    2015-09-01

    We present novel 3D multi-scale smoothed particle hydrodynamics (SPH) simulations of gas-rich galaxy mergers between the most massive galaxies at z ˜ 8-10, designed to scrutinize the direct collapse formation scenario for massive black hole seeds proposed in Mayer et al. The simulations achieve a resolution of 0.1 pc, and include both metallicity-dependent optically thin cooling and a model for thermal balance at high optical depth. We consider different formulations of the SPH hydrodynamical equations, including thermal and metal diffusion. When the two merging galaxy cores collide, gas infall produces a compact, optically thick nuclear disk with densities exceeding 10-10 g cm3. The disk rapidly accretes higher angular momentum gas from its surroundings reaching ˜5 pc and a mass of ≳109 M⊙ in only a few 104 years. Outside ≳2 pc it fragments into massive clumps. Instead, supersonic turbulence prevents fragmentation in the inner parsec region, which remains warm (˜3000-6000 K) and develops strong non-axisymmetric modes that cause prominent radial gas inflows (>104 M⊙ yr-1), forming an ultra-dense massive disky core. Angular momentum transport by non-axisymmetric modes should continue below our spatial resolution limit, quickly turning the disky core into a supermassive protostar which can collapse directly into a massive black hole of mass 108-109 M⊙ via the relativistic radial instability. Such a “cold direct collapse” explains naturally the early emergence of high-z QSOs. Its telltale signature would be a burst of gravitational waves in the frequency range of 10-4-10-1 Hz, possibly detectable by the planned eLISA interferometer.

  9. Particle acceleration from an inner accretion disc into compact corona and further out: case of an organised magnetic field near a supermassive black hole

    Science.gov (United States)

    Karas, Vladimir; Kopacek, Ondrej; Kunneriath, Devaky; Kovar, Jiri; Slany, Petr

    2016-04-01

    Upcoming observational techniques in X-rays and millimeter spectral bands will allow to probe the inner corona of accretion discs near supermassive black holes. Size of this region only a few gravitational radii has been inferred from various circumstantial evidence. To populate ithe region with particles, pair-creation in ergosphere and transport of particles via accretion have been invoked.Electromagnetic fields are a likely agent of acceleration in strong gravity of a rotating black hole. We put forward a scenario with an organised component of the magnetic field near a supermassive black hole. An emergent flow of particles may be induced in a preferentially bi-polar direction. Our mechanism does not seem to be capable of producing ultra-high energy cosmic rays but it does expel particles along unbound trajectories.The mentioned concept is relevant also from a purely theoretical viewpoint of dynamical properties of particle motion in General Relativity, namely, the onset of chaos near a black hole. We conclude that the role of black-hole spin in setting the chaos is more complicated than initially thought (based on http://arxiv.org/abs/1408.2452).

  10. Revealing general relativity effects from accretion events near a supermassive black hole

    Czech Academy of Sciences Publication Activity Database

    Karas, Vladimír; Dovčiak, Michal; Eckart, A.; Kunneriath, Devaky; Zamaninasab, M.

    Opava: Silesian University, 2014 - (Stuchlík, Z.), s. 93-102. (Publications of the Institute of Physics. 6). ISBN 9788075101242. ISSN 2336-5668. [RAGtime /10.-13./. Opava (CZ), 15.09.2008-17.09.2008] R&D Projects: GA ČR(CZ) GC13-00070J Institutional support: RVO:67985815 Keywords : black hole s * galactic center * relativity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  11. Science with the space-based interferometer eLISA. I: Supermassive black hole binaries

    CERN Document Server

    Klein, Antoine; Sesana, Alberto; Petiteau, Antoine; Berti, Emanuele; Babak, Stanislav; Gair, Jonathan; Aoudia, Sofiane; Hinder, Ian; Ohme, Frank; Wardell, Barry

    2016-01-01

    We compare the science capabilities of different eLISA mission designs, including four-link (two-arm) and six-link (three-arm) configurations with different arm lengths, low-frequency noise sensitivities and mission durations. For each of these configurations we consider a few representative massive black hole formation scenarios. These scenarios are chosen to explore two physical mechanisms that greatly affect eLISA rates, namely (i) black hole seeding, and (ii) the delays between the merger of two galaxies and the merger of the black holes hosted by those galaxies. We assess the eLISA parameter estimation accuracy using a Fisher matrix analysis with spin-precessing, inspiral-only waveforms. We quantify the information present in the merger and ringdown by rescaling the inspiral-only Fisher matrix estimates using the signal-to-noise ratio from non-precessing inspiral-merger-ringdown phenomenological waveforms, and from a reduced set of precessing numerical relativity/post-Newtonian hybrid waveforms. We find ...

  12. Unification of the Fundamental Plane and Super-Massive Black Holes Masses

    CERN Document Server

    Bosch, Remco van den

    2016-01-01

    According to the Virial Theorem, all gravitational systems in equilibrium sit on a plane in the 3D parameter space defined by their mass, size and second moment of the velocity tensor. While these quantities cannot be directly observed, there are suitable proxies: the luminosity Lk, half-light radius Re and dispersion sigma_e. These proxies indeed lie on a very tight Fundamental Plane (FP). How do the black holes in the centers of galaxies relate to the FP? Their masses are known to exhibit no strong correlation with total galaxy mass, but they do correlate weakly with bulge mass (when present), and extremely well with the velocity dispersion through the Mbh = sigma_e^5.3 relation. These facts together imply that a tight plane must also exist defined by black hole mass, total galaxy mass and size. Here I show that this is indeed the case using a heterogeneous set of 225 black holes. The sample includes BHs from zero to 10 billion solar masses and host galaxies ranging from low surface brightness dwarfs, throu...

  13. BLACK HOLE MASS ESTIMATES AND RAPID GROWTH OF SUPERMASSIVE BLACK HOLES IN LUMINOUS z ∼ 3.5 QUASARS

    International Nuclear Information System (INIS)

    We present new near-infrared (IR) observations of the Hβ λ4861 and Mg II λ2798 lines for 32 luminous quasars with 3.2 < z < 3.9 using the Palomar Hale 200 inch telescope and the Large Binocular Telescope. We find that the Mg II FWHM is well correlated with the Hβ FWHM, confirming itself as a good substitute for the Hβ FWHM in the black hole mass estimates. The continuum luminosity at 5100 Å well correlates with the continuum luminosity at 3000 Å and the broad emission line luminosities (Hβ and Mg II). With simultaneous near-IR spectroscopy of the Hβ and Mg II lines to exclude the influences of flux variability, we are able to evaluate the reliability of estimating black hole masses based on the Mg II line for high redshift quasars. With the reliable Hβ line based black hole mass and Eddington ratio estimates, we find that the z ∼ 3.5 quasars in our sample have black hole masses 1.90 × 109 M ☉ ≲ M BH ≲ 1.37 × 1010 M ☉, with a median of ∼5.14 × 109 M ☉ and are accreting at Eddington ratios between 0.30 and 3.05, with a median of ∼1.12. Assuming a duty cycle of 1 and a seed black hole mass of 104 M ☉, we show that the z ∼ 3.5 quasars in this sample can grow to their estimated black hole masses within the age of the universe at their redshifts

  14. BLACK HOLE MASS ESTIMATES AND RAPID GROWTH OF SUPERMASSIVE BLACK HOLES IN LUMINOUS z ∼ 3.5 QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Wenwen; Wu, Xue-Bing [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Fan, Xiaohui; Green, Richard [Steward Observatory, The University of Arizona, Tucson, AZ 85721 (United States); Wang, Ran [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Bian, Fuyan [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston ACT 2611 (Australia)

    2015-02-01

    We present new near-infrared (IR) observations of the Hβ λ4861 and Mg II λ2798 lines for 32 luminous quasars with 3.2 < z < 3.9 using the Palomar Hale 200 inch telescope and the Large Binocular Telescope. We find that the Mg II FWHM is well correlated with the Hβ FWHM, confirming itself as a good substitute for the Hβ FWHM in the black hole mass estimates. The continuum luminosity at 5100 Å well correlates with the continuum luminosity at 3000 Å and the broad emission line luminosities (Hβ and Mg II). With simultaneous near-IR spectroscopy of the Hβ and Mg II lines to exclude the influences of flux variability, we are able to evaluate the reliability of estimating black hole masses based on the Mg II line for high redshift quasars. With the reliable Hβ line based black hole mass and Eddington ratio estimates, we find that the z ∼ 3.5 quasars in our sample have black hole masses 1.90 × 10{sup 9} M {sub ☉} ≲ M {sub BH} ≲ 1.37 × 10{sup 10} M {sub ☉}, with a median of ∼5.14 × 10{sup 9} M {sub ☉} and are accreting at Eddington ratios between 0.30 and 3.05, with a median of ∼1.12. Assuming a duty cycle of 1 and a seed black hole mass of 10{sup 4} M {sub ☉}, we show that the z ∼ 3.5 quasars in this sample can grow to their estimated black hole masses within the age of the universe at their redshifts.

  15. Unification of the Fundamental Plane and Super-Massive Black Holes Masses

    OpenAIRE

    Bosch, Remco van den

    2016-01-01

    According to the Virial Theorem, all gravitational systems in equilibrium sit on a plane in the 3D parameter space defined by their mass, size and second moment of the velocity tensor. While these quantities cannot be directly observed, there are suitable proxies: the luminosity Lk, half-light radius Re and dispersion sigma_e. These proxies indeed lie on a very tight Fundamental Plane (FP). How do the black holes in the centers of galaxies relate to the FP? Their masses are known to exhibit n...

  16. Black Hole Mass Estimates and Rapid Growth of Supermassive Black Holes in Luminous $z \\sim$ 3.5 Quasars

    CERN Document Server

    Zuo, Wenwen; Fan, Xiaohui; Green, Richard; Wang, Ran; Bian, Fuyan

    2014-01-01

    We present new near-infrared (IR) observations of the H$\\beta\\ \\lambda4861$ and MgII $\\lambda2798$ lines for 32 luminous quasars with $3.2black hole mass estimates. The continuum luminosity at 5100 \\AA\\ well correlates with the continuum luminosity at 3000 \\AA\\ and the broad emission line luminosities (H$\\beta$ and MgII). With simultaneous near-IR spectroscopy of the H$\\beta$ and MgII lines to exclude the influences of flux variability, we are able to evaluate the reliability of estimating black hole masses based on the MgII line for high redshift quasars. With the reliable H$\\beta$ line based black hole mass and Eddington ratio estimates, we find that the $z\\sim3.5$ quasars in our sample have black hole masses $1.90\\times10^{9} M_{\\odot} \\lesssim M_{\\rm B...

  17. A rapidly spinning supermassive black hole at the centre of NGC 1365

    CERN Document Server

    Risaliti, G; Madsen, K K; Walton, D J; Boggs, S E; Christensen, F E; Craig, W W; Grefenstette, B W; Hailey, C J; Nardini, E; Stern, Daniel; Zhang, W W

    2013-01-01

    Broad X-ray emission lines from neutral and partially ionized iron observed in active galaxies have been interpreted as fluorescence produced by the reflection of hard X-rays off the inner edge of an accretion disk. In this model, line broadening and distortion result from rapid rotation and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims that the black hole (2E6 solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe line emission and an associated Compton scattering excess of 10-30 keV. Using temporal and spectral analyses, we disentangle continuum chang...

  18. Do Circumnuclear Dense Gas Disks Drive Mass Accretion onto Supermassive Black Holes?

    CERN Document Server

    Izumi, Takuma; Kohno, Kotaro

    2016-01-01

    We present a positive correlation between the mass of dense molecular gas ($M_{\\rm dense}$) of $\\sim 100$ pc scale circumnuclear disks (CNDs) and the black hole mass accretion rate ($\\dot{M}_{\\rm BH}$) in total 10 Seyfert galaxies, based on data compiled from the literature and an archive (median aperture $\\theta_{\\rm med}$ = 220 pc). A typical $M_{\\rm dense}$ of CNDs is 10$^{7-8}$ $M_\\odot$, estimated from the luminosity of the dense gas tracer, the HCN($1-0$) emission line. Because dense molecular gas is the site of star formation, this correlation is virtually equivalent to the one between nuclear star formation rate and $\\dot{M}_{\\rm BH}$ revealed previously. Moreover, the $M_{\\rm dense}-\\dot{M}_{\\rm BH}$ correlation was tighter for CND-scale gas than for the gas on kpc or larger scales. This indicates that CNDs likely play an important role in fueling black holes, whereas $>$kpc scale gas does not. To demonstrate a possible approach for studying the CND-scale accretion process with the Atacama Large Mill...

