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Sample records for lyman line profiles

  1. Interplanetary Lyman $\\alpha$ line profiles: variations with solar activity cycle

    CERN Document Server

    Quemerais, E; Bertaux, J L; Koutroumpa, D; Clarke, J; Kyrola, E; Schmidt, W; Qu\\'emerais, Eric; Lallement, Rosine; Bertaux, Jean-Loup; Koutroumpa, Dimitra; Clarke, John; Kyrola, Erkki; Schmidt, Walter

    2006-01-01

    Interplanetary Lyman alpha line profiles are derived from the SWAN H cell data measurements. The measurements cover a 6-year period from solar minimum (1996) to after the solar maximum of 2001. This allows us to study the variations of the line profiles with solar activity. These line profiles were used to derive line shifts and line widths in the interplanetary medium for various angles of the LOS with the interstellar flow direction. The SWAN data results were then compared to an interplanetary background upwind spectrum obtained by STIS/HST in March 2001. We find that the LOS upwind velocity associated with the mean line shift of the IP \\lya line varies from 25.7 km/s to 21.4 km/s from solar minimum to solar maximum. Most of this change is linked with variations in the radiation pressure. LOS kinetic temperatures derived from IP line widths do not vary monotonically with the upwind angle of the LOS. This is not compatible with calculations of IP line profiles based on hot model distributions of interplanet...

  2. The LyAlpha Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage

    CERN Document Server

    Martin, Crystal L; Henry, Alaina; Soto, Kurt T; Danforth, Charles W; Wong, Joseph

    2015-01-01

    We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect H Lyman alpha emission from 8 ULIRGs and the companion to IRAS09583+4714. In contrast to the P Cygni profiles often seen in galaxy spectra, the H Lyman alpha profiles exhibit prominent, blueshifted emission out to Doppler shifts exceeding -1000 km/s in three HII-dominated and two AGN-dominated ULIRGs. To better understand the role of resonance scattering in shaping the H Lyman alpha line profiles, we directly compare them to non-resonant emission lines in optical spectra. We find that the line wings are already present in the intrinsic nebular spectra, and scattering merely enhances the wings relative to the line core. The H Lyman alpha attenuation (as measured in the COS aperture) ranges from that ...

  3. A study of the Lyman-$\\alpha$ line profile in DBA white dwarfs

    CERN Document Server

    Genest-Beaulieu, C

    2016-01-01

    The hydrogen abundances in DBA white dwarfs determined from optical or UV spectra have been reported to differ significantly in some studies. We revisit this problem using our own model atmospheres and synthetic spectra, and present a theoretical investigation of the Lyman-$\\alpha$ line profile as a function of effective temperature and hydrogen abundance. We identify one possible solution to this discrepancy and show considerable improvement from a detailed analysis of optical and UV spectra of DBA stars.

  4. THE Lyα LINE PROFILES OF ULTRALUMINOUS INFRARED GALAXIES: FAST WINDS AND LYMAN CONTINUUM LEAKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Crystal L.; Wong, Joseph [Department of Physics, University of California, Santa Barbara, CA, 93106 (United States); Dijkstra, Mark [Institute of Theoretical Astrophysics, University of Oslo, Postboks 1029, 0858 Oslo (Norway); Henry, Alaina [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Soto, Kurt T. [Institute for Astronomy, Department of Physics, ETH Zurich, CH-8093 Zurich (Switzerland); Danforth, Charles W., E-mail: cmartin@physics.ucsb.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO, 80309 (United States)

    2015-04-10

    We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect Lyα emission from eight ULIRGs and the companion to IRAS09583+4714. In contrast to the P Cygni profiles often seen in galaxy spectra, the Lyα profiles exhibit prominent, blueshifted emission out to Doppler shifts exceeding −1000 km s{sup −1} in three H ii-dominated and two AGN-dominated ULIRGs. To better understand the role of resonance scattering in shaping the Lyα line profiles, we directly compare them to non-resonant emission lines in optical spectra. We find that the line wings are already present in the intrinsic nebular spectra, and scattering merely enhances the wings relative to the line core. The Lyα attenuation (as measured in the COS aperture) ranges from that of the far-UV continuum to over 100 times more. A simple radiative transfer model suggests the Lyα photons escape through cavities which have low column densities of neutral hydrogen and become optically thin to the Lyman continuum in the most advanced mergers. We show that the properties of the highly blueshifted line wings on the Lyα and optical emission-line profiles are consistent with emission from clumps of gas condensing out of a fast, hot wind. The luminosity of the Lyα emission increases nonlinearly with the ULIRG bolometric luminosity and represents about 0.1–1% of the radiative cooling from the hot winds in the H ii-dominated ULIRGs.

  5. The Lyα Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage

    Science.gov (United States)

    Martin, Crystal L.; Dijkstra, Mark; Henry, Alaina; Soto, Kurt T.; Danforth, Charles W.; Wong, Joseph

    2015-04-01

    We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect Lyα emission from eight ULIRGs and the companion to IRAS09583+4714. In contrast to the P Cygni profiles often seen in galaxy spectra, the Lyα profiles exhibit prominent, blueshifted emission out to Doppler shifts exceeding -1000 km s-1 in three H ii-dominated and two AGN-dominated ULIRGs. To better understand the role of resonance scattering in shaping the Lyα line profiles, we directly compare them to non-resonant emission lines in optical spectra. We find that the line wings are already present in the intrinsic nebular spectra, and scattering merely enhances the wings relative to the line core. The Lyα attenuation (as measured in the COS aperture) ranges from that of the far-UV continuum to over 100 times more. A simple radiative transfer model suggests the Lyα photons escape through cavities which have low column densities of neutral hydrogen and become optically thin to the Lyman continuum in the most advanced mergers. We show that the properties of the highly blueshifted line wings on the Lyα and optical emission-line profiles are consistent with emission from clumps of gas condensing out of a fast, hot wind. The luminosity of the Lyα emission increases nonlinearly with the ULIRG bolometric luminosity and represents about 0.1-1% of the radiative cooling from the hot winds in the H ii-dominated ULIRGs.

  6. Kinetic-Energy Distribution of D(2p) Atoms from Analysis of the D Lyman-Alpha Line Profile

    Science.gov (United States)

    Ciocca, M.; Ajello, Joseph M.; Liu, Xianming; Maki, Justin

    1997-01-01

    The kinetic-energy distribution of D(2p) atoms resulting from electron-impact dissociation of D2 has been measured. A high-resolution vacuum ultraviolet spectrometer was employed for the first measurement of the D Lyman-alpha (D L(alpha)) emission line profiles at 20- and 100-eV excitation energies. Analysis of the deconvoluted line profile of D L(alpha) at 100 eV reveals the existence of a narrow line central peak of 29+/-2 mA full width at half maximum and a broad pedestal wing structure about 190 mA wide. The wings of the line can be used to determine the fast atom distribution. The wings of D L(alpha) arise from dissociative excitation of a series of doubly excited states that cross the Franck-Condon region between 23 and 40 eV. The fast atom distribution at 100-eV electron impact energy spans the energy range from 1 to 10 eV with a peak value near 6 eV. Slow D(2p) atoms characterized by a distribution function with peak energy near 100 meV produce the central peak profile, which is nearly independent of the impact energy. The deconvoluted line profiles of the central peak at 20 eV for dissociative excitation of D2 and H2 are fitted with an analytical function for use in calibration of space flight instrumentation equipped with a D/H absorption cell. The kinetic-energy and line profile results are compared to similar measurements for H2. The absolute cross sections for the line center (slow atoms) and wings (fast atoms) and total emission line profile were measured from threshold to 400 eV. Analytical model coefficients are given for the energy dependence of the measured slow atom cross section.

  7. Kinetic Energy Distribution of D(2p) Atoms From Analysis of the D Lyman-a Line Profile

    Science.gov (United States)

    Ciocca, Marco; Ajello, Joseph M.; Liu, Xianming; Maki, Justin

    1997-01-01

    The absolute cross sections of the line center (slow atoms) and wings (fast atoms) and total emission line profile were measured from threshold to 400 eV. Analytical model coeffiecients are given for the energy dependence of the measured slow atom cross section.

  8. Hydrogen Lyman-alpha and Lyman-beta radiances and profiles in polar coronal holes

    CERN Document Server

    Tian, Hui; Curdt, Werner; Vial, Jean-Claude

    2009-01-01

    The hydrogen Lyman-alpha plays a dominant role in the radiative energy transport in the lower transition region, and is important for the stud- ies of transition-region structure as well as solar wind origin. We investigate the Ly-alpha profiles obtained by SUMER in coronal holes and quiet Sun. In a subset of these observations, also the Hi Lyman-beta, Si iii, and O vi lines were (quasi-) simultaneously recorded. We find that the distances between the two peaks of Ly-alpha profiles are larger in coronal holes than in the quiet Sun, indicating a larger opacity in coronal holes. This difference might result from the different magnetic structures or the different radiation fields in the two regions. Most of the Ly-beta profiles in the coronal hole have a stronger blue peak, in contrast to those in quiet-Sun regions. Whilst in both regions the Ly-alpha profiles are stronger in the blue peak. Although the asymmetries are likely to be produced by differential flows in the solar atmosphere, their detailed formation ...

  9. A possible solution to the Lyman/Balmer line problem in hot DA white dwarfs

    CERN Document Server

    Preval, S P; Badnell, N R; Holberg, J B; Hubeny, I

    2014-01-01

    Arguably, the best method for determining the effective temperature ($T_{\\mathrm{eff}}$) and surface gravity (log $g$) of a DA white dwarf is by fitting the Hydrogen Lyman and Balmer absorption features. However, as has been shown for white dwarfs with $T_{\\mathrm{eff}}$>50,000K, the calculated value from the Lyman and Balmer lines are discrepant, which worsens with increasing temperature. Many different solutions have been suggested, ranging from the input physics used to calculate the models, to interstellar reddening. We will focus on the former, and consider three variables. The first is the atomic data used, namely the number of transitions included in line blanketing treatments and the photoionization cross sections. The second is the stark broadening treatment used to synthesise the Lyman and Balmer line profiles, namely the calculations performed by Lemke (1997) and Tremblay & Bergeron (2009). Finally, the third is the atmospheric content. The model grids are calculated with a pure H composition, ...

  10. Lyman alpha line formation in starbursting galaxies I. Moderately thick, dustless, and static HI media

    CERN Document Server

    Ahn, S H; Lee, H M; Ahn, Sang-Hyeon; Lee, Hee-Won; Lee, Hyung Mok

    2000-01-01

    We investigate the Lyman alpha line transfer in nearby and high redshift starbursting galaxies, where the effect of high optical depths and the role of dust in the scattering medium are expected to be conspicuous and should be treated in a very careful manner. We present our first results in dustless, static, and uniform HI media with moderate optical depths \\tau_0=10^{3-7}, where \\tau_0 is the line center optical depth of Lyman alpha and temperatures T=10^{1-4}K using a Monte Carlo code. We investigate the basic physics of the line transfer and confirm the criterion of a\\tau_0>10^3 for the validity of diffusion approximation suggested by Neufeld in 1990, where $a$ is the Voigt parameter. Adopting the model suggested by Tenorio-Tagle et al. in 1999, we performed a detailed calculation on the Lyman alpha line formation for each evolutionary stage of an expanding supershell. The emergent Lyman alpha profiles are characterized by the double peaks and the absorption trough at the line center. It is found that the...

  11. Reconnaissance of the TRAPPIST-1 exoplanet system in the Lymanline

    Science.gov (United States)

    Bourrier, V.; Ehrenreich, D.; Wheatley, P. J.; Bolmont, E.; Gillon, M.; de Wit, J.; Burgasser, A. J.; Jehin, E.; Queloz, D.; Triaud, A. H. M. J.

    2017-02-01

    The TRAPPIST-1 system offers the opportunity to characterize terrestrial, potentially habitable planets orbiting a nearby ultracool dwarf star. We performed a four-orbit reconnaissance with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope to study the stellar emission at Lyman-α, to assess the presence of hydrogen exospheres around the two inner planets, and to determine their UV irradiation. We detect the Lymanline of TRAPPIST-1, making it the coldest exoplanet host star for which this line has been measured. We reconstruct the intrinsic line profile, showing that it lacks broad wings and is much fainter than expected from the stellar X-ray emission. TRAPPIST-1 has a similar X-ray emission as Proxima Cen but a much lower Ly-α emission. This suggests that TRAPPIST-1 chromosphere is only moderately active compared to its transition region and corona. We estimated the atmospheric mass loss rates for all planets, and found that despite a moderate extreme UV emission the total XUV irradiation could be strong enough to strip the atmospheres of the inner planets in a few billions years. We detect marginal flux decreases at the times of TRAPPIST-1b and c transits, which might originate from stellar activity, but could also hint at the presence of extended hydrogen exospheres. Understanding the origin of these Lyman-α variations will be crucial in assessing the atmospheric stability and potential habitability of the TRAPPIST-1 planets.

  12. Doppler speeds of the hydrogen Lyman lines in solar flares from EVE

    CERN Document Server

    Brown, Stephen A; Labrosse, Nicolas

    2016-01-01

    The hydrogen Lyman lines provide important diagnostic information about the dynamics of the chromosphere, but there have been few systematic studies of their variability during flares. We investigate Doppler shifts in these lines in several flares, and use these to calculate plasma speeds. We use spectral data from the Multiple EUV Grating Spectrograph B (MEGS-B) detector of the Extreme-Ultraviolet Variability Experiment (EVE) instrument on the Solar Dynamics Observatory. MEGS-B obtains full-disk spectra of the Sun at a resolution of 0.1nm in the range 37-105 nm, which we analyse using three independent methods. The first method performs Gaussian fits to the lines, and compares the quiet-Sun centroids with the flaring ones to obtain the Doppler shifts. The second method uses cross-correlation to detect wavelength shifts between the quiet-Sun and flaring line profiles. The final method calculates the "center-of-mass" of the line profile, and compares the quiet-Sun and flaring centroids to obtain the shift. In ...

  13. On the inversion of the scattering polarization and the Hanle effect signals in the hydrogen Lyman-$\\alpha$ line

    CERN Document Server

    Ishikawa, R; Belluzzi, L; Sainz, R Manso; Stepan, J; Bueno, J Trujillo; Goto, M; Tsuneta, S

    2014-01-01

    Magnetic field measurements in the upper chromosphere and above, where the gas-to-magnetic pressure ratio $\\beta$ is lower than unity, are essential for understanding the thermal structure and dynamical activity of the solar atmosphere. Recent developments in the theory and numerical modeling of polarization in spectral lines have suggested that information on the magnetic field of the chromosphere-corona transition region could be obtained by measuring the linear polarization of the solar disk radiation at the core of the hydrogen Lyman-$\\alpha$ line at 121.6~nm, which is produced by scattering processes and the Hanle effect. The Chromospheric Lyman-$\\alpha$ Spectropolarimeter (CLASP) sounding rocket experiment aims to measure the intensity (Stokes $I$) and the linear polarization profiles ($Q/I$ and $U/I$) of the hydrogen Lyman-$\\alpha$ line. In this paper we clarify the information that the Hanle effect can provide by applying a Stokes inversion technique based on a database search. The database contains a...

  14. Lyman α emission from the first galaxies: signatures of accretion and infall in the presence of line trapping

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, Dominik R. G.; Spaans, M.; Zaroubi, S.

    2011-01-01

    The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock heated to temperatures of similar to 10(4) K, leading to potentially strong fluxes in the Lyman alpha line. Indeed, a number of Lyman alpha blobs have been detected at

  15. Lyman α emission from the first galaxies : Signatures of accretion and infall in the presence of line trapping

    NARCIS (Netherlands)

    Latif, M.A.; Schleicher, Dominik R. G.; Spaans, Maarten; Zaroubi, S.

    2011-01-01

    The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock heated to temperatures of ˜104 K, leading to potentially strong fluxes in the Lyman α line. Indeed, a number of Lyman α blobs have been detected at high redshift. In th

  16. Lyman α emission from the first galaxies: signatures of accretion and infall in the presence of line trapping

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, Dominik R. G.; Spaans, M.; Zaroubi, S.

    2011-01-01

    The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock heated to temperatures of ˜104 K, leading to potentially strong fluxes in the Lyman α line. Indeed, a number of Lyman α blobs have been detected at high redshift. In th

  17. Lyman alpha emission from the first galaxies : signatures of accretion and infall in the presence of line trapping

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, Dominik R. G.; Spaans, M.; Zaroubi, S.

    2011-01-01

    The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock heated to temperatures of similar to 10(4) K, leading to potentially strong fluxes in the Lyman alpha line. Indeed, a number of Lyman alpha blobs have been detected at

  18. Lyman α emission from the first galaxies: signatures of accretion and infall in the presence of line trapping

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, Dominik R. G.; Spaans, M.; Zaroubi, S.

    The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock heated to temperatures of similar to 10(4) K, leading to potentially strong fluxes in the Lyman alpha line. Indeed, a number of Lyman alpha blobs have been detected at

  19. Diagnosing galactic feedback with the line broadening in the low redshift Lyman-alpha forest

    CERN Document Server

    Viel, M; Bolton, J S; Kim, T -S; Puchwein, E; Nasir, F; Wakker, B P

    2016-01-01

    We compare the low redshift (z ~ 0.1) Lyman-alpha forest from hydrodynamical simulations with data from the Cosmic Origin Spectrograph (COS). We find tension between the observed number of lines with b-parameters in the range 25-45 km/s and the predictions from simulations that incorporate either vigorous feedback from active galactic nuclei or that exclude feedback altogether. The gas in these simulations is, respectively, either too hot to contribute to the Lyman-alpha absorption or too cold to produce the required line widths. Matching the observed b-parameter distribution therefore requires feedback processes that thermally or turbulently broaden the absorption features without collisionally (over-)ionising hydrogen. This suggests the Lyman-alpha forest b-parameter distribution is a valulable diagnostic of galactic feedback in the low redshift Universe. We furthermore confirm the low redshift Lyman-alpha forest column density distribution is better reproduced by an ultraviolet background with an HI photo-...

  20. A coronagraphic absorbing cloud reveals the narrow-line region and extended Lyman-$\\alpha$ emission of QSO J0823+0529

    CERN Document Server

    Fathivavsari, Hassan; Noterdaeme, Pasquier; Pâris, Isabelle; Finley, Hayley; López, Sebastian; Srianand, Raghunathan; Sánchez, Paula

    2015-01-01

    We report long-slit spectroscopic observations of the quasar SDSS J082303.22+052907.6 ($z_{\\rm CIV}$$\\sim$3.1875), whose Broad Line Region (BLR) is partly eclipsed by a strong damped Lyman-$\\alpha$ (DLA; log$N$(HI)=21.7) cloud. This allows us to study the Narrow Line Region (NLR) of the quasar and the Lyman-$\\alpha$ emission from the host galaxy. Using CLOUDY models that explain the presence of strong NV and PV absorption together with the detection of SiII$^*$ and OI$^{**}$ absorption in the DLA, we show that the density and the distance of the cloud to the quasar are in the ranges 180 $$ $r_0$ $>$230 pc, respectively. Sizes of the neutral($\\sim$2-9pc) and highly ionized phases ($\\sim$3-80pc) are consistent with the partial coverage of the CIV broad line region by the CIV absorption from the DLA (covering factor of $\\sim$0.85). We show that the residuals are consistent with emission from the NLR with CIV/Lyman-$\\alpha$ ratios varying from 0 to 0.29 through the profile. Remarkably, we detect extended Lyman-$\\...

  1. Lyman alpha emission from the first galaxies: Signatures of accretion and infall in the presence of line trapping

    CERN Document Server

    Latif, M A; Spaans, M; Zaroubi, S

    2011-01-01

    The formation of the first galaxies is accompanied by large accretion flows and virialization shocks, during which the gas is shock-heated to temperatures of $\\sim10^4$ K, leading to potentially strong fluxes in the Lyman alpha line. Indeed, a number of Lyman alpha blobs has been detected at high redshift. In this letter, we explore the origin of such Lyman alpha emission using cosmological hydrodynamical simulations that include a detailed model of atomic hydrogen as a multi-level atom and the effects of line trapping with the adaptive mesh refinement code FLASH. We see that baryons fall into the center of a halo through cold streams of gas, giving rise to a Lyman alpha luminosity of at least $\\rm 10^{44} erg s^{-1}$ at $\\rm z=4.7$, similar to observed Lyman alpha blobs. We find that a Lyman alpha flux of $\\rm 5.0\\times 10^{-17} erg cm^{-2} s^{-1}$ emerges from the envelope of the halo rather than its center, where the photons are efficiently trapped. Such emission can be probed in detail with the upcoming J...

  2. The Mean Metal-line Absorption Spectrum of Damped Lyman Alpha Systems in BOSS

    CERN Document Server

    Mas-Ribas, Lluís; Pérez-Ràfols, Ignasi; Arinyo-i-Prats, Andreu; Noterdaeme, Pasquier; Petitjean, Patrick; Schneider, Donald P; York, Donald G; Ge, Jian

    2016-01-01

    We study the average absorption spectrum of the Damped Lyman Alpha system (DLA) population at $z ~ 2.5$ by stacking normalized, rest-frame shifted spectra of $\\sim 27\\,000$ DLAs from the Data Release 12 of the BOSS survey of SDSS-III. We list measurements of the mean equivalent width of 50 individual metal absorption lines in 5 intervals of DLA hydrogen column density $N_{\\rm HI}$, and overall mean equivalent widths for an additional 13 absorption features from groups of strongly blended lines. We show that the mean equivalent width of low-ionization lines increases with $N_{\\rm HI}$ as expected, but this increase is much weaker or non-existent for high-ionization lines. We develop a theoretical model to infer mean column densities from the equivalent widths of partially saturated lines, based on the presence of multiple absorption components observed in high-resolution spectra. We use this model to infer mean column densities in DLAs of 14 low-ionization species, as well as for AlIII, SIII, SiIII, CIV, SiIV,...

  3. 类星体对的Lyman-α吸收线和发射线的相互关系%Relation between the Lyman-α Emission and Absorption Lines of Quasar Pairs

    Institute of Scientific and Technical Information of China (English)

    李有兵; 吕连忠; 彭青松

    2008-01-01

    通过探究类星体对的Lyman-α的吸收线和发射线的等值宽度,研究了它们之间可能存在的相互关系.研究了来自SDSS巡天的12对中等分辨率的类星体对.发现Lyman-α的发射线和吸收线的等值宽度没有任何的相关性.它支持了前人的建议,即背景类星体的Lyman-α吸收线来自前景类星体附近的光学厚吸收体,而Lyman-α的发射线来自前景类星体本身.%We investigated the relation between the Lyman-α emission and absorption lines of quasar pairs by exploring possible correlation between the equivalent widths of the two kinds of lines. We used 12 moderately resolved quasar pairs from the Sloan Digitized Sky Survey (SDSS) for the study, where the equivalent widths of the Lyman-α emission lines of the foreground quasars are available in literature. The equivalent widths of the corresponding Ly-α absorption lines of the background quasars were measured from their spectra data downloaded from the SDSS web-site. We found no correlation between rest-frame equivalent widths of the Ly-α emission and absorption lines, favoring the previous suggestion that the Ly-α absorption lines in background quasars are due to optically thick absorbers near the foreground quasars, and the Ly-α emission lines originate from the foreground quasars themselves.

  4. Asymmetry of the natural line profile for the hydrogen atom.

    Science.gov (United States)

    Labzowsky, L N; Solovyev, D A; Plunien, G; Soff, G

    2001-10-01

    The asymmetry of the natural line profile for transitions in hydrogenlike atoms is evaluated within a QED framework. For the Lyman- alpha 1s-2p absorption transition in neutral hydrogen this asymmetry results in an additional energy shift of 2.929 856 Hz. For the 2s(1/2)-2p(3/2) transition it amounts to -1.512 674 Hz. As a new feature this correction turns out to be process dependent. The quoted numbers refer to the Compton-scattering process.

  5. HST Emission Line Galaxies at z ~ 2: Comparing Physical Properties of Lyman Alpha and Optical Emission Line Selected Galaxies

    CERN Document Server

    Hagen, Alex; Behrens, Christoph; Ciardullo, Robin; Gebhardt, Henry S Grasshorn; Gronwall, Caryl; Bridge, Joanna S; Fox, Derek B; Schneider, Donald P; Trump, Jonathan R; Blanc, Guillermo A; Chiang, Yi-Kuan; Chonis, Taylor S; Finkelstein, Steven L; Hill, Gary J; Jogee, Shardha; Gawiser, Eric

    2015-01-01

    We compare the physical and morphological properties of z ~ 2 Lyman-alpha emitting galaxies (LAEs) identified in the HETDEX Pilot Survey and narrow band studies with those of z ~ 2 optical emission line galaxies (oELGs) identified via HST WFC3 infrared grism spectroscopy. Both sets of galaxies extend over the same range in stellar mass (7.5 < logM < 10.5), size (0.5 < R < 3.0 kpc), and star-formation rate (~1 < SFR < 100). Remarkably, a comparison of the most commonly used physical and morphological parameters -- stellar mass, half-light radius, UV slope, star formation rate, ellipticity, nearest neighbor distance, star formation surface density, specific star formation rate, [O III] luminosity, and [O III] equivalent width -- reveals no statistically significant differences between the populations. This suggests that the processes and conditions which regulate the escape of Ly-alpha from a z ~ 2 star-forming galaxy do not depend on these quantities. In particular, the lack of dependence on ...

  6. The Lyman alpha reference sample

    DEFF Research Database (Denmark)

    Hayes, M.; Östlin, G.; Schaerer, D.

    2013-01-01

    We report on new imaging observations of the Lyman alpha emission line (Lyα), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028 Lyman alpha emission line (Lyα), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028

  7. The Properties of Lyman Alpha Nebulae: Gas Kinematics from Non-resonant Lines

    CERN Document Server

    Yang, Yujin; Jahnke, Knud; Davé, Romeel

    2014-01-01

    [Abridged] With VLT/X-shooter, we obtain optical and NIR spectra of six Ly-alpha blobs at z~2.3. Using three measures --- the velocity offset between the Lya line and the non-resonant [OIII] or H-alpha line (Dv_Lya), the offset of stacked interstellar metal absorption lines, and the spectrally-resolved [OIII] line profile --- we study the kinematics of gas along the line of sight to galaxies within each blob center. These three indicators generally agree in velocity and direction, and are consistent with a simple picture in which the gas is stationary or slowly outflowing at a few hundred km/s from the embedded galaxies. The absence of stronger outflows is not a projection effect: the covering fraction for our sample is limited to <1/8 (13%). The outflow velocities exclude models in which star formation or AGN produce "super" or "hyper" winds of up to ~1000km/s. The Dv_Lya offsets here are smaller than typical of LBGs, but similar to those of compact LAEs. The latter suggests that outflow speed cannot be a...

  8. Low-redshift evolution of the Lyman $\\alpha$ Forest

    CERN Document Server

    Theuns, T; Efstathiou, G P

    1998-01-01

    The low-redshift evolution of the intergalactic medium is investigated using hydrodynamic cosmological simulations. The assumed cosmological model is a critical density cold dark matter universe. The imposed uniform background of ionizing radiation has the amplitude, shape and redshift evolution as computed from the observed quasar luminosity function by Haardt & Madau. We have analysed simulated Lyman-alpha spectra using Voigt-profile fitting, mimicking the procedure with which quasar spectra are analysed. Our simulations reproduce the observed evolution of the number of Lyman-alpha absorption lines over the whole observed interval of z=0.5 to z=4. In particular, our simulations show that the decrease in the rate of evolution of Lyman-alpha absorption lines at z< 2, as observed by Hubble Space Telescope, can be explained by the steep decline in the photo-ionizing background resulting from the rapid decline in quasar numbers at low redshift.

  9. Predicted profiles of ultraviolet interstellar absorption lines

    Energy Technology Data Exchange (ETDEWEB)

    Welty, D.E.; Hobbs, L.M.; York, D.G. (Chicago, University, IL (USA))

    1991-02-01

    In this paper, values of the column density, line width parameter, and velocity are determined for as many components derived from optical interstellar absorption-line profiles of Na I and K I as needed to reproduce the observed high-resolution optical profiles of the D lines of Na I toward eight lightly reddened stars and of the 7698 A line of K I toward six moderately reddened stars. The derived component structures are then used to predict UV absorption-line profiles due to C I, Mg I, S I, Si I, and Fe I along the same lines of sight. Comparison of the predicted profiles with existing lower resolution line profiles and equivalent width data suggests that this simple scaling procedure can in many cases fairly reliably predict the UV profiles from the observed optical ones. 64 refs.

  10. Low redshift Lyman alpha absorption lines and the dark matter halos of disk galaxies

    Science.gov (United States)

    Maloney, Philip

    1993-01-01

    Recent observations using the Hubble Space Telescope of the z = 0.156 QSO 3C 273 have discovered a surprisingly large number of Ly-alpha absorption lines. In particular, Morris et al. found 9 certain and 7 possible Ly-alpha lines with equivalent widths above 25 mA. This is much larger (by a factor of 5-10) than the number expected from extrapolation of the high-redshift behavior of the Ly-alpha forest. Within the context of pressure-confined models for the Ly-alpha clouds, this behavior can be understood if the ionizing background declines sharply between z is approximately 2 and z is approximately 0. However, this requires that the ionizing photon flux drop as rapidly as the QSO volume emissivity; moreover, the absorbers must have a space density n(sub O) is approximately 2.6(N/10)h/((D/100 kpc)(sup 2)) Mpc(sup -3) where D is the present-day diameter of the absorbers. It is somewhat surprising that such necessarily fragile objects could have survived in such numbers to the present day. It is shown that it is plausible that the atomic hydrogen extents of spiral and irregular galaxies are large enough to produce the observed number of Ly-alpha absorption lines toward 3C 273, and that the neutral column densities and doppler b-values expected under these conditions fall in the range found by Morris et al. (1991).

  11. Project Lyman

    CERN Document Server

    McCandliss, Stephan R; Blair, William P; Kaiser, Mary Elizabeth; Feldman, Paul D; Meurer, Gerhardt R; Dixon, William V; Sahnow, David J; Neufeld, David A; Lupu, Roxana E; Fleming, Brian; Smee, Stephen A; Andersson, B G; Moseley, Samuel H; Kutyrev, Alexander S; Li, Mary J; Sonneborn, George; Siegmund, Oswald H W; Vallerga, John V; Welsh, Barry Y; Stiavelli, Massimo; Windhorst, Rogier A; Shapley, Alice E

    2008-01-01

    We explore the design of a space mission, Project Lyman, which has the goal of quantifying the ionization history of the universe from the present epoch to a redshift of z ~ 3. Observations from WMAP and SDSS show that before a redshift of z >~ 6 the first collapsed objects, possibly dwarf galaxies, emitted Lyman continuum (LyC) radiation shortward of 912 A, reionizing most of the universe. How LyC escapes from galactic environments, whether it induces positive or negative feedback on the local and global collapse of structures, and the role played by clumping, molecules, metallicity and dust are major unanswered theoretical questions, requiring observational constraint. Numerous intervening Lyman limit systems, which frustrate the detection of LyC from high z objects, thin below z ~ 3 where there are a few objects with apparently very high fesc. At low z there are only controversial detections and a handful of upper limits. A wide-field multi-object spectroscopic survey with moderate spectral and spatial res...

  12. C IV and He II Line Emission of Lyman Alpha Blobs: Powered by Shock Heated Gas

    CERN Document Server

    Cabot, Samuel H C; Zheng, Zheng

    2016-01-01

    Utilizing {\\it ab initio} ultra-high resolution hydrodynamical simulations, we investigate the properties of the interstellar and circum-galactic medium of Ly$\\alpha$ Blobs (LABs) at $z=3$, focusing on three important emission lines: Ly$\\alpha$ 1216\\AA, \\heii 1640\\AA\\ and \\civ 1449\\AA. Their relative strengths provide a powerful probe of the thermodynamic properties of the gas when confronted with observations. By adjusting the dust attenuation effect using one parameter and matching the observed size-luminosity relation of LABs using another parameter, we show that our simulations can reproduce the observed \\civ/\\lya\\ and \\heii/\\lya\\ ratios adequately. This analysis provides the first successful physical model to account for simultaneously the LAB luminosity function, luminosity-size relation, and the \\civ/Ly$\\alpha$ and \\heii/Ly$\\alpha$ ratios, with only two parameters. The physical underpinning for this model is that, in addition to the stellar component for the \\lya\\ emission, the \\lya\\ and \\civ\\ emission...

  13. H2 Lyman and Werner band lines and their sensitivity for a variation of the proton-electron mass ratio in the gravitational potential of white dwarfs

    Science.gov (United States)

    Salumbides, E. J.; Bagdonaite, J.; Abgrall, H.; Roueff, E.; Ubachs, W.

    2015-06-01

    Recently we published an accurate analysis of molecular hydrogen absorption in the photospheres of the white dwarf stars GD133 and GD29-38, previously observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. Constraints were derived on a possible dependence of the proton-electron mass ratio on gravitational fields that are 10 000 times stronger than at the Earth's surface. Here we present further details of that study, in particular a re-evaluation of the spectrum of the B^1Σ _u^+ - X^1Σ _g^+ (v^' },v^' ' }) Lyman bands relevant for the prevailing temperatures (12 000-14 000 K) of the photospheres. The emphasis is on the calculation of so-called Ki-coefficients, that represent the sensitivity of each individual line to a possible change in the proton-electron mass ratio. Such calculations were performed by semi-empirical methods and by ab initio methods providing accurate and consistent values. A full listing is provided for the molecular physics data on the Lyman bands (wavelengths λi, line oscillator strengths fi, radiative damping rates Γi, and sensitivity coefficients Ki) as required for the analyses of H2-spectra in hot dwarf stars. A similar listing of the molecular physics parameters for the C^1Π_u - X^1Σ _g^+ (v^' },v^' ' }) Werner bands is provided for future use in the analysis of white dwarf spectra.

  14. Damped Lyman-α Systems

    Science.gov (United States)

    Petitjean, P.; Ledoux, C.