  19. ON THE COMPLEMENTARITY OF PULSAR TIMING AND SPACE LASER INTERFEROMETRY FOR THE INDIVIDUAL DETECTION OF SUPERMASSIVE BLACK HOLE BINARIES

    International Nuclear Information System (INIS)

    Gravitational waves coming from supermassive black hole binaries (SMBHBs) are targeted by both the Pulsar Timing Array (PTA) and Space Laser Interferometry (SLI). The possibility of a single SMBHB being tracked first by PTA, through inspiral, and later by SLI, up to merger and ring-down, has been previously suggested. Although the bounding parameters are drawn by the current PTA or the upcoming Square Kilometer Array (SKA), and by the New Gravitational Observatory (NGO), derived from the Laser Interferometer Space Antenna (LISA), this paper also addresses sequential detection beyond specific project constraints. We consider PTA-SKA, which is sensitive from 10–9 to p × 10–7 Hz (p = 4, 8), and SLI, which operates from s × 10–5 up to 1 Hz (s = 1, 3). An SMBHB in the range of 2 × 108-2 × 109 M ☉ (the masses are normalized to a (1 + z) factor, the redshift lying between z = 0.2 and z = 1.5) moves from the PTA-SKA to the SLI band over a period ranging from two months to fifty years. By combining three supermassive black hole (SMBH)-host relations with three accretion prescriptions, nine astrophysical scenarios are formed. They are then related to three levels of pulsar timing residuals (50, 5, 1 ns), generating 27 cases. For residuals of 1 ns, sequential detection probability will never be better than 4.7 × 10–4 yr–2 or 3.3 × 10–6 yr–2 (per year to merger and per year of survey), according to the best and worst astrophysical scenarios, respectively; put differently this means one sequential detection every 46 or 550 years for an equivalent maximum time to merger and duration of the survey. The chances of sequential detection are further reduced by increasing values of the s parameter (they vanish for s = 10) and of the SLI noise, and by decreasing values of the remnant spin. The spread in the predictions diminishes when timing precision is improved or the SLI low-frequency cutoff is lowered. So while transit times and the SLI signal-to-noise ratio

  20. Collapse of dense star clusters to supermassive black holes - binaries and gravitational radiation

    International Nuclear Information System (INIS)

    The formation of binaries as a result of normal stellar-dynamic processes in dense clusters of compact stars is investigated analytically. The results of numerical simulations based on a simple homological model for the evolution of a cluster up to the point of catastrophic collapse are presented in extensive graphs and characterized in detail. It is shown that gravitational radiation begins to have a significant effect long before the onset of the high-redshift state. In the later stages, radiative dissipation from binary captures and flyby orbits acts to increase the final core mass that can undergo catastrophic collapse. Realistic initial conditions are found to lead to final cores of 100-100,000 solar masses, which can then collapse in a few dynamical time scales to form black holes 10-150 times larger. It is suggested that gravitational radiation from compact-star binaries may be detectable by ground-based interferometers. 55 references

  1. The Merger-Free Co-Evolution of Galaxies and Supermassive Black Holes

    Science.gov (United States)

    Simmons, Brooke; Smethurst, Rebecca Jane; Lintott, Chris; Galaxy Zoo Team

    2016-06-01

    Calm, "secular" accretion and evolutionary processes, once thought to be relegated to the sidelines of galaxy evolution, are now understood to play a significant role in the buildup of stellar mass in galaxies. Most galaxies are formed and evolve via a mix of secular-driven evolution and more violent processes like strong disk instabilities and galaxy mergers; this makes isolating the effects of secular evolution in galaxies very difficult. Massive pure disk galaxies, lacking the classical or "pseudo" bulge components that arise naturally from mergers and disk instabilities (respectively), are a unique opportunity to study galaxy evolution in the absence of violent processes. Previous studies have disagreed on whether the black hole-galaxy mass correlation is driven by galaxy-galaxy interactions or something more fundamental. Here we present new evidence using a statistically significant sample of AGN hosted in bulgeless disk galaxies at z evolution in the absence of mergers.

  2. Empirical Constraints on the Coevolution of Supermassive Black Holes and their Host Spheroids

    CERN Document Server

    Li, Gongjie; Loeb, Abraham

    2011-01-01

    We investigate the evolution of the MBH-{\\sigma} relation by examining the relationship between the intrinsic scatter in the MBH-{\\sigma} relation and galaxy bolometric nuclear luminosity, the latter being a probe of the accretion rate of the black hole (BH). Our sample is composed of galaxies with classical bulges when possible, of which 38 have dynamically measured BHs masses, and 17 have BHs masses measured by reverberation mapping. In order to obtain the bolometric nuclear luminosity for galaxies with low nuclear luminosity, we convert the X-ray nuclear luminosity measured by Chandra to bolometric luminosity. We find that the scatter in the MBH-{\\sigma} relation is uncorrelated with nuclear luminosity over seven orders of magnitude in luminosity, with the high luminosity end approaching the Eddington luminosity. This suggests that at the present epoch galaxies evolve along the MBH-{\\sigma} relation. This conclusion is consistent with the standard paradigm that BHs grow contemporaneously with their host st...

  3. Accretion onto Supermassive Black Holes in Quasars: Learning from Optical/UV Observations

    CERN Document Server

    Marziani, P; Sulentic, J W; Marziani, Paola; Dultzin-Hacyan, Deborah; Sulentic, Jack W.

    2006-01-01

    Accretion processes in quasars and active galactic nuclei are still poorly understood, especially as far as the connection between observed spectral properties and physical parameters is concerned. Quasars show an additional degree of complexity compared to stars that is related to anisotropic emission/obscuration influencing the observed properties in most spectral ranges. This complicating factor has hampered efforts to define the equivalent of an Hertzsprung-Russel diagram for quasars. Even if it has recently become possible to estimate black hole mass and Eddington ratio for sources using optical and UV broad emission lines, the results are still plagued by large uncertainties. Nevertheless, robust trends are emerging from multivariate analysis of large spectral datasets of quasars. A firm observational basis is being laid out by accurate measurements of broad emission line properties especially when the source rest-frame is known. We consider the most widely discussed correlations (i.e. the so-called "ei...

  4. Infalling clouds on to supermassive black hole binaries - II. Binary evolution and the final parsec problem

    CERN Document Server

    Goicovic, Felipe G; Cuadra, Jorge; Stasyszyn, Federico

    2016-01-01

    The formation of massive black hole binaries (MBHBs) is an unavoidable outcome of galaxy evolution via successive mergers. However, the mechanism that drives their orbital evolution from parsec separations down to the gravitational wave (GW) dominated regime is poorly understood and their final fate is still unclear. If such binaries are embedded in gas-rich and turbulent environments, as observed in remnants of galaxy mergers, the interaction with gas clumps (such as molecular clouds) may efficiently drive their orbital evolution. Using numerical simulations, we test this hypothesis by studying the dynamical evolution of an equal-mass, circular MBHB accreting infalling molecular clouds. We investigate different orbital configurations, modelling a total of 13 systems to explore different possible pericentre distances and relative inclinations of the cloud-binary encounter. We show that the evolution of the binary orbit is dominated by the exchange of angular momentum through gas accretion during the first sta...

  5. EVIDENCE FOR A RECEDING DUST SUBLIMATION REGION AROUND A SUPERMASSIVE BLACK HOLE

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Makoto; Tristram, Konrad R. W.; Weigelt, Gerd [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Hönig, Sebastian F.; Antonucci, Robert [Physics Department, University of California, Santa Barbara, CA 93106 (United States); Millan-Gabet, Rafael [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Barvainis, Richard [National Science Foundation, 4301 Wilson Boulevard, Arlington, VA 22230 (United States); Millour, Florentin [Observatoire de la Côte d Azur, Departement FIZEAU, Boulevard de l' Observatoire, BP 4229, F-06304 Nice Cedex 4 (France); Kotani, Takayuki, E-mail: mk@mpifr-bonn.mpg.de [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2013-10-01

    The near-IR emission in Type 1 active galactic nuclei (AGNs) is thought to be dominated by the thermal radiation from dust grains that are heated by the central engine in the UV/optical and are almost at the sublimation temperature. A brightening of the central source can thus further sublimate the innermost dust, leading to an increase in the radius of the near-IR emitting region. Such changes in radius have been indirectly probed by the measurements of the changes in the time lag between the near-IR and UV/optical light variation. Here we report direct evidence for such a receding sublimation region through the near-IR interferometry of the brightest Type 1 AGN in NGC 4151. The increase in radius follows a significant brightening of the central engine with a delay of at least a few years, which is thus the implied destruction timescale of the innermost dust distribution. Compiling historic flux variations and radius measurements, we also infer the reformation timescale for the inner dust distribution to be several years in this galactic nucleus. More specifically and quantitatively, we find that the radius at a given time seems to be correlated with a long-term average of the flux over the previous several (∼6) years, instead of the instantaneous flux. Finally, we also report measurements of three more Type 1 AGNs newly observed with the Keck interferometer, as well as the second epoch measurements for three other AGNs.

  6. The supermassive black hole and double nucleus of the core elliptical NGC5419

    CERN Document Server

    Mazzalay, X; Saglia, R P; Wegner, G A; Bender, R; Erwin, P; Fabricius, M H; Rusli, S

    2016-01-01

    We obtained adaptive-optics assisted SINFONI observations of the central regions of the giant elliptical galaxy NGC5419 with a spatial resolution of 0.2 arcsec ($\\approx 55$ pc). NGC5419 has a large depleted stellar core with a radius of 1.58 arcsec (430 pc). HST and SINFONI images show a point source located at the galaxy's photocentre, which is likely associated with the low-luminosity AGN previously detected in NGC5419. Both the HST and SINFONI images also show a second nucleus, off-centred by 0.25 arcsec ($\\approx 70$ pc). Outside of the central double nucleus, we measure an almost constant velocity dispersion of $\\sigma \\sim 350$ km/s. In the region where the double nucleus is located, the dispersion rises steeply to a peak value of $\\sim 420$ km/s. In addition to the SINFONI data, we also obtained stellar kinematics at larger radii from the South African Large Telescope. While NGC5419 shows low rotation ($v < 50$ km/s), the central regions (inside $\\sim 4 \\, r_b$) clearly rotate in the opposite direc...

  7. EVIDENCE FOR A RECEDING DUST SUBLIMATION REGION AROUND A SUPERMASSIVE BLACK HOLE

    International Nuclear Information System (INIS)

    The near-IR emission in Type 1 active galactic nuclei (AGNs) is thought to be dominated by the thermal radiation from dust grains that are heated by the central engine in the UV/optical and are almost at the sublimation temperature. A brightening of the central source can thus further sublimate the innermost dust, leading to an increase in the radius of the near-IR emitting region. Such changes in radius have been indirectly probed by the measurements of the changes in the time lag between the near-IR and UV/optical light variation. Here we report direct evidence for such a receding sublimation region through the near-IR interferometry of the brightest Type 1 AGN in NGC 4151. The increase in radius follows a significant brightening of the central engine with a delay of at least a few years, which is thus the implied destruction timescale of the innermost dust distribution. Compiling historic flux variations and radius measurements, we also infer the reformation timescale for the inner dust distribution to be several years in this galactic nucleus. More specifically and quantitatively, we find that the radius at a given time seems to be correlated with a long-term average of the flux over the previous several (∼6) years, instead of the instantaneous flux. Finally, we also report measurements of three more Type 1 AGNs newly observed with the Keck interferometer, as well as the second epoch measurements for three other AGNs

  8. Evidence for a receding dust sublimation region around a supermassive black hole

    CERN Document Server

    Kishimoto, Makoto; Antonucci, Robert; Millan-Gabet, Rafael; Barvainis, Richard; Millour, Florentin; Kotani, Takayuki; Tristram, Konrad R W; Weigelt, Gerd

    2013-01-01

    The near-IR emission in Type 1 AGNs is thought to be dominated by the thermal radiation from dust grains that are heated by the central engine in the UV/optical and are almost at the sublimation temperature. A brightening of the central source can thus further sublimate the innermost dust, leading to an increase in the radius of the near-IR emitting region. Such changes in radius have been indirectly probed by the measurements of the changes in the time lag between the near-IR and UV/optical light variation. Here we report direct evidence for such a receding sublimation region through the near-IR interferometry of the brightest Type 1 AGN in NGC4151. The increase in radius follows a significant brightening of the central engine with a delay of at least a few years, which is thus the implied destruction timescale of the innermost dust distribution. Compiling historic flux variations and radius measurements, we also infer the reformation timescale for the inner dust distribution to be several years in this gala...

  9. OBSERVATIONAL CONSTRAINTS ON THE CO-EVOLUTION OF SUPERMASSIVE BLACK HOLES AND GALAXIES

    International Nuclear Information System (INIS)

    The star formation rate (SFR) and black hole accretion rate (BHAR) functions are measured to be proportional to each other at z ∼* > 2 x 1010 Msun, ultraviolet and infrared-derived SFRs from Spitzer and Galaxy Evolution Explorer, and morphologies from GEMS Hubble Space Telescope/Advanced Camera for Surveys imaging. Using stacking techniques, we find that 2.5), while the BHAR that we would expect if the global scalings held is 3 times higher. This rules out the simplest picture of co-evolution, in which SF and BHA trace each other at all times. These results could be explained if SF and BHA occur in the same events, but offset in time, for example at different stages of a merger event. However, one would then expect to see the corresponding star formation activity in early-stage mergers, in conflict with observations. We conclude that the major episodes of SF and BHA occur in different events, with the bulk of SF happening in isolated disks and most BHA occurring in major mergers. The apparent global co-evolution results from the regulation of the BH growth by the potential well of the galactic spheroid, which includes a major contribution from disrupted disk stars.

  10. Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies: Supplemental Material

    CERN Document Server

    Kormendy, John

    2013-01-01

    This is the Supplemental Material to Kormendy and Ho 2013, ARAA, 51, 511 (arXiv:1304.7762). Section S1 summarizes indirect methods that are used to estimate black hole (BH) masses for galaxies with active nuclei (AGNs). Section S2 lists the observational criteria that are used to classify classical and pseudo bulges. The (pseudo)bulge classifications used in the main paper are not based on physical interpretation; rather, they are based on these observational criteria. Section S3 supplements the BH database in Section 5 of the main paper and Section S4 here. It discusses corrections to galaxy and BH parameters, most importantly to 2MASS K-band apparent magnitudes. It presents evidence that corrections are needed because 2MASS misses light at large radii when the images of galaxies subtend large angles on the sky or have shallow outer brightness gradients. Section S4 reproduces essentially verbatim the first part of Section 5 in the main paper, the BH database. It includes the list of BH and host-galaxy proper...

  11. Electromagnetic counterparts of supermassive black hole binaries resolved by pulsar timing arrays

    CERN Document Server

    Tanaka, Takamitsu; Menou, Kristen

    2011-01-01

    Pulsar timing arrays (PTAs) are expected to detect gravitational waves (GWs) from individual low-redshift (z10^9 Msun) black hole (SMBH) binaries with orbital periods of approx. 0.1 - 10 yrs. Identifying the electromagnetic (EM) counterparts of these sources would provide confirmation of putative direct detections of GWs, present a rare opportunity to study the environments of compact SMBH binaries, and could enable the use of these sources as standard sirens for cosmology. Here we consider the feasibility of such an EM identification. We show that because the host galaxies of resolved PTA sources are expected to be exceptionally massive and rare, it should be possible to find unique hosts of resolved sources out to redshift z=0.2. At higher redshifts, the PTA error boxes are larger, and may contain as many as 100 massive-galaxy interlopers. The number of candidates, however, remains tractable for follow-up searches in upcoming wide-field EM surveys. We develop a toy model to characterize the dynamics and the...

  12. High-velocity OH megamasers in IRAS 20100-4156: Evidence for a Supermassive Black Hole

    CERN Document Server

    Harvey-Smith, L; Green, J A; Bannister, K W; Chippendale, A; Edwards, P G; Heywood, I; Hotan, A W; Lenc, E; Marvil, J; McConnell, D; Phillips, C P; Sault, R J; Serra, P; Stevens, J; Voronkov, M; Whiting, M

    2016-01-01

    We report the discovery of new, high-velocity narrow-line components of the OH megamaser in IRAS 20100-4156. Results from the Australian Square Kilometre Array Pathfinder (ASKAP)'s Boolardy Engineering Test Array (BETA) and the Australia Telescope Compact Array (ATCA) provide two independent measurements of the OH megamaser spectrum. We found evidence for OH megamaser clumps at $-$409 and $-$562 km/s (blue-shifted) from the systemic velocity of the galaxy, in addition to the lines previously known. The presence of such high velocities in the molecular emission from IRAS 20100$-$4156 could be explained by a ~50 pc molecular ring enclosing an approximately 3.8 billion solar mass black hole. We also discuss two alternatives, i.e. that the narrow-line masers are dynamically coupled to the wind driven by the active galactic nucleus or they are associated with two separate galactic nuclei. The comparison between the BETA and ATCA spectra provides another scientific verification of ASKAP's BETA. Our data, combined w...

  13. Enhancing the rate of tidal disruptions of stars by a self-gravitating disc around a massive central black hole

    Directory of Open Access Journals (Sweden)

    Šubr L.

    2012-12-01

    Full Text Available We further study the idea that a self-gravitating accretion disc around a supermassive black hole can increase the rate of gradual orbital decay of stellar trajectories (and hence tidal disruption events by setting some stars on eccentric trajectories. Cooperation between the gravitational field of the disc and the dissipative environment can provide a mechanism explaining the origin of stars that become bound tightly to the central black hole. We examine this process as a function of the black hole mass and conclude that it is most efficient for intermediate central masses of the order of ∼ 104Mʘ. Members of the cluster experience the stage of orbital decay via collisions with an accretion disc and by other dissipative processes, such as tidal effects, dynamical friction and the emission of gravitational waves. Our attention is concentrated on the region of gravitational dominance of the central body. Mutual interaction between stars and the surrounding environment establishes a non-spherical shape and anisotropy of the nuclear cluster. In some cases, the stellar sub-system acquires ring-type geometry. Stars of the nuclear cluster undergo a tidal disruption event as they plunge below the tidal radius of the supermassive black hole.

  14. High-velocity OH megamasers in IRAS 20100-4156: Evidence for a Supermassive Black Hole

    Science.gov (United States)

    Harvey-Smith, L.; Allison, J. R.; Green, J. A.; Bannister, K. W.; Chippendale, A.; Edwards, P. G.; Heywood, I.; Hotan, A. W.; Lenc, E.; Marvil, J.; McConnell, D.; Phillips, C. P.; Sault, R. J.; Serra, P.; Stevens, J.; Voronkov, M.; Whiting, M.

    2016-05-01

    We report the discovery of new, high-velocity narrow-line components of the OH megamaser in IRAS 20100-4156. Results from the Australian Square Kilometre Array Pathfinder (ASKAP)'s Boolardy Engineering Test Array (BETA) and the Australia Telescope Compact Array (ATCA) provide two independent measurements of the OH megamaser spectrum. We found evidence for OH megamaser clumps at -409 and -562 km s-1 (blue-shifted) from the systemic velocity of the galaxy, in addition to the lines previously known. The presence of such high velocities in the molecular emission from IRAS 20100-4156 could be explained by a ˜50 pc molecular ring enclosing a ˜3.8 billion solar mass black hole. We also discuss two alternatives, i.e. that the narrow-line masers are dynamically coupled to the wind driven by the active galactic nucleus or they are associated with two separate galactic nuclei. The comparison between the BETA and ATCA spectra provides another scientific verification of ASKAP's BETA. Our data, combined with previous measurements of the source enabled us to study the variability of the source over a twenty-six year period. The flux density of the brightest OH maser components has reduced by more than a factor of two between 1988 and 2015, whereas a secondary narrow-line component has more than doubled in the same time. Plans for high-resolution VLBI follow-up of this source are discussed, as are prospects for discovering new OH megamasers during the ASKAP early science program.

  15. High-velocity OH megamasers in IRAS 20100-4156: evidence for a supermassive black hole

    Science.gov (United States)

    Harvey-Smith, L.; Allison, J. R.; Green, J. A.; Bannister, K. W.; Chippendale, A.; Edwards, P. G.; Heywood, I.; Hotan, A. W.; Lenc, E.; Marvil, J.; McConnell, D.; Phillips, C. J.; Sault, R. J.; Serra, P.; Stevens, J.; Voronkov, M.; Whiting, M.

    2016-08-01

    We report the discovery of new, high-velocity narrow-line components of the OH megamaser in IRAS 20100-4156. Results from the Australian Square Kilometre Array Pathfinder (ASKAP)'s Boolardy Engineering Test Array (BETA) and the Australia Telescope Compact Array (ATCA) provide two independent measurements of the OH megamaser spectrum. We found evidence for OH megamaser clumps at -409 and -562 km s-1 (blue-shifted) from the systemic velocity of the galaxy, in addition to the lines previously known. The presence of such high velocities in the molecular emission from IRAS 20100-4156 could be explained by a ˜50 pc molecular ring enclosing a ˜3.8 billion solar mass black hole. We also discuss two alternatives, i.e. that the narrow-line masers are dynamically coupled to the wind driven by the active galactic nucleus or they are associated with two separate galactic nuclei. The comparison between the BETA and ATCA spectra provides another scientific verification of ASKAP's BETA. Our data, combined with previous measurements of the source enabled us to study the variability of the source over a 26 yr period. The flux density of the brightest OH maser components has reduced by more than a factor of 2 between 1988 and 2015, whereas a secondary narrow-line component has more than doubled in the same time. Plans for high-resolution very long baseline interferometry follow-up of this source are discussed, as are prospects for discovering new OH megamasers during the ASKAP early science programme.

  16. RADIO MONITORING OF THE TIDAL DISRUPTION EVENT SWIFT J164449.3+573451. I. JET ENERGETICS AND THE PRISTINE PARSEC-SCALE ENVIRONMENT OF A SUPERMASSIVE BLACK HOLE

    OpenAIRE

    Berger, E.; Zauderer, A.; Pooley, G. G.; Soderberg, A. M.; Sari, R.; Brunthaler, A.; Bietenholz, M. F.

    2012-01-01

    We present continued radio observations of the tidal disruption event SwiftJ164449.3+573451 extending to \\sim216 days after discovery. The data are part of a long-term program to monitor the expansion and energy scale of the relativistic outflow, and to trace the parsec-scale environment around a previously-dormant supermassive black hole (SMBH). The new observations reveal a significant change in the radio evolution starting at \\sim1 month, with a brightening at all frequencies that requires...

  17. Suppressing star formation in quiescent galaxies with supermassive black hole winds

    Science.gov (United States)

    Cheung, Edmond; Bundy, Kevin; SDSS-IV/MaNGA

    2016-01-01

    In the last 10 billion years (i.e., since redshift z ~2) the number of quiescent galaxies with little to no ongoing star formation has grown by a factor ~25. This is challenging to understand since galaxy formation models predict that these galaxies will continue to accrete fresh gas over their lifetimes, relatively little of which is required to reignite measurable star formation. It is thought that feedback from fresh gas accreting onto a central active galactic nucleus (AGN) might help such galaxies maintain their quiescence, but observational evidence for such ``maintenance mode feedback'' remains sparse. Using novel imaging spectroscopy from the SDSS-IV MaNGA Survey (Sloan Digital Sky Survey IV: Mapping Nearby Galaxies at Apache Point Observatory), we present evidence for a new maintenance mode phenomenon we term ``red geysers,'' a potentially episodic but relatively low-power AGN driven wind present in typical quiescent field galaxies of moderate mass and spheroidal morphology. We examine an archetypal red geyser that appears to be accreting gas from a low-mass companion but has no corresponding star formation. Instead, we find evidence for a galaxy-scale ionized wind with outflow velocities reaching more than 300 km/s and high velocity dispersions. We also detect a narrow biconical pattern of strong emission line equivalent widths consistent with fast shocks. Given additional confirmation of a radio AGN present in the galaxy, we propose that red geysers such as this may be a common mode in which gas accretion activates an ionized wind feedback mechanism that prevents star formation and helps moderate luminosity quiescent galaxies maintain their quiescence.

  18. CONSTRAINING SUB-PARSEC BINARY SUPERMASSIVE BLACK HOLES IN QUASARS WITH MULTI-EPOCH SPECTROSCOPY. I. THE GENERAL QUASAR POPULATION

    International Nuclear Information System (INIS)

    We perform a systematic search for sub-parsec binary supermassive black holes (BHs) in normal broad-line quasars at z BLR, where RBLR ∼ 0.01-0.1 pc is the BLR size. We search for the expected line-of-sight acceleration of the broad-line velocity from binary orbital motion by cross-correlating SDSS spectra from two epochs separated by up to several years in the quasar rest frame. Out of ∼700 pairs of spectra for which we have good measurements of the velocity shift between two epochs (1σ error ∼40 km s–1), we detect 28 systems with significant velocity shifts in broad Hβ, among which 7 are the best candidates for the hypothesized binaries, 4 are most likely due to broad-line variability in single BHs, and the rest are ambiguous. Continued spectroscopic observations of these candidates will easily strengthen or disprove these claims. We use the distribution of the observed accelerations (mostly non-detections) to place constraints on the abundance of such binary systems among the general quasar population. Excess variance in the velocity shift is inferred for observations separated by longer than 0.4 yr (quasar rest frame). Attributing all the excess to binary motion would imply that most of the quasars in this sample must be in binaries, that the inactive BH must be on average more massive than the active one, and that the binary separation is at most a few times the size of the BLR. However, if this excess variance is partly or largely due to long-term broad-line variability, the requirement of a large population of close binaries is much weakened or even disfavored for massive companions. Future time-domain spectroscopic surveys of normal quasars can provide vital prior information on the structure function of stochastic velocity shifts induced by broad-line variability in single BHs. Such surveys with improved spectral quality, increased time baseline, and more epochs can greatly improve the statistical constraints of this method on the general binary

  19. Current and Future X-ray Studies of High-Redshift AGNs and the First Supermassive Black Holes

    Science.gov (United States)

    Brandt, Niel

    2016-01-01

    X-ray observations of high-redshift AGNs at z = 4-7 have played a critical role in understanding the physical processes at work inthese objects as well as their basic demographics. Since 2000, Chandra and XMM-Newton have provided new X-ray detections for more than 120 such objects, and well-defined samples of z > 4 AGNs now allow reliable X-ray population studies. Once luminosity effectsare considered, the basic X-ray continuum properties of most high-redshift AGNs appear remarkably similar to those of local AGNs, although there are some notable apparent exceptions (e.g., highly radio-loud quasars). Furthermore, the X-ray absorption found in some objects has been used as a diagnostic of outflowing winds and circumnuclear material. Demographically, the X-ray data now support an exponential decline in the number density of luminous AGNs above z ~ 3, and quantitative space-density comparisons for optically selected and X-ray selected quasars indicate basic statistical agreement.The current X-ray discoveries point the way toward the future breakthroughs that will be possible with, e.g., Athena and the X-raySurveyor. These missions will execute powerful blank-field surveys to elucidate the demographics of the first growing supermassive black holes (SMBHs), including highly obscured systems, up to z ~ 10. They will also carry out complementary X-ray spectroscopic and variability investigations of high-redshift AGNs by targeting the most-luminous z = 7-10 quasars found in wide-field surveys by, e.g., Euclid, LSST, and WFIRST. X-ray spectroscopic and variability studies of the X-ray continuum and reflection signatures will help determine Eddington ratios and disk/corona properties; measuring these will clarify how the first quasars grew so quickly. Furthermore, absorption line/edge studies will reveal how outflows from the first SMBHs influenced the growth of the first galaxies. I will suggest some efficient observational strategies for Athena and the X-ray Surveyor.

  20. Gravitational waves from individual supermassive black hole binaries in circular orbits: limits from the North American nanohertz observatory for gravitational waves

    International Nuclear Information System (INIS)

    We perform a search for continuous gravitational waves from individual supermassive black hole binaries using robust frequentist and Bayesian techniques. We augment standard pulsar timing models with the addition of time-variable dispersion measure and frequency variable pulse shape terms. We apply our techniques to the Five Year Data Release from the North American Nanohertz Observatory for Gravitational Waves. We find that there is no evidence for the presence of a detectable continuous gravitational wave; however, we can use these data to place the most constraining upper limits to date on the strength of such gravitational waves. Using the full 17 pulsar data set we place a 95% upper limit on the strain amplitude of h 0 ≲ 3.0 × 10–14 at a frequency of 10 nHz. Furthermore, we place 95% sky-averaged lower limits on the luminosity distance to such gravitational wave sources, finding that dL ≳ 425 Mpc for sources at a frequency of 10 nHz and chirp mass 1010 M ☉. We find that for gravitational wave sources near our best timed pulsars in the sky, the sensitivity of the pulsar timing array is increased by a factor of ∼four over the sky-averaged sensitivity. Finally we place limits on the coalescence rate of the most massive supermassive black hole binaries.