    Recently, Prochaska & Wolfe (1997) have used Keck spectra of 17 DLA absorbers to investigate the kinematics of the neutral gas using unsaturated low excitation transitions such as Si iiλ 1808. They show that the absorption profiles are inconsistent with models of galactic haloes with random motions, spherically infalling gas and slowly rotating hot disks. The CDM model (Kauffmann 1996) is rejected as it produces disks with rotation velocities too small to account for the large observed velocity broadening of the absorption lines. Models of thick disks (h ~0.3 R, where h is the vertical scale and R the radius) with large rotational velocity (v 225kms-1) can reproduce the data. By combining new data on five damped systems with information gathered in the literature, we study the kinematics of the low and high-ionization phases in a sample of 26 damped Lyman-α systems in the redshift range 1.17 - 4.38. We show that the broader the line the more asymmetric, as expected in case rotation dominates the line broadening. However this correlation does not hold for velocities larger than 150 km/s indicating that evidence for rotational motions if any is restricted to velocity broadenings Δ V 200kms-1 are peculiar with kinematics consistent with random motions. They show sub-systems as those expected if the objects are in the process of merging.

  15. KECK SPECTROSCOPY OF FAINT 3 < z < 8 LYMAN BREAK GALAXIES: EVIDENCE FOR A DECLINING FRACTION OF EMISSION LINE SOURCES IN THE REDSHIFT RANGE 6 < z < 8

    Energy Technology Data Exchange (ETDEWEB)

    Schenker, Matthew A.; Ellis, Richard S.; Robertson, Brant E. [Department of Astrophysics, California Institute of Technology, MS 105-24, Pasadena, CA 91125 (United States); Stark, Daniel P. [Kavli Institute of Cosmology and Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Dunlop, James S.; McLure, Ross J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Kneib, Jean-Paul [Laboratoire d' Astrophysique de Marseille, F-13388 Marseille cedex 13 (France); Richard, Johan [Observatoire de Lyon, F-69561 Saint-Genis-Laval (France)

    2012-01-10

    Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with the Wide Field Camera 3 on board the Hubble Space Telescope, we present new evidence for a reversal in the redshift-dependent fraction of star-forming galaxies with detectable Lyman alpha (Ly{alpha}) emission in the redshift range 6.3 < z < 8.8. Our earlier surveys with the DEIMOS spectrograph demonstrated a significant increase with redshift in the fraction of line emitting galaxies over the interval 4 < z < 6, particularly for intrinsically faint systems which dominate the luminosity density. Using the longer wavelength sensitivities of Low Resolution Imaging Spectrometer and NIRSPEC, we have targeted 19 Lyman break galaxies selected using recent WFC3/IR data whose photometric redshifts are in the range 6.3 < z < 8.8 and which span a wide range of intrinsic luminosities. Our spectroscopic exposures typically reach a 5{sigma} sensitivity of <50 A for the rest-frame equivalent width (EW) of Ly{alpha} emission. Despite the high fraction of emitters seen only a few hundred million years later, we find only two convincing and one possible line emitter in our more distant sample. Combining with published data on a further seven sources obtained using FORS2 on the ESO Very Large Telescope, and assuming continuity in the trends found at lower redshift, we discuss the significance of this apparent reversal in the redshift-dependent Ly{alpha} fraction in the context of our range in continuum luminosity. Assuming all the targeted sources are at their photometric redshift and our assumptions about the Ly{alpha} EW distribution are correct, we would expect to find so few emitters in less than 1% of the realizations drawn from our lower redshift samples. Our new results provide further support for the suggestion that, at the redshifts now being probed spectroscopically, we are entering the era where the intergalactic medium is partially neutral. With the arrival of more

  16. Iron Line Profiles in Strong Gravity

    CERN Document Server

    Beckwith, K; Beckwith, Kris; Done, Chris

    2004-01-01

    We describe a new code which can accurately calculate the relativistic effects which distort the emission from an accretion disc around a black hole. We compare our results for a disk from 6-20r_g in both Schwarzchild and extreme Kerr spacetimes with the two line profile codes which are on general release in the XSPEC spectral fitting package. These are generally accurate at the 10-20% level for this range of radii, but have some drawbacks in terms of assumptions and/or resolution. In particular we show that the assumed form of the angular emissivity law (limb darkening or brightening) can make significant changes to the derived line profile. Lightbending effects are never negligible at these radii, so the observed line is produced from a range of different emitted angles, and this can affect the derived radial emissivity law. The line profile is not simply determined by the well defined (but numerically difficult) physical effects of strong gravity, but is also dependent on the poorly known astrophysics of t...

  17. Modelling of asymmetric nebulae. II. Line profiles

    CERN Document Server

    Morisset, C

    2006-01-01

    We present a tool, VELNEB_3D, which can be applied to the results of 3D photoionization codes to generate emission line profiles, position-velocity maps and 3D maps in any emission line by assuming an arbitrary velocity field. We give a few examples, based on our pseudo-3D photoionization code NEBU_3D (Morisset, Stasinska and Pena, 2005) which show the potentiality and usefulness of our tool. One example shows how complex line profiles can be obtained even with a simple expansion law if the nebula is bipolar and the slit slightly off-center. Another example shows different ways to produce line profiles that could be attributed to a turbulent velocity field while there is no turbulence in the model. A third example shows how, in certain circumstances, it is possible to discriminate between two very different geometrical structures -- here a face-on blister and its ``spherical impostor'' -- when using appropriate high resolution spectra. Finally, we show how our tool is able to generate 3D maps, similar to the ...

  18. On the Lack of Correlation Between Mg II 2796, 2803 Angstrom and Lyman alpha Emission in Lensed Star-Forming Galaxies

    Science.gov (United States)

    Rigby, Jane Rebecca; Bayliss, M. B.; Gladders, M. D.; Sharon, K.; Wuyts, E.; Dahle, H.

    2014-01-01

    We examine the Mg II 2796, 2803 Angstrom, Lyman alpha, and nebular line emission in five bright star-forming galaxies at 1.66 less than z less than 1.91 that have been gravitationally lensed by foreground galaxy clusters. All five galaxies show prominent Mg II emission and absorption in a P Cygni profile. We find no correlation between the equivalent widths of Mg II and Lyman alpha emission. The Mg II emission has a broader range of velocities than do the nebular emission line profiles; the Mg II emission is redshifted with respect to systemic by 100 to 200 km s(exp-1). When present, Lyman alpha is even more redshifted. The reddest components of Mg II and Lyman alpha emission have tails to 500-600 km s(exp-1), implying a strong outflow. The lack of correlation in the Mg II and Lyman alpha equivalent widths, the differing velocity profiles, and the high ratios of Mg II to nebular line fluxes together suggest that the bulk of Mg II emission does not ultimately arise as nebular line emission, but may instead be reprocessed stellar continuum emission.

  19. Berry phases and profiles of line wings and rainbow satellites induced by optical collisions

    Science.gov (United States)

    Ciuryło, R.; Szudy, J.; Baylis, W. E.

    2015-09-01

    The concept of Berry phase is included in an analysis of the intensity distribution in far wings of pressure-broadened spectral lines emitted or absorbed by atoms placed in an external cone-rotating electric field. Particular attention is focused on frequency regions where rainbow satellite bands appear. A classical-path treatment that employs the time-dependent Schrödinger equation is used to derive an expression for the line shape, and it uses a dipole transition moment calculated with quasimolecular wave functions given by the Berry version of the adiabatic approximation. It is found that in the presence of an external rotating electric field, the intensity distribution in far wings can be expressed in terms of the universal line shape function of the unified Franck-Condon theory once energy shifts due to Stark and Berry effects are taken into account. We show that the influence of Berry phase in the profiles of the far wings can be manifested either in the form of deviations of observed profiles from the quasistatic distribution or the appearance of additional features in the vicinity of the maximum of the rainbow satellite band. As an example, the modification of the rainbow satellite at 162.3 nm in the red wing of the self-broadened Lymanline of hydrogen, caused by an external rotating electric field, is considered.

  20. The Stacked Lyman-Alpha Emission Profile from the Circum-Galactic Medium of z~2 Quasars

    CERN Document Server

    Battaia, Fabrizio Arrigoni; Cantalupo, Sebastiano; Prochaska, J Xavier

    2016-01-01

    In the context of the FLASHLIGHT survey, we obtained deep narrow band images of 15 $z\\sim2$ quasars with GMOS on Gemini-South in an effort to measure Ly$\\alpha$ emission from circum- and inter-galactic gas on scales of hundreds of kpc from the central quasar. We do not detect bright giant Ly$\\alpha$ nebulae (SB~10$^{-17}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$ at distances >50 kpc) around any of our sources, although we routinely ($\\simeq47$%) detect smaller scale <50 kpc Ly$\\alpha$ emission at this SB level emerging from either the extended narrow emission line regions powered by the quasars or by star-formation in their host galaxies. We stack our 15 deep images to study the average extended Ly$\\alpha$ surface brightness profile around $z\\sim2$ quasars, carefully PSF-subtracting the unresolved emission component and paying close attention to sources of systematic error. Our analysis, which achieves an unprecedented depth, reveals a surface brightness of SB$_{\\rm Ly\\alpha}\\sim10^{-19}$ erg s$^{-1}$ cm$^{-2}...

  1. Spectroscopy of 7 Radio-Loud QSOs at 2Lyman-alpha Nebulae Accreting onto Host Galaxies

    CERN Document Server

    Roche, Nathan; Binette, Luc

    2014-01-01

    We performed long-slit optical spectroscopy (GTC-OSIRIS) of 6 radio-loud QSOs at redshifts $2Lyman-$\\alpha$ emitting nebulae, and detect extended Lyman-$\\alpha$ emission for 4, with surface brightness $\\sim10^{-16}$ ergs $\\rm cm^{-2}s^{-1}arcsec^{-2}$ and line width FWHM 400-1100 (mean 863) km $\\rm s^{-1}$. We also observed the $z\\simeq 5.9$ radio-loud QSO, SDSS J2228+0110, and find evidence of a $\\geq 10$ kpc extended Lyman-$\\alpha$ emission nebula, a new discovery for this high-redshift object. Spatially-resolved kinematics of the 5 nebulae are examined by fitting the Lyman-$\\alpha$ wavelength at a series of positions along the slit. We found the line-of-sight velocity $\\Delta(v)$ profiles to be relatively flat. However, 3 of the nebulae appear systematically redshifted by 250-460 km $\\rm s^{-1}$ relative to the Lyman-$\\alpha$ line of the QSO (with no offset for the other two), which we argue is evidence for infall. One of these (Q0805+046) had a small ($...

  2. Lyman Alpha Control

    CERN Document Server

    Nielsen, Daniel Stefaniak

    2015-01-01

    This document gives an overview of how to operate the Lyman Alpha Control application written in LabVIEW along with things to watch out for. Overview of the LabVIEW code itself as well as the physical wiring of and connections from/to the NI PCI-6229 DAQ box is also included. The Lyman Alpha Control application is the interface between the ALPHA sequencer and the HighFinesse Wavelength Meter as well as the Lyman Alpha laser setup. The application measures the wavelength of the output light from the Lyman Alpha cavity through the Wavelength Meter. The application can use the Wavelength Meter’s PID capabilities to stabilize the Lyman Alpha laser output as well as switch between up to three frequencies.

  3. C IV and He II line emission of Lyman α blobs: powered by shock-heated gas

    Science.gov (United States)

    Cabot, Samuel H. C.; Cen, Renyue; Zheng, Zheng

    2016-10-01

    Utilizing ab initio ultrahigh resolution hydrodynamical simulations, we investigate the properties of the interstellar and circumgalactic medium of Lyα blobs (LABs) at z = 3, focusing on three important emission lines: Lyα 1216 Å, He II 1640 Å and C IV 1549 Å. Their relative strengths provide a powerful probe of the thermodynamic properties of the gas when confronted with observations. By adjusting the dust attenuation effect using one parameter and matching the observed size-luminosity relation of LABs using another parameter, we show that our simulations can reproduce the observed C IV/Lyα and He II/Lyα ratios adequately. This analysis provides the first successful physical model to account for simultaneously the LAB luminosity function, luminosity-size relation and the C IV/Lyα and He II/Lyα ratios, with only two parameters. The physical underpinning for this model is that, in addition to the stellar component for the Lyα emission, the Lyα and C IV emission lines due to shock-heated gas are primarily collisional excitation driven and the He II emission line collisional ionization driven. We find that the density, temperature and metallicity of the gas responsible for each emission line is significantly distinct, in a multiphase interstellar and circumgalactic medium that is shock heated primarily by supernovae and secondarily by gravitational accretion of gas.

  4. An Ultraluminous Lyman Alpha Emitter with a Blue Wing at z=6.6

    CERN Document Server

    Hu, E M; Songaila, A; Barger, A J; Rosenwasser, B; Wold, I

    2016-01-01

    We report the detection of the most luminous high-redshift Lyman Alpha Emitting galaxy (LAE) yet seen, with log L(Ly alpha) = 43.9 ergs/s. The galaxy -- COSMOS Lyman alpha 1, or COLA1 -- was detected in a search for ultra-luminous LAEs with Hyper Suprime-Cam on the Subaru telescope. It was confirmed to lie at z = 6.593 based on a Lyman alpha line detection obtained from followup spectroscopy with the DEIMOS spectrograph on Keck2. COLA1 is the first very high-redshift LAE to show a multi-component Lyman alpha line profile with a blue wing, which suggests that it could lie in a highly ionized region of the intergalactic medium and could have significant infall. If this interpretation is correct, then ultra-luminous LAEs like COLA1 offer a unique opportunity to determine the properties of the HII regions around these galaxies which will help in understanding the ionization of the z ~ 7 intergalactic medium.

  5. Metal Abundances in a Damped Lyman-alpha System Along Two Lines of Sight at z=0.93

    CERN Document Server

    López, S; Gregg, M D; Wisotzki, L; Wucknitz, O; Guzman, A

    2005-01-01

    We study metal abundances in the z=0.9313 damped Lya system observed in the two lines-of-sight, A and B, toward the gravitationally-lensed double QSO HE0512-3329. Spatially resolved STIS spectra constrain the neutral-gas column density to be LogN(HI)=20.5 in both Aand B. UVES spectra (spectral resolution FWHM=9.8 km/s) show, in contrast, significant line-of-sight differences in the column densities of MnII and FeII; these are not due to observational systematics. We find that [Mn/H]=-1.44 and [Fe/H]=-1.52 in damped Lya system A, while [Mn/H]=-0.98 and [Fe/H]>-1.32, and possibly as high as [Fe/H] approx. -1 in damped Lya system B. A careful assessment of possible systematic errors leads us to conclude that these transverse differences are significant at a 5 sigma level or greater. Although nucleosynthesis effects may also be at play, we favor differential dust-depletion as the main mechanism producing the observed abundance gradient. The transverse separation is 5 kpc at the redshift of the absorber, which is ...

  6. First Detection of NaI D lines in High-Redshift Damped Lyman-alpha Systems

    CERN Document Server

    Kondo, S; Gässler, W; Hayano, Y; Iye, M; Kamata, Y; Kanzawa, T; Kobayashi, N; Minowa, Y; Nedachi, K; Oya, S; Pyo, T S; Saint-Jacques, D; Takami, H; Takato, N; Terada, H; Tokunaga, A; Tsujimoto, T; Churchill, Christopher W.; Gaessler, Wolfgang; Hayano, Yutaka; Iye, Masanori; Kamata, Yukiko; Kanzawa, Tomio; Kobayashi, Naoto; Kondo, Sohei; Minowa, Yosuke; Nedachi, Ko; Oya, Shin; Pyo, Tae-Soo; Takami, Hideki; Takato, Naruhisa; Terada, Hiroshi; Tokunaga, Alan; Tsujimoto, Takuji

    2006-01-01

    A Near-infrared (1.18-1.35 micron) high-resolution spectrum of the gravitationally-lensed QSO APM 08279+5255 was obtained with the IRCS mounted on the Subaru Telescope using the AO system. We detected strong NaI D 5891,5897 doublet absorption in high-redshift DLAs at z=1.062 and 1.181, confirming the presence of NaI, which was first reported for the rest-frame UV NaI 3303.3,3303.9 doublet by Petitjean et al. This is the first detection of NaI D absorption in a high-redshift (z>1) DLA. In addition, we detected a new NaI component in the z=1.062 DLA and four new components in the z=1.181 DLA. Using an empirical relationship between NaI and HI column density, we found that all "components" have large HI column density, so that each component is classified as DLA absorption. We also detected strong NaI D absorption associated with a MgII system at z=1.173. Because no other metal absorption lines were detected in this system at the velocity of the NaI absorption in previously reported optical spectra (observed 3.6...

  7. Precision Measurement of the Energies and Line Shapes of Antiprotonic Lyman and Balmer Transitions From Hydrogen and Helium Isotopes

    CERN Multimedia

    2002-01-01

    % PS207 \\\\ \\\\ For the study of the antiproton-proton and antiproton-nuclear spin-spin and spin-orbital interaction at threshold a high resolution measurement is proposed of the line shapes and energy shifts of antiprotonic K$\\alpha$ and L$\\alpha$ transitions of hydrogen and helium isotopes. The intense LEAR beam, stopped in the cyclotron trap at low gas pressure, provides a unique~X-ray~source with sufficient brightness. Charge coupled devices with their excellent background rejection and energy resolution allow a precise determination of the strong shifts and widths of the 1s hyperfine states of protonium, in addition the detection of the $\\bar{p}$D K$\\alpha$ transition should be possible. A focussing crystal spectrometer with a resolution $\\Delta$E/E of about l0$ ^- ^{4} $, which is superior in the accuracy of the energy determination by two orders of magnitude as compared to the present detection methods, will be used to measure the energies of the L$\\alpha$ transitions. This permits a first direct measure...

  8. The Lyman-$\\alpha$ signature of the first galaxies

    CERN Document Server

    Smith, Aaron; Bromm, Volker; Milosavljević, Miloš

    2014-01-01

    We present the Cosmic Lyman-$\\alpha$ Transfer code (COLT), a new massively parallel Monte-Carlo radiative transfer code, to simulate Lyman-$\\alpha$ (Ly$\\alpha$) resonant scattering through neutral hydrogen as a probe of the first galaxies. We explore the interaction of centrally produced Ly$\\alpha$ radiation with the host galactic environment. The Ly$\\alpha$ photons emitted from the luminous starburst region escape with characteristic features in the line profile depending on the density distribution, ionization structure, and bulk velocity fields. For example, the presence of anisotropic ionization exhibits a tall peak close to line centre with a skewed tail that drops off gradually. Furthermore, moderate (~10 km/s) outflow produces an amplified peak redward of line centre. Idealized models of first galaxies explore the effect of mass, anisotropic H II regions, and radiation pressure driven winds on Ly$\\alpha$ observables. We employ mesh refinement to resolve critical structures. We also post-process an ab i...

  9. The Lyman α signature of the first galaxies

    Science.gov (United States)

    Smith, Aaron; Safranek-Shrader, Chalence; Bromm, Volker; Milosavljević, Miloš

    2015-06-01

    We present the Cosmic Lyman α Transfer code, a massively parallel Monte Carlo radiative transfer code, to simulate Lyman α (Lyα) resonant scattering through neutral hydrogen as a probe of the first galaxies. We explore the interaction of centrally produced Lyα radiation with the host galactic environment. Lyα photons emitted from the luminous starburst region escape with characteristic features in the line profile depending on the density distribution, ionization structure, and bulk velocity fields. For example, anisotropic ionization exhibits a tall peak close to line centre with a skewed tail that drops off gradually. Idealized models of first galaxies explore the effect of mass, anisotropic H II regions, and radiation pressure driven winds on Lyα observables. We employ mesh refinement to resolve critical structures. We also post-process an ab initio cosmological simulation and examine images captured at various distances within the 1 Mpc3 comoving volume. Finally, we discuss the emergent spectra and surface brightness profiles of these objects in the context of high-z observations. The first galaxies will likely be observed through the red damping wing of the Lyα line. Observations will be biased towards galaxies with an intrinsic red peak located far from line centre that reside in extensive H II super bubbles, which allows Hubble flow to sufficiently redshift photons away from line centre and facilitate transmission through the intergalactic medium. Even with gravitational lensing to boost the luminosity this preliminary work indicates that Lyα emission from stellar clusters within haloes of Mvir Telescope.

  10. Speed-dependent spectral line profile including line narrowing and mixing

    Science.gov (United States)

    Kochanov, Victor P.

    2016-07-01

    A line profile model was developed that accounts for all essential underlying physical mechanisms. The model is based on the quantum-mechanical collision integral kernel calculated for intermolecular interaction potentials ∝r-n with n=3…6 where r is the distance between colliding molecules. It was shown that collisions of molecules with scattering on classical small angles flatten the line profile. The relative flattening reaches 10% for n=3 and has a smaller value, ~2%, for n=6 in conditions of inhomogeneous line broadening. An algebraic expression for the line profile was obtained, which allows processing recorded spectra with preliminary estimation and constraint of some of the profile's parameters.

  11. Resolution of the discrepancy between Balmer alpha emission rates, the solar Lyman beta flux, and models of geocoronal hydrogen concentration

    Science.gov (United States)

    Levasseur, A.-C.; Meier, R. R.; Tinsley, B. A.

    1976-01-01

    New satellite Balmer alpha measurements and solar Lyman beta flux and line profile measurements, together with new measurements of the zodiacal light intensity used in correcting both ground and satellite Balmer alpha measurements for the effects of the Fraunhofer line in the zodiacal light, have been used in a reevaluation of the long-standing discrepancy between ground-based Balmer alpha emission rates and other geocoronal hydrogen parameters. The solar Lyman beta line center flux is found to be (4.1 plus or minus 1.3) billion photons per sq cm per sec per angstrom at S(10.7) equals 110 and, together with a current hydrogen model which has 92,000 atoms per cu cm at 650 km for T(inf) equals 950 K, gives good agreement between calculated Balmer alpha emission rates and the ground-based and satellite measurements.

  12. A catalogue of Paschen-line profiles in standard stars

    CERN Document Server

    Huang, Wenjin; Stone, Myra; 10.1051/0004-6361/201219804

    2012-01-01

    We have assembled an atlas of line profiles of the Paschen Delta line at 10,049 angstroms for the use of stellar modelling. For a few stars we have substituted the Paschen Gamma line at 10,938 angstroms because the Paschen Delta line blends with other features. Most of the targets are standard stars of spectral types from B to M. A few metal-poor stars have been included. For many of the stars we have also observed the Hydrogen Alpha line so as to compare the profiles of lines originating from the meta-stable n=2 level with lines originating from the n=3 level. The greatest difference in line profile is found for high luminosity and cool stars where the departures from LTE in the population of the n=2 level is expected to be the greatest. For a few stars, sample line profiles have been calculated in the LTE approximation to demonstrate the usefulness of the tabulated and displayed catalogue.

  13. Explaining the unusual line profiles of SN 2006gy

    Science.gov (United States)

    Chugai, Nikolai N.

    2017-02-01

    This paper explores the origin of the enigmatic line profiles of the extremely luminous Type IIn supernova, SN 2006gy, on day 96. Among the conceivable possibilities, the most preferred is the model that suggests there are holes in the optically thick cool dense shell (CDS). The line radiation emitted at the inner side of the opaque CDS escapes through the holes, thus producing an unusual line profile with the emission shifted redward. The holes could emerge as a result of the vigorous Rayleigh-Taylor instability, leading to the CDS fragmentation. The model light curve with the CDS fragmentation is shown to be consistent with the SN 2006gy bolometric light curve.

  14. Explaining unusual line profiles of SN 2006gy

    CERN Document Server

    Chugai, Nikolai

    2016-01-01

    Origin of enigmatic line profiles of extremely luminous type IIn supernova SN~2006gy on day 96 is explored. Among conceivable possibilities the most preferred is the model that suggests holes in the optically thick cool dense shell (CDS). The line radiation emitted at the inner side of the opaque CDS escapes through the holes thus producing unusual line profile with the emission shifted redward. The holes could emerge as a result of a vigorous Rayleigh-Taylor instability leading to the CDS fragmentation. The model light curve with the CDS fragmentation is shown to be consistent with the SN~2006gy bolometric light curve.

  15. Dislocation Effects on the Diffraction Line Profiles from Nanocrystalline Domains

    Science.gov (United States)

    Leonardi, Alberto; Scardi, Paolo

    2016-12-01

    A Pd nano-polycrystalline microstructure was simulated by molecular dynamics, including edge or screw dislocations in one of the 50 grains, so as to produce a realistic model of nanocrystalline domain with line defect. The same crystalline domain was also studied, with or without line defects, as a free-standing, isolated nanocrystal. Atomic coordinates of the selected domain were used to generate powder patterns by means of the Debye scattering equation, and these patterns were used as "experimental" data to test existing methods of line profile analysis in controlled condition, i.e., with known type and density of defects. Results show that the Krivolgaz-Wilkens theory of dislocation line broadening qualitatively agrees with the MD model, but errors can be larger than 50 pct. A critical issue arises from the instability of the Krivolgaz-Wilkens model when all line profile parameters are simultaneously refined: reasonable results can be obtained by fixing or restricting some parameters.

  16. Theory of satellite structures on spectral-line profiles.

    Science.gov (United States)

    Atakan, A. K.; Jacobson, H. C.

    1973-01-01

    A systematic comparison with experiment of various explanations for the problem of satellite-band formation on spectral-line profiles was initiated. The experiments were performed under a variety of conditions in an effort to construct a consistent model of entire line shapes. A composite theory is detailed which is the result of the insights of many individuals. The calculations indicate that the main features of the problem, the line, the high-intensity red satellites, and the blue satellite can be described simultaneously. The results also indicate that widely different potentials can lead to very similar line profiles. Ancillary conclusions are presented concerning the role of Lennard-Jones potentials in line-shape calculations.

  17. Line Profile Asymmetries and the Chromospheric Flare Velocity Field

    Science.gov (United States)

    Kuridze, D.; Mathioudakis, M.; Simões, P. J. A.; Rouppe van der Voort, L.; Carlsson, M.; Jafarzadeh, S.; Allred, J. C.; Kowalski, A. F.; Kennedy, M.; Fletcher, L.; Graham, D.; Keenan, F. P.

    2015-11-01

    The asymmetries observed in the line profiles of solar flares can provide important diagnostics of the properties and dynamics of the flaring atmosphere. In this paper the evolution of the Hα and Ca ii λ8542 lines are studied using high spatial, temporal, and spectral resolution ground-based observations of an M1.1 flare obtained with the Swedish 1 m Solar Telescope. The temporal evolution of the Hα line profiles from the flare kernel shows excess emission in the red wing (red asymmetry) before flare maximum and excess in the blue wing (blue asymmetry) after maximum. However, the Ca ii λ8542 line does not follow the same pattern, showing only a weak red asymmetry during the flare. RADYN simulations are used to synthesize spectral line profiles for the flaring atmosphere, and good agreement is found with the observations. We show that the red asymmetry observed in Hα is not necessarily associated with plasma downflows, and the blue asymmetry may not be related to plasma upflows. Indeed, we conclude that the steep velocity gradients in the flaring chromosphere modify the wavelength of the central reversal in the Hα line profile. The shift in the wavelength of maximum opacity to shorter and longer wavelengths generates the red and blue asymmetries, respectively.

  18. Detection of Voigt Spectral Line Profiles of Hydrogen Radio Recombination Lines toward Sagittarius B2(N)

    CERN Document Server

    von Prochazka, Azrael A; Balser, Dana S; Ryans, Robert S I; Marshall, Adele H; Schwab, Fredric R; Hollis, Jan M; Jewell, Philip R; Lovas, Frank J

    2010-01-01

    We report the detection of Voigt spectral line profiles of radio recombination lines (RRLs) toward Sagittarius B2(N) with the 100-m Green Bank Telescope (GBT). At radio wavelengths, astronomical spectra are highly populated with RRLs, which serve as ideal probes of the physical conditions in molecular cloud complexes. An analysis of the Hn(alpha) lines presented herein shows that RRLs of higher principal quantum number (n>90) are generally divergent from their expected Gaussian profiles and, moreover, are well described by their respective Voigt profiles. This is in agreement with the theory that spectral lines experience pressure broadening as a result of electron collisions at lower radio frequencies. Given the inherent technical difficulties regarding the detection and profiling of true RRL wing spans and shapes, it is crucial that the observing instrumentation produce flat baselines as well as high sensitivity, high resolution data. The GBT has demonstrated its capabilities regarding all of these aspects,...

  19. Research Into a Neon Spectral Line Profile of Dusty Plasma

    CERN Document Server

    Pikalev, Aleksandr

    2014-01-01

    Ordered dusty structures influence plasma conditions. This influence can be revealed, when plasma spectral characteristics change, as dusty particles are injected. For example, a variation in the atomic temperature leads to a variation in the profiles of spectral lines. We studied the profile of a 585 nm neon spectral line in the dusty structures. The structures levitated in a positive column of a glow discharge at a pressure of 50-150 Pa and with a current of 1-9 mA. We scanned the profile with the use of a Fabry-Perot interferometer, by changing the air pressure between the interferometer mirrors. To process the data, a special algorithm was developed. The algorithm is resistant to a noise and a scanning speed instability. We have found an upper bound of the impact of dusty structures on the profile width. The appearance of macroparticles changes the atomic plasma temperature less than by 10 K.

  20. Quantifying Distributions of Lyman Continuum Escape Fraction

    CERN Document Server

    Cen, Renyue

    2015-01-01

    Simulations have indicated that most of the escaped Lyman continuum photons escape through a minority of solid angles with near complete transparency, with the remaining majority of the solid angles largely opaque, resulting in a very broad and skewed probability distribution function (PDF) of the escape fraction when viewed at different angles. Thus, the escape fraction of Lyman continuum photons of a galaxy observed along a line of sight merely represents the properties of the interstellar medium along that line of sight, which may be an ill-representation of true escape fraction of the galaxy averaged over its full sky. Here we study how Lyman continuum photons escape from galaxies at $z=4-6$, utilizing high-resolution large-scale cosmological radiation-hydrodynamic simulations. We compute the PDF of the mean escape fraction ($\\left$) averaged over mock observational samples, as a function of the sample size, compared to the true mean (had you an infinite sample size). We find that, when the sample size is...

  1. An atlas of synthetic line profiles of planetary nebulae

    CERN Document Server

    Morisset, C

    2008-01-01

    We have constructed a grid of photoionization models of spherical, elliptical and bipolar planetary nebulae. Assuming different velocity fields, we have computed line profiles corresponding to different orientations, slit sizes and positions. The atlas is meant both for didactic purposes and for the interpretation of data on real nebulae. As an application, we have shown that line profiles are often degenerate, and that recovering the geometry and velocity field from observations requires lines from ions with different masses and different ionization potentials. We have also shown that the empirical way to measure mass-weighted expansion velocities from observed line widths is reasonably accurate if considering the HWHM. For distant nebulae, entirely covered by the slit, the unknown geometry and orientation do not alter the measured velocities statistically. The atlas is freely accessible from internet. The Cloudy_3D suite and the associated VISNEB tool are available on request.

  2. PROFIT: a new alternative for emission-line PROfile FITting

    CERN Document Server

    Riffel, Rogemar A

    2010-01-01

    I briefly describe a simple routine for emission-line profiles fitting by Gaussian curves or Gauss-Hermite series. The PROFIT (line-PROfile FITting) routine represent a new alternative for use in fits data cubes, as those from Integral Field Spectroscopy or Fabry-Perot Interferometry, and may be useful to better study the emission-line flux distributions and gas kinematics in distinct astrophysical objects, such as the central regions of galaxies and star forming regions. The PROFIT routine is written in IDL language and is available at http://www.ufsm.br/rogemar/software.html. The PROFIT routine was used to fit the [Fe II]1.257um emission-line profiles for about 1800 spectra of the inner 350 pc of the Seyfert galaxy Mrk1066 obtained with Gemini NIFS and shows that the line profiles are better reproduced by Gauss-Hermite series than by the commonly used Gaussian curves. The two-dimensional map of the h_3 Gauss-Hermite moment shows its highest absolute values in regions close to the edge of the radio structure...

  3. Simulations of Line Profile Structure in Shell Galaxies

    CERN Document Server

    Jilkova, L; Krizek, M; Ebrova, I; Stoklasova, I; Bartakova, T; Bartoskova, K

    2009-01-01

    In the context of exploring mass distributions of dark matter haloes in giant ellipticals, we extend the analysis carried out Merrifield and Kuijken (1998) for stellar line profiles of shells created in nearly radial mergers of galaxies. We show that line-of-sight velocity distributions are more complex than previously predicted. We simulate shell formation and analyze the detectability of spectroscopic signatures of shells after convolution with spectral PSFs.

  4. Fluctuations in the High-Redshift Lyman-Werner and Lyman-alpha Radiation Backgrounds

    CERN Document Server

    Holzbauer, Lauren N

    2011-01-01

    We use a new method to model fluctuations of the Lyman-Werner (LW) and Lyman-alpha radiation backgrounds at high redshift. At these early epochs the backgrounds are symptoms of a universe newly lit with its first stars. LW photons (11.5-13.6 eV) are of particular interest because they dissociate molecular hydrogen, the primary coolant in the first minihalos. By using a variation of the halo model, we efficiently generate power spectra for any choice of radiation background. We find that the LW power spectrum typically traces the matter power spectrum at large scales but turns over at the scale corresponding to the effective `horizon' of LW photons (~100 comoving Mpc), unless the sources are extremely rare. The series of horizons that characterize the Lyman-alpha flux profile shape the fluctuations of that background in a similar fashion, though those imprints are washed out once one considers fluctuations in the brightness temperature of the 21-cm signal. The Lyman-alpha background strongly affects the redshi...

  5. Lyman alpha emission from the first galaxies : Implications of UV backgrounds and the formation of molecules

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, D. R. G.; Spaans, Maarten; Zaroubi, S.

    2011-01-01

    The Lyman alpha line is a robust tracer of high redshift galaxies. We present estimates of Lyman alpha emission from a protogalactic halo illuminated by UV background radiation fields with various intensities. For this purpose, we performed cosmological hydrodynamics simulations with the adaptive me

  6. Lyman alpha emission from the first galaxies : Implications of UV backgrounds and the formation of molecules

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, D. R. G.; Spaans, Maarten; Zaroubi, S.

    The Lyman alpha line is a robust tracer of high redshift galaxies. We present estimates of Lyman alpha emission from a protogalactic halo illuminated by UV background radiation fields with various intensities. For this purpose, we performed cosmological hydrodynamics simulations with the adaptive

  7. Lyman-alpha spectral properties of five newly discovered Lyman continuum emitters

    CERN Document Server

    Verhamme, A; Schaerer, D; Izotov, Y; Worseck, G; Thuan, T X; Guseva, N

    2016-01-01

    We have recently reported the discovery of five low redshift Lyman continuum (LyC) emitters (LCEs, hereafter) with absolute escape fractions fesc(LyC) ranging from 6 to 13%, higher than previously found, and which more than doubles the number of low redshift LCEs.We use these observations to test theoretical predictions about a link between the characteristics of the Lyman-alpha (Lya) line from galaxies and the escape of ionising photons. We analyse the Lya spectra of eight LCEs of the local Universe observed with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope (our five leakers and three galaxies from the litterature), and compare their strengths and shapes to the theoretical criteria and comparison samples of local galaxies: the Lyman Alpha Reference Survey, Lyman Break Analogs, Green Peas, and the high-redshift strong LyC leaker Ion2. Our LCEs are found to be strong Lya emitters, with high equivalent widths, EW(Lya)> 70 {\\AA}, and large Lya escape fractions, fesc(Lya) > 20%. The Lya prof...

  8. MgII Absorption Lines in z=2.974 Damped Lyman-alpha System toward Gravitationally Lensed QSO APM 08279+5255 Detection of Small-scale Structure in MgII Absorbing Clouds

    CERN Document Server

    Kobayashi, N; Goto, M; Tokunaga, A; Kobayashi, Naoto; Terada, Hiroshi; Goto, Miwa; Tokunaga, Alan

    2002-01-01

    1.02-1.16 micron spectra (R ~ 7,000) of the gravitationally lensed QSO APM 08279+5255 at z_em=3.911 were obtained during the commissioning run of IRCS, the 1-5 micron near-infrared camera and spectrograph for the Subaru 8.2 m Telescope. Strong MgII doublet at 2976,2800 angstrom and FeII (2600 angstrom), FeII (2587 angstrom) absorption lines at z_abs=2.974 were clearly detected in the rest-frame UV spectra, confirming the presence of a damped Lyman-alpha system at the redshift as suggested by Petitjean et al. Also MgI (2853 angstrom) absorption line is probably detected. An analysis of the absorption lines including velocity decomposition was performed. This is a first detailed study of MgII absorption system at high redshift (z > 2.5) where the MgII doublet shifts into the near-infrared in the observer's frame. The spectra of the lensed QSO pair A and B with 0.38 arcsec separation were resolved in some exposure frames under excellent seeing condition. We extracted the MgII doublet spectra of A and B separatel...

  9. Relationships between the HI 21-cm line strength, MgII equivalent width and metallicity in damped Lyman-alpha absorption systems

    CERN Document Server

    Curran, S J; Pihlström, Y M; Webb, J K

    2007-01-01

    We present the results of a survey for 21-cm absorption in four never previously searched damped Lyman-alpha absorption systems (DLAs) with the Westerbork Synthesis Radio Telescope. We add our results to other recent studies in order to address the important issues regarding the detection of cold gas, through 21-cm absorption, in DLAs: Although, due to the DLAs identified with spiral galaxies, there is a mix of spin temperature/covering factor ratios at low redshift, two recent high redshift end points confirm that this ratio does not generally rise over the whole redshift range searched (up to z = 3.39). That is, if the covering factors of many of these galaxies were a factor of >2 smaller than for the spirals, then no significant difference in the spin temperatures between these two classes would be required. Furthermore, although it is difficult to separate the relative contributions of the spin temperature and covering factor, the new results confirm that 21-cm detections tend to occur at low angular diam...

  10. Halpha line profile asymmetries and the chromospheric flare velocity field

    CERN Document Server

    Kuridze, D; Simões, P J A; van der Voort, L Rouppe; Carlsson, M; Jafarzadeh, S; Allred, J C; Kowalski, A F; Kennedy, M; Fletcher, L; Graham, D; Keenan, F P

    2015-01-01

    The asymmetries observed in the line profiles of solar flares can provide important diagnostics of the properties and dynamics of the flaring atmosphere. In this paper the evolution of the Halpha and Ca II 8542 {\\AA} lines are studied using high spatial, temporal and spectral resolution ground-based observations of an M1.1 flare obtained with the Swedish 1-m Solar Telescope. The temporal evolution of the Halpha line profiles from the flare kernel shows excess emission in the red wing (red asymmetry) before flare maximum, and excess in the blue wing (blue asymmetry) after maximum. However, the Ca II 8542 {\\AA} line does not follow the same pattern, showing only a weak red asymmetry during the flare. RADYN simulations are used to synthesise spectral line profiles for the flaring atmosphere, and good agreement is found with the observations. We show that the red asymmetry observed in Halpha is not necessarily associated with plasma downflows, and the blue asymmetry may not be related to plasma upflows. Indeed, w...

  11. Line profiles of the two-phase medium broad-line region in active galactic nuclei

    Institute of Scientific and Technical Information of China (English)

    薛随建; 林宣滨; 程福臻; John Kwan

    1996-01-01

    In the framework of BLR in AGNs, i.e. large number of small, cold and dense emission-line clouds immerging in an intercloud hot medium, a delicate radiation model for a typical emission cloud is established, in which the backside photoionization of the cloud against the central continuum source by the scattered diffuse continuum in the hot medium is considered. Under the assumption of the radial kinematics of the BLR clouds, the line profiles for the two important UV emission-lines, Lya and CIV/11549 are computed; and based on these calculations, various physical factors that affect the properties of the emission-line profiles are discussed. It is concluded that: (i) when the BLR clouds is inflow, there exists a confining hot medium with density around 2 x 105 cm-3. In this case, theoretical line profiles agree well with the observational; (ii) both symmetric Lya and nearly symmetric CIV line profiles show blue velocity shifts, the quantities of which are sensitive to the cutoff of the outer radius of t

  12. Time Ordering Effects on Hydrogen Zeeman-Stark Line Profiles in Low-Density Magnetized Plasmas

    Directory of Open Access Journals (Sweden)

    J. Rosato

    2010-01-01

    Full Text Available Stark broadening of hydrogen lines is investigated in low-density magnetized plasmas, at typical conditions of magnetic fusion experiments. The role of time ordering is assessed numerically, by using a simulation code accounting for the evolution of the microscopic electric field generated by the charged particles moving at the vicinity of the atom. The Zeeman effect due to the magnetic field is also retained. Lyman lines with a low principal quantum number n are first investigated, for an application to opacity calculations; next Balmer lines with successively low and high principal quantum numbers are considered for diagnostic purposes. It is shown that neglecting time ordering results in a dramatic underestimation of the Stark effect on the low-n lines. Another conclusion is that time ordering becomes negligible only when ion dynamics effects vanish, as shown in the case of high-n lines.

  13. Abundance sensitive points of line profiles in the stellar spectra

    CERN Document Server

    Sheminova, V A

    2014-01-01

    Many abundance studies are based on spectrum synthesis and $\\chi$-squared differences between the synthesized and an observed spectrum. Much of the spectra so compared depend only weakly on the elemental abundances. Logarithmic plots of line depths rather than relative flux make this more apparent. We present simulations that illustrate a simple method for finding regions of the spectrum most sensitive to abundance, and also some caveats for using such information. As expected, we find that weak features are the most sensitive. Equivalent widths of weak lines are ideal features, because of their sensitivity to abundances, and insensitivity to factors that broaden the line profiles. The wings of strong lines can also be useful, but it is essential that the broadening mechanisms be accurately known. The very weakest features, though sensitive to abundance, should be avoided or used with great caution because of uncertainty of continuum placement as well as numerical uncertainties associated with the subtraction...

  14. Spectroscopic confirmation of two Lyman break galaxies at redshift beyond 7

    CERN Document Server

    Vanzella, E; Fontana, A; Grazian, A; Castellano, M; Boutsia, K; Cristiani, S; Dickinson, M; Gallozzi, S; Giallongo, E; Giavalisco, M; Maiolino, R; Moorwood, A; Paris, D; Santini, P

    2010-01-01

    We report the spectroscopic confirmation of two Lyman break galaxies at redshift > 7. The galaxies were observed as part of an utra-deep spectroscopic campaign with FORS2 at the ESO/VLT for the confirmation of z~7 "z--band dropout'' candidates selected from our VLT/Hawk-I imaging survey. Both galaxies show a prominent emission line at 9735A and 9858A respectively: the lines have fluxes around ~ 1-1.2 x 10^(-17) erg/s/cm2 and exhibit a sharp decline on the blue side and a tail on the red side. The asymmetry is quantitatively comparable to the observed asymmetry in z~6 Lya lines, where absorption by neutral hydrogen in the IGM truncates the blue side of the emission line profile. We carefully evaluate the possibility that the galaxies are instead at lower redshift and we are observing either [OII], [OIII] or Ha emission: however from the spectroscopic and the photometric data we conclude that there are no other plausible identifications, except for Lya at redshift > 7, making these the first robust Lyman break ...

  15. Statistical Properties of Diffuse Lyman-alpha Halos around Star-forming Galaxies at z~2

    CERN Document Server

    Momose, Rieko; Nakajima, Kimihiko; Ono, Yoshiaki; Shibuya, Takatoshi; Shimasaku, Kazuhiro; Yuma, Suraphong; Mori, Masao; Umemura, Masayuki

    2015-01-01

    We present statistical properties of diffuse Lyman-alpha halos (LAHs) around high-$z$ star-forming galaxies with large Subaru samples of Lyman-alpha emitters (LAEs) at $z=2.2$. We make subsamples defined by the physical quantities of LAEs' central Lyman-alpha luminosities, UV magnitudes, Lyman-alpha equivalent widths, and UV slopes, and investigate LAHs' radial surface brightness (SB) profiles and scale lengths $r_n$ as a function of these physical quantities. We find that there exist prominent LAHs around LAEs with faint Lyman-alpha luminosities, bright UV luminosities, and small Lyman-alpha equivalent widths in cumulative radial Lyman-alpha SB profiles. We confirm this trend with the anti-correlation between $r_n$ and Lyman-alpha luminosities (equivalent widths) based on the Spearman's rank correlation coefficient that is $\\rho=-0.9$ ($-0.7$) corresponding to the $96\\%$ ($93\\%$) confidence level, although the correlation between $r_n$ and UV magnitudes is not clearly found in the rank correlation coefficien...

  16. FIR line profiles as probes of warm gas dynamics

    Science.gov (United States)

    Betz, A. L.; Boreiko, R. T.

    1995-01-01

    Measurements of the shapes, velocities, and intensities of FIR lines all help to probe the dynamics, physical associations, and excitation conditions of warm gas in molecular clouds. With this in mind, we have observed the J=9-8, 12-11,14-13, and 16-15 lines of (12)CO and the 158 micron line of C II in a number of positions in 4 selected clouds. The data were obtained with a laser heterodyne spectrometer aboard NASA's Kuiper Airborne Observatory. Line measurements at 0.6 km/s resolution allow us to resolve the profiles completely, and thereby to distinguish between UV-and shock-heating mechanisms for the high-excitation gas. For CO, the high-J linewidths lie in the range of 4-20 km/s (FWHM), similar to those observed for low-J (J less than 4) transitions in these sources. This correspondence suggests that the hotter gas (T = 200-600 K) is dynamically linked to the quiescent gas component, perhaps by association with the UV-heated peripheries of the numerous cloud clumps. Much of the C II emission is thought to emanate from these cloud peripheries, but the line profiles generally do not match those seen in CO. None of the observed sources show any evidence in high-J (12)CO emission for shock-excitation (i.e., linewidths greater than 30 km/s).

  17. Interpreting the Mg IIh andk Line Profiles of Mira Variables

    Science.gov (United States)

    Wood, B. E.; Karovska, M.

    2000-11-01

    We use radiative transfer calculations to reproduce the basic appearance of Mg II lines observed from Mira variables. These lines have centroids that are blueshifted by at least 30 km s-1 from the stellar rest frame. It is unlikely that flow velocities in the stellar atmospheres are this fast, so radiative transfer effects must be responsible for this behavior. Published hydrodynamic models predict the existence of cool, downflowing material above the shocked material responsible for the Mg II emission, and we demonstrate that scattering in this layer can result in Mg II profiles as highly blueshifted as those that are observed. However, our models also show that scattering within the shock plays an equally strong role in shaping the Mg II profiles, and our calculations illustrate the importance of partial redistribution and the effects of being out of ionization equilibrium.

  18. Alpha Virginis: line-profile variations and orbital elements

    CERN Document Server

    Harrington, David; Olguín, Enrique; Ilyin, Ilya; Berdyugina, Svetlana V; Lara, Bruno; Moreno, Edmundo

    2016-01-01

    Abridged: Alpha Virginis is a binary system whose proximity and brightness allow detailed investigations of the internal structure and evolution of stars undergoing time-variable tidal interactions. Previous studies have led to the conclusion that the internal structure of Spica's primary star may be more centrally condensed than predicted by theoretical models of single stars, raising the possibility that the interactions could lead to effects that are currently neglected in structure and evolution calculations. The key parameters in confirming this result are the values of the orbital eccentricity $e$, the apsidal period $U$, and the primary star's radius, R_1. We analyze the impact that line profile variability has on the derivation of its orbital elements and R_1. We use high SNR observations obtained in 2000, 2008, and 2013 to derive the orbital elements from fits to the radial velocity curves. We produce synthetic line profiles using an ab initio tidal interaction model. Results: The variations in the l...

  19. Lyman- photodissociation of CH3CFCl2 (HCFC-141b): Quantum yield and translational energy of hydrogen atoms

    Indian Academy of Sciences (India)

    Almuth Laeuter; Hans-Robert Volpp; Jai P Mittal; Rajesh K Vatsa

    2007-07-01

    The collision-free, room temperature gas-phase photodissociation dynamics of CH3CFCl2 (HCFC-141b) was studied using Lyman- laser radiation (121.6 nm) by the laser photolysis/laserinduced fluorescence `pump/probe’ technique. Lyman- radiation was used both to photodissociate the parent molecule and to detect the nascent H atom products via (22P → 12S) laser-induced fluorescence. Absolute H atom quantum yield, H = (0.39 ± 0.09) was determined by calibration method in which CH4 photolysis at 121.6 nm was used as a reference source of well-defined H atom concentrations. The line shapes of the measured H atom Doppler profiles indicate a Gaussian velocity distribution suggesting the presence of indirect H atom formation pathways in the Lyman- photodissociation of CH3CFCl2. The average kinetic energy of H atoms calculated from Doppler profiles was found to be T(lab) = (50 ± 3) kJ/mol. The nearly statistical translational energy together with the observed Maxwell-Boltzmann velocity distribution indicates that for CH3CFCl2 the H atom forming dissociation process comes closer to the statistical limit.

  20. Alpha Virginis: line-profile variations and orbital elements

    Science.gov (United States)

    Harrington, David; Koenigsberger, Gloria; Olguín, Enrique; Ilyin, Ilya; Berdyugina, Svetlana V.; Lara, Bruno; Moreno, Edmundo

    2016-05-01

    Context. Alpha Virginis (Spica) is a B-type binary system whose proximity and brightness allow detailed investigations of the internal structure and evolution of stars undergoing time-variable tidal interactions. Previous studies have led to the conclusion that the internal structure of Spica's primary star may be more centrally condensed than predicted by theoretical models of single stars, raising the possibility that the interactions could lead to effects that are currently neglected in structure and evolution calculations. The key parameters in confirming this result are the values of the orbital eccentricity e, the apsidal period U, and the primary star's radius, R1. Aims: The aim of this paper is to analyze the impact that Spica's line profile variability has on the derivation of its orbital elements and to explore the use of the variability for constraining R1. Methods: We use high signal-to-noise and high spectral resolution observations obtained in 2000, 2008, and 2013 to derive the orbital elements from fits to the radial velocity curves. We produce synthetic line profiles using an ab initio tidal interaction model. Results: The general variations in the line profiles can be understood in terms of the tidal flows, whose large-scale structure is relatively fixed in the rotating binary system reference frame. Fits to the radial velocity curves yield e = 0.108 ± 0.014. However, the analogous RV curves from theoretical line profiles indicate that the distortion in the lines causes the fitted value of e to depend on the argument of periastron; i.e., on the epoch of observation. As a result, the actual value of e may be as high as 0.125. We find that U = 117.9 ± 1.8, which is in agreement with previous determinations. Using the value R1 = 6.8 R⊙ derived by Palate et al. (2013) the value of the observational internal structure constant k2,obs is consistent with theory. We confirm the presence of variability in the line profiles of the secondary star. RV

  1. The MUSCLES Treasury Survey II: Intrinsic Lyman Alpha and Extreme Ultraviolet Spectra of K and M Dwarfs with Exoplanets

    CERN Document Server

    Youngblood, Allison; Loyd, R O Parke; Linsky, Jeffrey L; Redfield, Seth; Schneider, P Christian; Wood, Brian E; Brown, Alexander; Froning, Cynthia; Miguel, Yamila; Rugheimer, Sarah; Walkowicz, Lucianne

    2016-01-01

    The ultraviolet (UV) spectral energy distributions of low-mass (K- and M-type) stars play a critical role in the heating and chemistry of exoplanet atmospheres, but are not observationally well-constrained. Direct observations of the intrinsic flux of the Lyman alpha line (the dominant source of UV photons from low-mass stars) are challenging, as interstellar HI absorbs the entire line core for even the closest stars. To address the existing gap in empirical constraints on the UV flux of K and M dwarfs, the MUSCLES HST Treasury Survey has obtained UV observations of 11 nearby M and K dwarfs hosting exoplanets. This paper presents the Lyman alpha and extreme-UV spectral reconstructions for the MUSCLES targets. Most targets are optically inactive, but all exhibit significant UV activity. We use a Markov Chain Monte Carlo technique to correct the observed Lyman alpha profiles for interstellar absorption, and we employ empirical relations to compute the extreme-UV spectral energy distribution from the intrinsic L...

  2. The broad Fe K line profile in NGC 4151

    CERN Document Server

    Wang, J; Wang, T; Wang, Junxian.; Zhou, Youyuan.; Wang, Tinggui.

    1999-01-01

    We present an analysis of the Fe K line profile of NGC 4151 by using long ASCA observation data obtained in May 1995. The unprecedented good data quality, which is much better in the energy band around 6.4 keV than that of the famous 4.2-day ASCA observation of MCG -6-30-15 in July 1994, offers a unique opportunity to study the details of Fe K line profile. Apart from those characteristics already noticed in earlier ASCA observations on this object (Yaqoob et al. 1995): a broad and skewed profile, with a strong peak at about 6.4 keV and a large red wing extending to $\\sim$4 - 5 keV, which is remarkably similar to that of MCG -6-30-15, we also find a weak blue wing extending to about 8 keV, thanks to the good quality of the data. When fitted by a relativistic accretion disk line plus a narrow core at 6.4 keV, the data constrain the accretion disk to be nearly face-on, contrary to the edge-on geometry inferred from optical and UV observations. However, the extended blue wing can not be well fitted even after we...

  3. Green Peas and diagnostics for Lyman continuum leaking in star-forming dwarf galaxies

    Science.gov (United States)

    Thuan, Trinh

    2014-10-01

    One of the key questions in observational cosmology is the identification of the sources responsible for cosmic reionization. The general consensus is that a population of faint low-mass galaxies must be responsible for the bulk of the ionizing photons. However, attempts at identifying individual galaxies showing Lyman continuum (LyC) leakage have so far not been successful, both at high and low redshifts. We propose here to observe directly the LyC of five so-called "Green Pea" (GP) galaxies. GPs share many of the properties of the Lyman Break galaxies at high z (compactness, low mass, low metallicity, high specific star formation rate, gas-rich and clumpy morphology) and may constitute local examples of the long sought-after LyC leaking galaxies. The five GPs have been identified by searching the Sloan Data Release 10 spectral data base of 2 million spectra for non-AGN emission-line objects that meet the following criteria: high [OIII]5007/[OII]3727 ratios, large GALEX FUV fluxes, and redshifted enough (z~0.3) so that the LyC is shifted into the sensitive spectral range of COS. Our unique GP sample will allow us to combine for the first time four fundamental tests for LyC leaking in galaxies and validate their usefulness as LyC leaking indicators : 1) direct measurements of the LyC; 2) high [OIII]/[OII] ratios; 3) characteristics of the Lyman alpha line profile; and 4) residual intensities in the low-ionization ISM absorption UV lines.

  4. Cosmological adventures in the Lyman forest

    CERN Document Server

    Cristiani, S

    1995-01-01

    The properties of the Lyman-\\alpha absorptions observed in the spectra of QSOs are reviewed: the distribution of column densities and Doppler widths, the redshift evolution, the ``inverse effect'', the clustering. By interpreting the statistics of the line parameters insight is gained about the nature of the absorbers, their sizes, temperatures, confining agents. On the basis of the ``inverse effect'' it is possible to estimate the ultraviolet background radiation at high redshift and, linking this information with the limits on the Gunn-Peterson optical depth, the density of the diffuse part of the intergalactic medium is derived. Future prospects are briefly discussed.

  5. Lyman-alpha observations of astrospheres

    CERN Document Server

    Linsky, Jeffrey L

    2014-01-01

    Charge-exchange reactions between outflowing stellar wind protons and interstellar neutral hydrogen atoms entering a stellar astrosphere produce a region of piled-up-decelerated neutral hydrogen called the hydrogen wall. Absorption by this gas, which is observed in stellar Lyman-alpha emission lines, provides the only viable technique at this time for measuring the mass-loss rates of F-M dwarf stars. We describe this technique, present an alternative way for understanding the relation of mass-loss rate with X-ray emission, and identify several critical issues.

  6. Relativistic emission lines from accreting black holes - The effect of disk truncation on line profiles

    CERN Document Server

    Müller, A; Mueller, Andreas; Camenzind, Max

    2004-01-01

    Relativistic emission lines generated by thin accretion disks around rotating black holes are an important diagnostic tool for testing gravity near the horizon. The iron K-line is of special importance for the interpretation of the X-ray emission of Seyfert galaxies, quasars and galactic X-ray binary systems. A generalized kinematic model is presented which includes radial drifts and non-Keplerian rotations for the line emitters. The resulting line profiles are obtained with an object-oriented ray tracer operating in the curved Kerr background metric. The general form of the Doppler factor is presented which includes all kinds of poloidal and toroidal motions near the horizon. The parameters of the model include the spin parameter, the inclination, the truncation and outer radius of the disk, velocity profiles for rotation and radial drift, the emissivity profile and a multi-species line-system. The red wing flux is generally reduced when radial drift is included as compared to the pure Keplerian velocity fie...

  7. Rest-frame Optical Emission Lines in z ˜ 3.5 Lyman-break-selected Galaxies: The Ubiquity of Unusually High [OIII]/Hβ Ratios at 2 Gyr

    Science.gov (United States)

    Holden, B. P.; Oesch, P. A.; González, V. G.; Illingworth, G. D.; Labbé, I.; Bouwens, R.; Franx, M.; van Dokkum, P.; Spitler, L.

    2016-03-01

    We present K-band spectra of rest-frame optical emission lines for 24 star-forming galaxies at z ˜ 3.2-3.7 using MOSFIRE on the Keck I telescope. Strong rest-frame optical [O iii] and Hβ emission lines were detected in 18 Lyman break galaxies (LBGs). The median flux ratio of [O iii]λ5007 to Hβ is {5.1}-0.5+0.5. This is a factor of 5-10 times higher than in local galaxies with similar stellar masses. None of our sources are detected in deep X-ray stacks, ruling out significant contamination by active galactic nuclei. Combining our sample with a variety of LBGs from the literature, including 49 galaxies selected in a very similar manner, we find a high median ratio of [O iii]/Hβ = {4.8}-1.7+0.8. This high ratio seems to be a ubiquitous feature of z ˜ 3-4 LBGs, very different from typical local star-forming galaxies at similar stellar masses. The only comparable systems at z ˜ 0 are those with similarly high specific star formation rates (SSFRs), though ˜5 times lower stellar masses. High SSFRs may result in a higher ionization parameter, higher electron density, or harder ionizing radiation, which, combined different elemental abundances, result in a much higher [O iii]/Hβ line ratio. This implies a strong relation between a global property of a galaxy, the SSFR, and the local conditions of ISM in star-forming regions. Partially based on data obtained with the Hubble Space Telescope operated by AURA, Inc. for NASA under contract NAS5-26555. Partially based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407.

  8. On Spectral Line Profiles in Type Ia Supernova Spectra

    CERN Document Server

    Foley, Ryan J

    2013-01-01

    We present a detailed analysis of spectral line profiles in Type Ia supernova (SN Ia) spectra. We focus on the feature at ~3500 - 4000 A, which is commonly thought to be caused by blueshifted absorption of Ca H&K. Unlike some other spectral features in SN Ia spectra, this feature often has two overlapping (blue and red) components. It is accepted that the red component comes from photospheric calcium. However, it has been proposed that the blue component is caused by either high-velocity calcium (from either abundance or density enhancements above the photosphere of the SN) or Si II 3858. By looking at multiple data sets and model spectra, we conclude that the blue component of the Ca H&K feature is caused by Si II 3858 for most SNe Ia. The strength of the Si II 3858 feature varies strongly with the light-curve shape of a SN. As a result, the velocity measured from a single-Gaussian fit to the full line profile correlates with light-curve shape. The velocity of the Ca H&K component of the profile ...

  9. Profiles of Strong Permitted Lines in Classical T Tauri Stars

    CERN Document Server

    Alencar, S; Alencar, Silvia; Basri, Gibor

    2000-01-01

    We present a spectral analysis of 30 T Tauri stars observed with the Hamilton echelle spectrograph over more than a decade. One goal is to test magnetospheric accretion model predictions. Observational evidence previously published supporting the model, such as emission line asymmetry and a high frequency of redshifted absorption components, are considered. We also discuss the relation between different line forming regions and search for good accretion rate indicators. In this work we confirm several important points of the models, such as the correlation between accretion and outflow, broad emission components that are mostly central or slightly blueshifted and only the occasional presence of redshifted absorption. We also show, however, that the broad emission components supposedly formed in the magnetospheric accretion flow only partially support the models. Unlike the predictions, they are sometimes redshifted, and are mostly found to be symmetric. The published theoretical profiles do not have a strong ...

  10. Medium-resolution spectroscopy of FORJ0332-3557: Probing the interstellar medium and stellar populations of a lensed Lyman-break galaxy at z=3.77

    CERN Document Server

    Cabanac, Remi A; Lidman, Chris

    2008-01-01

    We recently reported the discovery of FORJ0332-3557, a lensed Lyman-break galaxy at z=3.77 in a remarkable example of strong galaxy-galaxy gravitational lensing. We present here a medium-resolution rest-frame UV spectrum of the source, which appears to be similar to the well-known Lyman-break galaxy MS1512-cB58 at z=2.73. The spectral energy distribution is consistent with a stellar population of less than 30 Ma, with an extinction of A(V)=0.5 mag and an extinction-corrected star formation rate SFR(UV) of 200-300 Msun/a. The Lyman-alpha line exhibits a damped profile in absorption produced by a column density of about N(HI) = (2.5+_1.0) 10^21 atoms/cm^2, superimposed on an emission line shifted both spatially (0.5 arcsec with respect to the UV continuum source) and in velocity space (+830 km/s with respect to the low-ionisation absorption lines from its interstellar medium), a clear signature of outflows with an expansion velocity of about 270 km/s. A strong emission line from HeII 164.04nm indicates the pres...

  11. Comparative Metabolic Flux Profiling of Melanoma Cell Lines

    Science.gov (United States)

    Scott, David A.; Richardson, Adam D.; Filipp, Fabian V.; Knutzen, Christine A.; Chiang, Gary G.; Ronai, Ze'ev A.; Osterman, Andrei L.; Smith, Jeffrey W.

    2011-01-01

    Metabolic rewiring is an established hallmark of cancer, but the details of this rewiring at a systems level are not well characterized. Here we acquire this insight in a melanoma cell line panel by tracking metabolic flux using isotopically labeled nutrients. Metabolic profiling and flux balance analysis were used to compare normal melanocytes to melanoma cell lines in both normoxic and hypoxic conditions. All melanoma cells exhibited the Warburg phenomenon; they used more glucose and produced more lactate than melanocytes. Other changes were observed in melanoma cells that are not described by the Warburg phenomenon. Hypoxic conditions increased fermentation of glucose to lactate in both melanocytes and melanoma cells (the Pasteur effect). However, metabolism was not strictly glycolytic, as the tricarboxylic acid (TCA) cycle was functional in all melanoma lines, even under hypoxia. Furthermore, glutamine was also a key nutrient providing a substantial anaplerotic contribution to the TCA cycle. In the WM35 melanoma line glutamine was metabolized in the “reverse” (reductive) direction in the TCA cycle, particularly under hypoxia. This reverse flux allowed the melanoma cells to synthesize fatty acids from glutamine while glucose was primarily converted to lactate. Altogether, this study, which is the first comprehensive comparative analysis of metabolism in melanoma cells, provides a foundation for targeting metabolism for therapeutic benefit in melanoma. PMID:21998308

  12. Transcription profiles of non-immortalized breast cancer cell lines

    Directory of Open Access Journals (Sweden)

    Holland James F

    2006-04-01

    Full Text Available Abstract Background Searches for differentially expressed genes in tumours have made extensive use of array technology. Most samples have been obtained from tumour biopsies or from established tumour-derived cell lines. Here we compare cultures of non-immortalized breast cancer cells, normal non-immortalized breast cells and immortalized normal and breast cancer cells to identify which elements of a defined set of well-known cancer-related genes are differentially expressed. Methods Cultures of cells from pleural effusions or ascitic fluids from breast cancer patients (MSSMs were used in addition to commercially-available normal breast epithelial cells (HMECs, established breast cancer cell lines (T-est and established normal breast cells (N-est. The Atlas Human Cancer 1.2 cDNA expression array was employed. The data obtained were analysed using widely-available statistical and clustering software and further validated through real-time PCR. Results According to Significance Analysis of Microarray (SAM and AtlasImage software, 48 genes differed at least 2-fold in adjusted intensities between HMECs and MSSMs (p Conclusion The expression profiles of 1176 genes were determined in finite life-span cultures of metastatic breast cancer cells and of normal breast cells. Significant differences were detected between the finite life-span breast cancer cell cultures and the established breast cancer cell lines. These data suggest caution in extrapolating information from established lines for application to clinical cancer research.

  13. Characterizing Lyman Alpha Scattering in Nearby Galaxies

    Science.gov (United States)

    Bridge, Joanna; Hayes, Matthew; Melinder, Jens; Östlin, Göran; Gronwall, Caryl

    2017-01-01

    The hydrogen emission line of Lyman alpha (Lyα) has long been recognized as key to studying high redshift star-forming galaxies. However, due to the resonance of the emission line, the path that a Lyα photon takes from emission to eventual escape from the galaxy is essentially a mystery. This scattering poses a problem for using Lyα as a key emission feature of galaxies because it results in Lyα not being observed in all star-forming galaxies, and, in galaxies where it is observed, the place where the photon is originally emitted and where it is observed are two very different things. We discuss here how the Lyman-Alpha Reference Sample (LARS) provides a unique sample of 14 nearby (0.02 Space Telescope imaging. We compare the Lyα/Hα ratios with those expected from pure dust attenuation models, finding that in some cases significant positive departures are found on small scales, consistent with geometrical effects being important on sizes comparable to the HII regions. We then develop a simple scattering model in which we are able to estimate the average path length a Lyα photon travels with respect to non-resonant radiation, and quantifiy the excess dust optical depth to which Lyα radiation may be susceptible.

  14. Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies

    CERN Document Server

    Izotov, Y I; Thuan, T X; Worseck, G; Orlitova, I; Verhamme, A

    2016-01-01

    Following our first detection reported in Izotov et al. (2016), we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST). These galaxies, at redshifts of z~0.3, are characterized by high emission-line flux ratios [OIII]5007/[OII]3727 > 5. The escape fractions of the LyC radiation fesc(LyC) in these galaxies are in the range of ~6%-13%, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Lyalpha emission lines are detected in the spectra of all four galaxies, compatible with predictions for Lyman continuum leakers. We find escape fractions of Lyalpha, fesc(Lyalpha) ~60%-90%, among the highest known for Lyalpha emitters (LAEs). Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the center and exponential discs in the outskirts with disc scale lengths alpha in the range ~0.6-1.4 k...

  15. Multiwavelength laser line profile sensing for agricultural crop characterization

    Science.gov (United States)

    Strothmann, Wolfram; Ruckelshausen, Arno; Hertzberg, Joachim

    2014-05-01

    Triangulation-based laser line profile sensing is a widely used technique for precise and fast 3D measurement in industrial applications. More recently, it is used for applications in the area of outdoor agricultural sensing as well. However, in many agricultural applications high resolution range data by itself is insufficient. There is also a strong need for local spectral intensity information. As a consequence the combination of image-based range scanners with spectral imaging is often necessary. Under varying environmental conditions this is a tedious and error-prone problem, though. In contrast, the novel approach shown here allows capturing range data along with spectral laser reflectance and pixel-wise backscattering information at multiple, selectable wavelengths using a single sensor system. The system consists of multiple continuous wave (CW) line lasers simultaneously captured by a single monochrome imager. A system ready to capture 3 line lasers at 100 Hz was set up. Line lasers at different wavelengths in the visible and NIR range can be combined in accordance with the requirements of a specific application. Consecutively captured images are matched using sum of absolute differences (SAD) in order for tracking relative movement between the sensor system and the analyzed object. This allows normalizing images before the evaluation of reflectance and scattering. Furthermore, the SAD-based matching is used for accurate assembly of range and reflectance information gathered from different laser lines. It results in 3D point clouds with spectral laser reflectance and backscattering information at multiple, selectable wavelengths available for each point.