  1. Gravitational waves from individual supermassive black hole binaries in circular orbits: limits from the North American nanohertz observatory for gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Arzoumanian, Z. [Center for Research and Exploration in Space Science and Technology and X-Ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Brazier, A.; Chatterjee, S.; Cordes, J. M.; Dolch, T.; Lam, M. T. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Burke-Spolaor, S. [California Institute of Technology, Pasadena, CA 91125 (United States); Chamberlin, S. J.; Ellis, J. A. [Center for Gravitation, Cosmology and Astrophysics, Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201 (United States); Demorest, P. B. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Deng, X.; Koop, M. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Ferdman, R. D.; Kaspi, V. M. [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Garver-Daniels, N.; Lorimer, D. R. [Department of Physics, West Virginia University, P.O. Box 6315, Morgantown, WV 26505 (United States); Jenet, F. [Center for Gravitational Wave Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States); Jones, G. [Department of Physics, Columbia University, New York, NY 10027 (United States); Lazio, T. J. W. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91106 (United States); Lommen, A. N., E-mail: justin.ellis18@gmail.com [Department of Physics and Astronomy, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17604 (United States); Collaboration: NANOGrav Collaboration; and others

    2014-10-20

    We perform a search for continuous gravitational waves from individual supermassive black hole binaries using robust frequentist and Bayesian techniques. We augment standard pulsar timing models with the addition of time-variable dispersion measure and frequency variable pulse shape terms. We apply our techniques to the Five Year Data Release from the North American Nanohertz Observatory for Gravitational Waves. We find that there is no evidence for the presence of a detectable continuous gravitational wave; however, we can use these data to place the most constraining upper limits to date on the strength of such gravitational waves. Using the full 17 pulsar data set we place a 95% upper limit on the strain amplitude of h {sub 0} ≲ 3.0 × 10{sup –14} at a frequency of 10 nHz. Furthermore, we place 95% sky-averaged lower limits on the luminosity distance to such gravitational wave sources, finding that d{sub L} ≳ 425 Mpc for sources at a frequency of 10 nHz and chirp mass 10{sup 10} M {sub ☉}. We find that for gravitational wave sources near our best timed pulsars in the sky, the sensitivity of the pulsar timing array is increased by a factor of ∼four over the sky-averaged sensitivity. Finally we place limits on the coalescence rate of the most massive supermassive black hole binaries.

  2. X-shaped radio galaxies as observational evidence for the interaction of supermassive binary black holes and accretion disk at pc scale

    CERN Document Server

    Liu, F K

    2004-01-01

    A supermassive black hole binary may form during galaxy mergering. we investigate the interaction of the supermassive binary black holes (SMBBHs) and an accretion disk and show that the detected X-shaped structure in some FRII radio galaxies may be due to the interaction-realignment of inclined binary and accretion disk occurred within the pc scale of the galaxy center. We compare in detail the model and observations and show that the configuration is consistent very well with the observations of X-shaped radio sources. X-shaped radio feature form only in FRII radio sources due to the strong interaction between the binary and a standard disk, while the absence of X-shaped FRI radio galaxies is due to that the interaction between the binary and the radiatively inefficient accretion flow in FRI radio sources is negligible. It is suggested that the binary would keep misaligned with the outer disk for most of the life time of FRII radio galaxies and the orientation of jet in most FRII radio galaxies distributes r...

  3. Testing the nature of the supermassive black hole candidate in SgrA* with light curves and images of hot spots

    International Nuclear Information System (INIS)

    General relativity makes clear predictions about the spacetime geometry around black holes. In the near future, new facilities will have the capability to explore the metric around SgrA*, the supermassive black hole candidate at the center of our Galaxy, and to open a new window to test the Kerr black hole hypothesis. In this paper, we compute light curves and images associated with compact emission regions (hot spots) orbiting around Kerr and non-Kerr black holes. We study how the analysis of the properties of the radiation emitted by a hot spot can be used to test the Kerr nature of SgrA*. We find that the sole observation of the hot spot light curve can at most constrain a combination of the black hole spin and of possible deviations from the Kerr solution. This happens because the same orbital frequency around a Kerr black hole can be found for a non-Kerr object with a different spin parameter. Second order corrections in the light curve due to the background geometry are typically too small to be identified. While the observation of the hot spot centroid track can potentially bound possible deviations from the Kerr solution, that is out of reach for the near future for the Very Large Telescope Interferometer instrument GRAVITY. The Kerr black hole hypothesis could really be tested in the case of the discovery of a radio pulsar in a compact orbit around SgrA*. Radio observations of such a pulsar would provide precise estimates of the mass and the spin of SgrA*, and the combination of these measurements (probing the weak field) with the hot spot light curve information (probing the strong field) may constrain/find possible deviations from the Kerr solution with quite good precision.

  4. Central black hole mass determination for blazars

    Institute of Scientific and Technical Information of China (English)

    Yuan Yu-Hai; Fan Jun-Hui; Huang Yong

    2008-01-01

    In this paper, we use a method to determine some basic parameters for the (r)-ray loud blazars. The parameters include the central black mass (M), the boosting factor (δ), the propagation angle (φ), the distance along the axis to the site of the (r)-ray production (d). A sample including 32 (r)-ray loud blazars with available variability time scaleshas been used to discuss the above properties. In this method, the (r)-ray energy, the emission size and the property of the accretion disc determine the absorption effect. If we take the intrinsic(γ)-ray luminosity to be λ Times the Eddington luminosity, I.e. Lin(r) =λLedd, then we have the following results: the mass of the black hole is in the range of (0.59 - 67.99) ⊙ (λ= 1.0) or (0.90 - 104.13) ⊙ (λ = 0.1); the boosting factor (δ) in the range of 0.16 - 2.09(λ=1.0) or 0.24 - 2.86 (λ=0.1); the angle (φ) in the range of 9.53 (λ =1.0) or 7.36°=0.1); and the distance (d/Rg) in the range of 22.39 - 609.36 (λ= 1.0) or 17.54 - 541.88 (λ = 0.1).

  5. The Hot and Energetic Universe: Understanding the build-up of supermassive black holes and galaxies at the heyday of the Universe

    CERN Document Server

    Georgakakis, A; Lanzuisi, G; Brightman, M; Buchner, J; Aird, J; Page, M; Cappi, M; Afonso, J; Alonso-Herrero, A; Ballo, L; Barcons, X; Ceballos, M T; Comastri, A; Georgantopoulos, I; Mateos, S; Nandra, K; Rosario, D; Salvato, M; Schawinski, K; Severgnini, P; Vignali, C

    2013-01-01

    Observations in the last decade have provided strong evidence that the growth of supermassive black holes at the centres of galaxies is among the most influential processes in galaxy evolution. Open questions that relate to our current understanding of black hole growth and its relation to the build-up of galaxies at redshifts z=1-4, when most black holes and stars we see in present-day galaxies were put in place, include: what is the nature of AGN feedback and whether it plays a significant role in the evolution of galaxies? what is the dominant population of accreting AGN at that critical epoch? is it dominated by obscured objects as required by many current observations and models? The Athena+ mission concept will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe. The high throughput of Athena+ will allow the systematic study of the incidence, nature and energetics of AGN feedback processes to z~4 via the identification...

  6. Spoon-Feeding Giant Stars to Supermassive Black Holes: Episodic Roche Lobe Overflow from Evolving Stars and Their Contribution to the Quiescent Activity of Galactic Nuclei

    CERN Document Server

    MacLeod, Morgan; Grady, Sean; Guillochon, James

    2013-01-01

    Stars may be tidally disrupted if, in a single orbit, they are scattered too close to a supermassive black hole (SMBH). Tidal disruption events are thought to power luminous but short-lived accretion episodes that can light up otherwise quiescent SMBHs in transient flares. Here we explore a more gradual process of tidal stripping where stars approach the tidal disruption radius by stellar evolution while in an eccentric orbit. After the onset of mass transfer, these stars episodically overflow their Roche lobes every pericenter passage giving rise to low-level flares that repeat on the orbital timescale. Giant stars, in particular, will exhibit a runaway response to mass loss and "spoon-feed" material to the black hole for tens to hundreds of orbital periods. In contrast to full tidal disruption events, the duty cycle of this feeding mode is of order unity for black holes with mass greater than approximately 10 million solar masses. This mode of quasi-steady SMBH feeding is competitive with indirect SMBH feed...

  7. Central black hole in M32

    International Nuclear Information System (INIS)

    Observations are presented of the stellar rotation and velocity dispersion in M32. The projected rotation curve has an unresolved cusp at the center, with an amplitude of at least 60 km/s. The stellar velocity dispersion is constant at 56 + or - 5 km/s to a radius of 20 arcsec; a central bump in the observed dispersion is an artifact due to the rotation. The form of the rotation is such that isophotes have constant angular rotation velocity. The three-dimensional rotation field is modeled and the internal mean rotation of the stars around the center of M32 must reach at least 90 km/s at a radius of 2 pc. Hydrostatic equilibrium then requires 3-10 x 10 to the 6th solar masses of dark mass within the central parsec of M32. The possibility that M32 is undergoing core collapse and that this dark mass consists of dark stellar remnants is discussed, but ultimately rejected because the time scale for core collapse of M32 should be 2000 Hubble times. A more likely explanation of this dark mass, especially because of the presence of an X-ray point source at the center of M32, is a massive black hole. 37 references

  8. Confined-exotic-matter wormholes with no gluing effects -- Imaging supermassive type (1) wormholes and black holes

    CERN Document Server

    Azreg-Aïnou, Mustapha

    2014-01-01

    We classify wormholes endowed with redshift effects and finite mass into three types. Type (1) wormholes have their radial pressure dying out faster, as one moves away from the throat, than any other component of the stress-energy and thus violate the least the local energy conditions. We introduce a novel and generalizable method for deriving, with no cutoff in the stress-energy or gluing, the three types of wormholes. We focus on type (1) wormholes and construct different asymptotically flat solutions with finite, upper- and lower-bounded, mass $M$. It is observed that the radial pressure is negative, and the null energy condition is violated, only inside a narrow shell, adjacent to the throat, of relative spacial extent $\\epsilon$. Reducing the relative size of the shell, without harming the condition of traversability, yields an inverse square law of $\\epsilon$ versus $M$ for supermassive wormholes. We show that the diameter of the shadow of this type (1) supermassive wormhole overlaps with that of the bl...

  9. Central black hole mass determination for blazers

    International Nuclear Information System (INIS)

    In this paper, we use a method to determine some basic parameters for the γ-ray loud blazars. The parameters include the central black mass (M), the boosting factor (δ), the propagation angle (Φ), the distance along the axis to the site of the γ-ray production (d). A sample including 32 γ-ray loud blazars with available variability time scales has been used to discuss the above properties. In this method, the γ-ray energy, the emission size and the property of the accretion disc determine the absorption effect. If we take the intrinsic γ-ray luminosity to be λ times the Eddington luminosity, i.e. Lγin = λLEdd, then we have the following results: the mass of the black hole is in the range of (0.59 – 67.99) × 107Msun (λ = 1.0) or (0.90 – 104.13) × 107Msun (λ = 0.1); the boosting factor (δ) in the range of 0.16 – 2.09(λ = 1.0) or 0.24 – 2.86 (λ = 0.1); the angle (Φ) in the range of 9.53° – 73.85° (λ = 1.0) or 7.36° – 68.89° (λ = 0.1); and the distance (d/Rg) in the range of 22.39 – 609.36 (λ = 1.0) or 17.54 – 541.88 (λ = 0.1)

  10. THE DYNAMICS, APPEARANCE, AND DEMOGRAPHICS OF RELATIVISTIC JETS TRIGGERED BY TIDAL DISRUPTION OF STARS IN QUIESCENT SUPERMASSIVE BLACK HOLES

    International Nuclear Information System (INIS)

    and the long-wavelength emission produced at the head of the jet. Many of the observed properties of the Swift 1644+57/GRB 110328A event can be understood as resulting from accretion onto and jets driven by a 106 M ☉ central mass black hole following the disruption of a sun-like star. With the inclusion of a stochastic contribution to the luminosity due to variations in the feeding rate driven by instabilities near the tidal radius, we find that our model can explain the X-ray light curve without invoking a rarely occurring deep encounter. In conjunction with the number density of black holes in the local universe, we hypothesize that the conditions required to produce the Swift event are not anomalous, but are in fact representative of the jet-driven flare population arising from tidal disruptions.

  11. The Dynamics, Appearance, and Demographics of Relativistic Jets Triggered by Tidal Disruption of Stars in Quiescent Supermassive Black Holes

    Science.gov (United States)

    De Colle, Fabio; Guillochon, James; Naiman, Jill; Ramirez-Ruiz, Enrico

    2012-12-01

    and the long-wavelength emission produced at the head of the jet. Many of the observed properties of the Swift 1644+57/GRB 110328A event can be understood as resulting from accretion onto and jets driven by a 106 M ⊙ central mass black hole following the disruption of a sun-like star. With the inclusion of a stochastic contribution to the luminosity due to variations in the feeding rate driven by instabilities near the tidal radius, we find that our model can explain the X-ray light curve without invoking a rarely occurring deep encounter. In conjunction with the number density of black holes in the local universe, we hypothesize that the conditions required to produce the Swift event are not anomalous, but are in fact representative of the jet-driven flare population arising from tidal disruptions.