  16. Simulating the Lyman Alpha Forest

    CERN Document Server

    Machacek, M E; Anninos, P; Meiksin, A; Norman, M L; Machacek, Marie E.; Bryan, Greg L.; Anninos, Peter; Meiksin, Avery; Norman, Michael L.

    1998-01-01

    In this paper we review the importance of the Lyman alpha forest as a probe of structure formation in the universe. We first discuss the statistics used to describe the Lyman alpha forest and the numerical techniques used to produce simulated spectra of the forest from a given cosmological model. We then discuss the physical picture of the absorbing structures that emerges from these numerical simulations. Finally, we comment on how two of the statistics, the slope of the column density distribution and the b parameter distribution, may be used to constrain competing cosmologies.

  17. The Dynamical Masses, Densities, and Star Formation Scaling Relations of Lyman Alpha Galaxies

    CERN Document Server

    Rhoads, James E; Finkelstein, Steven L; Fynbo, Johan P U; McLinden, Emily M; Richardson, Mark L A; Tilvi, Vithal S

    2013-01-01

    We present the first dynamical mass measurements for Lyman alpha galaxies at high redshift, based on velocity dispersion measurements from rest-frame optical emission lines and size measurements from HST imaging, for a sample of nine galaxies drawn from four surveys. These measurements enable us to study the nature of Lyman alpha galaxies in the context of galaxy scaling relations. The resulting dynamical masses range from 1e9 to 1e10 solar masses. We also fit stellar population models to our sample, and use them to plot the Lyman alpha sample on a stellar mass vs. line width relation. Overall, the Lyman alpha galaxies follow well the scaling relation established by observing star forming galaxies at lower redshift (and without regard for Lyman alpha emission), though in 1/3 of the Lyman alpha galaxies, lower-mass fits are also acceptable. In all cases, the dynamical masses agree with established stellarmass-linewidth relation. Using the dynamical masses as an upper limit on gas mass, we show that Lyman alpha...

  18. Lyman-alpha radiation hydrodynamics of galactic winds before cosmic reionization

    Science.gov (United States)

    Smith, Aaron; Bromm, Volker; Loeb, Abraham

    2017-01-01

    Radiation from the first stars and galaxies initiated the dramatic phase transition marking an end to the cosmic dark ages. The emission and absorption signatures from the Lyman-alpha transition of neutral hydrogen have been indispensable in extending the observational frontier for high-redshift galaxies into the epoch of reionization. Lyman-alpha radiative transfer provides clues about the processes leading to Lyman-alpha escape from individual galaxies and the subsequent transmission through the intergalactic medium. Cosmological simulations incorporating Lyman-alpha radiative transfer enhance our understanding of fundamental physics by supplying the inferred spectra and feedback on the gas. We discuss the dynamical impact of Lyman-alpha radiation pressure on galaxy formation throughout cosmic reionization with the first fully coupled Lyman-alpha radiation-hydrodynamics simulations. We self-consistently follow the chemistry, cooling, self-gravity, and ionizing radiation in protogalaxies and find that Lyman-alpha radiation pressure turns out to be dynamically important in several spherically symmetric simulations. As a case in point we apply our model to the COSMOS redshift 7 (CR7) galaxy at z = 6.6, which exhibits a +160 km/s velocity offset between the Lyman-alpha and HeII line peaks. We find that a massive black hole with a nonthermal Compton-thick spectrum is able to reproduce the observed Lyman-alpha signatures as a result of higher photon trapping and longer potential lifetime. We conclude with a general discussion of Lyman-alpha radiation in the first galaxies by considering simulations that cover the expected range of halo and source properties.

  19. A LYMAN BREAK GALAXY IN THE EPOCH OF REIONIZATION FROM HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Zheng Zhenya [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ (United States); Pirzkal, Norbert; Grogin, Norman; Koekemoer, Anton; Peth, Michael A. [Space Telescope Science Institute, Baltimore, MD (United States); Spinrad, Hyron [University of California, Berkeley, CA (United States); Reddy, Naveen [University of California, Riverside, CA (United States); Hathi, Nimish [Observatories of the Carnegie Institution of Washington, Pasadena, CA (United States); Budavari, Tamas [Johns Hopkins University, Baltimore, MD (United States); Ferreras, Ignacio [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); Gardner, Jonathan P. [NASA Goddard Space Flight Center, Astrophysics Science Division, Observational Cosmology Laboratory, Code 665, Greenbelt, MD 20771 (United States); Gronwall, Caryl [Department of Astronomy and Astrophysics, and Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); Haiman, Zoltan [Columbia University, New York, NY (United States); Kuemmel, Martin [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Meurer, Gerhardt, E-mail: James.Rhoads@asu.edu [International Centre for Radio Astronomy Research, University of Western Australia, M468, 35 Stirling Highway, Crawley, WA 6009 (Australia); and others

    2013-08-10

    We present observations of a luminous galaxy at z = 6.573-the end of the reionization epoch-which has been spectroscopically confirmed twice. The first spectroscopic confirmation comes from slitless Hubble Space Telescope Advanced Camera for Surveys grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically), which show a dramatic continuum break in the spectrum at rest frame 1216 A. The second confirmation is done with Keck + DEIMOS. The continuum is not clearly detected with ground-based spectra, but high wavelength resolution enables the Ly{alpha} emission line profile to be determined. We compare the line profile to composite line profiles at z = 4.5. The Ly{alpha} line profile shows no signature of a damping wing attenuation, confirming that the intergalactic gas is ionized at z = 6.57. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms, even at redshifts where Ly{alpha} is too attenuated by the neutral intergalactic medium to be detectable using traditional spectroscopy from the ground.

  20. Rest-Frame Optical Emission Lines in z~3.5 Lyman Break selected Galaxies: The Ubiquity of Unusually High [OIII]/Hbeta Ratios at 2 Gyr

    CERN Document Server

    Holden, B P; Gonzalez, V G; Illingworth, G D; Labbe, I; Bouwens, R; Franx, M; van Dokkum, P; Spitler, L

    2014-01-01

    We present K-band spectra of rest-frame optical emission lines for 24 star-forming galaxies at z~3.2-3.7 using MOSFIRE on the Keck 1 telescope. Strong rest-frame optical [O III] and Hbeta emission lines were detected in 18 LBGs. The median flux ratio of [O III]5007 to Hbeta is 5.1+/-0.5, a factor of 5-10x higher than in local galaxies with similar stellar masses. The observed Hbeta luminosities are in good agreement with expectations from the estimated star-formation rates, and none of our sources are detected in deep X-ray stacks, ruling out significant contamination by active galactic nuclei. Combining our sample with a variety of LBGs from the literature, including 49 galaxies selected in a very similar manner, we find a high median ratio of [OIII]/Hbeta = 4.8+0.8-1.7. This high ratio seems to be an ubiquitous feature of z~3-4 LBGs, very different from typical local star-forming galaxies at similar stellar masses. The only comparable systems at z~0 are those with similarly high specific star-formation rate...

  1. Line Profile Measurements of the Lunar Exospheric Sodium

    Science.gov (United States)

    Oliversen, Ronald J.; Mierkiewicz, Edwin J.; Line, Michael R.; Roesler, Fred L.; Lupie, Olivia L.

    2012-01-01

    We report ongoing results of a program to measure the lunar sodium exospheric line profile from near the lunar limb out to two lunar radii (approx 3500 km). These observations are conducted from the National Solar Observatory McMath-Pierce telescope using a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,600 (1.7 km/s) to measure line widths and velocity shifts of the Na D2 (5889 950 A) emission line in equatorial and polar regions at different lunar phases. The typical field of view (FOV) is 3 arcmin (approx 360 km) with an occasional smaller 1 arcmin FOV used right at the limb edge. The first data were obtained from full Moon to 3 days following full Moon (waning phase) in March 2009 as part of a demonstration run aimed at establishing techniques for a thorough study of temperatures and velocity variations in the lunar sodium exosphere. These data indicate velocity displacements from different locations off the lunar limb range between 150 and 600 m/s from the lunar rest velocity with a precision of +/- 20 to +/- 50 m/s depending on brightness. The measured Doppler line widths for observations within 10.5 arcmin of the east and south lunar limbs for observations between 5 deg and 40 deg lunar phase imply temperatures ranging decreasing from 3250 +/- 260K to 1175 +/- 150K. Additional data is now being collected on a quarterly basis since March 2011 and preliminary results will be reported.

  2. What Powers Lyman alpha Blobs?

    CERN Document Server

    Ao, Y; Beelen, A; Henkel, C; Cen, R; De Breuck, C; Francis, P; Kovacs, A; Lagache, G; Lehnert, M; Mao, M; Menten, K M; Norris, R; Omont, A; Tatemastu, K; Weiss, A; Zheng, Z

    2015-01-01

    Lyman alpha blobs (LABs) are spatially extended lyman alpha nebulae seen at high redshift. The origin of Lyman alpha emission in the LABs is still unclear and under debate. To study their heating mechanism(s), we present Australia Telescope Compact Array (ATCA) observations of the 20 cm radio emission and Herschel PACS and SPIRE measurements of the far-infrared (FIR) emission towards the four LABs in the protocluster J2143-4423 at z=2.38. Among the four LABs, B6 and B7 are detected in the radio with fluxes of 67+/-17 microJy and 77+/-16 microJy, respectively, and B5 is marginally detected at 3 sigma (51+/-16 microJy). For all detected sources, their radio positions are consistent with the central positions of the LABs. B6 and B7 are obviously also detected in the FIR. By fitting the data with different templates, we obtained redshifts of 2.20$^{+0.30}_{-0.35}$ for B6 and 2.20$^{+0.45}_{-0.30}$ for B7 which are consistent with the redshift of the lyman alpha emission within uncertainties, indicating that both ...

  3. Line profile modelling for multi-pixel CZT detectors

    Science.gov (United States)

    Chattopadhyay, T.; Vadawale, S. V.; Rao, A. R.; Bhattacharya, D.; Mithun, N. P. S.; Bhalerao, V.

    2016-07-01

    Cadmium Zinc Telluride (CZT) detectors have been the mainstay for hard X-ray astronomy for its high quantum efficiency, fine energy resolution, near room temperature operation, and radiation hardness. In order to fully utilize the spectroscopic capabilities of CZT detectors, it is important to generate accurate response matrix, which in turn requires precise modelling of the line profiles for the CZT detectors. We have developed a numerical model taking into account the mobility and lifetime of the charge carriers and intrpixel charge sharing for the CZT detectors. This paper describes the details of the modelling along with the experimental measurements of mobility, lifetime and charge sharing fractions for the CZT detector modules of thickness of 5 mm and 2.5 mm pixel size procured from Orbotech Medical Solutions (same modules used in AstroSat-CZTI).

  4. Discovery of a very Lyman-α-luminous quasar at z = 6.62.

    Science.gov (United States)

    Koptelova, Ekaterina; Hwang, Chorng-Yuan; Yu, Po-Chieh; Chen, Wen-Ping; Guo, Jhen-Kuei

    2017-02-02

    Distant luminous quasars provide important information on the growth of the first supermassive black holes, their host galaxies and the epoch of reionization. The identification of quasars is usually performed through detection of their Lymanline redshifted to 0.9 microns at z > 6.5. Here, we report the discovery of a very Lyman-α luminous quasar, PSO J006.1240 + 39.2219 at redshift z = 6.618, selected based on its red colour and multi-epoch detection of the Lyman-α emission in a single near-infrared band. The Lymanline luminosity of PSO J006.1240 + 39.2219 is unusually high and estimated to be 0.8 × 10(12) Solar luminosities (about 3% of the total quasar luminosity). The Lyman-α emission of PSO J006.1240 + 39.2219 shows fast variability on timescales of days in the quasar rest frame, which has never been detected in any of the known high-redshift quasars. The high luminosity of the Lymanline, its narrow width and fast variability resemble properties of local Narrow-Line Seyfert 1 galaxies which suggests that the quasar is likely at the active phase of the black hole growth accreting close or even beyond the Eddington limit.

  5. Discovery of a very Lyman-α-luminous quasar at z = 6.62

    Science.gov (United States)

    Koptelova, Ekaterina; Hwang, Chorng-Yuan; Yu, Po-Chieh; Chen, Wen-Ping; Guo, Jhen-Kuei

    2017-01-01

    Distant luminous quasars provide important information on the growth of the first supermassive black holes, their host galaxies and the epoch of reionization. The identification of quasars is usually performed through detection of their Lymanline redshifted to 0.9 microns at z > 6.5. Here, we report the discovery of a very Lyman-α luminous quasar, PSO J006.1240 + 39.2219 at redshift z = 6.618, selected based on its red colour and multi-epoch detection of the Lyman-α emission in a single near-infrared band. The Lymanline luminosity of PSO J006.1240 + 39.2219 is unusually high and estimated to be 0.8 × 1012 Solar luminosities (about 3% of the total quasar luminosity). The Lyman-α emission of PSO J006.1240 + 39.2219 shows fast variability on timescales of days in the quasar rest frame, which has never been detected in any of the known high-redshift quasars. The high luminosity of the Lymanline, its narrow width and fast variability resemble properties of local Narrow-Line Seyfert 1 galaxies which suggests that the quasar is likely at the active phase of the black hole growth accreting close or even beyond the Eddington limit. PMID:28150701

  6. The Line-Profile Variations of Theta2 Tauri

    Science.gov (United States)

    Kennelly, E. J.; Walker, G. A. H.

    1996-04-01

    With a 5.4-hour time series of high-resolution CFHT spectra, the oscillations of the rapidly-rotating delta Scuti star Theta2 Tauri (A7 IV + A5 V) are investigated. Line-profile variations are discovered and identified with the spectrum of the primary star of this binary system. Radial velocity variations are derived from the data and analyzed to reveal an oscillation frequency near 13.7 cycles day^-1. Variations within the absorption profiles are analyzed with a Fourier-Doppler Imaging (FDI) technique to reveal that high-degree oscillations with a frequency of 16.1 cycles day ^-1 and an apparent degree of about l = 8 are also present in the star. Whereas the low-degree variations of Theta2 Tau have been shown to be consistent with p-modes of radial order n=2 or 3, the identification of the high-degree variations in terms of pressure modes requires confirmation with theoretical models. (SECTION: Stars)

  7. Predicting Lyman-alpha and Mg II Fluxes from K and M Dwarfs Using GALEX Ultraviolet Photometry

    CERN Document Server

    Shkolnik, Evgenya L; Peacock, Sarah; Barman, Travis S

    2014-01-01

    A star's UV emission can greatly affect the atmospheric chemistry and physical properties of closely orbiting planets with the potential for severe mass loss. In particular, the Lyman-alpha emission line at 1216 Angstroms, which dominates the far-ultraviolet spectrum, is a major source of photodissociation of important atmospheric molecules such as water and methane. The intrinsic flux of Lyman-alpha, however, cannot be directly measured due to the absorption of neutral hydrogen in the interstellar medium and contamination by geocoronal emission. To date, reconstruction of the intrinsic Lyman-alpha line based on Hubble Space Telescope spectra has been accomplished for 46 FGKM nearby stars, 28 of which have also been observed by the Galaxy Evolution Explorer (GALEX). Our investigation provides a correlation between published intrinsic Lyman-alpha and GALEX far- and near-ultraviolet chromospheric fluxes for K and M stars. The negative correlations between the ratio of the Lyman-alpha to the GALEX fluxes reveal ...

  8. Analysis of the solar coronal green line profiles from eclipse observations

    CERN Document Server

    Prabhakar, Maya; Chandrasekhar, T

    2013-01-01

    Analysis of the solar coronal green line profiles reveals information regarding the physical conditions of the solar corona like temperature, density, Doppler velocity, non-thermal velocity etc. It provides insights to the unresolved problems like the coronal heating and the acceleration of the solar winds. Recent studies have reported excess blueshifts in the coronal line profiles and are interpreted as due to nanoflare heating, type II spicules and nascent solar wind flow. We have analyzed a time series of Fabry-Perot interferograms of the solar corona obtained during the total solar eclipse of 2001 June 21 from Lusaka, Zambia. The spatial behavior of the coronal green line profiles were examined and variations in intensity, linewidth, Doppler velocity and line asymmetry were obtained. Several line profiles showed asymmetry indicating the presence of multicomponents. Such line profiles were fitted with double Gaussian curves. It has been found that 42% of the line profiles were single components, 34% were b...

  9. Computing Intrinsic Lyman-alpha Fluxes of F5 V to M5 V Stars

    CERN Document Server

    Linsky, Jeffrey L; Ayres, Tom

    2013-01-01

    The Lyman-alpha emission line dominates the far-ultraviolet spectra of late-type stars and is a major source for photodissociation of important molecules including H2O, CH4, and CO2 in exoplanet atmospheres. The incident flux in this line illuminating an exoplanet's atmosphere cannot be measured directly as neutral hydrogen in the interstellar medium (ISM) attenuates most of the flux reaching the Earth. Reconstruction of the intrinsic Lyman-alpha line has been accomplished for a limited number of nearby stars, but is not feasible for distant or faint host stars. We identify correlations connecting the intrinsic Lyman-alpha flux with the flux in other emission lines formed in the stellar chromosphere, and find that these correlations depend only gradually on the flux in the other lines. These correlations, which are based on HST spectra, reconstructed Lyman-alpha line fluxes, and irradiance spectra of the quiet and active Sun, are required for photochemical models of exoplanet atmospheres when intrinsic Lyman-...

  10. Correlation between asymmetric profiles in slits and standard prewetting lines

    Directory of Open Access Journals (Sweden)

    Leszek Szybisz

    2009-09-01

    Full Text Available The adsorption of Ar on substrates of Li is investigated within the framework of a density functional theory which includes an effective pair potential recently proposed. This approach yields good results for the surface tension of the liquid-vapor interface. The behavior of the adsorbate in the cases of a single planar wall and a slit geometry is analyzed as a function of temperature. Asymmetric density profiles are found for fluid confined in a slit built up of two identical planar walls leading to the spontaneous symmetry breaking (SSB effect. We found that the asymmetric solutions occur even above the wetting temperature $T_w$ in a range of average densities $ho^*_{ssb1} le ho^*_{av} le ho^*_{ssb2}$, which diminishes with increasing temperatures until its disappearance at the critical prewetting point $T_{m cpw}$. In this way a correlation between the disappearance of the SSB effect and the end of prewetting lines observed in the adsorption on a one-wall planar substrate is established. In addition, it is shown that a value for $T_{m cpw}$ can be precisely determined by analyzing the asymmetry coefficients.

  11. Investigating the Metallicity Evolution of Sub-damped Lyman alpha Systems

    Science.gov (United States)

    Konchady, Tarini; Jorgenson, Regina

    2017-01-01

    A clear understanding of the production and build up of metals across cosmic time is a key ingredient to any theory of galaxy formation and evolution. We present chemical abundance measurements for a sample of ~20 sub-damped Lyman alpha systems (subDLAs) detected in the absorption spectra of high redshift quasars taken by the Echellette Spectrograph and Imager (ESI) on the Keck II telescope. The sample contains absorbers with neutral hydrogen column densities of 1019.0 Metal line column densities were measured using the apparent optical depth method while neutral hydrogen column densities were measured via Voigt profile fitting. We compare our measurements to those of DLAs and subDLAs from the literature to investigate the potential differences in metallicity evolution between these types of galaxies.

  12. A Spectroscopic Redshift Measurement for a Luminous Lyman Break Galaxy at z=7.730 using Keck/MOSFIRE

    CERN Document Server

    Oesch, P A; Illingworth, G D; Bouwens, R J; Momcheva, I; Holden, B; Roberts-Borsani, G W; Smit, R; Franx, M; Labbe, I; Gonzalez, V; Magee, D

    2015-01-01

    We present a spectroscopic redshift measurement of a very bright Lyman break galaxy at z=7.7302+-0.0006 using Keck/MOSFIRE. The source was pre-selected photometrically in the EGS field as a robust z~8 candidate with H=25.0 mag based on optical non-detections and a very red Spitzer/IRAC [3.6]-[4.5] broad-band color driven by high equivalent width [OIII]+Hbeta line emission. The Lyalpha line is reliably detected at >6 sigma and shows an asymmetric profile as expected for a galaxy embedded in a relatively neutral inter-galactic medium near the Planck peak of cosmic reionization. The line has a rest-frame equivalent width of EW0=21+-4 A and is extended with V_FWHM=376+89-70 km/s. The source is perhaps the brightest and most massive z~8 Lyman break galaxy in the full CANDELS and BoRG/HIPPIES surveys, having assembled already 10^(9.9+-0.2) M_sol of stars at only 650 Myr after the Big Bang. The spectroscopic redshift measurement sets a new redshift record for galaxies. This enables reliable constraints on the stella...

  13. Lyman-alpha and CIII] Emission in z=7-9 Galaxies: Accelerated Reionization Around Luminous Star Forming Systems?

    CERN Document Server

    Stark, Daniel P; Charlot, Stephane; Chevallard, Jacopo; Tang, Mengtao; Belli, Sirio; Zitrin, Adi; Mainali, Ramesh; Gutkin, Julia; Vidal-Garcia, Alba; Bouwens, Rychard; Oesch, Pascal

    2016-01-01

    We discuss new Keck/MOSFIRE spectroscopic observations of four luminous galaxies at z~7-9 selected to have intense optical line emission by Roberts-Borsani et al. (2016). Previous follow-up has revealed Lyman-alpha in two of the four galaxies. Our new MOSFIRE observations confirm that Lyman-alpha is present in the entire sample. We detect Lyman-alpha emission in COS-zs7-1, confirming its redshift as z=7.154, and we detect Lyman-alpha in EGS-zs8-2 at z=7.477, verifying a tentative detection presented in an earlier study. The ubiquity of Lyman-alpha in this sample is puzzling given that the IGM is likely significantly neutral over 77 is expected to be strongly luminosity-dependent, with the most effective transmission occurring in systems with intense star formation.

  14. Variability of Lyman-alpha and the ultraviolet continuum of 3C 446

    Science.gov (United States)

    Bregman, J. N.; Glassgold, A. E.; Huggins, P. J.; Kinney, A. L.

    1986-01-01

    IUE observations have been conducted over the 1230-3175 A range for the violently variable quasar 3C 446, beginning in June 1980, at intervals of 1.2, 2.2, 0.5, and 0.4 yr. Strong absorption of the continuum was found below 1830 A, probably corresponding to a Lyman edge at z of 1.00 + or - 0.01. The absence of Mg II 2798 A absorption implies that the column density is in the lower end of the range, unless the gas is metal-poor. The Lyman-alpha emission line was detected in five spectra; relative to the number of ionizing protons, the line strengths are the same as in normal quasars, and line equivalent widths are small due to the continuum's rise redward of 912 A, which is much steeper than in normal quasars. The Lyman-alpha line and the nearby continuum vary so as to maintain constant equivalent width.

  15. Effect of a progressive sound wave on the profiles of spectral lines. 2: Asymmetry of faint Fraunhofer lines. [absorption spectra

    Science.gov (United States)

    Kostyk, R. I.

    1974-01-01

    The absorption coefficient profile was calculated for lines of different chemical elements in a medium with progressive sound waves. Calculations show that (1) the degree and direction of asymmetry depend on the atomic ionization potential and the potential of lower level excitation of the individual line; (2) the degree of asymmetry of a line decreases from the center toward the limb of the solar disc; and (3) turbulent motions 'suppress' the asymmetry.

  16. Modeling the Lyman-alpha Forest in Collisionless Simulations

    CERN Document Server

    Sorini, Daniele; Lukić, Zarija; Hennawi, Joseph F

    2016-01-01

    Cosmological hydrodynamic simulations can accurately predict the properties of the intergalactic medium (IGM), but only under the condition of retaining high spatial resolution necessary to resolve density fluctuations in the IGM. This resolution constraint prohibits simulating large volumes, such as those probed by BOSS and future surveys, like DESI and 4MOST. To overcome this limitation, we present Iteratively Matched Statistics (IMS), a novel method to accurately model the Lyman-alpha forest with collisionless N-body simulations, where the relevant density fluctuations are unresolved. We use a small-box, high-resolution hydrodynamic simulation to obtain the probability distribution function (PDF) and the power spectrum of the real-space Lyman-alpha forest flux. These two statistics are iteratively mapped onto a pseudo-flux field of an N-body simulation, which we construct from the matter density. We demonstrate that our method can perfectly reproduce line-of-sight observables, such as the PDF and power spe...

  17. Indirect Evidence for Escaping Lyman Continuum Photons in Local Lyman Break Galaxy Analogs

    Science.gov (United States)

    Alexandroff, Rachael; Heckman, Timothy M.; Borthakur, Sanchayeeta; Overzier, Roderik

    2015-01-01

    A population of early star-forming galaxies is the leading candidate for the re-ionization of the universe. It is still unclear, however, what conditions and physical processes would enable a significant fraction of the ionizing photons to escape from these gas-rich galaxies. In addition, studies of high redshift galaxies have yet to uncover a large sample of galaxies with the required high escape fraction of ionizing photons.We have uncovered a sample of local analogs to high-redshift, star-forming Lyman Break Galaxies (LBGs) called Lyman Break Analogs (LBAs) by matching the Sloan Digital Sky Survey (SDSS) and Galaxy Evolution Explorer (GALEX) catalogs. These galaxies are remarkably similar to LBGs in their properties-- morphology, size, UV luminosity, SFR, mass, velocity dispersion, metallicity and dust content. We obtained HST COS far-UV spectroscopy plus ancillary multi-waveband data of a sample of 22 LBAs to look for indirect evidence of escaping ionizing radiation (leakiness).We measure three parameters: (1) the residual intensity in the cores of saturated interstellar low-ionization absorption-lines, which indicates incomplete covering by that gas in the galaxy. (2) The relative amount of blue-shifted Lyman alpha line emission, which can indicate the existence of holes in the neutral hydrogen on the front-side of the galaxy outflow, and (3) the relative weakness of the [SII] optical emission lines that trace matter-bounded HII regions. We find all three diagnostics agree well with one another. Finally, we find the strongest correlation between these leakiness indicators and both the compactness of the galactic star-forming region (size and star formation rate/area) and the speed of the galactic outflow. This suggests that extreme feedback- a high intensity of ionizing radiation and strong pressure from both radiation and a hot galactic wind- combines to create significant holes in the neutral gas. These results not only shed new light on the physical

  18. Lyman alpha emission from the first galaxies: implications of UV backgrounds and the formation of molecules : implications of UV backgrounds and the formation of molecules

    NARCIS (Netherlands)

    Latif, M. A.; Schleicher, D. R. G.; Spaans, M.; Zaroubi, S.

    The Lyman alpha line is a robust tracer of high redshift galaxies. We present estimates of Lyman alpha emission from a protogalactic halo illuminated by UV background radiation fields with various intensities. For this purpose, we performed cosmological hydrodynamics simulations with the adaptive

  19. The Lyman Alpha Reference Sample: III. Properties of the Neutral ISM from GBT and VLA Observations

    CERN Document Server

    Pardy, Stephen A; Östlin, Göran; Hayes, Matthew; Rivera-Thorsen, Thøger; Sandberg, Andreas; Adamo, Angela; Freeland, Emily; Heren, E Christian; Guaita, Lucia; Kunth, Daniel; Laursen, Peter; Mas-Hesse, J M; Melinder, Jens; Orlitová, Ivana; Otí-Floranes, Héctor; Puschnig, Johannes; Schaerer, Daniel; Verhamme, Anne

    2014-01-01

    We present new H I imaging and spectroscopy of the 14 UV-selected star-forming galaxies in the Lyman Alpha Reference Sample (LARS), aimed for a detailed study of the processes governing the production, propagation, and escape of Ly$\\alpha$ photons. New H I spectroscopy, obtained with the 100m Green Bank Telescope (GBT), robustly detects the H I spectral line in 11 of the 14 observed LARS galaxies (although the profiles of two of the galaxies are likely confused by other sources within the GBT beam); the three highest redshift galaxies are not detected at our current sensitivity limits. The GBT profiles are used to derive fundamental H I line properties of the LARS galaxies. We also present new pilot H I spectral line imaging of 5 of the LARS galaxies obtained with the Karl G. Jansky Very Large Array (VLA). This imaging localizes the H I gas and provides a measurement of the total H I mass in each galaxy. In one system, LARS 03 (UGC 8335 or Arp 238), VLA observations reveal an enormous tidal structure that ext...

  20. Lyman Alpha Spicule Observatory (LASO)

    Science.gov (United States)

    Chamberlin, P. C.; Allred, J. C.; Airapetian, V.; Gong, Q.; Mcintosh, S. W.; De Pontieu, B.; Fontenla, J. M.

    2011-12-01

    The Lyman Alpha Spicule Observatory (LASO) sounding rocket will observe small-scale eruptive events called "Rapid Blue-shifted Events" (RBEs) [Rouppe van der Voort et al., 2009], the on-disk equivalent of Type-II spicules, and extend observations that explore their role in the solar coronal heating problem [De Pontieu et al., 2011]. LASO utilizes a new and novel optical design to simultaneously observe two spatial dimensions at 4.2" spatial resolution (2.1" pixels) over a 2'x2' field of view with high spectral resolution of 66mÅ (33mÅ pixels) across a broad 20Å spectral window. This spectral window contains three strong chromospheric and transition region emissions and is centered on the strong Hydrogen Lyman-α emission at 1216Å. This instrument makes it possible to obtain new data crucial to the physical understanding of these phenomena and their role in the overall energy and momentum balance from the upper chromosphere to lower corona. LASO was submitted March 2011 in response to the ROSES SHP-LCAS call.

  1. Hudson River Sub-Bottom Profile Lines_r09272010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Subbottom Profiler Tracklines. Data was collected November 5 to December 15, 2009, in the estuary north from Saugerties to Troy. Fugro utilized the GeoAcoustics...

  2. Analysis of the coronal green line profiles: evidence of excess blueshifts

    CERN Document Server

    Raju, K P; Ashok, N M

    2011-01-01

    The coronal green line (Fe XIV 5303 A) profiles were obtained from Fabry-Perot interferometric observations of the solar corona during the total solar eclipse of 21 June 2001 from Lusaka, Zambia. The instrumental width is about 0.2 A and the spectral resolution is about 26000. About 300 line profiles were obtained within a radial range of 1.0-1.5 R\\odot and position angle coverage of about 240\\circ. The line profiles were fitted with single Gaussian and their intensity, Doppler velocity, and line width have been obtained. Also obtained are the centroids of the line profiles which give a measure of line asymmetry. The histograms of Doppler velocity show excess blueshifts while the centroids reveal a pre-dominant blue wing in the line profiles. It has been found that the centroids and the Doppler velocities are highly correlated. This points to the presence of multiple components in the line profiles with an excess of blueshifted components. We have then obtained the(Blue-Red) wing intensity which clearly revea...

  3. Lyman-alpha emission in star-forming galaxies

    Science.gov (United States)

    Hartmann, Lee W.; Huchra, John P.; Geller, Margaret J.; O'Brien, Paul; Wilson, Robert

    1988-01-01

    IUE observations of five blue, low-metallicity, star-forming galaxies sufficiently redshifted to permit detection of Lyman-alpha are reported. The galaxies with metallicities 0.1 time solar or more have weak or absent Lyman-alpha emission. There is evidence for increasing Lyman-alpha emission with decreasing metallicity. The reduction of Lyman-alpha fluxes from recombination values is attributed to absorption of multiply scattered Lyman-alpha by dust.

  4. Reaching Higher Densities for Laboratory White Dwarf Photospheres to Measure Spectroscopic Line Profiles

    CERN Document Server

    Falcon, Ross E; Gomez, T A; Schaeuble, M; Nagayama, T; Montgomery, M H; Winget, D E; Rochau, G A

    2016-01-01

    As part of our laboratory investigation of the theoretical line profiles used in white dwarf atmosphere models, we extend the electron-density ($n_{\\rm e}$) range measured by our experiments to higher densities (up to $n_{e}\\sim80\\times10^{16}$ cm$^{-3}$). Whereas inferred parameters using the hydrogen-$\\beta$ spectral line agree among different line-shape models for $n_{\\rm e}\\lesssim30\\times10^{16}$ cm$^{-3}$, we now see divergence between models. These are densities beyond the range previously benchmarked in the laboratory, meaning theoretical profiles in this regime have not been fully validated. Experimentally exploring these higher densities enables us to test and constrain different line-profile models, as the differences in their relative H-Balmer line shapes are more pronounced at such conditions. These experiments also aid in our study of occupation probabilities because we can measure these from relative line strengths.

  5. Elemental Abundances in Two High Column Density Damped Lyman Alpha Systems at z < 1.5

    CERN Document Server

    Rao, S M; Howk, J C; Wolfe, A M; Rao, Sandhya M.; Prochaska, Jason X.; Wolfe, Arthur M.

    2004-01-01

    We present Keck/HIRES abundance measurements and metal-line kinematic profiles of the damped Lyman alpha systems (DLAs) towards the quasars Q0933+733 (z_abs=1.479) and Q0948+433 (z_abs=1.233). These two DLAs have among the five highest HI column densities at any redshift: N(HI)=4.2E21 cm^{-2}. The metal-line data, presented here for the first time, reveal that these DLAs are noteworthy for several other reasons as well. 1) The Q0933+733 DLA exhibits simple kinematic structure with unusually narrow velocity widths as measured from its unsaturated metal lines (delta v=16 km/s). At 2.6% solar, it has the second lowest metallicity at z -1) and a significant alpha-enhancement. The strong metal lines of this DLA have made possible the detection of TiII1910, CoII2012, and MgI2026. 3) We find that the relative gas-phase abundances of both DLAs follow the general trend seen at high redshift, e.g., enhanced Zn/Fe and Si/Fe, and sub-solar Mn/Fe, indicating that there is little evolution in the nucleosynthetic patterns o...