  12. MEASURING MASS ACCRETION RATE ONTO THE SUPERMASSIVE BLACK HOLE IN M87 USING FARADAY ROTATION MEASURE WITH THE SUBMILLIMETER ARRAY

    International Nuclear Information System (INIS)

    We present the first constraint on the Faraday rotation measure (RM) at submillimeter wavelengths for the nucleus of M87. By fitting the polarization position angles (χ) observed with the Submillimeter Array at four independent frequencies around ∼230 GHz and interpreting the change in χ as a result of external Faraday rotation associated with accretion flow, we determine the RM of the M87 core to be between –7.5 × 105 and 3.4 × 105 rad m–2. Assuming a density profile of the accretion flow that follows a power-law distribution and a magnetic field that is ordered, radial, and has equipartition strength, the limit on the RM constrains the mass accretion rate M-dot to be below 9.2 × 10–4 M ☉ yr–1 at a distance of 21 Schwarzschild radii from the central black hole. This value is at least two orders of magnitude smaller than the Bondi accretion rate, suggesting significant suppression of the accretion rate in the inner region of the accretion flow. Consequently, our result disfavors the classical advection-dominated accretion flow and prefers the adiabatic inflow-outflow solution or convection-dominated accretion flow for the hot accretion flow in M87

  13. On the Hydrodynamic Interplay Between a Young Nuclear Starburst and a Central Supermassive Black Hole

    Czech Academy of Sciences Publication Activity Database

    Hueyotl-Zahuantitla, F.; Tenorio-Tagle, G.; Wünsch, Richard; Silich, S.; Palouš, Jan

    2010-01-01

    Roč. 716, č. 1 (2010), s. 324-331. ISSN 0004-637X R&D Projects: GA MŠk(CZ) LC06014 Institutional research plan: CEZ:AV0Z10030501 Keywords : accretion, * accretion disks, * active galaxies Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 7.436, year: 2010

  14. MASSIVE BLACK HOLES IN CENTRAL CLUSTER GALAXIES

    International Nuclear Information System (INIS)

    We explore how the co-evolution of massive black holes (MBHs) and galaxies is affected by environmental effects, addressing in particular MBHs hosted in the central cluster galaxies (we will refer to these galaxies in general as ''CCGs''). Recently, the sample of MBHs in CCGs with dynamically measured masses has increased, and it has been suggested that these MBH masses (MBH) deviate from the expected correlations with velocity dispersion (σ) and mass of the bulge (Mbulge) of the host galaxy: MBHs in CCGs appear to be ''overmassive''. This discrepancy is more pronounced when considering the MBH-σ relation than the MBH-Mbulge one. We show that this behavior stems from a combination of two natural factors: (1) CCGs experience more mergers involving spheroidal galaxies and their MBHs and (2) such mergers are preferentially gas poor. We use a combination of analytical and semi-analytical models to investigate the MBH-galaxy co-evolution in different environments and find that the combination of these two factors is in accordance with the trends observed in current data sets.

  15. The SINFONI Black Hole Survey: The Black Hole Fundamental Plane revisited and the paths of (co-) evolution of supermassive black holes and bulges

    CERN Document Server

    Saglia, R P; Erwin, P; Thomas, J; Beifiori, A; Fabricius, M; Mazzalay, X; Nowak, N; Rusli, S P; Bender, R

    2016-01-01

    We investigate the correlations between the black hole mass $M_{BH}$, the velocity dispersion $\\sigma$, the bulge mass $M_{Bu}$, the bulge average spherical density $\\rho_h$ and its spherical half mass radius $r_h$, constructing a database of 97 galaxies (31 core ellipticals, 17 power-law ellipticals, 30 classical bulges, 19 pseudo bulges) by joining 72 galaxies from the literature to 25 galaxies observed during our recent SINFONI black hole survey. For the first time we discuss the full error covariance matrix. We analyse the well known \\msig\\ and \\mbu\\ relations and establish the existence of statistically significant correlations between $M_{Bu}$ and $r_h$ and anti-correlations between $M_{Bu}$ and $\\rho_h$. We establish five significant bivariate correlations (\\msigrho, \\msigr, \\mbus, \\mburho, \\mbur) that predict $M_{BH}$ of 77 core and power-law ellipticals and classical bulges with measured and intrinsic scatter as small as $\\approx 0.36$ dex and $\\approx 0.33$ dex respectively, or 0.26 dex when the sub...

  16. Tidal disruption jets of supermassive black holes as hidden sources of cosmic rays: explaining the IceCube TeV-PeV neutrinos

    CERN Document Server

    Wang, Xiang-Yu

    2015-01-01

    Cosmic ray interactions that produce high-energy neutrinos also inevitably generate high-energy gamma rays, which finally contribute to the diffuse high-energy gamma-ray background after they escape the sources. It was recently found that, the high flux of neutrinos at $\\sim30$ TeV detected by IceCube lead to a cumulative gamma-ray flux exceeding the Fermi isotropic gamma-ray background at 10-100 GeV, implying that the neutrinos are produced by hidden sources of cosmic rays, where GeV-TeV gamma-rays are not transparent. Here we suggest that relativistic jets in tidal disruption events (TDEs) of supermassive black holes are such hidden sources. We consider the jet propagation in an extended,optically thick envelope around the black hole, which is resulted from the ejected material during the disruption. While powerful jets can break free from the envelope, less powerful jets would be choked inside the envelope. The jets accelerate cosmic rays through internal shocks or reverse shocks and further produce neutri...

  17. A Radial Velocity Test for Supermassive Black Hole Binaries as an Explanation for Broad, Double-Peaked Emission Lines in Active Galactic Nuclei

    CERN Document Server

    Liu, Jia; Halpern, Jules P

    2015-01-01

    One of the proposed explanations for the broad, double-peaked Balmer emission lines observed in the spectra of some active galactic nuclei (AGNs) is that they are associated with sub-parsec supermassive black hole (SMBH) binaries. Here, we test the binary broad-line region hypothesis through several decades of monitoring of the velocity structure of double-peaked H-alpha emission lines in 13 low-redshift, mostly radio-loud AGNs. This is a much larger set of objects compared to an earlier test by Eracleous et al. (1997) and we use much longer time series for the three objects studied in that paper. Although systematic changes in radial velocity can be traced in many of their lines, they are demonstrably not like those of a spectroscopic binary in a circular orbit. Any spectroscopic binary period must therefore be much longer than the span of the monitoring (assuming a circular orbit), which in turn would require black hole masses that exceed by 1-2 orders of magnitude the values obtained for these objects usin...

  18. Supermassive black holes with high accretion rates in active galactic nuclei. I. First results from a new reverberation mapping campaign

    International Nuclear Information System (INIS)

    We report first results from a large project to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). Such objects may be different from other AGNs in being powered by slim accretion disks and showing saturated accretion luminosities, but both are not yet fully understood. The results are part of a large reverberation mapping (RM) campaign using the 2.4 m Shangri-La telescope at the Yunnan Observatory in China. The goals are to investigate the gas distribution near the BH and the properties of the central accretion disks, to measure BH mass and Eddington ratios, and to test the feasibility of using such objects as a new type of cosmological candles. The paper presents results for three objects, Mrk 335, Mrk 142, and IRAS F12397+3333, with Hβ time lags relative to the 5100 Å continuum of 10.6−2.9+1.7, 6.4−2.2+0.8 and 11.4−1.9+2.9 days, respectively. The corresponding BH masses are (8.3−3.2+2.6)×106 M⊙, (3.4−1.2+0.5)×106 M⊙, and (7.5−4.1+4.3)×106 M⊙, and the lower limits on the Eddington ratios are 0.6, 2.3, and 4.6 for the minimal radiative efficiency of 0.038. Mrk 142 and IRAS F12397+333 (extinction corrected) clearly deviate from the currently known relation between Hβ lag and continuum luminosity. The three Eddington ratios are beyond the values expected in thin accretion disks and two of them are the largest measured so far among objects with RM-based BH masses. We briefly discuss implications for slim disks, BH growth, and cosmology.

  19. Short-living Supermassive Magnetar Model for the Early X-ray Flares Following Short GRBs

    Institute of Scientific and Technical Information of China (English)

    Wei-Hong Gao; Yi-Zhong Fan

    2006-01-01

    We suggest a short-lived supermassive magnetar model to account for the X-ray flares following short γ-ray bursts. In this model the central engine of the short γ-ray bursts is a supermassive millisecond magnetar, formed in coalescence of double neutron stars. The X-ray flares are powered by the dipole radiation of the magnetar. When the magnetar has lost a significant part of its angular momentum, it collapses to a black hole and the X-ray flares cease abruptly.

  20. 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.

  1. The SINFONI Black Hole Survey: The Black Hole Fundamental Plane Revisited and the Paths of (Co)evolution of Supermassive Black Holes and Bulges

    Science.gov (United States)

    Saglia, R. P.; Opitsch, M.; Erwin, P.; Thomas, J.; Beifiori, A.; Fabricius, M.; Mazzalay, X.; Nowak, N.; Rusli, S. P.; Bender, R.

    2016-02-01

    We investigate the correlations between the black hole (BH) mass MBH, the velocity dispersion σ, the bulge mass MBu, the bulge average spherical density {ρ }{{h}}, and its spherical half-mass radius rh, constructing a database of 97 galaxies (31 core ellipticals, 17 power-law ellipticals, 30 classical bulges, and 19 pseudobulges) by joining 72 galaxies from the literature to 25 galaxies observed during our recent SINFONI BH survey. For the first time we discuss the full error covariance matrix. We analyze the well-known MBH-σ and MBH-MBu relations and establish the existence of statistically significant correlations between MBu and rh and anticorrelations between MBu and {ρ }{{h}}. We establish five significant bivariate correlations (MBH-σ-ρh, MBH-σ-rh, MBH-MBu-σ, MBH-MBu-ρh, MBH-MBu-rh) that predict MBH of 77 core and power-law ellipticals and classical bulges with measured and intrinsic scatter as small as ≈ 0.36 dex and ≈ 0.33 dex, respectively, or 0.26 dex when the subsample of 45 galaxies defined by Kormendy & Ho is considered. In contrast, pseudobulges have systematically lower MBH but approach the predictions of all of the above relations at spherical densities {ρ }{{h}}≥slant {10}10 {M}⊙ {{kpc}}-3 or scale lengths {r}{{h}}≤slant 1 {{kpc}}. These findings fit in a scenario of coevolution of BH and classical-bulge masses, where core ellipticals are the product of dry mergers of power-law bulges and power-law ellipticals and bulges the result of (early) gas-rich mergers and of disk galaxies. In contrast, the (secular) growth of BHs is decoupled from the growth of their pseudobulge hosts, except when (gas) densities are high enough to trigger the feedback mechanism responsible for the existence of the correlations between MBH and galaxy structural parameters.

  2. Coevolution Between Supermassive Black Holes and Bulges Is Not Via Internal Feedback Regulation But By Rationed Gas Supply Due To Angular Momentum Distribution

    CERN Document Server

    Cen, Renyue

    2015-01-01

    We reason that, without physical fine-tuning, neither the supermassive black holes (SMBHs) nor the stellar bulges can self-regulate or inter-regulate by driving away already fallen cold gas to produce the observed correlation between them. We suggest an alternative scenario where the observed mass ratios of the SMBHs to bulges reflect the angular momentum distribution of infallen gas such that the mass reaching the stable accretion disc is a small fraction of that reaching the bulge region, averaged over the cosmological time scales. We test this scenario using high resolution, large-scale cosmological hydrodynamic simulations (without AGN feedback), assuming the angular momentum distribution of gas landing in the bulge region to yield a Mestel disc that is supported by independent simulations resolving the Bondi radii of SMBHs. A mass ratio of $0.1-0.3\\%$ between the very low angular momentum gas that free-falls to the sub-parsec region to accrete to the SMBH and the overall star formation rate is found. Thi...

  3. Self-regulated growth of supermassive black holes by a dual jet/heating AGN feedback mechanism: methods, tests and implications for cosmological simulations

    CERN Document Server

    Dubois, Yohan; Slyz, Adrianne; Teyssier, Romain

    2011-01-01

    We develop a new sub-grid model for the growth of supermassive Black Holes (BHs) and their associated Active Galactic Nuclei (AGN) feedback in hydrodynamical cosmological simulations. Assuming that BHs are created in the early stages of galaxy formation, they grow by mergers and accretion of gas at a Eddington-limited Bondi accretion rate. However this growth is regulated by AGN feedback which we model using two different modes: a quasar-heating mode when accretion rates onto the BHs are comparable to the Eddington rate, and a radio-jet mode at lower accretion rates. In other words, our feedback model deposits energy as a succession of thermal bursts and jet outflows depending on the properties of the gas surrounding the BHs. We assess the plausibility of such a model by comparing our results to observational measurements of the coevolution of BHs and their host galaxy properties, and check their robustness with respect to numerical resolution. We show that AGN feedback must be a crucial physical ingredient f...

  4. HST STIS spectroscopy of the triple nucleus of M31: two nested disks in Keplerian rotation around a Supermassive Black Hole

    CERN Document Server

    Bender, R; Bower, G; Green, R; Thomas, J; Danks, A C; Gull, T R; Hutchings, J B; Joseph, C L; Kaiser, M E; Lauer, T R; Nelson, C H; Richstone, D O; Weistrop, D; Woodgate, B; Bender, Ralf; Kormendy, John; Bower, Gary; Green, Richard; Thomas, Jens; Danks, Anthony C.; Gull, Theodore; Lauer, Tod R.; Nelson, Charles H.; Richstone, Douglas; Weistrop, Donna; Woodgate, Bruce

    2005-01-01

    We present HST spectroscopy of the nucleus of M31 obtained with STIS. Spectra taken around the CaT lines at 8500 see only the red giants in the double bright- ness peaks P1 and P2. In contrast, spectra taken at 3600-5100 A are sensitive to the tiny blue nucleus embedded in P2, the lower surface brightness red nucleus. P2 has a K-type spectrum, but the embedded blue nucleus has an A-type spectrum with strong Balmer absorption lines. Given the small likelihood for stellar collisions, a 200 Myr old starburst appears to be the most plausible origin of the blue nucleus. In stellar population, size, and velocity dispersion, the blue nucleus is so different from P1 and P2 that we call it P3. The line-of-sight velocity distributions of the red stars in P1+P2 strengthen the support for Tremaine s eccentric disk model. The kinematics of P3 is consistent with a circular stellar disk in Keplerian rotation around a super-massive black hole with M_bh = 1.4 x 10^8 M_sun. The P3 and the P1+P2 disks rotate in the same sense a...