  6. Spectroscopic Confirmation of Two Lyman Break Galaxies at Redshift Beyond 7

    Science.gov (United States)

    Vanzella, E.; Pentericci, L.; Fontana, A.; Grazian, A.; Castellano, M.; Boutsia, K.; Cristiani, S.; Dickinson, M.; Gallozzi, S.; Giallongo, E.; Giavalisco, M.; Maiolino, R.; Moorwood, A.; Paris, D.; Santini, P.

    2011-04-01

    We report the spectroscopic confirmation of two Lyman break galaxies at redshift >7. The galaxies were observed as part of an ultra-deep spectroscopic campaign with FORS2 at the ESO/VLT for the confirmation of z ~= 7 "z-band dropout" candidates selected from our VLT/Hawk-I imaging survey. Both galaxies show a prominent emission line at 9735 Å and 9858 Å, respectively: the lines have fluxes of ~(1.6-1.2) × 10-17 erg s-1 cm-2 and exhibit a sharp decline on the blue side and a tail on the red side. The asymmetry is quantitatively comparable to the observed asymmetry in z ~ 6 Lyα lines, where absorption by neutral hydrogen in the intergalactic medium (IGM) truncates the blue side of the emission-line profile. We carefully evaluate the possibility that the galaxies are instead at lower redshift and we are observing either [O II], [O III], or Hα emission: however from the spectroscopic and the photometric data we conclude that there are no other plausible identifications, except for Lyα at redshift >7, implying that these are two of the most robust redshift determination for galaxies in the reionization epoch. Based on their redshifts and broadband photometry, we derive limits on the star formation rate and on the ultraviolet spectral slopes of the two galaxies. We argue that these two galaxies alone are unlikely to have ionized the IGM in their surroundings.

  7. XRAYL: a program for producing idealized powder diffraction line profiles from overlapped powder patterns

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, C.R.; Morosin, B. [Sandia National Labs., Albuquerque, NM (United States); Stewart, J.M. [Maryland Univ., College Park, MD (United States)

    1996-09-01

    The X-ray diffraction patterns of samples of polycrystalline materials are used to identify and characterize phases. Very often the total (or composite) profile consists of a series of overlapping profiles. In many applications it is necessary to separate the component profiles from the total profile. (In this document the terms {ital profile, line}, and {ital peak} are used interchangeably to represent these features of X-ray or neutron diffraction patterns.) A computer program, XRAYL, first developed in the 1980s and subsequently enlarged and improved, allows the fitting of analytical functions to powder diffraction lines. The fitting process produces parameters of chosen profile functions, diffraction line by diffraction line. The resulting function parameters may then be used to generate ``idealized`` powder diffraction lines as counts at steps in 2{Omega}. The generated lines are effectively free of statistical noise and contributions from overlapping lines. Each separated line extends to background on both sides of the generated profile. XRAYL may, therefore, be used in X-ray powder diffraction profile analysis as a preprocessor program that is, separating peaks and feeding the ``resolved`` data to subsequent analysis programs. This self- contained document includes: (1) a description of the fitting functions coded into XRAYL, (2) an outline of the least-squares algorithm used in fitting the profile function, (3) the file formats and contents utilized by the computer code, (4) the user options and their presentation requirements for execution of the program, (5) an example of input and output for a test case, and (6) source code listings on a diskette.

  8. Deep SAURON Spectral-Imaging of the diffuse Lyman-alpha halo LAB1 in SSA22

    CERN Document Server

    Bower, R; Bacon, R; Wilman, R J; Sullivan, M; Chapman, S C; Davies, R L; De Zeeuw, P T; Emsellem, E; Bower, Richard

    2004-01-01

    We have used the SAURON panoramic integral field spectrograph to study the structure of the Ly-alpha emission-line halo, LAB1, surrounding the sub-millimeter galaxy SMM J221726+0013. This emission-line halo was discovered during a narrow-band imaging survey of the z=3.1 large-scale structure in the SSA22 region. Our observations trace the emission halo out to almost 100 kpc from the sub-millimeter source and identify two distinct Ly-alpha `mini-haloes' around the nearby Lyman-break galaxies. The main emission region has a broad line profile, with variations in the line profile seeming chaotic and lacking evidence for a coherent velocity structure. The data also suggests that Ly-alpha emission is suppressed around the sub-mm source. Interpretation of the line structure needs care because Ly-alpha may be resonantly scattered, leading to complex radiative transfer effects, and we suggest that the suppression in this region arises because of such effects. We compare the structure of the central emission-line halo...

  9. Seismic lines with digital seg-y profiles, northern Afghanistan (segyafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains polylines that describe the location of seismic lines in northern Afghanistan for which digital seismic profiles in seg-y format are...

  10. Iron line profiles in Suzaku spectra of bare Seyfert galaxies

    CERN Document Server

    Patrick, A R; Porquet, D; Markowitz, A G; Lobban, A P; Terashima, Y

    2010-01-01

    We methodically model the broad-band Suzaku spectra of a small sample of six 'bare' Seyfert galaxies: Ark 120, Fairall 9, MCG-02-14-009, Mrk 335, NGC 7469 and SWIFT J2127.4+5654. The analysis of bare Seyferts allows a consistent and physical modelling of AGN due to a weak amount of any intrinsic warm absorption, removing the degeneracy between the spectral curvature due to warm absorption and the red-wing of the Fe K region. Through effective modelling of the broad-band spectrum and investigating the presence of narrow neutral or ionized emission lines and reflection from distant material, we obtain an accurate and detailed description of the Fe K line region using models such as laor, kerrdisk and kerrconv. Results suggest that ionized emission lines at 6.7 keV and 6.97 keV (particularly Fe XXVI) are relatively common and the inclusion of these lines can greatly affect the parameters obtained with relativistic models i.e. spin, emissivity, inner radius of emission and inclination. Moderately broad components...

  11. Comparative Proteomic Profiling of Pancreatic Ductal Adenocarcinoma Cell Lines

    Science.gov (United States)

    Kim, Yikwon; Han, Dohyun; Min, Hophil; Jin, Jonghwa; Yi, Eugene C.; Kim, Youngsoo

    2014-01-01

    Pancreatic cancer is one of the most fatal cancers and is associated with limited diagnostic and therapeutic modalities. Currently, gemcitabine is the only effective drug and represents the preferred first-line treatment for chemotherapy. However, a high level of intrinsic or acquired resistance of pancreatic cancer to gemcitabine can contribute to the failure of gemcitabine treatment. To investigate the underlying molecular mechanisms for gemcitabine resistance in pancreatic cancer, we performed label-free quantification of protein expression in intrinsic gemcitabine-resistant and - sensitive human pancreatic adenocarcinoma cell lines using our improved proteomic strategy, combined with filter-aided sample preparation, single-shot liquid chromatography-mass spectrometry, enhanced spectral counting, and a statistical method based on a power law global error model. We identified 1931 proteins and quantified 787 differentially expressed proteins in the BxPC3, PANC-1, and HPDE cell lines. Bioinformatics analysis identified 15 epithelial to mesenchymal transition (EMT) markers and 13 EMT-related proteins that were closely associated with drug resistance were differentially expressed. Interestingly, 8 of these proteins were involved in glutathione and cysteine/methionine metabolism. These results suggest that proteins related to the EMT and glutathione metabolism play important roles in the development of intrinsic gemcitabine resistance by pancreatic cancer cell lines. PMID:25518923

  12. Interface Profiles near Three-Phase Contact Lines in Electric Fields

    OpenAIRE

    Buehrle, Juergen; Herminghaus, Stephan; Mugele, Frieder

    2003-01-01

    Long-range electrostatic fields deform the surface profile of a conductive liquid in the vicinity of the contact line. We have investigated the equilibrium profiles by balancing electrostatic and capillary forces locally at the liquid vapor interface. Numerical results show that the contact angle at the contact line approaches Young's angle. Simultaneously, the local curvature displays a weak algebraic divergence. Furthermore, we present an asymptotic analytical model, which confirms these re...

  13. Geocoronal Lyman Alpha Observations with COS

    Science.gov (United States)

    Ake, Thomas B.

    2012-01-01

    The time-tagged mode of the Cosmic Origins Spectrograph (COS) provides a convenient method of studying the orbital variation of geocoronal Lyman-alpha emission at the altitude of HST. We have analyzed G130M blank sky exposures from scheduled STIS parallels and observations for which the target acquisition failed. We supplement these with observations of WD standard stars from flat field and sensitivity monitoring programs where the stellar Lyα profile can be modeled and its contribution to the geocoronal emission removed. Data were corrected for time-dependent sensitivity changes and gain sag. The measurements have been fit by an analytical model based on the orbital position of HST and the angle between the target and the Earth as seen from HST. The Lyα emission varies from less than 2 kR for a target observed at orbit midnight to 37 kR for one observed at the bright Earth limb at orbit noon. A long-term trend of increasing flux is evident, consistent with solar Lyα measurements by SOLSTICE on SORCE as the next solar maximum is approached. We expect the irradiance at solar maximum to be at least 50-55 kR. This level still should not trigger local count rate violations for the FUV detector, but will accelerate gain sag of the microchannel plates in the regions where Lyα falls.

  14. Optical alignment of the Chromospheric Lyman-Alpha Spectro-Polarimeter using sophisticated methods to minimize activities under vacuum

    Science.gov (United States)

    Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.; Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.; Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.

    2016-07-01

    The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a sounding-rocket instrument developed at the National Astronomical Observatory of Japan (NAOJ) as a part of an international collaboration. The instrument main scientific goal is to achieve polarization measurement of the Lymanline at 121.56 nm emitted from the solar upper-chromosphere and transition region with an unprecedented 0.1% accuracy. The optics are composed of a Cassegrain telescope coated with a "cold mirror" coating optimized for UV reflection and a dual-channel spectrograph allowing for simultaneous observation of the two orthogonal states of polarization. Although the polarization sensitivity is the most important aspect of the instrument, the spatial and spectral resolutions of the instrument are also crucial to observe the chromospheric features and resolve the Ly-α profiles. A precise alignment of the optics is required to ensure the resolutions, but experiments under vacuum conditions are needed since Ly-α is absorbed by air, making the alignment experiments difficult. To bypass this issue, we developed methods to align the telescope and the spectrograph separately in visible light. We explain these methods and present the results for the optical alignment of the CLASP telescope and spectrograph. We then discuss the combined performances of both parts to derive the expected resolutions of the instrument, and compare them with the flight observations performed on September 3rd 2015.

  15. A line-profile analysis of the large-amplitude beta Cephei star xi1 Canis Majoris

    NARCIS (Netherlands)

    Saesen, S.; Briquet, M.; Aerts, C.C.

    2006-01-01

    We present a detailed line-profile study of the beta Cephei star xi1 Canis Majoris, for which we have assembled numerous high-resolution spectra over a period of 4.5 years. It is the first time that the line-profile variations of this star have been analysed. We focused on the Si III line profiles c

  16. Constraining the End of Reionization with Deep Lyman-alpha Spectroscopy

    Science.gov (United States)

    Jung, Intae; Finkelstein, Steven L.; Livermore, Rachael C.; Wold, Isak; Larson, Rebecca L.

    2017-06-01

    An immediately accessible method for studying the intergalactic medium in the reionization era is to measure the equivalent width distribution of Lyman-alpha emission from continuum-selected galaxies with follow-up spectroscopy. To search for Lyman-alpha emission from galaxies at z = 5.5-8.2, we are performing ultra-deep spectroscopic observations of candidate galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. We utilize data from the DEIMOS (optical) and MOSFIRE (near-infrared) spectrographs on the Keck 10-meter telescopes, ensuring the comprehensive wavelength coverage of Lyman-alpha emission at z ~ 6-8. We have a total of 1169 hours of spectroscopic integration of galaxies at z > 6: 738 hours for 123 galaxies with DEIMOS and 432 hours for 69 galaxies with MOSFIRE with the additional optical spectroscopic data of our sample galaxies in the GOODS-S field from VLT VANDELS survey. The Lyman-alpha fraction, the ratio of galaxies with detected Lyman-alpha emission to the number of all candidate galaxies observed, is directly measured with the completeness test of our data set by constructing detailed simulations of mock emission lines, which consider observational conditions (e.g., observational depth, wavelength coverage, and sky emission) and the probability distribution function of galaxy photometric redshifts. We present the early result on the Lyman-alpha emission equivalent width distribution of galaxies at z ~ 6 from our analysis of the DEIMOS spectroscopic dataset, determining robust upper limits on the Lyman-alpha emission.

  17. Interface Profiles near Three-Phase Contact Lines in Electric Fields

    NARCIS (Netherlands)

    Buehrle, Juergen; Herminghaus, Stephan; Mugele, Frieder

    2003-01-01

    Long-range electrostatic fields deform the surface profile of a conductive liquid in the vicinity of the contact line. We have investigated the equilibrium profiles by balancing electrostatic and capillary forces locally at the liquid vapor interface. Numerical results show that the contact angle at

  18. Isolating the Lyman Alpha Forest BAO Anomaly

    CERN Document Server

    Evslin, Jarah

    2016-01-01

    A 2.5-3 sigma discrepancy has been reported between the baryonic acoustic oscillation peak (BAO) in the Lyman alpha forest at z=2.34 and the best fit Planck LCDM cosmology. To isolate the origin of the tension, we consider unanchored BAO, in which the standard BAO ruler is not calibrated, eliminating any dependence on cosmology before redshift z=2.34. We consider BOSS BAO measurements at z=0.32, 0.57 and 2.34, using the full 2-dimensional constraints on the best and worst determined combinations of the angular and line of sight BAO scale, as well as isotropic BAO measurements by 6dF and SDSS at z=0.106 and z=0.15. We find that the z>0.43 data alone is in 2.8 sigma of tension with LCDM with or without the Planck best fit values of the mass fraction and the BAO scale, indicating that the tension arises not from the LCDM parameters but from the dark energy evolution itself at 0.57

  19. Searching for Line Profile Variability in HgMn Stars

    CERN Document Server

    Turcotte, S; Knoglinger, P

    2002-01-01

    Spectra of four non-magnetic chemically peculiar late B type stars (HgMn) stars are analysed to detect periodic spectral line variations (LPVs). A procedure developed to study LPVs in Slowly Pulsating B stars has been adopted as pulsational properties of HgMn stars should be expected to be similar. In the preliminary results discussed here no conclusive evidence for periodic LPVs was uncovered. A more sensitive re-analysis of the data is under way.

  20. Internet Teaching By Style: Profiling the On-line Professor

    Directory of Open Access Journals (Sweden)

    Sharon Strand

    2000-01-01

    Full Text Available The goal of this article is to offer the results of a pilot study which examined the personality type and teaching style preferences of faculty who elected to teach an on-line course. The article will present a description of personality assessments, including the Myers-Briggs Type Indicator (MBTI and Anthony Gregorc's Transaction Ability Inventory used to determine teaching tendencies and styles. In addition, a structured written questionnaire developed by the researchers was used to assess teacher satisfaction with worldwide web-based instruction. Utilizing the results of these psychological assessments, a preliminary analysis of the personal characteristics of college professors who chose to teach on line will be presented. This pilot study found that some preferred teaching styles may be more compatible with the dynamics of distance learning formats. By determining successful teaching styles for on-line courses, we can develop more effective faculty development programs to assist others in successfully transitioning into the cyber-teaching and learning environment.

  1. Measurement of Plasma Ion Temperature and Flow Velocity from Chord-Averaged Emission Line Profile

    Indian Academy of Sciences (India)

    Xu Wei

    2011-03-01

    The distinction between Doppler broadening and Doppler shift has been analysed, the differences between Gaussian fitting and the distribution of chord-integral line shape have also been discussed. Local ion temperature and flow velocity have been derived from the chord-averaged emission line profile by a chosen-point Gaussian fitting technique.

  2. Radial dependence of line profile variability in seven O9--B0.5 stars

    CERN Document Server

    Martins, F; Hillier, D J; Donati, J -F; Bouret, J -C

    2014-01-01

    Massive stars show a variety of spectral variability: presence of discrete absorption components in UV P-Cygni profiles, optical line profile variability, X-ray variability, radial velocity modulations. Our goal is to study the spectral variability of single OB stars to better understand the relation between photospheric and wind variability. For that, we rely on high spectral resolution, high signal-to-noise ratio optical spectra collected with the spectrograph NARVAL on the Telescope Bernard Lyot at Pic du Midi. We investigate the variability of twelve spectral lines by means of the Temporal Variance Spectrum (TVS). The selected lines probe the radial structure of the atmosphere, from the photosphere to the outer wind. We also perform a spectroscopic analysis with atmosphere models to derive the stellar and wind properties, and to constrain the formation region of the selected lines. We show that variability is observed in the wind lines of all bright giants and supergiants, on a daily timescale. Lines form...

  3. Epoch-dependent absorption line profile variability in lambda Cep

    CERN Document Server

    Uuh-Sonda, J M; Eenens, P; Mahy, L; Palate, M; Gosset, E; Flores, C A

    2014-01-01

    We present the analysis of a multi-epoch spectroscopic monitoring campaign of the O6Ief star lambda Cep. Previous observations reported the existence of two modes of non-radial pulsations in this star. Our data reveal a much more complex situation. The frequency content of the power spectrum considerably changes from one epoch to the other. We find no stable frequency that can unambiguously be attributed to pulsations. The epoch-dependence of the frequencies and variability patterns are similar to what is seen in the wind emission lines of this and other Oef stars, suggesting that both phenomena likely have the same, currently still unknown, origin.

  4. The effects of black hole rotation on line profiles from accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Yasufumi (Tokyo Metropolitan Univ. (Japan). Dept. of Physics)

    1991-06-01

    The fluorescent line emitted from an accretion disc around a rotating black hole is examined. The line profiles for various models with inclination angle, Kerr parameter and disc parameters are given. If the emitting region is highly localized to the inner part, r<20 GM/c{sup 2}, the difference due to the black hole rotation appears in the line profiles. Otherwise, the difference is hidden due to photons emitted from larger radii, where the propagation of the radiation and the disc structure are almost independent of the Kerr parameter. (author).

  5. First Detection of Cosmic Microwave Background Lensing and Lyman-{\\alpha} Forest Bispectrum

    CERN Document Server

    Doux, Cyrille; Aubourg, Eric; Ganga, Ken; Lee, Khee-Gan; Spergel, David N; Tréguer, Julien

    2016-01-01

    We present the first detection of a correlation between the Lyman-$\\alpha$ forest and cosmic microwave background (CMB) lensing. For each Lyman-$\\alpha$ forest in SDSS-III/BOSS DR12, we correlate the one-dimensional power spectrum with the CMB lensing convergence on the same line of sight from Planck. This measurement constitutes a position-dependent power spectrum, or a squeezed bispectrum, and quantifies the non-linear response of the Lyman-$\\alpha$ forest power spectrum to a large-scale overdensity. The signal is measured at 5~$\\sigma$ and is consistent with the $\\Lambda$CDM expectation. We measure the linear and non-linear biases of the Lyman-$\\alpha$ forest with respect to the dark matter distribution. This new observable provides a consistency check for the Lyman-$\\alpha$ forest as a large-scale structure probe and tests our understanding of the relation between intergalactic gas and dark matter. In the future, it could be used to test hydrodynamical simulations and calibrate the relation between the Ly...

  6. Direct Detection of Lyman Continuum Escape from Local Starburst Galaxies with the Cosmic Origins Spectrograph

    CERN Document Server

    Leitherer, Claus; Lee, Janice C; Oey, M S

    2016-01-01

    We report on the detection of Lyman continuum radiation in two nearby starburst galaxies. Tol 0440-381, Tol 1247-232 and Mrk 54 were observed with the Cosmic Origins Spectrograph onboard the Hubble Space Telescopes. The three galaxies have radial velocities of ~13,000 km/s, permitting a ~35 A window on the restframe Lyman continuum shortward of the Milky Way Lyman edge at 912 A. The chosen instrument configuration using the G140L grating covers the spectral range from 912 to 2,000 {\\AA}. We developed a dedicated background subtraction method to account for temporal and spatial background variations of the detector, which is crucial at the low flux levels around 912 A. This modified pipeline allowed us to significantly improve the statistical and systematic detector noise and will be made available to the community. We detect Lyman continuum in all three galaxies. However, we conservatively interpret the emission in Tol 0440-381 as an upper limit due to possible contamination by geocoronal Lyman series lines. ...

  7. Two-phase equilibrium and molecular hydrogen formation in damped Lyman-alpha systems

    CERN Document Server

    Liszt, H S

    2002-01-01

    Molecular hydrogen is quite underabundant in damped Lyman-alpha systems at high redshift, when compared to the interstellar medium near the Sun. This has been interpreted as implying that the gas in damped Lyman-alpha systems is warm. like the nearby neutral intercloud medium, rather than cool, as in the clouds which give rise to most H I absorption in the Milky Way. Other lines of evidence suggest that the gas in damped Lyman-alpha systems -- in whole or part -- is actually cool; spectroscopy of neutral and ionized carbon, discussed here, shows that the damped Lyman-alpha systems observed at lower redshift z $$ 2.8 are warm (though not devoid of H2). To interpret the observations of carbon and hydrogen we constructed detailed numerical models of H2 formation under the conditions of two-phase thermal equilibrium, like those which account for conditions near the Sun, but with varying metallicity, dust-gas ratio, $etc$. We find that the low metallicity of damped Lyman-alpha systems is enough to suppress H2 form...

  8. Absorption line profile recovery based on TDLS and MEMS micro-mirror for photoacoustic gas sensing.

    Science.gov (United States)

    Li, Li; Arsad, Norhana; Stewart, George; Thursby, Graham; Uttamchandani, Deepak; Culshaw, Brian; Yi-ding, Wang

    2011-07-01

    A novel and efficient absorption line recovery technique is presented. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection. Tunable diode laser spectroscopy (TDLS) and photoacoustic spectroscopy (PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile. The target gas is 0.01% acetylene (C2H2) in a nitrogen host gas. The laser diode wavelength is swept across the P17 absorption line of acetylene at 1535.4 nm by a current ramp, and an erbium-doped fibre amplifier (EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio (SNR). A SNR of about 35 is obtained with 100 mW laser power from the EDFA. Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.

  9. Absorption Line Profile Recovery Based on TDLS and MEMS Micro-Mirror for Photoacoustic Gas Sensing

    Institute of Scientific and Technical Information of China (English)

    LI Li; Norhana Arsad; George Stewart; Graham Thursby; Deepak Uttamchandani; Brian Culshaw; WANG Yi-ding

    2011-01-01

    A novel and efficient absorption line recovery technique is presented. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection. Tunable diode laser spectroscopy (TDLS) and photoacoustic spectroscopy (PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile. The target gas is 0.01% acetylene (C2 H2 ) in a nitrogen host gas. The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp, and an erbium-doped fibre amplifier (EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio (SNR). A SNR of about 35 is obtained with 100 mW laser power from the EDFA Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.

  10. Variability of Hell and hydrogen line profiles in the spectrum of HD 93521

    Science.gov (United States)

    Rzaev, A. Kh.; Panchuk, V. E.

    2008-03-01

    We have studied the variability of the Hell λλ 4686 and 5411 Å H β, and H α lines in the spectrum of the pulsating star HD 93521. All these line profiles display the same variability pattern relative to the average profiles: a sinusoidal wave that moves systematically from the short-to the long-wavelength wing of the profile. This variability is due to non-radial pulsations. To study the pulsation movements and stratification of the radial velocity in the atmosphere of HD 93521, we analyzed the variability of the radial velocities measured individually for the blue and red halves of the absorption profile at the half-level of the line intensity. The periods and amplitudes of this radial-velocity variability are different for different lines and are well correlated with their central depths. In the transition from weak to strong lines (i.e., from lower to upper layers of the atmosphere), the period of the radial-velocity variations measured using both halves of the absorption profile increases, while its amplitude decreases. When the morphology and variability of photospheric and wind-driven lines are compared, it is clear that the variability of their absorption components is due to the same process—non-radial pulsations. In this way, the non-radial pulsations partly affect the variability of the stellar wind. The effect of the stellar wind on the profiles of strong lines is observed as a variable absorption feature that moves along the profiles synchronous with the axial rotation of the star.

  11. Lyman alpha emission in starbursts: implications for galaxies at high redshift

    CERN Document Server

    Mas-Hesse, J M; Tenorio-Tagle, G; Leitherer, C; Terlevich, R J; Terlevich, E

    2003-01-01

    We present the results of a high resolution UV 2-D spectroscopic survey of star forming galaxies observed with HST-STIS. Our main aim was to map the Lyman alpha profiles to learn about the gas kinematics and its relation with the escape of Lyman alpha photons and to detect extended Lyman alpha emission due to scattering in gaseous halos. We have combined our data with previously obtained UV spectroscopy on other three star-forming galaxies. We find that the P-Cygni profile is spatially extended, smooth and spans several kiloparsecs covering a region much larger than the starburst itself. We propose a scenario whereby an expanding super-shell is generated by the interaction of the combined stellar winds and supernova ejecta from the young starbursts, with an extended low density halo. The variety of observed Lyman alpha profiles both in our sample and in high redshift starbursts is explained as phases in the time evolution of the super-shell expanding into the disk and halo of the host galaxy. The observed sha...

  12. Consistency of spherical, gravity-dominated dynamics with quasar high-ionization emission-line profiles

    Science.gov (United States)

    Kallman, T. R.; Wilkes, B. J.; Krolik, J. H.; Green, Richard

    1993-01-01

    Line profile data are used to test a simple kinematic model - spherically symmetric gravitational free fall - in which the number of free parameters is limited by requiring physical self-consistency. The predictions of this model are fitted to high-resolution spectra of the stronger rest-frame UV emission lines in 12 quasars with z of about 2. It is found that if all the lines are radiated predominantly from the illuminated faces of the emission-line clouds, the profiles of Ly-alpha, N V 1240 A, and C IV 1549 A can be simultaneously well fitted with very similar parameters for all 12 quasars. It is concluded that spherically symmetric gravitational free fall does not correctly describe the dynamics of quasar broad emission-line regions.

  13. On the Diffuse Lyman-alpha Halo Around Lyman-alpha Emitting Galaxies

    CERN Document Server

    Lake, Ethan; Cen, Renyue; Sadoun, Raphael; Momose, Rieko; Ouchi, Masami

    2015-01-01

    Ly$\\alpha$ photons scattered by neutral hydrogen atoms in the circumgalactic media or produced in the halos of star-forming galaxies are expected to lead to extended Ly$\\alpha$ emission around galaxies. Such low surface brightness Ly$\\alpha$ halos (LAHs) have been detected by stacking Ly$\\alpha$ images of high-redshift star-forming galaxies. We study the origin of LAHs by performing radiative transfer modeling of nine $z=3.1$ Lyman-Alpha Emitters (LAEs) in a high resolution hydrodynamic galaxy formation simulation. We develop a method of computing the mean Ly$\\alpha$ surface brightness profile of each LAE by effectively integrating over many different observing directions. Without adjusting any parameters, our model yields an average Ly$\\alpha$ surface brightness profile in remarkable agreement with observations. We find that observed LAHs can not be accounted for solely by photons originating from the central LAE and scattered to large radii by hydrogen atoms in the circumgalactic gas. Instead, Ly$\\alpha$ em...

  14. Measurement the Thermal Profile of Steelmaking Ladle with Subsequent Evaluation the Reasons of Lining Damage

    Directory of Open Access Journals (Sweden)

    Vlček J.

    2016-03-01

    Full Text Available Based on the operational measurement, of which content was to determine ladle thermal profile, there were analysed causes of possible damage of lining in steel ladles by steel breakout through the ladle shell. There exists connection between thermal state of ladle lining during the operation and its lifetime. There were reached to the conclusion that the cause of failure in the lining of ladle is except for high temperature of bath, also wide interval of temperature change during the tap operation, in consequence with possible insufficient pre-heating of ladle, discontinuous operation of aggregate and damage of insulating lining layer, respectively deformation of ladles shell.

  15. The Lyman-alpha forest in f(R) modified gravity

    CERN Document Server

    Arnold, Christian; Springel, Volker

    2014-01-01

    In this work, we analyze the Lyman-$\\alpha$ forest in cosmological hydrodynamical simulations of chameleon-type f(R) gravity with the goal to assess whether the impact of such models is detectable in absorption line statistics. We carry out a set of hydrodynamical simulations with the cosmological simulation code MG-GADGET, including star formation and cooling effects, and create synthetic Lyman-$\\alpha$ absorption spectra from the simulation outputs. We statistically compare simulations with f(R) and ordinary general relativity, focusing on flux probability distribution functions (PDFs) and flux power-spectra, an analysis of the column density and line width distributions, as well as the matter power spectrum. We find that the influence of f(R) gravity on the Lyman-$\\alpha$ forest is rather small. Even models with strong modifications of gravity, like $|\\bar{f}_{R0}| = 10^{-4}$, do not change the statistical Lyman-$\\alpha$ properties by more than 10%. The column density and line width distributions are hardl...

  16. On-line (HPLC-NMR) and off-line phytochemical profiling of the Australian plant, Lasiopetalum macrophyllum.

    Science.gov (United States)

    Timmers, Michael; Urban, Sylvia

    2012-05-01

    On-line (HPLC-NMR) and off-line (HPLC, NMR and MS) methodologies were used to profile the constituents present in the crude extract of Lasiopetalum macrophyllum. On-flow and stop-flow HPLC-NMR supported the presence of trans-tiliroside and permitted partial identification of cis-tiliroside and 4'-methoxy-trans-tiliroside. Off-line isolation led to the unequivocal identification of four flavanoid glycosides including a new structural derivative, 4'-methoxycis-tiliroside. This is the first report of flavonoid glycosides occurring in this plant genus. In addition, a number of structure revisions have been proposed for previously reported flavonoid glycosides that were incorrectly assigned.

  17. Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experiment Spherical Torus

    Science.gov (United States)

    Kim, YooSung; Shi, Yue-Jiang; Yang, Jeong-hun; Kim, SeongCheol; Kim, Young-Gi; Dang, Jeong-Jeung; Yang, Seongmoo; Jo, Jungmin; Oh, Soo-Ghee; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-11-01

    Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of Hα and Hβ radiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.

  18. Relativistic effects in Lyman-alpha forest

    CERN Document Server

    Iršič, Vid; Viel, Matteo

    2015-01-01

    We present the calculation of the Lyman-alpha (Lyman-$\\alpha$) transmitted flux fluctuations with full relativistic corrections to the first order. Even though several studies exist on relativistic effects in galaxy clustering, this is the first study to extend the formalism to a different tracer of underlying matter at unique redshift range ($z = 2 - 5$). Furthermore, we show a comprehensive application of our calculations to the Quasar- Lyman-$\\alpha$ cross-correlation function. Our results indicate that the signal of relativistic effects can be as large as 30% at Baryonic Acoustic Oscillation (BAO) scale, which is much larger than anticipated and mainly due to the large differences in density bias factors of our tracers. We construct an observable, the anti-symmetric part of the cross- correlation function, that is dominated by the relativistic signal and offers a new way to measure the relativistic terms at relatively small scales. The analysis shows that relativistic effects are important when considerin...

  19. Unique Astrophysics in the Lyman Ultraviolet

    CERN Document Server

    Tumlinson, Jason; Kriss, Gerard; France, Kevin; McCandliss, Stephan; Sembach, Ken; Fox, Andrew; Tripp, Todd; Jenkins, Edward; Beasley, Matthew; Danforth, Charles; Shull, Michael; Stocke, John; Lehner, Nicolas; Howk, Christopher; Froning, Cynthia; Green, James; Oliveira, Cristina; Fullerton, Alex; Blair, Bill; Kruk, Jeff; Sonneborn, George; Penton, Steven; Wakker, Bart; Prochaska, Xavier; Vallerga, John; Scowen, Paul

    2012-01-01

    There is unique and groundbreaking science to be done with a new generation of UV spectrographs that cover wavelengths in the "Lyman Ultraviolet" (LUV; 912 - 1216 Ang). There is no astrophysical basis for truncating spectroscopic wavelength coverage anywhere between the atmospheric cutoff (3100 Ang) and the Lyman limit (912 Ang); the usual reasons this happens are all technical. The unique science available in the LUV includes critical problems in astrophysics ranging from the habitability of exoplanets to the reionization of the IGM. Crucially, the local Universe (z <= 0.1) is entirely closed to many key physical diagnostics without access to the LUV. These compelling scientific problems require overcoming these technical barriers so that future UV spectrographs can extend coverage to the Lyman limit at 912 Ang.

  20. Modelling Chromospheric Line Profiles in NGC2808: Evidence of Mass Loss from RGB Stars

    CERN Document Server

    Mauas, P J D; Pasquini, L

    2006-01-01

    In this study we test the possibility that the asymmetry in the profiles of the H-alpha and Ca II K lines in red giant stars is due to the presence of an active chromosphere rather than to mass loss. To this end, we compare line profiles computed using relevant model chromospheres to profiles of the H-alpha and Ca II K lines observed in five red giant stars of the globular cluster NGC 2808. The spectra were taken with FLAMES during Science Verification, using the UVES mode at high resolution (R=43,000) for the H-alpha line, and GIRAFFE in MEDUSA mode (R=20,000) for the Ca II K line. We find that the observed profiles are better described if a negative (outward) velocity field is included in the model chromospheres. This leads to mass loss rates of a few 10**(-9) solar masses per year, very close to the requirements of the stellar evolution theory.