  5. Tidal disruption jets of supermassive black holes as hidden sources of cosmic rays: Explaining the IceCube TeV-PeV neutrinos

    Science.gov (United States)

    Wang, Xiang-Yu; Liu, Ruo-Yu

    2016-04-01

    Cosmic ray interactions that produce high-energy neutrinos also inevitably generate high-energy gamma rays, which finally contribute to the diffuse high-energy gamma-ray background after they escape the sources. It was recently found that the high flux of neutrinos at ˜30 TeV detected by IceCube lead to a cumulative gamma-ray flux exceeding the Fermi isotropic gamma-ray background at 10-100 GeV, implying that the neutrinos are produced by hidden sources of cosmic rays, where GeV-TeV gamma rays are not transparent. Here we suggest that relativistic jets in tidal disruption events (TDEs) of supermassive black holes are such hidden sources. We consider the jet propagation in an extended, optically thick envelope around the black hole, which results from the ejected material during the disruption. While powerful jets can break free from the envelope, less powerful jets would be choked inside the envelope. The jets accelerate cosmic rays through internal shocks or reverse shocks and further produce neutrinos via interaction with the surrounding dense photons. All three TDE jets discovered so far are not detected by Fermi/LAT, suggesting that GeV-TeV gamma rays are absorbed in these jets. The cumulative neutrino flux from TDE jets can account for the neutrino flux observed by IceCube at PeV energies and may also account for the higher flux at ˜30 TeV if less powerful, choked jets are present in the majority of TDEs.

  6. Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the Black Hole Mass-Velocity Dispersion Relationship for Active Galactic Nuclei

    DEFF Research Database (Denmark)

    Onken, Christopher A.; Ferrarese, Laura; Merritt, David;

    2004-01-01

    We calibrate reverberation-based black hole masses in active galactic nuclei (AGNs) by using the correlation between black hole mass, M, and bulge/spheroid stellar velocity dispersion, sigma. We use new measurements of sigma for 6 AGNs and published velocity dispersions for 10 others......, in conjunction with improved reverberation mapping results, to determine the scaling factor required to bring reverberation-based black hole masses into agreement with the quiescent galaxy M-sigma relationship. The scatter in the AGN black hole masses is found to be less than a factor of 3. The current...

  7. Effects of environmental drag onto a fast-moving magnetic compact star near a supermassive black hole

    Czech Academy of Sciences Publication Activity Database

    Karas, Vladimír; Šubr, L.; Kunneriath, Devaky; Zajaček, Michal

    Opava: Silesian University, 2014 - (Stuchlík, Z.), s. 137-143. (Publications of the Institute of Physics. 7). ISBN 9788075101266. ISSN 2336-5668. [RAGtime /14.-16./. Opava (CZ), 18.09.2012-22.09.2012] R&D Projects: GA MŠk(CZ) LH14049; GA ČR(CZ) GC13-00070J Institutional support: RVO:67985815 Keywords : accretion discs * black hole physics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  8. Dust-enshrouded star near supermassive black hole: predictions for high-eccentricity passages near low-luminosity galactic nuclei

    Czech Academy of Sciences Publication Activity Database

    Zajaček, Michal; Karas, Vladimír; Eckart, A.

    2014-01-01

    Roč. 565, May (2014), A17/1-A17/15. ISSN 0004-6361 R&D Projects: GA ČR(CZ) GC13-00070J Grant ostatní: UK(CZ) SVV-26089 Institutional support: RVO:67985815 Keywords : galactic centre * black hole s * accretion disks Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

  9. Model for common growth of supermassive black holes, bulges and globular star clusters: ripping off Jeans clusters

    CERN Document Server

    Nieuwenhuizen, Theo M

    2011-01-01

    It is assumed that a galaxy starts as a dark halo of a few million Jeans clusters (JCs), each of which consists of nearly a trillion micro brown dwarfs, MACHOs of earth mass. JCs in the galaxy center heat up their MACHOs by tidal forces, which makes them expand, so that coagulation and star formation occurs. Being continuously fed by matter from bypassing JCs, the star(s) may transform into a super massive black hole. It has a fast $t^3$ growth during the first mega years, and a slow $t^{1/3}$ growth at giga years. JCs disrupted by a close encounter can provide matter for the bulge. Those that survive can be so agitated that they form stars and become globular star clusters. Thus black holes mostly arise together with galactic bulges in their own environment and are about as old as the oldest globular clusters. The age 13.2 Gyr of the star HE 1523-0901 (Frebel et al. 2007) puts forward that the Galactic halo was fully assembled at that moment. In case of merging super massive black holes the JCs passing near ...

  10. Models of galaxies with central black holes simulation methods

    CERN Document Server

    Sigurdsson, S; Quinlan, G D; Sigurdsson, Steinn; Hernquist, Lars; Quinlan, Gerald D

    1994-01-01

    We present a method for simulating numerically the effect of the adiabatic growth of black holes on the structure of elliptical galaxies. Using a parallel self--consistent field code, we add black holes to N--body realizations of model distribution functions for spherical galaxies, using a continuous mass--spectrum. The variable particle mass, combined with a simple multiple timestep integration scheme, makes it possible to evolve the models for many dynamical times with N \\sim 10^6-10^8, allowing high spatial and mass resolution. This paper discusses verification of the code using analytic models for spherical galaxies, comparing our numerical results of the effect of central black holes on the structure of the galaxies with previously published models. The intrinsic and projected properties of the final particle distribution, including higher order moments of the velocity distribution, permit comparison with observed characteristics of real galaxies, and constrain the masses of any central black holes prese...

  11. The interplay between a galactic bar and a supermassive black hole: nuclear fueling in a sub-parsec resolution galaxy simulation

    CERN Document Server

    Emsellem, Eric; Bournaud, Frédéric; Elmegreen, Bruce; Combes, Françoise; Gabor, Jared

    2014-01-01

    We study the connection between the large-scale dynamics and the gas fueling toward a central black hole via the analysis of a Milky Way-like simulation at sub-parsec resolution. This allows us to follow a set of processes at various scales (e.g., the triggering of inward gas motion towards inner resonances via the large-scale bar, the connection to the central black hole via mini spirals) in a self-consistent manner. This simulation provides further insights on the role of shear for the inhibition of star formation within the bar in regions with significant amount of gas. We also witness the decoupling of the central gas and nuclear cluster from the large-scale disc, via interactions with the black hole. This break of symmetry in the mass distribution triggers the formation of gas clumps organised in a time-varying 250 pc ring-like structure, the black hole being offset by about 70 pc from its centre. Some clumps form stars, while most get disrupted or merge. Supernovae feedback further creates bubbles and f...

  12. Supermassive black holes with high accretion rates in active galactic nuclei. II. The most luminous standard candles in the universe

    International Nuclear Information System (INIS)

    This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting massive black holes (SEAMBHs) and to use their unique properties to construct a new method for measuring cosmological distances. Based on theoretical models, the saturated bolometric luminosity of such sources is proportional to the BH mass, which can be used to obtain their distance. Here we report on five new RM measurements and show that in four of the cases, we can measure the BH mass and three of these sources are SEAMBHs. Together with the three sources from our earlier work, we now have six new sources of this type. We use a novel method based on a minimal radiation efficiency to identify nine additional SEAMBHs from earlier RM-based mass measurements. We use a Bayesian analysis to determine the parameters of the new distance expression and the method uncertainties from the observed properties of the objects in the sample. The ratio of the newly measured distances to the standard cosmological ones has a mean scatter of 0.14 dex, indicating that SEAMBHs can be use as cosmological distance probes. With their high luminosity, long period of activity, and large numbers at high redshifts, SEAMBHs have a potential to extend the cosmic distance ladder beyond the range now explored by Type Ia supernovae.

  13. The dynamics, appearance and demographics of relativistic jets triggered by tidal disruption of stars in quiescent supermassive black holes

    CERN Document Server

    De Colle, Fabio; Naiman, Jill; Ramirez-Ruiz, Enrico

    2012-01-01

    We examine the consequences of a model in which relativistic jets can be triggered in quiescent massive black holes when a geometrically thick and hot accretion disk forms as a result of the tidal disruption of a star. To estimate the power, thrust and lifetime of the jet, we use the mass accretion history onto the black hole as calculated by detailed hydrodynamic simulations of the tidal disruption of stars. We go on to determine the states of the interstellar medium in various types of quiescent galactic nuclei, and describe how this external matter can affect jets propagating through it. We use this information, together with a two-dimensional hydrodynamic model of the structure of the relativistic flow, to study the dynamics of the jet, the propagation of which is regulated by the density stratification of the environment and by its injection history. The breaking of symmetry involved in transitioning from one to two dimensions is crucial and leads to qualitatively new phenomena. Many of the observed prop...

  14. 3-cm Fine Structure Masers: A Unique Signature of Supermassive Black Hole Formation via Direct Collapse in the Early Universe

    CERN Document Server

    Dijkstra, Mark; Loeb, Abraham

    2016-01-01

    The direct collapse black hole (DCBH) scenario describes the isothermal collapse of a pristine gas cloud directly into a massive, M_BH=10^4-10^6 M_sun black hole. In this paper we show that large HI column densities of primordial gas at T~10^4 K with low molecular abundance - which represent key aspects of the DCBH scenario - provide optimal conditions for pumping of the 2p-level of atomic hydrogen by trapped Lyman alpha (Lya) photons. This Lya pumping mechanism gives rise to inverted level population of the 2s_1/2-2p_3/2 transition, and therefore to stimulated fine structure emission at 3.04 cm (rest-frame). We show that simplified models of the DCBH scenario amplify the CMB by up to a factor of 10^5, above which the maser saturates. Hyperfine splitting of the 3-cm transition gives rise to a characteristic broad (FWHM ~ tens of MHz in the observers frame) asymmetric line profile. This signal subtends an angular scale of ~ 1-10 mas, which translates to a flux of ~ 0.3-3 microJy, which is detectable with ultra...

  15. Sub-Arcsecond 2D Photometry and Spectrography of the Nucleus of M31 The Supermassive Black Hole Revisited

    CERN Document Server

    Bacon, R; Monnet, G; Nieto, J L

    1993-01-01

    Sub-arcsecond imagery (HRCAM, 0".35 - 0".57 FWHM) and two-dimensional spectrography (TIGER, 0".9 FWHM) of the central nucleus of M31 have been obtained at CFHT. The photometric data clearly show the double-peaked nucleus, in excellent agreement with a recent HST image by Lauer et al. 1993. We built deconvolved surface brightness models, using the multi-Gaussian expansion method. We then perform a detailed morphological analysis of the three central photometric components (bulge, nucleus and bright secondary peak) and derive various spatial luminosity models (oblate and triaxial). Stellar velocity and velocity dispersion fields were derived from the TIGER data: the former displays an extremely rapid rotation around the true center of the galaxy, while the latter exhibits a peaked structure offset in the opposite direction of the brightest light peak. Neglecting these offsets,both extended versions of the virial theorem and detailed hydrodynamical models confirm the classical strong central mass concentration, ...

  16. Sub-Arcsecond 2D Photometry and Spectrography of the Nucleus of M31: The Supermassive Black Hole Revisited

    OpenAIRE

    Bacon, R.; Emsellem, E.; Monnet, G.; Nieto, J. L.

    1993-01-01

    Sub-arcsecond imagery (HRCAM, 0".35 - 0".57 FWHM) and two-dimensional spectrography (TIGER, 0".9 FWHM) of the central nucleus of M31 have been obtained at CFHT. The photometric data clearly show the double-peaked nucleus, in excellent agreement with a recent HST image by Lauer et al. 1993. We built deconvolved surface brightness models, using the multi-Gaussian expansion method. We then perform a detailed morphological analysis of the three central photometric components (bulge, nucleus and b...

  17. 3-cm Fine Structure Masers: A Unique Signature of Supermassive Black Hole Formation via Direct Collapse in the Early Universe

    Science.gov (United States)

    Dijkstra, Mark; Sethi, Shiv; Loeb, Abraham

    2016-03-01

    The direct collapse black hole (DCBH) scenario describes the isothermal collapse of a pristine gas cloud directly into a massive, {M}{BH} = 104-106{M}⊙ black hole. In this paper we show that large H i column densities of primordial gas at T˜ {10}4 K with low molecular abundance—which represent key aspects of the DCBH scenario—provide optimal conditions for the pumping of the 2p-level of atomic hydrogen by trapped Lyα photons. This Lyα pumping mechanism gives rise to an inverted level population of the 2{s}1/2-2{p}3/2 transition, and therefore also gives rise to stimulated fine structure emission at λ =3.04 {cm} (rest-frame). We show that simplified models of the DCBH scenario amplify the CMB by up to a factor of ˜ {10}5, above which the maser saturates. Hyperfine splitting of the 3 cm transition gives rise to a characteristic broad (FWHM ˜ tens of MHz in the observers frame) asymmetric line profile. This signal subtends an angular scale of ˜1-10 mas, which translates to a flux of ˜0.3-3 μJy, which is detectable with ultra-deep surveys being planned with SKA1-MID. While challenging, as the signal is visible for a fraction of the collapse time of the cloud, the matching required physical conditions imply that a detection of the redshifted 3-cm emission line could provide direct evidence for the DCBH scenario.

  18. NuSTAR reveals the extreme properties of the super-Eddington accreting supermassive black hole in PG 1247+267

    Science.gov (United States)

    Lanzuisi, G.; Perna, M.; Comastri, A.; Cappi, M.; Dadina, M.; Marinucci, A.; Masini, A.; Matt, G.; Vagnetti, F.; Vignali, C.; Ballantyne, D. R.; Bauer, F. E.; Boggs, S. E.; Brandt, W. N.; Brusa, M.; Christensen, F. E.; Craig, W. W.; Fabian, A. C.; Farrah, D.; Hailey, C. J.; Harrison, F. A.; Luo, B.; Piconcelli, E.; Puccetti, S.; Ricci, C.; Saez, C.; Stern, D.; Walton, D. J.; Zhang, W. W.

    2016-05-01

    PG1247+267 is one of the most luminous known quasars at z ~ 2 and is a strongly super-Eddington accreting supermassive black hole (SMBH) candidate. We obtained NuSTAR data of this intriguing source in December 2014 with the aim of studying its high-energy emission, leveraging the broad band covered by the new NuSTAR and the archival XMM-Newton data. Several measurements are in agreement with the super-Eddington scenario for PG1247+267: the soft power law (Γ = 2.3 ± 0.1); the weak ionized Fe emission line; and a hint of the presence of outflowing ionized gas surrounding the SMBH. The presence of an extreme reflection component is instead at odds with the high accretion rate proposed for this quasar. This can be explained with three different scenarios; all of them are in good agreement with the existing data, but imply very different conclusions: i) a variable primary power law observed in a low state, superimposed on a reflection component echoing a past, higher flux state; ii) a power law continuum obscured by an ionized, Compton thick, partial covering absorber; and iii) a relativistic disk reflector in a lamp-post geometry, with low coronal height and high BH spin. The first model is able to explain the high reflection component in terms of variability. The second does not require any reflection to reproduce the hard emission, while a rather low high-energy cutoff of ~100 keV is detected for the first time in such a high redshift source. The third model require a face-on geometry, which may affect the SMBH mass and Eddington ratio measurements. Deeper X-ray broad-band data are required in order to distinguish between these possibilities.

  19. Connecting Star Formation Quenching with Galaxy Structure and Supermassive Black Holes through Gravitational Heating of Cooling Flows

    CERN Document Server

    Guo, Fulai

    2014-01-01

    Recent observations suggested that star formation quenching in galaxies is related to galaxy structure. Here we propose a new mechanism to explain the physical origin of this correlation. We assume that while quiescent galaxies are maintained quenched by a feedback mechanism, cooling flows in the hot halo gas can still develop intermittently. We study cooling flows in a large suite of around 90 hydrodynamic simulations of an isolated galaxy group, and find that the flow development depends significantly on the gravitational potential well in the central galaxy. If the galaxy's gravity is not strong enough, cooling flows result in a central cooling catastrophe, supplying cold gas and feeding star formation to galactic bulges. When the bulge grows prominent enough, compressional heating starts to offset radiative cooling and maintains cooling flows in a long-term hot mode without producing cooling catastrophe. Our model thus describes a self-limited growth channel for galaxy bulges, and naturally explains the c...

  20. RADIO MONITORING OF THE TIDAL DISRUPTION EVENT SWIFT J164449.3+573451. I. JET ENERGETICS AND THE PRISTINE PARSEC-SCALE ENVIRONMENT OF A SUPERMASSIVE BLACK HOLE

    International Nuclear Information System (INIS)

    We present continued radio observations of the tidal disruption event Swift J164449.3+573451 extending to δt ≈ 216 days after discovery. The data were obtained with the EVLA, AMI Large Array, CARMA, the SMA, and the VLBA+Effelsberg as part of a long-term program to monitor the expansion and energy scale of the relativistic outflow, and to trace the parsec-scale environment around a previously dormant supermassive black hole (SMBH). The new observations reveal a significant change in the radio evolution starting at δt ≈ 1 month, with a brightening at all frequencies that requires an increase in the energy by about an order of magnitude, and an overall density profile around the SMBH of ρ∝r–3/2 (0.1-1.2 pc) with a significant flattening at r ≈ 0.4-0.6 pc. The increase in energy cannot be explained with continuous injection from an L∝t–5/3 tail, which is observed in the X-rays. Instead, we conclude that the relativistic jet was launched with a wide range of Lorentz factors, obeying E(> Γj)∝Γ–2.5j. The similar ratios of duration to dynamical timescale for Sw 1644+57 and gamma-ray bursts (GRBs) suggest that this result may be applicable to GRB jets as well. The radial density profile may be indicative of Bondi accretion, with the inferred flattening at r ∼ 0.5 pc in good agreement with the Bondi radius for a ∼few × 106 M☉ black hole. The density at ∼0.5 pc is about a factor of 30 times lower than inferred for the Milky Way Galactic Center, potentially due to a smaller number of mass-shedding massive stars. From our latest observations (δt ≈ 216 days) we find that the jet energy is Ej,iso ≈ 5 × 1053 erg (Ej ≈ 2.4 × 1051 erg for θj = 0.1), the radius is r ≈ 1.2 pc, the Lorentz factor is Γj ≈ 2.2, the ambient density is n ≈ 0.2 cm–3, and the projected angular size is rproj ≈ 25 μas, below the resolution of the VLBA+Effelsberg. Assuming no future changes in the observed evolution and a final integrated total energy of Ej

  1. Forming Super-Massive Black Hole Seeds under the Influence of a Nearby Anisotropic Multi-Frequency Source

    CERN Document Server

    Regan, John; Wise, John

    2015-01-01

    The photo-dissociation of H$_2$ by a nearby anisotropic source of radiation is seen as a critical component in creating an environment in which a direct collapse black hole may form. Employing radiative transfer we model the effect of multi-frequency (0.76 eV - 60 eV) radiation on a collapsing halo at high redshift. We vary both the shape of the spectrum which emits the radiation and the distance to the emitting galaxy. We use blackbody spectra with temperatures of $\\rm{T = 10^4\\ K}$ and $\\rm{T = 10^5\\ K}$ and a realistic stellar spectrum. We find that an optimal zone exists between 1 kpc and 4 kpc from the emitting galaxy. If the halo resides too close to the emitting galaxy the photo-ionising radiation creates a large HII region which effectively disrupts the collapsing halo, too far from the source and the radiation flux drops below the level of the expected background and the H$_2$ fraction remains too high. When the emitting galaxy is initially placed between 1 kpc and 2 kpc from the collapsing halo, wit...

  2. The impact of magnetic fields on the IMF in star-forming clouds near a supermassive black hole

    CERN Document Server

    Hocuk, S; Spaans, M; Cazaux, S

    2012-01-01

    Star formation in the centers of galaxies is thought to yield massive stars with a possibly top-heavy stellar mass distribution. It is likely that magnetic fields play a crucial role in the distribution of stellar masses inside star-forming molecular clouds. In this context, we explore the effects of magnetic fields, with a typical field strength of 38 {\\mu}G, such as in RCW 38, and a field strength of 135 {\\mu}G, similar to NGC 2024 and the infrared dark cloud G28.34+0.06, on the initial mass function (IMF) near (\\leq 10 pc) a 10^7 solar mass black hole. Using these conditions, we perform a series of numerical simulations with the hydrodynamical code FLASH to elucidate the impact of magnetic fields on the IMF and the star-formation efficiency (SFE) emerging from an 800 solar mass cloud. We find that the collapse of a gravitationally unstable molecular cloud is slowed down with increasing magnetic field strength and that stars form along the field lines. The total number of stars formed during the simulations...

  3. Direct formation of supermassive black holes in metal-enriched gas at the heart of high-redshift galaxy mergers

    CERN Document Server

    Mayer, Lucio; Bonoli, Silvia; Quinn, Thomas; Roskar, Rok; Shen, Sijing; Wadsley, James

    2014-01-01

    We present novel 3D multi-scale SPH simulations of gas-rich galaxy mergers between the most massive galaxies at $z \\sim 8 - 10$, designed to scrutinize the direct collapse formation scenario for massive black hole seeds proposed in \\citet{mayer+10}. The simulations achieve a resolution of 0.1 pc, and include both metallicity-dependent optically-thin cooling and a model for thermal balance at high optical depth. We consider different formulations of the SPH hydrodynamical equations, including thermal and metal diffusion. When the two merging galaxy cores collide, gas infall produces a compact, optically thick nuclear disk with densities exceeding $10^{-10}$ g cm$^3$. The disk rapidly accretes higher angular momentum gas from its surroundings reaching $\\sim 5$ pc and a mass of $\\gtrsim 10^9$ $M_{\\odot}$ in only a few $10^4$ yr. Outside $\\gtrsim 2$ pc it fragments into massive clumps. Instead, supersonic turbulence prevents fragmentation in the inner parsec region, which remains warm ($\\sim 3000-6000$ K) and dev...

  4. Co-evolution of elliptical galaxies and their central black holes

    International Nuclear Information System (INIS)

    After the discovery that supermassive black holes (SMBHs) are ubiquitous at the center of stellar spheroids and that their mass MBH, in the range 106M-109 M, is tightly related to global properties of the host stellar system, the idea of the co-evolution of elliptical galaxies and of their SMBHs has become a central topic of modern astrophysics. Here, I summarize some consequences that can be derived from the galaxy Scaling Laws (SLs) and present a coherent scenario for the formation and evolution of elliptical galaxies and their central SMBHs, focusing in particular on the establishment and maintenance of their SLs. In particular, after a first observationally based part, the discussion focuses on the physical interpretation of the Fundamental Plane. Then, two important processes in principle able to destroy the galaxy and SMBH SLs, namely galaxy merging and cooling flows, are analyzed. Arguments supporting the necessity to clearly distinguish between the origin and maintenance of the different SLs, and the unavoidable occurrence of SMBH feedback on the galaxy ISM in the late stages of galaxy evolution (when elliptical galaxies are sometimes considered as dead, red objects), are then presented. At the end of the paper I will discuss some implications of the recent discovery of super-dense ellipticals in the distant Universe. In particular, I will argue that, if confirmed, these new observations would lead to the conclusion that at early epochs a relation between the stellar mass of the galaxy and the mass of the central SMBH should hold, consistent with the present day Magorrian relation, while the proportionality coefficient between MBH and the scale of velocity dispersion of the hosting spheroids should be significantly smaller than that at the present epoch

  5. Radio AGN in galaxy clusters: heating hot atmospheres and driving supermassive black hole growth over cosmic time

    CERN Document Server

    Ma, C -J; Nulsen, P E J

    2012-01-01

    We estimate the average radio-AGN (mechanical) power deposited into the hot atmospheres of galaxy clusters over more than three quarters of the age of the Universe. Our sample was drawn from eight major X-ray cluster surveys, and includes 685 clusters in the redshift range 0.1central NVSS radio sources using the relation between the radio synchrotron luminosities and X-ray cavity power measurements of Cavagnolo et al. (2010). We find only a weak correlation between radio luminosity and cluster X-ray luminosity across the sample. This trend is driven primarily by the most distant clusters, where the detection fraction and average radio powers are higher in the most luminous X-ray clusters at redshifts at or above z=0.3. The average AGN mechanical power of $3\\times10^{44}$ erg/s exceeds the X-ray luminosity of 44% of the clusters in our sample, indicating that the accumulation ...

  6. EFFECTS OF CIRCUMNUCLEAR DISK GAS EVOLUTION ON THE SPIN OF CENTRAL BLACK HOLES

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Umberto [Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, D-85748 Garching b. Muenchen (Germany); Dotti, Massimo [Department of Physics of the University of Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano (Italy); Petkova, Margarita [Max Planck Institute for Astrophysics, Karl-Schwarzschild-Strasse 1, D-85741 Garching b. Muenchen (Germany); Perego, Albino [Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland); Volonteri, Marta [Institut d' Astrophysique de Paris, 98bis Boulevard Arago, F-75014 Paris (France)

    2013-04-10

    Mass and spin are the only two parameters needed to completely characterize black holes (BHs) in general relativity. However, the interaction between BHs and their environment is where complexity lies, as the relevant physical processes occur over a large range of scales. That is particularly relevant in the case of supermassive black holes (SMBHs), hosted in galaxy centers, and surrounded by swirling gas and various generations of stars. These compete with the SMBH for gas consumption and affect both dynamics and thermodynamics of the gas itself. How the behavior of such a fiery environment influences the angular momentum of the gas accreted onto SMBHs, and, hence, BH spins, is uncertain. We explore the interaction between SMBHs and their environment via first three-dimensional sub-parsec resolution simulations (ranging from {approx}0.1 pc to {approx}1 kpc scales) that study the evolution of the SMBH spin by including the effects of star formation, stellar feedback, radiative transfer, and metal pollution according to the proper stellar yields and lifetimes. This approach is crucial in investigating the impact of star formation processes and feedback effects on the angular momentum of the material that could accrete on the central hole. We find that star formation and feedback mechanisms can locally inject significant amounts of entropy in the surrounding medium, and impact the inflow inclination angles and Eddington fractions. As a consequence, the resulting trends show upper-intermediate equilibrium values for the spin parameter of a {approx_equal} 0.6-0.9, corresponding to radiative efficiencies {epsilon} {approx_equal} 9%-15%. These results suggest that star formation feedback taking place in the circumnuclear disk during the infall alone cannot induce very strong chaotic trends in the gas flow, quite independently from the different numerical parameters.

  7. Determining Central Black Hole Masses in Distant Active Galaxies

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2002-01-01

    An empirical relationship, of particular interest for studies of high redshift active galactic nuclei (AGNs) and quasars, between the masses of their central black-holes and rest-frame ultraviolet (UV) parameters measured in single-epoch AGN spectra is presented. This relationship is calibrated...... black-hole demographics at high redshift as well as to statistically study the fundamental properties of AGNs. The broad line region size - luminosity relationship is key to the calibrations presented here. The fact that its intrinsic scatter is also the main source of uncertainty in the calibrations...