  1. The Lyman Alpha Reference Sample: V. The impact of neutral ISM kinematics and geometry on Lyman Alpha escape

    CERN Document Server

    Rivera-Thorsen, Thøger E; Östlin, Göran; Duval, Florent; Orlitová, Ivana; Verhamme, Anne; Mas-Hesse, J Miguel; Schaerer, Daniel; Cannon, John M; Otí-Floranes, Héctor; Sandberg, Andreas; Guaita, Lucia; Adamo, Angela; Atek, Hakim; Herentz, E Christian; Kunth, Daniel; Laursen, Peter; Melinder, Jens

    2015-01-01

    We present high-resolution far-UV spectroscopy of the 14 galaxies of the Lyman Alpha Reference Sample; a sample of strongly star-forming galaxies at low redshifts ($0.028 < z < 0.18$). We compare the derived properties to global properties derived from multi band imaging and 21 cm HI interferometry and single dish observations, as well as archival optical SDSS spectra. Besides the Lyman $\\alpha$ line, the spectra contain a number of metal absorption features allowing us to probe the kinematics of the neutral ISM and evaluate the optical depth and and covering fraction of the neutral medium as a function of line-of-sight velocity. Furthermore, we show how this, in combination with precise determination of systemic velocity and good Ly$\\alpha$ spectra, can be used to distinguish a model in which separate clumps together fully cover the background source, from the "picket fence" model named by Heckman et al. (2011). We find that no one single effect dominates in governing Ly$\\alpha$ radiative transfer and ...

  2. Procedure for analyzing the x-ray line profiles of disordered carbons

    Energy Technology Data Exchange (ETDEWEB)

    Henry, L.G.; Bragg, R.H.; Bose, S.

    1981-12-01

    A systematic procedure to correct for various distortions in the broad x-ray line profiles of glass-like carbons (GC) is described. The profile is first corrected for distortions due to low specimen absorption, secondly for incoherent (Compton) scattering, and then strong small angle scattering. The resulting profile is then multiplied by the appropriate trigonometric (Lorentz and polarization) factors. Finally, correction is made for the variation of the atomic scattering factor across the broad peaks. Two examples of the GC heat treatment at 1000/sup 0/C and 2700/sup 0/C have been used to illustrate the outcome of the corrections. 8 figures.

  3. Neon and [CII] 158 micron Emission Line Profiles in Dusty Starbursts and Active Galactic Nuclei

    CERN Document Server

    Samsonyan, Anahit; Lebouteiller, Vianney; Barry, Donald; Sargsyan, Lusine

    2016-01-01

    The sample of 379 extragalactic sources is presented that have mid-infrared, high resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS) and also spectroscopy of the [CII] 158 um line with the Herschel Photodetector Array Camera and Spectrometer (PACS). The emission line profiles of [NeII] 12.81 um, [NeIII] 15.55 um, and [CII] 158 um are presented, and intrinsic line widths are determined (full width half maximum of Gaussian profiles after instrumental correction). All line profiles together with overlays comparing positions of PACS and IRS observations are made available in the Cornell Atlas of Spitzer IRS Sources (CASSIS). Sources are classified from AGN to starburst based on equivalent widths of the 6.2 um polycyclic aromatic hydrocarbon feature. It is found that intrinsic line widths do not change among classification for [CII], with median widths of 207 km per s for AGN, 248 km per s for composites, and 233 km per s for starbursts. The [NeII] line widths also do not change with classificati...

  4. HST/COS Spectra of DF Tau and V4046 SGR: First Detection of Molecular Hydrogen Absorption Against the Ly$\\alpha$ Emission Line

    CERN Document Server

    Yang, Hao; France, Kevin

    2011-01-01

    We report the first detection of molecular hydrogen (H$_{2}$) absorption in the Lyman-$\\alpha$ emission line profiles of two classical T Tauri stars (CTTSs), DF Tau and V4046 Sgr, observed by \\emph{HST}/COS. This absorption is the energy source for many of the Lyman-band H$_{2}$ fluorescent lines commonly seen in the far-ultraviolet spectra of CTTSs. We find that the absorbed energy in the H$_{2}$ pumping transitions from a portion of the Lyman-$\\alpha$ line significantly differ from the amount of energy in the resulting fluorescent emission. By assuming additional absorption in the H I Lyman-$\\alpha$ profile along our light of sight, we can correct the H$_{2}$ absorption/emission ratios so that they are close to unity. The required H I absorption for DF Tau is at a velocity close to the radial velocity of the star, consistent with H I absorption in the edge-on disk and interstellar medium. For V4046 Sgr, a nearly face-on system, the required absorption is between +100 km/s and +290 km/s, most likely resultin...

  5. A Lyman-alpha tunable acousto-optic filter for detecting superthermal flare protons

    Science.gov (United States)

    Mickey, Donald L.

    1994-01-01

    The goal of this project was to develop and characterize a narrow-band, tunable filter for use near the Lyman-alpha line of hydrogen at 121.6 nm. Such a filter could form the critical component of an instrument to observe asymmetries in the solar Lyman-alpha line, caused by energetic protons accelerated during the impulsive phase of solar flares. Characteristic charge-exchange nonthermal emission at Lyman alpha should be produced when sub-MeV protons are injected into the chromosphere, but no instrument suitable for their detection has been developed. Such an instrument would require a narrow-band (less than 0.01 nm) tunable filter with aperture and throughput consistent with imaging a solar active region at 0.1 second intervals. The development of acousto-optic tunable filters (AOTF) suitable for use as compact, simple tunable filters for astronomical work suggested an investigation into the use of an AOTF at Lyman-alpha.

  6. Aeronomy, a 20th Century emergent science: the role of solar Lyman series

    Directory of Open Access Journals (Sweden)

    G. Kockarts

    Full Text Available Aeronomy is, by definition, a multidisciplinary science which can be used to study the terrestrial atmosphere, as well as any planetary atmosphere and even the interplanetary space. It was officially recognized in 1954 by the International Union of Geodesy and Geophysics. The major objective of the present paper is to show how aeronomy developed since its infancy. The subject is so large that a guide-line has been chosen to see how aeronomy affects our atmospheric knowledge. This guideline is the solar Lyman alpha radiation which has different effects in the solar system. After a short description of the origins of aeronomy the first observations of this line are summarized since the beginning of the space age. Then the consequences of these observations are analyzed for the physics and chemistry of the neutral terrestrial atmosphere. New chemical processes had to be introduced, as well as new transport phenomena. Solar Lyman alpha also influences the structure of the Earth’s ionosphere, particularly the D-region. In the terrestrial exosphere, solar Lyman alpha scattered resonantly by atomic hydrogen is at present the only way to estimate this constituent in an almost collisionless medium. Since planetary atmospheres also contain atomic hydrogen, the Lyman alpha line has been used to deduce the abundance of this constituent. The same is true for the interplanetary space where Lyman alpha observations can be a good tool to determine the concentration. The last section of the paper presents a question which is intended to stimulate further research in aeronomy.

    Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; thermosphere – composition and chemistry – history of geophysics (atmospheric sciences

  7. Pulsational mode-typing in line profile variables. I - Four Beta Cephei stars

    Science.gov (United States)

    Campos, A. J.; Smith, M. A.

    1980-01-01

    The detailed variations of line profiles in the Beta Cephei-type variable stars Gamma Pegasi, Beta Cephei, Delta Ceti and Sigma Scorpii are modeled throughout their pulsation cycles in order to classify the dominant pulsation mode as radial or nonradial. High-dispersion Reticon observations of the variables were obtained for the Si III line at 4567 A, and line profiles broadened by radial or nonradial pulsations, rotation and radial-tangential macroturbulence were calculated based on a model atmosphere. It is found that only a radial pulsation mode can reproduce the radial velocity amplitude, changes in line asymmetry and uniform line width observed in all four stars. Results are in agreement with the color-to-light arguments of Stamford and Watson (1978), and suggest that radial pulsation plays the dominant role in the observed variations in most Beta Cephei stars. Evidence for shocks or moving shells is also found in visual line data for Sigma Scorpii and an ultraviolet line of Beta Cephei, together with evidence of smooth, secular period changes in Beta Cephei and Delta Ceti.

  8. Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report)

    CERN Document Server

    Tennyson, Jonathan; Campargue, Alain; Csaszar, Attila G; Daumont, Ludovic; Gamache, Robert R; Hodges, Joseph T; Lisak, Daniel; Naumenko, Olga V; Rothman, Laurence S; Tran, Ha; Zobov, Nikolai F; Buldyreva, Jeanna; Boone, Chris D; De Vizia, Maria Domenica; Gianfrani, Livio; Hartmann, Jean-Michel; McPheat, Robert; Murray, Jonathan; Ngo, Ngoc Hoa; Polyansky, Oleg L; Weidmann, Damien

    2014-01-01

    The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should b...

  9. line profile variability in the B8Ia-type supergiant Rigel (β Ori)

    Science.gov (United States)

    Morrison, N. D.; Rother, R.; Kurschat, N.

    2008-04-01

    Hα observations of Rigel obtained on 184 nights during the past ten years with the 1-m telescope and ´echelle spectrograph of Ritter Observatory are surveyed. The line profiles were classified in terms of morphology. About 1/4 of them are of P Cygni type, about 15% inverse P Cygni, about 25% double-peaked, about 1/3 pure absorption, and a few are single emission lines. Transformation of the profile from one type to another typically takes a few days. Although the line stays in absorption for extended intervals, only one high-velocity absorption event of the intensity reported by Kaufer et al. (1996a) was observed, in late 2006. Late in this event, Hα absorption occurred farther to the red than the red wing of a plausible photospheric absorption component, an indication of infalling material. In general, as the absorption events come to an end, the emission typically returns with an inverse P Cygni profile. The Hα profile class shows no obvious correlation with the radial velocity of C II λ6578, a photospheric absorption line.

  10. Distorted cyclotron line profile in Cep X-4 as observed by NuSTAR

    DEFF Research Database (Denmark)

    Fürst, F.; Pottschmidt, K.; Miyasaka, H.;

    2015-01-01

    a powerlaw with a Fermi-Dirac cutoff at high energies. Cep X-4 has a very strong cyclotron resonant scattering feature (CRSF) around 30 keV. A simple absorption-like line with a Gaussian optical depth or a pseudo-Lorentzian profile both fail to describe the shape of the CRSF accurately, leaving significant...

  11. X-ray Emission Line Profiles from Wind Clump Bow Shocks in Massive Stars

    CERN Document Server

    Ignace, R; Cassinelli, J P

    2012-01-01

    The consequences of structured flows continue to be a pressing topic in relating spectral data to physical processes occurring in massive star winds. In a preceding paper, our group reported on hydrodynamic simulations of hypersonic flow past a rigid spherical clump to explore the structure of bow shocks that can form around wind clumps. Here we report on profiles of emission lines that arise from such bow shock morphologies. To compute emission line profiles, we adopt a two component flow structure of wind and clumps using two "beta" velocity laws. While individual bow shocks tend to generate double horned emission line profiles, a group of bow shocks can lead to line profiles with a range of shapes with blueshifted peak emission that depends on the degree of X-ray photoabsorption by the interclump wind medium, the number of clump structures in the flow, and the radial distribution of the clumps. Using the two beta law prescription, the theoretical emission measure and temperature distribution throughout the...

  12. Hydrodynamical Simulations of the Lyman $\\alpha$ Forest Model Comparisons

    CERN Document Server

    Machacek, M E; Meiksin, A; Anninos, P; Thayer, D; Norman, M L; Zhang, Y

    1999-01-01

    We investigate the properties of the Lyman alpha forest as predicted by numerical simulations for a range of currently viable cosmological models. This is done in order to understand the dependencies of the forest on cosmological parameters. Focusing on the redshift range from two to four, we show that: (1) most of the evolution in the distributions of optical depth, flux and column density can be understood by simple scaling relations, (2) the shape of optical depth distribution is a sensitive probe of the amplitude of density fluctuations on scales of a few hundred kpc, (3) the mean of the b distribution (a measure of the width of the absorption lines) is also very sensitive to fluctuations on these scales, and decreases as they increase. We perform a preliminary comparison to observations, where available. A number of other properties are also examined, including the evolution in the number of lines, the two-point flux distribution and the HeII opacity.

  13. Line printing solution-processable small molecules with uniform surface profile via ink-jet printer.

    Science.gov (United States)

    Liu, Huimin; Xu, Wei; Tan, Wanyi; Zhu, Xuhui; Wang, Jian; Peng, Junbiao; Cao, Yong

    2016-03-01

    Line printing offers a feasible approach to remove the pixel well structure which is widely used to confine the ink-jet printed solution. In the study, a uniform line is printed by an ink-jet printer. To achieve a uniform surface profile of the printed line, 10vol% low-volatile solvent DMA (3,4-Dimethylanisole) is mixed with high-volatile solvent Pxy (p-xylene) as the solvent. After a solution-processable small molecule is dissolved, the surface tension of DMA solution becomes lower than that of Pxy solution, which creates an inward Marangoni flow during the solvent evaporation. The inward Marangoni flow balances out the outward capillary flow, thereby forming a flat film surface. The line width of the printed line depends on the contact angle of the solution on the hole injection layer.

  14. Analysis of expression profiles of MAGE-A antigens in oral squamous cell carcinoma cell lines

    Directory of Open Access Journals (Sweden)

    Reichert Torsten E

    2009-04-01

    Full Text Available Abstract Background The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential expression profiles also modulate the course of the cancer disease and its response to antineoplastic drugs. Methods The expression profiles of MAGE-A2, -A3, -A4, -A6 and -A10 in five own oral squamous cell carcinoma cell lines were characterised by rt-PCR, qrt-PCR and immunocytochemistry with a global MAGE-A antibody (57B and compared with those of an adult keratinocyte cell line (NHEK. Results All tumour cell lines expressed MAGE-A antigens. The antigens were expressed in groups with different preferences. The predominant antigens expressed were MAGE-A2, -A3 and -A6. MAGE-A10 was not expressed in the cell lines tested. The MAGE-A gene products detected in the adult keratinocyte cell line NHEK were used as a reference. Conclusion MAGE-A antigens are expressed in oral squamous cell carcinomas. The expression profiles measured facilitate distinct examinations in forthcoming studies on responses to antineoplastic drugs or radiation therapy. MAGE-A antigens are still an interesting aim for immunotherapy.

  15. P-Cygni Profiles of Molecular Lines toward Arp 220 Nuclei

    CERN Document Server

    Sakamoto, Kazushi; Wilner, David J; Black, John H; Conway, John E; Costagliola, Francesco; Peck, Alison B; Spaans, Marco; Wang, Junzhi; Wiedner, Martina C

    2009-01-01

    We report ~100 pc (0.3") resolution observations of (sub)millimeter HCO+ and CO lines in the ultraluminous infrared galaxy Arp 220. The lines peak at two merger nuclei, with HCO+ being more spatially concentrated than CO. Asymmetric line profiles with blueshifted absorption and redshifted emission are discovered in HCO+(3-2) and (4-3) toward the two nuclei and in CO(3-2) toward one nucleus. We suggest that these P-Cygni profiles are due to ~100 km/s outward motion of molecular gas from the nuclei. This gas is most likely outflowing from the inner regions of the two nuclear disks rotating around individual nuclei, clearing the shroud around the luminosity sources there.

  16. Spectral Line-Shape Model to Replace the Voigt Profile in Spectroscopic Databases

    Science.gov (United States)

    Lisak, Daniel; Ngo, Ngoc Hoa; Tran, Ha; Hartmann, Jean-Michel

    2014-06-01

    The standard description of molecular line shapes in spectral databases and radiative transfer codes is based on the Voigt profile. It is well known that its simplified assumptions of absorber free motion and independence of collisional parameters from absorber velocity lead to systematic errors in analysis of experimental spectra, and retrieval of gas concentration. We demonstrate1,2 that the partially correlated quadratic speed-dependent hardcollision profile3. (pCqSDHCP) is a good candidate to replace the Voigt profile in the next generations of spectroscopic databases. This profile takes into account the following physical effects: the Doppler broadening, the pressure broadening and shifting of the line, the velocity-changing collisions, the speed-dependence of pressure broadening and shifting, and correlations between velocity- and phase/state-changing collisions. The speed-dependence of pressure broadening and shifting is incorporated into the pCqSDNGP in the so-called quadratic approximation. The velocity-changing collisions lead to the Dicke narrowing effect; however in many cases correlations between velocityand phase/state-changing collisions may lead to effective reduction of observed Dicke narrowing. The hard-collision model of velocity-changing collisions is also known as the Nelkin-Ghatak model or Rautian model. Applicability of the pCqSDHCP for different molecular systems was tested on calculated and experimental spectra of such molecules as H2, O2, CO2, H2O in a wide span of pressures. For all considered systems, pCqSDHCP is able to describe molecular spectra at least an order of magnitude better than the Voigt profile with all fitted parameters being linear with pressure. In the most cases pCqSDHCP can reproduce the reference spectra down to 0.2% or better, which fulfills the requirements of the most demanding remote-sensing applications. An important advantage of pCqSDHCP is that a fast algorithm for its computation was developedab4,5 and allows

  17. Quasistellar Objects Intervening Absorption Lines

    CERN Document Server

    Charlton, J C; Charlton, Jane C.; Churchill, Christopher W.

    2000-01-01

    We briefly review, at a level appropriate for graduate students and non-specialists, the field of quasar absorption lines (QALs). Emphasis is on the intervening absorbers. We present the anatomy of a quasar spectrum due to various classes of intervening absorption systems, and a brief historical review of each absorber class (Lyman-alpha forest and Lyman limit systems, and metal-line and damped Lyman-alpha absorbers). We also provide several heuristic examples on how the physical properties of both the intergalactic medium and the gaseous environments associated with earlier epoch galaxies can be inferred from QALs. The evolution of these environments from z=4 are discussed.

  18. First stars in Damped Lyman Alpha systems

    NARCIS (Netherlands)

    Salvadori, Stefania; Ferrara, Andrea

    2011-01-01

    In order to characterize Damped Lyman Alpha systems (DLAs) potentially host- ing first stars, we present a novel approach to investigate DLAs in the context of Milky Way (MW) formation, along with their connection with the most metal-poor stars and local dwarf galaxies. The merger tree method previo

  19. First stars in Damped Lyman Alpha systems

    NARCIS (Netherlands)

    Salvadori, Stefania; Ferrara, Andrea

    In order to characterize Damped Lyman Alpha systems (DLAs) potentially host- ing first stars, we present a novel approach to investigate DLAs in the context of Milky Way (MW) formation, along with their connection with the most metal-poor stars and local dwarf galaxies. The merger tree method

  20. Live image profiling of neural crest lineages in zebrafish transgenic lines.

    Science.gov (United States)

    Kwak, Jina; Park, Ok Kyu; Jung, Yoo Jung; Hwang, Byung Joon; Kwon, Seung-Hae; Kee, Yun

    2013-03-01

    Zebrafish transgenic lines are important experimental tools for lineage tracing and imaging studies. It is crucial to precisely characterize the cell lineages labeled in transgenic lines to understand their limitations and thus properly interpret the data obtained from their use; only then can we confidently select a line appropriate for our particular research objectives. Here we profiled the cell lineages labeled in the closely related neural crest transgenic lines Tg(foxd3:GFP), Tg(sox10:eGFP) and Tg(sox10:mRFP). These fish were crossed to generate embryos, in which foxd3 and sox10 transgenic neural crest labeling could be directly compared at the cellular level using live confocal imaging. We have identified key differences in the cell lineages labeled in each line during early neural crest development and demonstrated that the most anterior cranial neural crest cells initially migrating out of neural tube at the level of forebrain and anterior midbrain express sox10:eGFP and sox10:mRFP, but not foxd3:GFP. This differential profile was robustly maintained in the differentiating progeny of the neural crest lineages until 3.5dpf. Our data will enable researchers to make an informed choice in selecting transgenic lines for future neural crest research.

  1. Metabolic profiling of breast cancer: Differences in central metabolism between subtypes of breast cancer cell lines.

    Science.gov (United States)

    Willmann, Lucas; Schlimpert, Manuel; Halbach, Sebastian; Erbes, Thalia; Stickeler, Elmar; Kammerer, Bernd

    2015-09-01

    Although the concept of aerobic glycolysis in cancer was already reported in the 1930s by Otto Warburg, the understanding of metabolic pathways remains challenging especially due to the heterogeneity of cancer. In consideration of four different time points (1, 2, 4, and 7 days of incubation), GC-MS profiling of metabolites was performed on cell extracts and supernatants of breast cancer cell lines (MDA-MB-231, -453, BT-474) with different sub classification and the breast epithelial cell line MCF-10A. To the exclusion of trypsinization, direct methanolic extraction, cell scraping and cell disruption was executed to obtain central metabolites. Major differences in biochemical pathways have been observed in the breast cancer cell lines compared to the breast epithelial cell line, as well as between the breast cancer cell lines themselves. Characteristics of breast cancer subtypes could be correlated to their individual metabolic profiles. PLS-DA revealed the discrimination of breast cancer cell lines from MCF-10A based on elevated amino acid levels. The observed metabolic signatures have great potential as biomarker for breast cancer as well as an improved understanding of subtype specific phenomenons of breast cancer.

  2. A UV Ultra-luminous Lyman Break Galaxy at Z=2.78 in NDWFS Bootes Field

    CERN Document Server

    Bian, Fuyan; Jiang, Linhua; Dey, Arjun; Green, Richard F; Maiolino, Roberto; Walter, Fabian; McGreer, Ian; Wang, Ran; Lin, Yen-Ting

    2012-01-01

    We present one of the most ultraviolet (UV) luminous Lyman Break Galaxies (LBGs) (J1432+3358) at z=2.78, discovered in the NOAO Deep Wide-Field Survey (NDWFS) Bootes field. The R-band magnitude of J1432+3358 is 22.29 AB, more than two magnitudes brighter than typical L* LBGs at this redshift. The deep z-band image reveals two components of J1432+3358 separated by 1.0" with flux ratio of 3:1. The high signal-to-noise ratio (S/N) rest-frame UV spectrum shows Lya emission line and interstellar medium absorption lines. The absence of NV and CIV emission lines, the non-detection in X-ray and radio wavelengths and mid-infrared (MIR) colors indicate no or weak active galactic nuclei (AGN) (<10%) in this galaxy. The galaxy shows broader line profile with the full width half maximum (FWHM) of about 1000 km/s and larger outflow velocity (~500 km/s) than those of typical z~3 LBGs. The physical properties are derived by fitting the spectral energy distribution (SED) with stellar synthesis models. The dust extinction, ...

  3. The Impact of Different Physical Processes on the Statistics of Lyman-limit and Damped Lyman-alpha Absorbers

    CERN Document Server

    Altay, Gabriel; Schaye, Joop; Booth, C M; Vecchia, Claudio Dalla

    2013-01-01

    We compute the z = 3 neutral hydrogen column density distribution function f(NHI) for 19 simulations drawn from the OWLS project using a post-processing correction for self-shielding calculated with full radiative transfer of the ionising background radiation. We investigate how different physical processes and parameters affect the abundance of Lyman-limit systems (LLSs) and damped Lyman-alpha absorbers (DLAs) including: i) metal-line cooling; ii) the efficiency of feedback from SNe and AGN; iii) the effective equation of state for the ISM; iv) cosmological parameters; v) the assumed star formation law and; vi) the timing of hydrogen reionization . We find that the normalisation and slope, D = d log10 f /d log10 NHI, of f(NHI) in the LLS regime are robust to changes in these physical processes. Among physically plausible models, f(NHI) varies by less than 0.2 dex and D varies by less than 0.18 for LLSs. This is primarily due to the fact that these uncertain physical processes mostly affect star-forming gas w...

  4. Three Lyman-alpha Emitters at z approx 6: Early GMOS/Gemini Data from the GLARE Project

    CERN Document Server

    Stanway, E R; Bunker, A J; Abraham, R G; Hook, I; Rhoads, J; McCarthy, P J; Boyle, B; Colless, M; Crampton, D; Couch, W; Jorgensen, I; Malhotra, S; Murowinski, R; Roth, K; Savaglio, S; Tsvetanov, Z I; Stanway, Elizabeth R.; Glazebrook, Karl; Bunker, Andrew J.; Abraham, Roberto G.; Hook, Isobel; Rhoads, James; Carthy, Patrick J. Mc; Boyle, Brian; Colless, Matthew; Crampton, David; Couch, Warrick; J{\\o}rgensen, Inger; Malhotra, Sangeeta; Murowinski, Rick; Roth, Kathy; Savaglio, Sandra; Tsvetanov., Zlatan

    2004-01-01

    We report spectroscopic detection of three z \\sim 6 Lyman-alpha emitting galaxies, in the vicinity of the Hubble Ultra Deep Field, from the early data of the Gemini Lyman-alpha at Reionisation Era (GLARE) project. Two objects, GLARE#3001 (z =5.79) and GLARE#3011 (z =5.94), are new detections and are fainter in z' (z'_AB = 26.37 and 27.15) than any continuum-selected objects previously detected in Lyman-alpha. A third object, GLARE#1042 (z =5.83) has previously been detected in line emission from the ground; we report here a new spectroscopic continuum detection. Gemini/GMOS-S spectra of these objects, obtained using nod & shuffle, are presented together with a discussion of their photometric properties. All three objects were selected for spectroscopy via the i-drop Lyman Break technique, the two new detections from the GOODS v1.0 imaging data. The red i'-z' colors and high equivalent widths of these objects suggest a high-confidence z>5 Lyman-alpha identification of the emission lines. This brings the to...

  5. Io's SO2 Atmosphere Viewed in Silhouette by Jupiter Lyman

    Science.gov (United States)

    Retherford, Kurt D.; Roth, Lorenz; Feaga, Lori M.; Becker, Tracy M.; Tsang, Constantine; Jessup, Kandis-Lea; Grava, Cesare

    2016-10-01

    We report a new technique for mapping Io's SO2 vapor distribution. Hubble's Space Telescope Imaging Spectrograph (STIS) instrument observed Io during four Jupiter transit events to obtain medium resolution far-UV spectral images near the Lyman-α wavelength of 121.6 nm. Jupiter's bright Lyman-α dayglow provides a background light source for opacity measurements, much like during a stellar occultation or transiting exoplanet event. Peaks in the photoabsorption cross-sections for sulfur dioxide occur near 122 nm, with resulting absorptions raising the altitude where a tangential line of sight opacity of tau=1 is detected up to resolvable distances above the disk. This method of measuring column densities along lines of sight above the limb complements Lyman-α reflectance imaging and other methods for measuring Io's SO2 gas. For example, interpretation of Io's surface reflected components at far-UV wavelengths is complicated by SO2 frost features being correlated with regions of known volcanic outgassing activity, while Jupiter's Lyman-α dayglow provides a more spatially uniform background light source. Initial examination of these near-terminator limb observations with STIS confirms the findings from previous Lyman-α disk reflectance imaging using STIS's G140L mode (e.g., Feldman et al., GRL, 2000; Feaga et al. 2009) that Io's polar SO2 density is roughly an order of magnitude lower than found at the equator. As Strobel & Wolven (2001) described it, Io appears to wear its dayside atmosphere as "a belt" around the equator. We describe detailed simulations, now underway, that incorporate the STIS point spread function and consideration of additional attenuation by atmospheric hydrogen atoms, which are produced by charge exchange reactions between magnetospheric protons and Io's atmosphere.

  6. Thermonuclear Supernovae: Probing Magnetic Fields by Late-Time IR Line Profiles

    CERN Document Server

    Penney, R

    2014-01-01

    We study the imprint of magnetic fields B on late-time IR line profiles and light curves of Type Ia Supernovae. As a benchmark, we use the explosion of a Chandrasekhar mass M_{Ch White Dwarf (WD) and, specifically, a delayed detonation model. We assume WDs with initial magnetic surface fields between 1 and 1E9G. We discuss large-scale dipole and small-scale magnetic fields. We find that the [Fe II] line at 1.644 mu can be used to analyze the overall chemical and density structure of the exploding WD up to day 200 without considering B. Subsequently, positron transport and magnetic field effects become important. By day 500, the profile becomes sensitive to the morphology of B and directional dependent for dipole fields. Small or no directional dependence of the spectra is found for small-scale B. After about 200 days, persistent broad-line, flat-topped or stumpy profiles require high density burning which is the signature of a WD close to M_Ch. Narrow peaked profiles are a signature of chemical mixing or sub-...

  7. Study of H-alpha Spicule Profiles with Line Inversion Techniques

    Science.gov (United States)

    Tziotziou, K.; Kontogiannis, I.; Tsiropoula, G.; Kotrc, P.

    2008-09-01

    High resolution optical spectra of chromospheric spicules obtained in the H? line are studied together with slit-jaw filtergrams. The spectra were recorded along a vertical slit parallel to the solar limb with the HSFA2 (Horizontal-Sonnen-Forschungs-Anlage) Solar Spectrograph at Ondrejov Observatory on August 19, 2007 and show H? line profiles taken in spicules - due to the limb curvature - at different heights from the solar limb. A multi-cloud model that considers two or more spicules along the line-of-sight (LOS), together with a statistical approach that takes into account a large set of initial conditions for solving the radiative transfer equation, is used for the fitting of the observed profiles and the derivation of several parameters such as the LOS velocity, the source function, the optical thickness and the Doppler width that describe the respective spicules. The height-dependence of the shape of the observed profiles, as well as their dependence on the values of the derived parameters are studied in detail. The derived results are compared with the statistical theoretical results of a multi-cloud model where the aforementioned physical parameters, as well as a random number of spicules along the LOS were taken into account, in order to define the dependence of several spicule profile characteristics on them. Specific steps of the used procedures, as well as crucial problems are discussed.

  8. Oncogenic mutation profiling in new lung cancer and mesothelioma cell lines

    Directory of Open Access Journals (Sweden)

    Lam DC

    2015-01-01

    Full Text Available David CL Lam,1 Susan Y Luo,1 Wen Deng,2 Johnny SH Kwan,3 Jaime Rodriguez-Canales,4 Annie LM Cheung,5 Grace HW Cheng,6 Chi-Ho Lin,6 Ignacio I Wistuba,4 Pak C Sham,6 Thomas SK Wan,7 Sai-Wah Tsao5 1Department of Medicine, 2School of Nursing, 3Department of Psychiatry, University of Hong Kong, Hong Kong SAR, People’s Republic of China; 4Department of Translational Molecular Pathology, MD Anderson Cancer Center, University of Texas at Houston, Houston, TX, USA; 5Department of Anatomy, 6Center for Genome Sciences, 7Department of Pathology, University of Hong Kong, Hong Kong SAR, People’s Republic of China Background: Thoracic tumor, especially lung cancer, ranks as the top cancer mortality in most parts of the world. Lung adenocarcinoma is the predominant subtype and there is increasing knowledge on therapeutic molecular targets, namely EGFR, ALK, KRAS, and ROS1, among lung cancers. Lung cancer cell lines established with known clinical characteristics and molecular profiling of oncogenic targets like ALK or KRAS could be useful tools for understanding the biology of known molecular targets as well as for drug testing and screening. Materials and methods: Five new cancer cell lines were established from pleural fluid or biopsy tissues obtained from Chinese patients with primary lung adenocarcinomas or malignant pleural mesothelioma. They were characterized by immunohistochemistry, growth kinetics, tests for tumorigenicity, EGFR and KRAS gene mutations, ALK gene rearrangement and OncoSeq mutation profiling. Results: These newly established lung adenocarcinoma and mesothelioma cell lines were maintained for over 100 passages and demonstrated morphological and immunohistochemical features as well as growth kinetics of tumor cell lines. One of these new cell lines bears EML4-ALK rearrangement variant 2, two lung cancer cell lines bear different KRAS mutations at codon 12, and known single nucleotide polymorphism variants were identified in these cell

  9. Lyman alpha emission from the first galaxies: Implications of UV backgrounds and the formation of molecules

    CERN Document Server

    Latif, M A; Spaans, M; Zaroubi, S

    2011-01-01

    The Lyman alpha line is a robust tracer of high redshift galaxies. We present estimates of Lyman alpha emission from a protogalactic halo illuminated by UV background radiation fields with various intensities. For this purpose, we performed cosmological hydrodynamics simulations with the adaptive mesh refinement code FLASH, including a detailed network for primordial chemistry,comprising the formation of primordial molecules, a multi-level model for the hydrogen atom as well as the photo-ionization and photo-dissociation processes in a UV background. We find that the presence of a background radiation field J_21 excites the emission of Lyman alpha photons, increasing the Lyman alpha luminosity up to two orders of magnitude. For a halo of \\sim 10^10 M_sun, we find that a maximum flux of 5 \\times 10^-15 erg cm^-2 s^-1 is obtained for J21 \\times f_esc = 0.1, where f_esc is the escape fraction of the ionizing radiation. Depending on the environmental conditions, the flux may vary by three orders of magnitude. For...

  10. A Search for z>6.5 Lyman-alpha Emitting Galaxies with WISP

    Science.gov (United States)

    Bagley, Micaela B.; Scarlata, Claudia; Dai, Yu Sophia; Rafelski, Marc; Baronchelli, Ivano; Colbert, James W.; Dominguez, Alberto; Hathi, Nimish P.; Henry, Alaina L.; Malkan, Matthew Arnold; Martin, Crystal L.; Mehta, Vihang; Pahl, Anthony; Ross, Nathaniel; Rutkowski, Michael J.; Teplitz, Harry I.; WISP Team

    2016-01-01

    The observed number density of Lyman-alpha emitting galaxies at z>6 provides an important probe of the reionization history of the universe. Because Lyman-alpha photons are very sensitive to the presence of neutral hydrogen, the evolution of the galaxy number density above redshift 6 can be used as a measurement on the progress of reionization. However, the Lyman-alpha luminosity function is currently poorly constrained at high-z. We present the results of a systematic search for Lyman-alpha emitters (LAEs) at redshifts of ~6.5 to 7.5 using the HST WFC3 Infrared Spectroscopic Parallels (WISP) survey. WISP's uncorrelated fields are well-suited to the study of bright LAEs, minimizing the effects of clustering introduced by a patchy reionization. From the 30 deepest WISP fields, we compile a sample of single-line emitters, confirm redshifts with broadband colors, and identify LAE candidates that have "dropped out" (are undetected at the 1 sigma level) of the WFC3 UVIS filters. By combining our results with other z~7 studies, we determine whether the number density of LAEs evolves past z~6.5.

  11. Ultraviolet and Optical Line Profile Variations in the Spectrum of ɛ Persei

    Science.gov (United States)

    Gies, D. R.; Kambe, E.; Josephs, T. S.; Bagnuolo, W. G., Jr.; Choi, Y. J.; Gudehus, D.; Guyton, K. M.; Hartkopf, W. I.; Hildebrand, J. L.; Kaye, A. B.; Mason, B. D.; Riddle, R. L.; Sowers, J. W.; Turner, N. H.; Wilson, J. W.; Xiong, Y.

    1999-11-01

    The rapid variable star, ɛ Per (B0.5 IV-III), displays the largest amplitude profile fluctuations known among the growing number of massive, spectrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic, blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation functions of the individual spectra with that of a narrow-lined standard that produce a high signal-to-noise ratio representation of the blue-to-red moving bump patterns found in individual lines. We then use time series analysis methods to determine the periodic components of the profile variations (after reregistering the spectra to correct for binary motion). There are at least six periods present (ranging from 8.46 to 2.27 hr), and most of these signals are also found in optical line variations observed in 1986 (although the relative amplitudes have changed significantly). Furthermore, analysis of a shorter time series of IUE spectra from 1984 shows that similar periods were present then. We also present Hα and He I λ6678 profiles obtained with the Georgia State University Multi-Telescope Telescope, which were made simultaneously with IUE, and we show that the profile variations are essentially identical in the UV and optical ranges. We rule out rotational modulation and circumstellar gas obscuration as possible causes, and we suggest instead that the variations are the result of photospheric nonradial pulsations of relatively low degree (l=3-5). There were significant changes (~10%) in the equivalent widths of the UV stellar wind lines during the IUE run, and we suggest that wind strengthening events are related to episodes of large-amplitude, constructive interference between the NRP modes. Thus, intermode beating may play an important role in promoting wind loss from massive stars.

  12. Lipoprotein profiles of hepatic cell lines at various stages of differentiation.

    Science.gov (United States)

    Sasaki, Akira; Kimura, Fumiko; Miura, Mizuho; Toshima, Gen; Takahashi, Junichiro; Maruya, Sayuri; Kobayashi, Masayuki; Hata, Keishi

    2017-02-01

    We studied the lipoprotein profiles of human hepatic cells at various stages of differentiation. The production of three major classes of lipoproteins, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL), was detected in three well-differentiated human hepatoma cell lines and primary human hepatocytes; however, these lipoproteins were not detected in the culture medium in which undifferentiated hepatoma cell lines were grown. Reverse transcription polymerase chain reaction analysis demonstrated that the expression levels of apolipoprotein A1 (ApoA1), ApoB100, and microsomal triglyceride transfer protein (MTP) were markedly lower in the undifferentiated hepatoma cell lines than in the well-differentiated hepatoma cell lines and primary hepatocytes. These results indicate that apolipoprotein synthesis, and triglyceride-transport by MTP might be rate-limiting steps in lipoprotein production in mature hepatic cells.

  13. Genomic and phenotypic profiles of two Brazilian breast cancer cell lines derived from primary human tumors

    DEFF Research Database (Denmark)

    Corrêa, Natássia C R; Kuasne, Hellen; Faria, Jerusa A Q A

    2013-01-01

    Breast cancer is the most common type of cancer among women worldwide. Research using breast cancer cell lines derived from primary tumors may provide valuable additional knowledge regarding this type of cancer. Therefore, the aim of this study was to investigate the phenotypic profiles of MACL-1...... and MGSO-3, the only Brazilian breast cancer cell lines available for comparative studies. We evaluated the presence of hormone receptors, proliferation, differentiation and stem cell markers, using immunohistochemical staining of the primary tumor, cultured cells and xenografts implanted....... This shift in expression may be due to the selection of an 'establishment' phenotype in vitro. Whole-genome DNA evaluation showed a large amount of copy number alterations (CNAs) in the two cell lines. These findings render MACL-1 and MGSO-3 the first characterized Brazilian breast cancer cell lines...

  14. Expression profile of hypothalamic neuropeptides in chicken lines selected for high or low residual feed intake.

    Science.gov (United States)

    Sintubin, P; Greene, E; Collin, A; Bordas, A; Zerjal, T; Tesseraud, S; Buyse, J; Dridi, S

    2014-08-01

    The R(+) and R(-) chicken lines have been divergently selected for high (R(+)) or low (R(-)) residual feed intake. For the same body weight and egg production, the R(+) chickens consume 40% more food than their counterparts R(-) lines. In the present study we sought to determine the hypothalamic expression profile of feeding-related neuropeptides in these lines maintained under fed or food-deprived conditions. In the fed condition, the suppressor of cytokine signaling 3 (SOCS3) was 17-fold lower (Pfeeding-related genes that are differently expressed in the hypothalamus of R(+) and R(-) chickens and that might explain the difference in feed intake observed between the two lines. Published by Elsevier Ltd.

  15. Medium-resolution spectroscopy of FORJ0332-3557: probing the interstellar medium and stellar populations of a lensed Lyman-break galaxy at z = 3.77

    Science.gov (United States)

    Cabanac, Rémi A.; Valls-Gabaud, David; Lidman, Chris

    2008-06-01

    We recently reported the discovery of FORJ0332-3557, a lensed Lyman-break galaxy at z = 3.77 in a remarkable example of strong galaxy-galaxy gravitational lensing. We present here a medium-resolution rest-frame ultraviolet (UV) spectrum of the source, which appears to be similar to the well-known Lyman-break galaxy MS1512-cB58 at z = 2.73. The spectral energy distribution is consistent with a stellar population of less than 30Ma, with an extinction of Av = 0.5 mag and an extinction-corrected star formation rate SFRUV of 200-300h-170Msolara-1. The Lyα line exhibits a damped profile in absorption produced by a column density of about NHI = (2.5 +/- 1.0) × 1021cm-2, superimposed on an emission line shifted both spatially (0.5 arcsec with respect to the UV continuum source) and in velocity space (+830kms-1 with respect to the low-ionization absorption lines from its interstellar medium), a clear signature of outflows with an expansion velocity of about 270kms-1. A strong emission line from HeII λ164.04 nm indicates the presence of Wolf-Rayet stars and reinforces the interpretation of a very young starburst. The metallic lines indicate subsolar abundances of elements Si, Al and C in the ionized gas phase. Based on observations made at the ESO VLT under programmes 74.A-0536 and 78.A-0240. E-mail: remi.cabanac@ast.obs-mip.fr (RAC); david.valls-gabaud@obspm.fr (DV-G); clidman@eso.org (CL)

  16. The Temporal Behaviour of Lyman-alpha Emission During Solar Flares From SDO/EVE

    CERN Document Server

    Milligan, Ryan O

    2015-01-01

    Despite being the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyman-alpha (Ly$\\alpha$) emission during solar flares in recent years. The few examples that do exist, however, have shown Ly$\\alpha$ emission to be a substantial radiator of the total energy budget of solar flares (on the order of 10%). It is also a known driver of fluctuations in earth's ionosphere. The EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory now provides broadband, photometric Ly$\\alpha$ data at 10 s cadence, and has observed scores of solar flares in the 5 years since it was launched. However, the time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H$\\alpha$, Ly$\\beta$, LyC, C III, etc.). Furthermore, the Ly$\\alpha$ emission peaks around the time of the peak of thermal soft X-ray e...

  17. The High-Ion Content and Kinematics of Low-Redshift Lyman Limit Systems

    CERN Document Server

    Fox, Andrew J; Tumlinson, Jason; Howk, J Christopher; Tripp, Todd M; Prochaska, J Xavier; O'Meara, John M; Werk, Jessica K; Bordoloi, Rongmon; Katz, Neal; Oppenheimer, Benjamin D; Dave, Romeel

    2013-01-01

    We study the high-ionization phase and kinematics of the circumgalactic medium around low-redshift galaxies using a sample of 23 Lyman Limit Systems (LLSs) at 0.08profiles than metal-poor LLSs. The total H I line width (dv90 statistic) in LLSs is not correlated with metallicity, indicating that the H I kinematics alone cannot be used to distinguish inflow from outflow and gas recycling. Among the 17 LLSs with O VI detections, all but two show evidence of kinematic sub-structure, in the form of O VI-H I centroid offsets, multiple components, or both. Using various scenarios for how the metallicity in the high-ion and low...

  18. The First Observations of Low Redshift Damped Lyman-alpha Systems with the Cosmic Origins Spectrograph

    CERN Document Server

    Meiring, Joseph D; Prochaska, Jason X; Tumlinson, Jason; Werk, Jessica; Jenkins, Edward B; Thom, Chris; O'Meara, John M; Sembach, Kenneth R

    2011-01-01

    We report on the first Cosmic Origins Spectrograph (COS) observations of damped and sub-damped Lyman-alpha (DLA) systems discovered in a new survey of the gaseous halos of low-redshift galaxies. From observations of 37 sightlines, we have discovered three DLAs and four sub-DLAs. We measure the neutral gas density Omega(HI), and redshift density dN/dz, of DLA and sub-DLA systems at z<0.35. We find dN/dz=0.25 and Omega(HI)=1.4x10^-3 for DLAs, and dN/dz=0.08 with Omega(HI)=4.2x10^-5 for sub-DLAs over a redshift path delta z=11.9. To demonstrate the scientific potential of such systems, we present a detailed analysis of the DLA at z=0.1140 in the spectrum of SDSS J1009+0713. Profile fits to the absorption lines determine log N(H I)=20.68pm0.10 with a metallicity determined from the undepleted element Sulfur of [S/H]=-0.62pm0.18. The abundance pattern of this DLA is similar to that of higher z DLAs, showing mild depletion of the refractory elements Fe and Ti with [S/Fe]=+0.24pm0.22 and [S/Ti]=+0.28pm0.15. Nitro...

  19. Reproducing the Kinematics of Damped Lyman-alpha Systems

    CERN Document Server

    Bird, Simeon; Neeleman, Marcel; Genel, Shy; Vogelsberger, Mark; Hernquist, Lars

    2014-01-01

    We examine the kinematic structure of Damped Lyman-alpha Systems (DLAs) in a series of cosmological hydrodynamic simulations using the AREPO code. We are able to match the distribution of velocity widths of associated low ionisation metal absorbers substantially better than earlier work. Our simulations produce a population of DLAs dominated by halos with virial velocities around 70 km/s, consistent with a picture of relatively small, faint objects. In addition, we reproduce the observed correlation between velocity width and metallicity and the equivalent width distribution of SiII. Some discrepancies of moderate statistical significance remain; too many of our spectra show absorption concentrated at the edge of the profile and there are slight differences in the exact shape of the velocity width distribution. We show that the improvement over previous work is mostly due to our strong feedback from star formation and our detailed modelling of the metal ionisation state.

  20. Structural characterization of lead sulfide thin films by means of X-ray line profile analysis

    Indian Academy of Sciences (India)

    N Choudhury; B K Sarma

    2009-02-01

    X-ray diffraction patterns of chemically deposited lead sulphide thin films have been recorded and X-ray line profile analysis studies have been carried out. The lattice parameter, crystallite size, average internal stress and microstrain in the film are calculated and correlated with molarities of the solutions. Both size and strain are found to contribute towards the broadening of X-ray diffraction line. The values of the crystallite size are found to be within the range from 22–33 nm and the values of strain to be within the range from 1.0 × 10-3–2.5 × 10-3.

  1. Gene expression profiling in chemoresistant variants of three cell lines of different origin

    DEFF Research Database (Denmark)

    Johnsson, Anders; Vallon-Christensson, Johan; Strand, Carina

    2005-01-01

    BACKGROUND: Drug resistance is a major problem in clinical cancer chemotherapy. Several mechanisms of resistance have been identified, but the underlying genomic changes are still poorly understood. MATERIALS AND METHODS: Gene expression profiling, using cDNA microarray, was performed in eight cell....... Several genes encoding ABC transporters were highly up-regulated, most notably ABCB1 (MDR1) and ABCB4 in several cell lines and ABCG2 (MXR) specifically in MX-resistant cell lines. A pronounced down-regulation of several histones was noted in the MCF-7-derived resistant sublines. Altered expression...

  2. Detailed Characterization of H_beta emission line profile in low z SDSS quasars

    OpenAIRE

    Zamfir, S.; Sulentic, J. W.; Marziani, P; D. Dultzin

    2009-01-01

    We explore the properties of the H_beta emission line profile in a large, homogeneous and bright sample of N~470 low redshift quasars extracted from Sloan Digital Sky Survey (DR5). We approach the investigation from two complementary directions: composite/median spectra and a set of line diagnostic measures (asymmetry index, centroid shift and kurtosis) in individual quasars. The project is developed and presented in the framework of the so-called 4D Eigenvector 1 (4DE1) Parameter Space, with...

  3. On the selection of damped Lyman α systems using Mg II absorption at 2 < zabs < 4

    Science.gov (United States)

    Berg, T. A. M.; Ellison, S. L.; Prochaska, J. X.; Sánchez-Ramírez, R.; Lopez, S.; D'Odorico, V.; Becker, G.; Christensen, L.; Cupani, G.; Denney, K.; Worseck, G.

    2017-01-01

    The XQ-100 survey provides optical and near-infrared coverage of 36 blindly selected, intervening damped Lyman α systems (DLAs) at 2 frame equivalent width (W0^{2796}) at these redshifts. Of the 29 DLAs with clean Mg II profiles, we find that six (20 per cent of DLAs) have W0^{2796} effect on the H I-weighted mean metallicity.

  4. Interpreting the Mg II h and k Line Profiles of Mira Variables

    CERN Document Server

    Wood, B E; Wood, Brian E.; Karovska, Margarita

    2000-01-01

    We use radiative transfer calculations to reproduce the basic appearance of Mg II lines observed from Mira variables. These lines have centroids that are blueshifted by at least 30 km/s from the stellar rest frame. It is unlikely that flow velocities in the stellar atmospheres are this fast, so radiative transfer effects must be responsible for this behavior. Published hydrodynamic models predict the existence of cool, downflowing material above the shocked material responsible for the Mg II emission, and we demonstrate that scattering in this layer can result in Mg II profiles as highly blueshifted as those that are observed. However, our models also show that scattering within the shock plays an equally strong role in shaping the Mg II profiles, and our calculations illustrate the importance of partial redistribution and the effects of being out of ionization equilibrium.

  5. Fundamental Parameter Method Applied to X-Ray Line Profile Analysis

    OpenAIRE

    Florica Matei; Nicolae Aldea; Marius Rada; Ioana Pop

    2016-01-01

    Crystallite size strain effect the mechanical, electric, magnetic and optical properties of many kind of the nanomaterials. The effects of the finite crystallite size and lattice strain can be very well observed as the deformation in the shape of the X-ray line profile (XRLP). In this contribution we have used the fundamental parameter (FP) [1,2] method to evaluate the nanostructure materials assuming a theoretical model of experimental XRLP.  In this contribution we have used various distrib...

  6. Detecting Damped Lyman-$\\alpha$ Absorbers with Gaussian Processes

    CERN Document Server

    Garnett, Roman; Bird, Simeon; Schneider, Jeff

    2016-01-01

    We develop an automated technique for detecting damped Lyman-$\\alpha$ absorbers (DLAs) along spectroscopic sightlines to quasi-stellar objects (QSOs or quasars). The detection of DLAs in large-scale spectroscopic surveys such as SDSS-III sheds light on galaxy formation at high redshift, showing the nucleation of galaxies from diffuse gas. We use nearly 50 000 QSO spectra to learn a novel tailored Gaussian process model for quasar emission spectra, which we apply to the DLA detection problem via Bayesian model selection. We propose models for identifying an arbitrary number of DLAs along a given line of sight. We demonstrate our method's effectiveness using a large-scale validation experiment, with excellent performance. We also provide a catalog of our results applied to 162 861 spectra from SDSS-III data release 12.

  7. Baryon Acoustic Oscillations in the Lyman Alpha Forest

    CERN Document Server

    Norman, Michael L; Harkness, Robert

    2009-01-01

    We use hydrodynamic cosmological simulations in a (600 Mpc)^3 volume to study the observability of baryon acoustic oscillations (BAO) in the intergalactic medium as probed by Lyman alpha forest (LAF) absorption. The large scale separation between the wavelength of the BAO mode (~150 Mpc) and the size of LAF absorbers (~100 kpc) makes this a numerically challenging problem. We report on several 2048^3 simulations of the LAF using the ENZO code. We adopt WMAP5 concordance cosmological parameters and power spectrum including BAO perturbations. 5000 synthetic HI absorption line spectra are generated randomly piercing the box face. We calculate the cross-correlation function between widely separated pairs. We detect the BAO signal at z=3 where theory predicts to moderate statistical significance.

  8. Detection of Lyman continuum absorption in the BL Lacertae object PKS 0735+178

    Science.gov (United States)

    Bregman, J. N.; Glassgold, A. E.; Huggins, P. J.

    1981-01-01

    The detection of the Lyman edge in the BL Lac object PKS 0735+178 at the absorption red shift determined by optical measurements leads to a lower limit for the column density of atomic hydrogen, N(H I) not less than 4(17)/sq cm. The Lyman-alpha absorption line appears to have been detected, but only an approximate upper limit can be obtained from the data, of the order of 2(19)/sq cm. This amount of atomic hydrogen is less than that for a line of sight through the disk of a normal spiral galaxy. It is suggested that the absorbing material exists either in the halo of a galaxy or in the tenuous, extended, gaseous disk of a galaxy.

  9. Reprocessed emission line profiles from dense clouds in geometrically thick accretion engines

    CERN Document Server

    Hartnoll, S A; Hartnoll, Sean A.

    2000-01-01

    The central engines of active galactic nuclei (AGN) contain cold, dense material as well as hot X-ray emitting gas. The standard paradigm for the engine geometry is a cold thin disc sandwiched between hot X-ray coronae. Strong support for this geometry in Seyferts comes from the study of fluorescent iron line profiles, although the evidence is not ubiquitously air tight. The thin disc model of line profiles in AGN and in X-ray binaries should be bench marked against other plausible possibilities. One proposed alternative is an engine consisting of dense clouds embedded in an optically thin, geometrically thick X-ray emitting engine. This model is further motivated by studies of geometrically thick engines such as advection dominated accretion flows (ADAFs). Here we compute the reprocessed iron line profiles from dense clouds embedded in geometrically thick, optically thin X-ray emitting discs near a Schwarzchild black hole. We consider a range of cloud distributions and disc solutions, including ADAFs, pure r...

  10. Detection method of proximal caries using line profile in digital intra-oral radiography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Suk; Kim, Gyu Tae; Hwang, Eui Hwan; Lee, Min Ja; Choi, Sam Jin; Park, Hun Kuk [Department of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Biology, Kyung Hee University, Seoul (Korea, Republic of); Park, Jeong Hoon [Department of Biomedical Engineering, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of)

    2009-12-15

    The purpose of this study was to investigate how to detect proximal caries using line profile and validate linear measurements of proximal caries lesions by basic digital manipulation of radiographic images. The X-ray images of control group (15) and caries teeth (15) from patients were used. For each image, the line profile at the proximal caries-susceptible zone was calculated. To evaluate the contrast as a function of line profile to detect proximal caries, a difference coefficient (D) that indicates the relative difference between caries and sound dentin or intact enamel was measured. Mean values of D were 0.0354 {+-} 0.0155 in non-caries and 0.2632 {+-} 0.0982 in caries (p<0.001). The mean values of caries group were higher than non-caries group and there was correlation between proximal dental caries and D. It is demonstrated that the mean value of D from caries group was higher than that of control group. From the result, values of D possess great potentiality as a new detection parameter for proximal dental caries.

  11. Fourier-Doppler Imaging of Line Profile Variations in ζ Ophiuchi

    Science.gov (United States)

    Jankov, S.; Janot-Pacheco, E.; Leister, N. V.

    2000-09-01

    We present, for the first time, the Fourier-Doppler Imaging (FDI) analysis of periodic line profile variations in a ζ Oph-type star. For this purpose we obtained, in the period from 1996 May 3 to May 5, a total of 242 high-resolution, high signal-to-noise ratio spectra of the Be star ζ Oph itself. Using the FDI technique, we examine the variations in both time and wavelength and complement it with time series analysis. This kind of analysis is valid for both the nonradial pulsator model and the rotation modulation model, but we discuss the results in terms of the former model, considering it the more likely explanation for the observed line profile variability. Two distinct groups of modes are detected: medium (4high-degree modes (which could be associated with 13high-frequency oscillations were strongly confined to an equatorial belt narrower than 20° and that the line profile variability was caused predominantly by sectoral modes, although tesseral modes |m|=l-1 are not excluded in taking into account the effect of fast rotation. We discuss the modal nature of the waves with respect to the characteristic oscillation periods in the corotating frame and the high amplitude of the projected rotational velocity variations (~20 km s-1).

  12. Distinctive characteristics of transcriptional profiles from two epithelial cell lines upon interaction with Actinobacillus actinomycetemcomitans.

    Science.gov (United States)

    Mans, J J; Baker, H V; Oda, D; Lamont, R J; Handfield, M

    2006-08-01

    Transcriptional profiling and gene ontology analyses were performed to investigate the unique responses of two different epithelial cell lines to an Actinobacillus actinomycetemcomitans challenge. A total of 2867 genes were differentially regulated among all experimental conditions. The analysis of these 2867 genes revealed that the predominant specific response to infection in HeLa cells was associated with the regulation of enzyme activity, RNA metabolism, nucleoside and nucleic acid transport and protein modification. The predominant specific response in immortalized human gingival keratinocytes (IHGK) was associated with the regulation of angiogenesis, chemotaxis, transmembrane receptor protein tyrosine kinase signaling, cell differentiation, apoptosis and response to stress. Of particular interest, stress response genes were significantly - yet differently - affected in both cell lines. In HeLa cells, only three regulated genes impacted the response to stress, and the response to unfolded protein was the only term that passed the ontology filters. This strikingly contrasted with the profiles obtained for IHGK, in which 61 regulated genes impacted the response to stress and constituted an extensive network of cell responses to A. actinomycetemcomitans interaction (response to pathogens, oxidative stress, unfolded proteins, DNA damage, starvation and wounding). Hence, while extensive similarities were found in the transcriptional profiles of these two epithelial cell lines, significant differences were highlighted. These differences were predominantly found in pathways that are associated with host-pathogen interactions.

  13. Method for measuring radial impurity emission profiles using correlations of line integrated signals

    Science.gov (United States)

    Kuldkepp, M.; Brunsell, P. R.; Drake, J.; Menmuir, S.; Rachlew, E.

    2006-04-01

    A method of determining radial impurity emission profiles is outlined. The method uses correlations between line integrated signals and is based on the assumption of cylindrically symmetric fluctuations. Measurements at the reversed field pinch EXTRAP T2R show that emission from impurities expected to be close to the edge is clearly different in raw as well as analyzed data to impurities expected to be more central. Best fitting of experimental data to simulated correlation coefficients yields emission profiles that are remarkably close to emission profiles determined using more conventional techniques. The radial extension of the fluctuations is small enough for the method to be used and bandpass filtered signals indicate that fluctuations below 10kHz are cylindrically symmetric. The novel method is not sensitive to vessel window attenuation or wall reflections and can therefore complement the standard methods in the impurity emission reconstruction procedure.

  14. Lyman Break Galaxies in the NGST Era

    CERN Document Server

    Ferguson, H C; Papovich, C; Ferguson, Henry C.; Dickinson, Mark; Papovich, Casey

    2002-01-01

    With SIRTF and NGST in the offing, it is interesting to examine what the stellar populations of z~3 galaxies models imply for the existence and nature of Lyman-break galaxies at higher redshift. To this end, we ``turn back the clock'' on the stellar population models that have been fit to optical and infrared data of Lyman-break galaxies at z~3. The generally young ages (typically 10^8 +- 0.5 yr) of these galaxies imply that their stars were not present much beyond z=4. For smooth star-formation histories SFR(t) and Salpeter IMFs, the ionizing radiation from early star-formation in these galaxies would be insufficient to reionize the intergalactic medium at z~6, and the luminosity density at z~4 would be significantly lower than observed. We examine possible ways to increase the global star-formation rate at higher redshift without violating the stellar-population constraints at z~3.

  15. Large-Scale Profiling of Kinase Dependencies in Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    James Campbell

    2016-03-01

    Full Text Available One approach to identifying cancer-specific vulnerabilities and therapeutic targets is to profile genetic dependencies in cancer cell lines. Here, we describe data from a series of siRNA screens that identify the kinase genetic dependencies in 117 cancer cell lines from ten cancer types. By integrating the siRNA screen data with molecular profiling data, including exome sequencing data, we show how vulnerabilities/genetic dependencies that are associated with mutations in specific cancer driver genes can be identified. By integrating additional data sets into this analysis, including protein-protein interaction data, we also demonstrate that the genetic dependencies associated with many cancer driver genes form dense connections on functional interaction networks. We demonstrate the utility of this resource by using it to predict the drug sensitivity of genetically or histologically defined subsets of tumor cell lines, including an increased sensitivity of osteosarcoma cell lines to FGFR inhibitors and SMAD4 mutant tumor cells to mitotic inhibitors.

  16. The implementation of non-Voigt line profiles in the HITRAN database: H2 case study

    Science.gov (United States)

    Wcisło, P.; Gordon, I. E.; Tran, H.; Tan, Y.; Hu, S.-M.; Campargue, A.; Kassi, S.; Romanini, D.; Hill, C.; Kochanov, R. V.; Rothman, L. S.

    2016-07-01

    Experimental capabilities of molecular spectroscopy and its applications nowadays require a sub-percent or even sub-per mille accuracy of the representation of the shapes of molecular transitions. This implies the necessity of using more advanced line-shape models which are characterized by many more parameters than a simple Voigt profile. It is a great challenge for modern molecular spectral databases to store and maintain the extended set of line-shape parameters as well as their temperature dependences. It is even more challenging to reliably retrieve these parameters from experimental spectra over a large range of pressures and temperatures. In this paper we address this problem starting from the case of the H2 molecule for which the non-Voigt line-shape effects are exceptionally pronounced. For this purpose we reanalyzed the experimental data reported in the literature. In particular, we performed detailed line-shape analysis of high-quality spectra obtained with cavity-enhanced techniques. We also report the first high-quality cavity-enhanced measurement of the H2 fundamental vibrational mode. We develop a correction to the Hartmann-Tran profile (HTP) which adjusts the HTP to the particular model of the velocity-changing collisions. This allows the measured spectra to be better represented over a wide range of pressures. The problem of storing the HTP parameters in the HITRAN database together with their temperature dependences is also discussed.

  17. Generation and gene expression profiling of 48 transcription-factor-inducible mouse embryonic stem cell lines

    Science.gov (United States)

    Yamamizu, Kohei; Sharov, Alexei A.; Piao, Yulan; Amano, Misa; Yu, Hong; Nishiyama, Akira; Dudekula, Dawood B.; Schlessinger, David; Ko, Minoru S. H.

    2016-01-01

    Mouse embryonic stem cells (ESCs) can differentiate into a wide range – and possibly all cell types in vitro, and thus provide an ideal platform to study systematically the action of transcription factors (TFs) in cell differentiation. Previously, we have generated and analyzed 137 TF-inducible mouse ESC lines. As an extension of this “NIA Mouse ESC Bank,” we generated and characterized 48 additional mouse ESC lines, in which single TFs in each line could be induced in a doxycycline-controllable manner. Together, with the previous ESC lines, the bank now comprises 185 TF-manipulable ESC lines (>10% of all mouse TFs). Global gene expression (transcriptome) profiling revealed that the induction of individual TFs in mouse ESCs for 48 hours shifts their transcriptomes toward specific differentiation fates (e.g., neural lineages by Myt1 Isl1, and St18; mesodermal lineages by Pitx1, Pitx2, Barhl2, and Lmx1a; white blood cells by Myb, Etv2, and Tbx6, and ovary by Pitx1, Pitx2, and Dmrtc2). These data also provide and lists of inferred target genes of each TF and possible functions of these TFs. The results demonstrate the utility of mouse ESC lines and their transcriptome data for understanding the mechanism of cell differentiation and the function of TFs. PMID:27150017

  18. Lyman Spitzer: Life, Times, and Science

    Indian Academy of Sciences (India)

    2016-11-01

    Lyman Spitzer was one of the major figures of twentieth centurytheoretical astrophysics. Over more than fifty years,he kept up sustained research of his own, on problems concerningthe interstellar medium, star formation, and galaxies.In addition he was a major influence on observationalprogrammes, and created a thriving school of theoretical astrophysicsat Princeton University along with a strong plasmaphysics programme. This article brings out his contributions,placing them in context.

  19. Lyman edges in AGN accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Czerny, B. (Copernicus Astronomical Center, Warsaw (Poland)); Pojmanski, G. (Warsaw Univ. (Poland). Obserwatorium Astronomiczne)

    1990-07-01

    We show that the basic difference in the two principal approaches to predictions of the Lyman edge in an accretion disc lies in the implicit assumption about the density of the radiating gas. Independent from the details, models predict a broad range of the edge sizes, both in absorption and in emission. Observed spectra do not exhibit any strong feature at 912 A but may still be consistent with an accretion disc mechanism if more advanced theory is developed. (author).

  20. Doppler ghosts in a hall of mirrors polarisation profiles of scattered emission lines

    CERN Document Server

    Henney, W J

    1994-01-01

    The Doppler shifts of optical emission lines which have been scattered by surrounding dust and electrons can provide useful information about the kinematics, geometry and physical conditions of astrophysical flows. In principle, the scatterers can provide views of the line-emitting gas from different directions, allowing the 3-d velocity field of the emitting gas to be determined and revealing sources which are hidden from direct view. Unfortunately, as in a Hall of Mirrors, the resultant multiple images can be confusing and hard to interpret. In general, the scattering geometry will be unknown, which makes it difficult to disentangle the effect of the motion of the scatterers from that of the motion of the emitting source. In this situation, spectropolarimetric observations can be a great help, since the scattered light will be partially polarised to a degree dependent on the angle of scattering and on the details of the scattering process. Analysis of the polarisation profiles of the scattered emission line...

  1. Lyman-alpha observations of comets West 1976 VI and P d'Arrest 1976 XI with Copernicus

    Science.gov (United States)

    Festou, M. C.; Keller, H. U.; Bertaux, J. L.; Barker, E. S.

    1983-02-01

    Lyman-alpha observations by the Copernicus satellite have been used to determine the production rates of hydrogen atoms of comets West 1976 VI and P/d'Arrest 1976 XI at a time when they were dynamically active (splitting or outburst of the nucleus). The observed Lyman-alpha line widths are in agreement with those observed in comet Kobayashi-Berger-Milon 1975 IX and, consequently, do not contradict the assumption that the H atoms are produced by the photodissociation of water vapor, even in CO(plus) rich comets..

  2. The Lyman-$\\alpha$ emission in local Star-Forming Galaxies Scenario and Connection with Primeval Galaxies

    CERN Document Server

    Kunth, D; Terlevich, R J; Tenorio-Tagle, G

    1998-01-01

    We review the Lyan alpha emission in local star-forming galaxies. In most cases as already shown by the IUE, the emission is absent or much weaker than expected. This occurs because Lyman alpha photons can be resonantly scattered by the neutral gas and destroyed by even very low amounts of dust. However new Hubble Space Telescope observations (HST) indicate that other factors such as the velocity structure of the gas play a crucial role. Gas flows are likely to occur as powered by the kinetic energy released via stellar winds and supernova. We propose a scenario based on the hydrodynamics of superbubbles powered by massive bursts of star formation that naturally accounts for the variety of Lyman alpha line detections in star-forming galaxies. We caution with the attempts to derive the co-moving star formation rate at high redshift from Lyman alpha emission searches.

  3. Exploring the nature of the Lyman-$\\alpha$ emitter CR7

    CERN Document Server

    Hartwig, Tilman; Magg, Mattis; Bromm, Volker; Klessen, Ralf S; Glover, Simon C O; Whalen, Daniel J; Pellegrini, Eric W; Volonteri, Marta

    2015-01-01

    CR7 is the brightest Lyman-$\\alpha$ emitter observed at $z>6$, which shows very strong Lyman-$\\alpha$ and HeII 1640 \\AA\\ line luminosities, but no metal line emission. Previous studies suggest that CR7 hosts either young primordial stars with a total stellar mass of $\\sim 10^7\\,\\mathrm{M}_\\odot$ or a black hole of $\\sim 10^6\\,\\mathrm{M}_\\odot$. Here, we explore different formation scenarios for CR7 with a semianalytical model, based on the random sampling of dark matter merger trees. We find that primordial stars cannot account for the observed line luminosities because of their short lifetimes and because of early metal enrichment. Black holes that are the remnants of the first stars are either not massive enough, or reside in metal-polluted haloes, ruling out this possible explanation of CR7. Our models instead suggest that direct collapse black holes, which form in metal-free haloes exposed to large Lyman-Werner fluxes, are more likely the origin of CR7. However, this result is derived under optimistic ass...

  4. On the use of the Fourier Transform to determine the projected rotational velocity of line-profile variable B stars

    CERN Document Server

    Aerts, C; Groot, P J; Degroote, P

    2014-01-01

    The Fourier Transform method is a popular tool to derive the rotational velocities of stars from their spectral line profiles. However, its domain of validity does not include line-profile variables with time-dependent profiles. We investigate the performance of the method for such cases, by interpreting the line-profile variations of spotted B stars, and of pulsating B tars, as if their spectral lines were caused by uniform surface rotation along with macroturbulence. We perform time-series analysis and harmonic least-squares fitting of various line diagnostics and of the outcome of several implementations of the Fourier Transform method. We find that the projected rotational velocities derived from the Fourier Transform vary appreciably during the pulsation cycle whenever the pulsational and rotational velocity fields are of similar magnitude. The macroturbulent velocities derived while ignoring the pulsations can vary with tens of km/s during the pulsation cycle. The temporal behaviour of the deduced rotat...