  8. Slender Galaxy with Robust Black Hole

    Science.gov (United States)

    2008-01-01

    This plot of data from NASA's Spitzer Space Telescope indicates that a flat, spiral galaxy called NGC 3621 has a feeding, supermassive black hole lurking within it -- a surprise considering that astronomers thought this particular class of super-thin galaxies lacked big black holes. The data were captured by Spitzer's infrared spectrograph, an instrument that cracks infrared light open to reveal the signatures of elements. In this case, the data, or spectrum, for NGC 3621, shows the signature of highly ionized neon -- a sure sign of an active, supermassive black hole. Only a black hole that is actively consuming gas and stars has enough energy to ionize neon to this state. The other features in this plot are polycyclic aromatic hydrocarbons and chlorine, produced in the gas surrounding stars. The results challenge current theories, which hold that supermassive black holes require the bulbous central bulges that poke out from many spiral galaxies to form and grow. NGC 3621 is the second disk galaxy without any bulge found to harbor a supermassive black hole; the first, found in 2003, is NGC 4395. Astronomers have also used Spitzer to find six other mega black holes in thin spirals with only minimal bulges. Together, the findings indicate that, for a galaxy, being plump in the middle is not a necessary condition for growing a rotund black hole.

  9. TIME SERIES ANALYSIS OF GAMMA-RAY BLAZARS AND IMPLICATIONS FOR THE CENTRAL BLACK-HOLE MASS

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Kenji; Mori, Masaki [Department of Physical Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan)

    2013-08-20

    Radiation from the blazar class of active galactic nuclei (AGNs) exhibits fast time variability which is usually ascribed to instabilities in the emission region near the central supermassive black hole. The variability time scale is generally faster in higher energy region, and data recently provided by the Fermi Gamma-ray Space Telescope in the GeV energy band enable a detailed study of the temporal behavior of AGN. Due to its wide field-of-view in the scanning mode, most sky regions are observed for several hours per day and daily light curves of many AGNs have been accumulated for more than 4 yr. In this paper we investigate the time variability of 15 well-detected AGNs by studying the normalized power spectrum density of their light curves in the GeV energy band. One source, 3C 454.3, shows a specific time scale of 6.8 Multiplication-Sign 10{sup 5} s, and this value suggests, assuming the internal shock model, a mass for the central black hole of (10{sup 8}-10{sup 10}) M{sub Sun} which is consistent with other estimates. It also indicates the typical time interval of ejected blobs is (7-70) times the light crossing time of the Schwarzschild radius.

  10. TIME SERIES ANALYSIS OF GAMMA-RAY BLAZARS AND IMPLICATIONS FOR THE CENTRAL BLACK-HOLE MASS

    International Nuclear Information System (INIS)

    Radiation from the blazar class of active galactic nuclei (AGNs) exhibits fast time variability which is usually ascribed to instabilities in the emission region near the central supermassive black hole. The variability time scale is generally faster in higher energy region, and data recently provided by the Fermi Gamma-ray Space Telescope in the GeV energy band enable a detailed study of the temporal behavior of AGN. Due to its wide field-of-view in the scanning mode, most sky regions are observed for several hours per day and daily light curves of many AGNs have been accumulated for more than 4 yr. In this paper we investigate the time variability of 15 well-detected AGNs by studying the normalized power spectrum density of their light curves in the GeV energy band. One source, 3C 454.3, shows a specific time scale of 6.8 × 105 s, and this value suggests, assuming the internal shock model, a mass for the central black hole of (108-1010) M☉ which is consistent with other estimates. It also indicates the typical time interval of ejected blobs is (7-70) times the light crossing time of the Schwarzschild radius

  11. Probing the origin of the iron K_alpha line around stellar and supermassive black holes using X-ray polarimetry

    CERN Document Server

    Marin, Frederic

    2013-01-01

    Asymmetric, broad iron lines are a common feature in the X-ray spectra of both X-ray binaries (XRBs) and type-1 Active Galactic Nuclei (AGN). It was suggested that the distortion of the Fe K_alpha emission results from Doppler and relativistic effects affecting the radiative transfer close to the strong gravitational well of the central compact object: a stellar mass black hole (BH) or neutron star (NS) in the case of XRBs, or a super massive black hole (SMBH) in the case of AGN. However, alternative approaches based on reprocessing and transmission of radiation through surrounding media also attempt to explain the line broadening. So far, spectroscopic and timing analyzes have not yet convinced the whole community to discriminate between the two scenarios. Here we study to which extent X-ray polarimetric measurements of black hole X-ray binaries (BHXRBs) and type-1 AGN could help to identify the possible origin of the line distortion. To do so, we report on recent simulations obtained for the two BH flavors ...

  12. Nonthermal Supermassive Dark Matter

    Science.gov (United States)

    Chung, Daniel J. H.; Kolb, Edward W.; Riotto, Antonio

    1999-01-01

    We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may he elementary particles of mass much greater than the weak scale. Searches for dark matter should ma be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.

  13. GALAXY ZOO: THE FUNDAMENTALLY DIFFERENT CO-EVOLUTION OF SUPERMASSIVE BLACK HOLES AND THEIR EARLY- AND LATE-TYPE HOST GALAXIES

    International Nuclear Information System (INIS)

    We use data from the Sloan Digital Sky Survey and visual classifications of morphology from the Galaxy Zoo project to study black hole growth in the nearby universe (z III]>1040 erg s-1 in early- and late-type galaxies is fundamentally different. AGN host galaxies as a population have a broad range of stellar masses (1010-1011 Msun), reside in the green valley of the color-mass diagram and their central black holes have median masses around 106.5 Msun. However, by comparing early- and late-type AGN host galaxies to their non-active counterparts, we find several key differences: in early-type galaxies, it is preferentially the galaxies with the least massive black holes that are growing, while in late-type galaxies, it is preferentially the most massive black holes that are growing. The duty cycle of AGNs in early-type galaxies is strongly peaked in the green valley below the low-mass end (1010 Msun) of the red sequence at stellar masses where there is a steady supply of blue cloud progenitors. The duty cycle of AGNs in late-type galaxies on the other hand peaks in massive (1011 Msun) green and red late-types which generally do not have a corresponding blue cloud population of similar mass. At high-Eddington ratios (L/LEdd>0.1), the only population with a substantial fraction of AGNs are the low-mass green valley early-type galaxies. Finally, the Milky Way likely resides in the 'sweet spot' on the color-mass diagram where the AGN duty cycle of late-type galaxies is highest. We discuss the implications of these results for our understanding of the role of AGNs in the evolution of galaxies.

  14. Concurrent Supermassive Black Hole and Galazy Growth: Linking Environment and Nuclear Activity in Zeta Equals 2.23 H Alpha Emitters

    Science.gov (United States)

    Lehmer, B. D.; Lucy, A. B.; Alexander, D. M.; Best, P. N.; Geach, J. E.; Harrison, C. M.; Hornschemeier, A. E.; Matsuda, Y.; Mullaney, J. R.; Smail, Ian; Sobral, D.; Swinbank, A. M.

    2013-01-01

    We present results from an approximately equal 100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15 × 15 arcmin square region. Narrow-band imaging in the near-IR (within the K band) revealed that the structure contains an additional overdensity of 22 z = 2.23 H alpha-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs (22 within the Chandra field of view). Our Chandra observations reveal that three HAEs in addition to the four QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of approximately equal (8-60) × 10(exp 43) erg s(exp-1) and X-ray spectral slopes consistent with unobscured active galactic nucleus (AGN). Using a large comparison sample of 210 z = 2.23 HAEs in the Chandra-COSMOS field (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of approximately equal 2 times over the field), and after excluding optically-selected QSOs, we find that the AGN fraction is a factor of approximately equal 3.5(+3.8/ -2.2) times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250micrometers, we respectively estimate mean SMBH accretion rates ( M(BH)) and star formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked X-ray luminosity is QSO-like (L(2-10 keV) approximately equal [6-10] × 10(exp 43) erg s(exp -1)), and the implied M(BH)/SFR approximately equal (1.6-3.2) × 10(exp -3) is broadly consistent with the local M(BH)/Stellar Mass relation and z approximately equal 2 X-ray selected AGN. In contrast, the C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and have M(BH)/SFR approximately

  15. Food Habits of Black Ducks Wintering in West Central Tennessee: Annual report 1990-91

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study was conducted to describe the food habits of black ducks (Anas rubripes) wintering in west central Tennessee and to compare foods of black ducks and...

  16. Low-luminosity Active Galaxies and their Central Black Holes

    CERN Document Server

    Dong, X; Dong, Xiaoyi; Robertis, Michael M. De

    2005-01-01

    Central black hole masses for 118 spiral galaxies representing morphological stages S0/a through Sc and taken from the large spectroscopic survey of Ho, Filippenko & Sargent (1997) are derived using 2MASS Ks data. Black hole (BH) masses are found using a calibrated black-hole - Ks bulge luminosity relation, while bulge luminosities are measured using GALFIT, a two-dimensional bulge/disk decomposition routine. The BH masses are correlated against a variety of nuclear and host-galaxy properties. Nuclear properties such as line width and line ratios show a very high degree of correlation with BH mass. The excellent correlation with line-width supports the view that the emission-line gas is in virial equilibrium with either the BH or bulge potential. The very good emission-line ratio correlations may indicate a change in ionizing continuum shape with BH mass in the sense that more massive BHs generate harder spectra. Apart from the inclination-corrected rotational velocity, no excellent correlations are found...

  17. Selection bias in dynamically-measured super-massive black holes: its consequences and the quest for the most fundamental relation

    Science.gov (United States)

    Shankar, Francesco; Bernardi, Mariangela; Sheth, Ravi K.; Ferrarese, Laura; Graham, Alister W.; Savorgnan, Giulia; Allevato, Viola; Marconi, Alessandro; Läsker, Ronald; Lapi, Andrea

    2016-03-01

    We compare the set of local galaxies having dynamically measured black holes with a large, unbiased sample of galaxies extracted from the Sloan Digital Sky Survey. We confirm earlier work showing that the majority of black hole hosts have significantly higher velocity dispersions σ than local galaxies of similar stellar mass. We use Monte-Carlo simulations to illustrate the effect on black hole scaling relations if this bias arises from the requirement that the black hole sphere of influence must be resolved to measure black hole masses with spatially resolved kinematics. We find that this selection effect artificially increases the normalization of the Mbh-σ relation by a factor of at least ˜3; the bias for the Mbh-Mstar relation is even larger. Our Monte Carlo simulations and analysis of the residuals from scaling relations both indicate that σ is more fundamental than Mstar or effective radius. In particular, the Mbh-Mstar relation is mostly a consequence of the Mbh-σ and σ-Mstar relations, and is heavily biased by up to a factor of 50 at small masses. This helps resolve the discrepancy between dynamically-based black hole-galaxy scaling relations versus those of active galaxies. Our simulations also disfavour broad distributions of black hole masses at fixed σ. Correcting for this bias suggests that the calibration factor used to estimate black hole masses in active galaxies should be reduced to values of fvir ˜ 1. Black hole mass densities should also be proportionally smaller, perhaps implying significantly higher radiative efficiencies/black hole spins. Reducing black hole masses also reduces the gravitational wave signal expected from black hole mergers.

  18. Determination of masses of the central black holes in NGC524 and NGC2549 using Laser Guide Star Adaptive Optics

    CERN Document Server

    Krajnovic, Davor; Cappellari, Michele; Davies, Roger L

    2009-01-01

    [abridged] We present observations of NGC524 and NGC2549 with LGS AO obtained at GEMINI North telescope using the NIFS IFU in the K band. The purpose of these observations, together with previously obtained observations with the SAURON IFU, is to determine the masses (Mbh) of the supermassive black holes (SMBH). The targeted galaxies were chosen to have central light profiles showing a core (NGC524) and a cusp (NGC2549), to probe the feasibility of using the galaxy centre as the NGS required for LGS AO. We employ an innovative `open loop' technique. The data have spatial resolution of 0.23" and 0.17" FWHM, showing that high quality LGS AO observations of these objects are possible. We construct axisymmetric three-integral dynamical models which are constrained with both the NIFS and SAURON data. The best fitting models yield Mbh=(8.3 +2.7 -1.3) x 10^8 Msun for NGC524 and Mbh=(1.4 +0.2 -1.3) x 10^7 Msun for NGC2549 (all errors are at the 3 sigma CL). We demonstrate that the wide-field SAURON data play a crucia...

  19. A Periodically Varying Luminous Quasar at z=2 from the Pan-STARRS1 Medium Deep Survey: A Candidate Supermassive Black Hole Binary in the Gravitational Wave-Driven Regime

    CERN Document Server

    Liu, Tingting; Heinis, Sebastien; Magnier, Eugene A; Burgett, William S; Chambers, Kenneth; Flewelling, Heather; Huber, Mark; Hodapp, Klaus W; Kaiser, Nicholas; Kudritzki, Rolf-Peter; Tonry, John L; Wainscoat, Richard J; Waters, Christopher

    2015-01-01

    Supermassive black hole binaries (SMBHBs) should be an inevitable consequence of the hierarchical growth of massive galaxies through mergers, and the strongest sirens of gravitational waves (GWs) in the cosmos. And yet, their direct detection has remained elusive due to the compact (sub-parsec) orbital separations of gravitationally bound SMBHBs. Here we exploit a theoretically predicted signature of a SMBHB in the time domain: periodic variability caused by a mass accretion rate that is modulated by the binary's orbital motion. We report our first significant periodically varying quasar detection from the systematic search in the Pan-STARRS1 (PS1) Medium Deep Survey. Our SMBHB candidate, PSO J334.2028+01.4075, is a luminous radio-loud quasar at $z=2.060$, with extended baseline photometry from the Catalina Real-Time Transient Survey, as well as archival spectroscopy from the FIRST Bright Quasar Survey. The observed period ($542 \\pm 15$ days) and estimated black hole mass ($\\log (M_{\\rm BH}/M_\\odot) = 9.97 \\p...

  20. The cloud of gas falling toward the central black hole in the milky way

    Directory of Open Access Journals (Sweden)

    Miralda-Escudé J.

    2012-12-01

    Full Text Available The cloud of gas that will pass within 200AU of the central black hole of our Galaxy in 2013 may be generated by a disk around an old, low-mass star that was created in a tidal encounter with one of the stellar black holes that are expected to accumulate in the central region of the stellar cusp.