  5. The Lyman α forest in a blazar-heated Universe

    Science.gov (United States)

    Puchwein, Ewald; Pfrommer, Christoph; Springel, Volker; Broderick, Avery E.; Chang, Philip

    2012-06-01

    It has been realized only recently that TeV emission from blazars can significantly heat the intergalactic medium (IGM) by pair-producing high-energy electrons and positrons, which in turn excite vigorous plasma instabilities, leading to a local dissipation of the pairs' kinetic energy. In this work, we use cosmological hydrodynamical simulations to model the impact of this blazar heating on the Lyman α forest at intermediate redshifts (z˜ 2-3). We find that blazar heating produces an inverted temperature-density relation in the IGM and naturally resolves many of the problems present in previous simulations of the forest that included photoionization heating alone. In particular, our simulations with blazar heating simultaneously reproduce the observed effective optical depth and temperature as a function of redshift, the observed probability distribution functions (PDFs) of the transmitted flux, and the observed flux power spectra, over the full redshift range 2 sum of thermally broadened individual lines, we find superb agreement with the observed lower cut-off of the linewidth distribution and abundances of neutral hydrogen column densities per unit redshift. Using the most recent constraints on the cosmic ultraviolet (UV) background, this excellent agreement with observations does not require rescaling the amplitude of the UV background - a procedure that was routinely used in the past to match the observed level of transmitted flux. We also show that our blazar-heated model matches the data better than standard simulations even when such a rescaling is allowed. This concordance between Lyman α data and simulation results, which are based on the most recent cosmological parameters, also suggests that the inclusion of blazar heating alleviates previous tensions on constraints for σ8 derived from Lyman α measurements and other cosmological data. Finally, we show that blazar heating dramatically alters the volume-weighted temperature PDF, implying an

  6. First evidence of non-Gaussian solar flare EUV spectral line profiles and accelerated non-thermal ion motion

    CERN Document Server

    Jeffrey, Natasha; Labrosse, Nicolas

    2016-01-01

    The properties of solar flare plasma can be determined from observations of optically thin EUV lines. The spectral line profiles emitted in a flaring MK plasma are expected to be dominated by Doppler broadening, producing Gaussian line profiles, if the underlying ion velocity distribution is Maxwellian. We look for non-Gaussian line profiles during a flare, that may indicate the presence of accelerated ion and/or plasma non-thermal velocity distributions. We study EUV spectral lines during a flare SOL2013-05-15T01:45 using the Hinode EUV Imaging Spectrometer (EIS). The flare is located close to the eastern solar limb. It has an extended loop structure, allowing different flare features: ribbons, hard X-ray (HXR) footpoints and the loop-top source to be clearly observed in EUV and X-rays. EUV line spectroscopy is performed in seven regions covering the flare features. We study the line profiles of isolated and unblended Fe XVI lines (262.9760 A) formed at temperatures of 2-4 MK. Suitable Fe XVI line profiles c...

  7. Simultaneous Ultraviolet and Optical Emission-line Profiles of Quasars: Implications for Black Hole Mass Determination

    CERN Document Server

    Ho, Luis C; Dong, Xiao-Bo; Greene, Jenny E; Ponti, Gabriele

    2012-01-01

    The X-shooter instrument on the VLT was used to obtain spectra of seven moderate-redshift quasars simultaneously covering the spectral range 3000 Ang to 2.5 microns. At z ~ 1.5, most of the prominent broad emission lines in the ultraviolet to optical region are captured in their rest frame. We use this unique dataset, which mitigates complications from source variability, to intercompare the line profiles of C IV 1549, C III] 1909, Mg II 2800, and Halpha and evaluate their implications for black hole mass estimation. We confirm that Mg II and the Balmer lines share similar kinematics and that they deliver mutually consistent black hole mass estimates with minimal internal scatter (< 0.1 dex) using the latest virial mass estimators. Although no virial mass formalism has yet been calibrated for C III], this line does not appear promising for such an application because of the large spread of its velocity width compared to lines of both higher and lower ionization; part of the discrepancy may be due to the di...

  8. Ultraviolet and Optical Line Profile Variations in the Spectrum of {epsilon} Persei

    Energy Technology Data Exchange (ETDEWEB)

    Gies, D. R.; Kambe, E.; Josephs, T. S.; Bagnuolo, W. G. Jr.; Choi, Y. J.; Gudehus, D.; Guyton, K. M.; Hartkopf, W. I.; Hildebrand, J. L.; Kaye, A. B. (and others)

    1999-11-01

    The rapid variable star, {epsilon} Per (B0.5 IV-III), displays the largest amplitude profile fluctuations known among the growing number of massive, spectrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic, blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation functions of the individual spectra with that of a narrow-lined standard that produce a high signal-to-noise ratio representation of the blue-to-red moving bump patterns found in individual lines. We then use time series analysis methods to determine the periodic components of the profile variations (after reregistering the spectra to correct for binary motion). There are at least six periods present (ranging from 8.46 to 2.27 hr), and most of these signals are also found in optical line variations observed in 1986 (although the relative amplitudes have changed significantly). Furthermore, analysis of a shorter time series of IUE spectra from 1984 shows that similar periods were present then. We also present H{alpha} and He i {lambda}6678 profiles obtained with the Georgia State University Multi-Telescope Telescope, which were made simultaneously with IUE, and we show that the profile variations are essentially identical in the UV and optical ranges. We rule out rotational modulation and circumstellar gas obscuration as possible causes, and we suggest instead that the variations are the result of photospheric nonradial pulsations of relatively low degree (l=3-5). There were significant changes ({approx}10%) in the equivalent widths of the UV stellar wind lines during the IUE run, and we suggest that wind strengthening events are related to episodes of large-amplitude, constructive interference between the NRP modes. Thus, intermode beating may play an important role in promoting wind loss from massive stars. (c) (c) 1999

  9. Comprehensive expression profiling of tumor cell lines identifies molecular signatures of melanoma progression.

    Directory of Open Access Journals (Sweden)

    Byungwoo Ryu

    Full Text Available BACKGROUND: Gene expression profiling has revolutionized our ability to molecularly classify primary human tumors and significantly enhanced the development of novel tumor markers and therapies; however, progress in the diagnosis and treatment of melanoma over the past 3 decades has been limited, and there is currently no approved therapy that significantly extends lifespan in patients with advanced disease. Profiling studies of melanoma to date have been inconsistent due to the heterogeneous nature of this malignancy and the limited availability of informative tissue specimens from early stages of disease. METHODOLOGY/PRINCIPLE FINDINGS: In order to gain an improved understanding of the molecular basis of melanoma progression, we have compared gene expression profiles from a series of melanoma cell lines representing discrete stages of malignant progression that recapitulate critical characteristics of the primary lesions from which they were derived. Here we describe the unsupervised hierarchical clustering of profiling data from melanoma cell lines and melanocytes. This clustering identifies two distinctive molecular subclasses of melanoma segregating aggressive metastatic tumor cell lines from less-aggressive primary tumor cell lines. Further analysis of expression signatures associated with melanoma progression using functional annotations categorized these transcripts into three classes of genes: 1 Upregulation of activators of cell cycle progression, DNA replication and repair (CDCA2, NCAPH, NCAPG, NCAPG2, PBK, NUSAP1, BIRC5, ESCO2, HELLS, MELK, GINS1, GINS4, RAD54L, TYMS, and DHFR, 2 Loss of genes associated with cellular adhesion and melanocyte differentiation (CDH3, CDH1, c-KIT, PAX3, CITED1/MSG-1, TYR, MELANA, MC1R, and OCA2, 3 Upregulation of genes associated with resistance to apoptosis (BIRC5/survivin. While these broad classes of transcripts have previously been implicated in the progression of melanoma and other malignancies, the

  10. Assessment of a systematic expression profiling approach in ENU-induced mouse mutant lines.

    Science.gov (United States)

    Seltmann, Matthias; Horsch, Marion; Drobyshev, Alexei; Chen, Yali; de Angelis, Martin Hrabé; Beckers, Johannes

    2005-01-01

    Comparative genomewide expression profiling is a powerful tool in the effort to annotate the mouse genome with biological function. The systematic analysis of RNA expression data of mouse lines from the Munich ENU mutagenesis screen might support the understanding of the molecular biology of such mutants and provide new insights into mammalian gene function. In a direct comparison of DNA microarray experiments of individual versus pooled RNA samples of organs from ENU-induced mouse mutants, we provide evidence that individual RNA samples may outperform pools in some aspects. Genes with high biological variability in their expression levels (noisy genes) are identified as false positives in pooled samples. Evidence suggests that highly stringent housing conditions and standardized procedures for the isolation of organs significantly reduce biological variability in gene expression profiling experiments. Data on wild-type individuals demonstrate the positive effect of controlling variables such as social status, food intake before organ sampling, and stress with regard to reproducibility of gene expression patterns. Analyses of several organs from various ENU-induced mutant lines in general show low numbers of differentially expressed genes. We demonstrate the feasibility to detect transcriptionally affected organs employing RNA expression profiling as a tool for molecular phenotyping.

  11. BEYOND THE STANDARD MODEL OF THE DISC–LINE SPECTRAL PROFILES FROM BLACK HOLE ACCRETION DISCS

    Directory of Open Access Journals (Sweden)

    Vjaceslav Sochora

    2014-08-01

    Full Text Available The strong gravitational field of a black hole has distinct effects on the observed profile of a spectral line from an accretion disc near a black hole. The observed profile of the spectral line is broadened and skewed by a fast orbital motion and redshifted by a gravitational field. These effects can help us to constrain the parameters of a system with a black hole, both in active galactic nuclei and in a stellar-mass black hole. Here we explore the fact that an accretion disc emission can be mathematically imagined as a superposition of radiating accretion rings that extend from the inner edge to the outer rim of the disc, with some radially varying emissivity. In our work, we show that a characteristic double-horn profile of several radially confined (relatively narrow accretion rings or belts could be recognized by the planned instruments onboard future satellites (such as the proposed ESA Large Observatory for X-ray Timing.

  12. Performance Characterization of UV Science Cameras Developed for the Chromospheric Lyman-Alpha Spectro-Polarimeter

    Science.gov (United States)

    Champey, P.; Kobayashi, K.; Winebarger, A.; Cirtain, J.; Hyde, D.; Robertson, B.; Beabout, D.; Beabout, B.; Stewart, M.

    2014-01-01

    The NASA Marshall Space Flight Center (MSFC) has developed a science camera suitable for sub-orbital missions for observations in the UV, EUV and soft X-ray. Six cameras will be built and tested for flight with the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP), a joint National Astronomical Observatory of Japan (NAOJ) and MSFC sounding rocket mission. The goal of the CLASP mission is to observe the scattering polarization in Lyman-alpha and to detect the Hanle effect in the line core. Due to the nature of Lyman-alpha polarization in the chromosphere, strict measurement sensitivity requirements are imposed on the CLASP polarimeter and spectrograph systems; science requirements for polarization measurements of Q/I and U/I are 0.1 percent in the line core. CLASP is a dual-beam spectro-polarimeter, which uses a continuously rotating waveplate as a polarization modulator, while the waveplate motor driver outputs trigger pulses to synchronize the exposures. The CCDs are operated in frame-transfer mode; the trigger pulse initiates the frame transfer, effectively ending the ongoing exposure and starting the next. The strict requirement of 0.1 percent polarization accuracy is met by using frame-transfer cameras to maximize the duty cycle in order to minimize photon noise. Coating the e2v CCD57-10 512x512 detectors with Lumogen-E coating allows for a relatively high (30 percent) quantum efficiency at the Lyman-alpha line. The CLASP cameras were designed to operate with 10 e-/pixel/second dark current, 25 e- read noise, a gain of 2.0 +/- 0.5 and 1.0 percent residual non-linearity. We present the results of the performance characterization study performed on the CLASP prototype camera; dark current, read noise, camera gain and residual non-linearity.

  13. Line-profile variations in radial-velocity measurements: Two alternative indicators for planetary searches

    CERN Document Server

    Figueira, P; Pepe, F; Lovis, C; Nardetto, N

    2013-01-01

    Aims. We introduce two methods to identify false-positive planetary signals in the context of radial-velocity exoplanet searches. The first is the bi-Gaussian cross-correlation function fitting, and the second is the measurement of asymmetry in radial-velocity spectral line information content, Vasy. Methods. We make a systematic analysis of the most used common line profile diagnosis, Bisector Inverse Slope and Velocity Span, along with the two proposed ones. We evaluate all these diagnosis methods following a set of well-defined common criteria and using both simulated and real data. We apply them to simulated cross-correlation functions created with the program SOAP and which are affected by the presence of stellar spots, and to real cross-correlation functions, calculated from HARPS spectra, for stars with a signal originating both in activity and created by a planet. Results. We demonstrate that the bi-Gaussian method allows a more precise characterization of the deformation of line profiles than the sta...

  14. Hodgkin Lymphoma Cell Lines Are Characterized by a Specific miRNA Expression Profile

    Directory of Open Access Journals (Sweden)

    Johan H. Gibcus

    2009-02-01

    Full Text Available Hodgkin lymphoma (HL is derived from preapoptotic germinal center B cells, although a general loss of B cell phenotype is noted. Using quantitative reverse transcription-polymerase chain reaction and miRNA microarray, we determined the microRNA (miRNA profile of HL and compared this with the profile of a panel of B-cell non-Hodgkin lymphomas. The two methods showed a strong correlation for the detection of miRNA expression levels. The HL-specific miRNA included miR-17-92 cluster members, miR-16, miR-21, miR-24, and miR-155. Using a large panel of cell lines, we found differential expression between HL and other B-cell lymphoma-derived cell lines for 27 miRNA. A significant down-regulation in HL compared to non-Hodgkin lymphoma was observed only for miR-150. Next, we performed target gene validation of predicted target genes for miR-155, which is highly expressed in HL and is differentially expressed between HL and Burkitt lymphoma. Using luciferase reporter assays, we validated 11 predicted miR-155 target genes in three different HL cell lines. We demonstrated that AGTR1, FGF7, ZNF537, ZIC3, and IKBKE are true miR-155 target genes in HL.

  15. Transcriptome Profiling Reveals Degree of Variability in Induced Pluripotent Stem Cell Lines: Impact for Human Disease Modeling.

    Science.gov (United States)

    Schuster, Jens; Halvardson, Jonatan; Pilar Lorenzo, Laureanne; Ameur, Adam; Sobol, Maria; Raykova, Doroteya; Annerén, Göran; Feuk, Lars; Dahl, Niklas

    2015-10-01

    Induced pluripotent stem cell (iPSC) technology has become an important tool for disease modeling. Insufficient data on the variability among iPSC lines derived from a single somatic parental cell line have in practice led to generation and analysis of several, usually three, iPSC sister lines from each parental cell line. We established iPSC lines from a human fibroblast line (HDF-K1) and used transcriptome sequencing to investigate the variation among three sister lines (iPSC-K1A, B, and C). For comparison, we analyzed the transcriptome of an iPSC line (iPSC-K5B) derived from a different fibroblast line (HDF-K5), a human embryonic stem cell (ESC) line (ESC-HS181), as well as the two parental fibroblast lines. All iPSC lines fulfilled stringent criteria for pluripotency. In an unbiased cluster analysis, all stem cell lines (four iPSCs and one ESC) clustered together as opposed to the parental fibroblasts. The transcriptome profiles of the three iPSC sister lines were indistinguishable from each other, and functional pathway analysis did not reveal any significant hits. In contrast, the expression profiles of the ESC line and the iPSC-K5B line were distinct from that of the sister lines iPSC-K1A, B, and C. Differentiation to embryoid bodies and subsequent analysis of germ layer markers in the five stem cell clones confirmed that the distribution of their expression profiles was retained. Taken together, our observations stress the importance of using iPSCs of different parental origin rather than several sister iPSC lines to distinguish disease-associated mechanisms from genetic background effects in disease modeling.

  16. The morphologies of breast cancer cell lines in three-dimensional assays correlate with their profiles of gene expression

    DEFF Research Database (Denmark)

    Kenny, Paraic A; Lee, Genee Y; Myers, Connie A;

    2007-01-01

    large scale comparison of the transcriptional profiles and 3D cell culture phenotypes of a substantial panel of human breast cancer cell lines. Each cell line adopts a colony morphology of one of four main classes in 3D culture. These morphologies reflect, at least in part, the underlying gene...... expression profile and protein expression patterns of the cell lines, and distinct morphologies were also associated with tumor cell invasiveness and with cell lines originating from metastases. We further demonstrate that consistent differences in genes encoding signal transduction proteins emerge when even...

  17. The Lyman alpha reference sample. VII. Spatially resolved Hα kinematics

    Science.gov (United States)

    Herenz, Edmund Christian; Gruyters, Pieter; Orlitova, Ivana; Hayes, Matthew; Östlin, Göran; Cannon, John M.; Roth, Martin M.; Bik, Arjan; Pardy, Stephen; Otí-Floranes, Héctor; Mas-Hesse, J. Miguel; Adamo, Angela; Atek, Hakim; Duval, Florent; Guaita, Lucia; Kunth, Daniel; Laursen, Peter; Melinder, Jens; Puschnig, Johannes; Rivera-Thorsen, Thøger E.; Schaerer, Daniel; Verhamme, Anne

    2016-03-01

    We present integral field spectroscopic observations with the Potsdam Multi-Aperture Spectrophotometer of all 14 galaxies in the z ~ 0.1 Lyman Alpha Reference Sample (LARS). We produce 2D line-of-sight velocity maps and velocity dispersion maps from the Balmer α (Hα) emission in our data cubes. These maps trace the spectral and spatial properties of the LARS galaxies' intrinsic Lyα radiation field. We show our kinematic maps that are spatially registered onto the Hubble Space Telescope Hα and Lyman α (Lyα) images. We can conjecture a causal connection between spatially resolved Hα kinematics and Lyα photometry for individual galaxies, however, no general trend can be established for the whole sample. Furthermore, we compute the intrinsic velocity dispersion σ0, the shearing velocity vshear, and the vshear/σ0 ratio from our kinematic maps. In general LARS galaxies are characterised by high intrinsic velocity dispersions (54 km s-1 median) and low shearing velocities (65 km s-1 median). The vshear/σ0 values range from 0.5 to 3.2 with an average of 1.5. It is noteworthy that five galaxies of the sample are dispersion-dominated systems with vshear/σ0 1. Our result indicates that turbulence in actively star-forming systems is causally connected to interstellar medium conditions that favour an escape of Lyα radiation. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).The reduced data cubes (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A78

  18. Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies

    Science.gov (United States)

    Izotov, Y. I.; Schaerer, D.; Thuan, T. X.; Worseck, G.; Guseva, N. G.; Orlitová, I.; Verhamme, A.

    2016-10-01

    Following our first detection reported in Izotov et al., we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope. These galaxies, at redshifts of z ˜ 0.3, are characterized by high emission-line flux ratios [O III] λ5007/[O II] λ3727 ≳ 5. The escape fractions of the LyC radiation fesc(LyC) in these galaxies are in the range of ˜6-13 per cent, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Ly α emission lines are detected in the spectra of all four galaxies, compatible with predictions for LyC leakers. We find escape fractions of Ly α, fesc(Ly α) ˜ 20-40 per cent, among the highest known for Ly α emitting galaxies. Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the centre and exponential discs in the outskirts with disc scalelengths α in the range ˜0.6-1.4 kpc. Our galaxies are characterized by low metallicity, ˜1/8-1/5 solar, low stellar mass ˜(0.2-4) × 109 M⊙, high star formation rates, SFR ˜ 14-36 M⊙ yr-1, and high SFR densities, Σ ˜ 2-35 M⊙ yr-1 kpc-2. These properties are comparable to those of high-redshift star-forming galaxies. Finally, our observations, combined with our first detection reported in Izotov et al., reveal that a selection for compact star-forming galaxies showing high [O III] λ5007/[O II] λ3727 ratios appears to pick up very efficiently sources with escaping LyC radiation: all five of our selected galaxies are LyC leakers.

  19. Performance comparison of digital microRNA profiling technologies applied on human breast cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Erik Knutsen

    Full Text Available MicroRNA profiling represents an important first-step in deducting individual RNA-based regulatory function in a cell, tissue, or at a specific developmental stage. Currently there are several different platforms to choose from in order to make the initial miRNA profiles. In this study we investigate recently developed digital microRNA high-throughput technologies. Four different platforms were compared including next generation SOLiD ligation sequencing and Illumina HiSeq sequencing, hybridization-based NanoString nCounter, and miRCURY locked nucleic acid RT-qPCR. For all four technologies, full microRNA profiles were generated from human cell lines that represent noninvasive and invasive tumorigenic breast cancer. This study reports the correlation between platforms, as well as a more extensive analysis of the accuracy and sensitivity of data generated when using different platforms and important consideration when verifying results by the use of additional technologies. We found all the platforms to be highly capable for microRNA analysis. Furthermore, the two NGS platforms and RT-qPCR all have equally high sensitivity, and the fold change accuracy is independent of individual miRNA concentration for NGS and RT-qPCR. Based on these findings we propose new guidelines and considerations when performing microRNA profiling.

  20. Gene expression profiles of human promyelocytic leukemia cell lines exposed to volatile organic compounds.

    Science.gov (United States)

    Sarma, Sailendra Nath; Kim, Youn-Jung; Ryu, Jae-Chun

    2010-05-27

    Benzene, toluene, o-xylene, ethylbenzene, trichloroethylene and dichloromethane are the most widely used volatile organic compounds (VOCs), and their toxic mechanisms are still undefined. This study analyzed the genome-wide expression profiles of human promyelocytic leukemia HL-60 cells exposed to VOCs using a 35-K whole human genome oligonucleotide microarray to ascertain potential biomarkers. Genes with a significantly increased expression levels (over 1.5-fold and p-values p53 signaling pathway, apoptosis, and natural killer cell-mediated cytotoxicity pathway. Functionally important immune response- and apoptosis-related genes were further validated by real-time RT-PCR. The results showed that IFIT1, IFIT2, IFIT3, USP18, INFGR2, PMAIP1, GADD45A, NFKBIA, TNFAIP3, and BIRC3 genes altered their expression profiles in a dose-dependent manner. Similar expressions profiles were also found in human erythromyeloblastoid leukemia K562 cells and in human leukemic monocyte lymphoma U937 cells. In conclusion, both gene expression profiles and gene ontology analysis have elucidated potential gene-based biomarkers and provided insights into the mechanism underlying the response of human leukemia cell lines to VOC exposure.

  1. Performance comparison of digital microRNA profiling technologies applied on human breast cancer cell lines.

    Science.gov (United States)

    Knutsen, Erik; Fiskaa, Tonje; Ursvik, Anita; Jørgensen, Tor Erik; Perander, Maria; Lund, Eiliv; Seternes, Ole Morten; Johansen, Steinar D; Andreassen, Morten

    2013-01-01

    MicroRNA profiling represents an important first-step in deducting individual RNA-based regulatory function in a cell, tissue, or at a specific developmental stage. Currently there are several different platforms to choose from in order to make the initial miRNA profiles. In this study we investigate recently developed digital microRNA high-throughput technologies. Four different platforms were compared including next generation SOLiD ligation sequencing and Illumina HiSeq sequencing, hybridization-based NanoString nCounter, and miRCURY locked nucleic acid RT-qPCR. For all four technologies, full microRNA profiles were generated from human cell lines that represent noninvasive and invasive tumorigenic breast cancer. This study reports the correlation between platforms, as well as a more extensive analysis of the accuracy and sensitivity of data generated when using different platforms and important consideration when verifying results by the use of additional technologies. We found all the platforms to be highly capable for microRNA analysis. Furthermore, the two NGS platforms and RT-qPCR all have equally high sensitivity, and the fold change accuracy is independent of individual miRNA concentration for NGS and RT-qPCR. Based on these findings we propose new guidelines and considerations when performing microRNA profiling.

  2. Geometric design and simulation of tooth profile using elliptical segments as its line of action

    Institute of Scientific and Technical Information of China (English)

    王建; 罗善明; 苏德瑜; 常雪峰

    2015-01-01

    A mathematical model of gear tooth profiles using the ellipse curve, whose curvature is convenient to control by changing the mathematical parameters as its line of action, was built based on the meshing theory. The equation of undercutting condition was derived from the model. A special epicycloidal tooth profile was also presented. An example gear drive with variation of the ellipse parameters was taken to illustrate the proposed method. The contact ratio of the gear drive designed by the proposed method was analyzed. A comparison of the property of the gear drive designed with the involute gear drive was also carried out. The results confirm that the proposed gear drive has higher contact ratio in comparison with the involute gear drive.

  3. The Lyman alpha Reference Sample VI: Lyman alpha escape from the edge-on disk galaxy Mrk1486

    CERN Document Server

    Duval, Florent; Hayes, Matthew; Zackrisson, Erik; Verhamme, Anne; Orlitova, Ivana; Adamo, Angela; Guaita, Lucia; Melinder, Jens; Cannon, John M; Laursen, Peter; Rivera-Thorsen, Thoger; Herenz, E Christian; Gruyters, Pieter; Mas-Hesse, J Miguel; Kunth, Daniel; Sandberg, Andreas; Schaerer, Daniel; Mansson, Tore

    2015-01-01

    While numerical simulations suggest that the strength of the Lyman alpha (Lya) line of star-forming disk galaxies strongly depends on the inclination at which they are observed (i.e. from edge-on to face-on, we expect to see a change from an attenuated Lya line to a strong Lya emission line), recent observations with the Hubble space telescope (HST) have highlighted few low-redshift highly inclined (edge-on) disk galaxies that breaks this trend. We aim to understand how a strong Lya emission line is able to escape from one of those inclined disk galaxies, named Mrk1486 (z=0.0338). For that purpose we used a large set of HST imaging and spectroscopic data to investigate both the ISM structure and the dominant source of Lya radiation inside Mrk1486. Moreover, we used a 3D Monte Carlo Lya radiation transfer code to study the radiative transfer of Lya and UV continuum photons inside a 3D geometry of neutral hydrogen (HI) and dust that models the ISM structure at the galaxy center. The analysis of IFU Halpha spect...

  4. Gene expression profile of colon cancer cell lines treated with SN-38

    DEFF Research Database (Denmark)

    Wallin, A; Francis, P; Nilbert, M

    2010-01-01

    Colorectal cancer is the third most common form of cancer in the industrial countries. Due to advances regarding the treatments, primarily development of improved surgical methods and the ability to make the earlier diagnosis, the mortality has remained constant during the past decades even though...... the incidence in fact has increased. To improve chemotherapy and enable personalised treatment, the need of biomarkers is of great significance. In this study, we evaluated the gene expression profiles of the colon cancer cell lines treated with SN-38, the active metabolite of topoisomerase-1 inhibitor...

  5. Gene expression profile of colon cancer cell lines treated with SN-38

    DEFF Research Database (Denmark)

    Wallin, A; Francis, P; Nilbert, M;

    2010-01-01

    the incidence in fact has increased. To improve chemotherapy and enable personalised treatment, the need of biomarkers is of great significance. In this study, we evaluated the gene expression profiles of the colon cancer cell lines treated with SN-38, the active metabolite of topoisomerase-1 inhibitor......Colorectal cancer is the third most common form of cancer in the industrial countries. Due to advances regarding the treatments, primarily development of improved surgical methods and the ability to make the earlier diagnosis, the mortality has remained constant during the past decades even though...

  6. Variations of flaring kernel sizes in various parts of the H-alpha line profile

    CERN Document Server

    Radziszewski, K

    2012-01-01

    We analyze the temporal variations of the sizes and emission intensities of thirtyone flaring kernels in various parts of the H{\\alpha} line profile. We have found that the areas of all kernels decrease systematically when observed in consecutive wavelengths toward the wings of the H{\\alpha} line, but their areas and emission intensity vary in time. Our results are in agreement with the commonly accepted model of the glass-shaped lower parts of the magnetic flaring loops channelling high energy variable particle beams toward the chromospheric plasma. High time resolution spectral-imaging data used in our work were collected using the Large Coronagraph and Horizontal Telescope equipped with the Multi-channel Subtractive Double Pass Spectrograph and the Solar Eclipse Coronal Imaging System (MSDP-SECIS) at the Bia{\\l}k\\'ow Observatory of the University of Wroc{\\l}aw, Poland.

  7. Sizes of flaring kernels in various parts of the Hα line profile

    Directory of Open Access Journals (Sweden)

    K. Radziszewski

    2008-10-01

    Full Text Available In this paper we present new results of spectra-photometrical investigations of the flaring kernels' sizes and their intensities measured simultaneously in various parts of the Hα line profile. Our investigations were based on the very high temporal resolution spectral-imaging observations of the solar flares collected with Large Coronagraph (LC, Multi-channel Subtractive Double Pass Spectrograph and Solar Eclipse Coronal Imaging System (MSDP-SECIS at Białkow Observatory (University of Wrocław, Poland.

    We have found that the areas of the investigated individual flaring kernels vary in time and in wavelengths, as well as the intensities and areas of the Hα flaring kernels decreased systematically when observed in consecutive wavelengths toward the wings of the Hα line. Our result could be explained as an effect of the cone-shaped lower parts of the magnetic loops channeling high energy particle beams exciting chromospheric plasma.

  8. Lyman continuum galaxies and the escape fraction of Lyman break galaxies

    CERN Document Server

    Cooke, Jeff; Garel, Thibault; Diaz, C Gonzalo

    2014-01-01

    Lyman break galaxies (LBGs) at z ~ 3-4 are targeted to measure the fraction of Lyman continuum (LyC) flux that escapes from high redshift galaxies. However, z ~ 3-4 LBGs are identified using the Lyman break technique which preferentially selects galaxies with little or no LyC. We re-examine the standard LBG selection criteria by performing spectrophotometry on composite spectra constructed from 794 U_nGR-selected z ~ 3 LBGs from the literature while adding LyC flux of varying strengths. The modified composite spectra accurately predict the range of redshifts, properties, and LyC flux of LBGs in the literature that have spectroscopic LyC measurements while predicting the existence of a significant fraction of galaxies outside the standard selection region. These galaxies, termed Lyman continuum galaxies (LCGs), are expected to have high levels of LyC flux and are estimated to have a number density ~30-50 percent that of the LBG population. We define R_obs(U_n) as the relative fraction of observed LyC flux, int...

  9. An extreme [OIII] emitter at $z=3.2$: a low metallicity Lyman continuum source

    CERN Document Server

    de Barros, S; Amorín, R; Castellano, M; Siana, B; Grazian, A; Suh, H; Balestra, I; Vignali, C; Verhamme, A; Zamorani, G; Mignoli, M; Hasinger, G; Comastri, A; Pentericci, L; Pérez-Montero, E; Fontana, A; Giavalisco, M; Gilli, R

    2016-01-01

    [Abridged] We investigate the physical properties of a Lyman continuum emitter candidate at $z=3.212$ with photometric coverage from $U$ to MIPS 24$\\mu$m band and VIMOS/VLT and MOSFIRE/Keck spectroscopy. Investigation of the UV spectrum confirms a direct spectroscopic detection of the Lyman continuum emission with $S/N>5$. Non-zero Ly$\\alpha$ flux at the systemic redshift and high Lyman-$\\alpha$ escape fraction suggest a low HI column density. The weak C and Si low-ionization absorption lines are also consistent with a low covering fraction along the line of sight. The [OIII]$\\lambda\\lambda4959,5007+\\mathrm{H}\\beta$ equivalent width is one of the largest reported for a galaxy at $z>3$ ($\\mathrm{EW}([\\mathrm{OIII}]\\lambda\\lambda4959,5007+\\mathrm{H}\\beta) \\simeq 1600\\AA$, rest-frame) and the NIR spectrum shows that this is mainly due to an extremely strong [OIII] emission. The large observed [OIII]/[OII] ratio ($>10$) and high ionization parameter are consistent with prediction from photoionization models in ca...

  10. No Evidence for Lyman-alpha Emission in Spectroscopy of z > 7 Candidate Galaxies

    CERN Document Server

    Caruana, Joseph; Wilkins, Stephen M; Stanway, Elizabeth R; Lacy, Mark; Jarvis, Matt J; Lorenzoni, Silvio; Hickey, Samantha

    2012-01-01

    We present Gemini/GNIRS spectroscopic observations of 4 z-band (z~7) dropout galaxies and VLT/XSHOOTER observations of one z-band dropout and 3 Y-band (z~8-9) dropout galaxies in the Hubble Ultra Deep Field, which were selected with Wide Field Camera 3 imaging on the Hubble Space Telescope. We find no evidence of Lyman-alpha emission with a typical 5-sigma sensitivity of 5X10^-18erg/cm^2/s, and we use the upper limits on Lyman-alpha flux and the broad-band magnitudes to constrain the rest-frame equivalent widths for this line emission. Accounting for incomplete spectral coverage, we survey 3.0 z-band dropouts and 2.9 Y-band dropouts to a Lyman-alpha rest-frame equivalent width limit > 120Ang (for an unresolved emission line); for an equivalent width limit of 50Ang the effective numbers of drop-outs surveyed fall to 1.2 z-band drop-outs and 1.5 Y-band drop-outs. A simple model where the fraction of high rest-frame equivalent width emitters follows the trend seen at z=3-6.5 is inconsistent with our non-detectio...

  11. Exploring the nature of the Lyman-α emitter CR7

    Science.gov (United States)

    Hartwig, Tilman; Latif, Muhammad A.; Magg, Mattis; Bromm, Volker; Klessen, Ralf S.; Glover, Simon C. O.; Whalen, Daniel J.; Pellegrini, Eric W.; Volonteri, Marta

    2016-10-01

    CR7 is the brightest Lyman-α emitter observed at z > 6, which shows very strong Lyman-α and He II 1640 Å line luminosities, but no metal-line emission. Previous studies suggest that CR7 hosts either young primordial stars with a total stellar mass of ˜107 M⊙ or a black hole of ≳106 M⊙. Here, we explore different formation scenarios for CR7 with a semi-analytical model, based on the random sampling of dark matter merger trees. We are unable to reproduce the observational constraints with a primordial stellar source, given our model assumptions, due to the short stellar lifetimes and the early metal enrichment. Black holes that are the remnants of the first stars are either not massive enough, or reside in metal-polluted haloes, ruling out this possible explanation of CR7. Our models instead suggest that direct collapse black holes, which form in metal-free haloes exposed to large Lyman-Werner fluxes, are more likely the origin of CR7. However, this result is derived under optimistic assumptions and future observations are necessary to further constrain the nature of CR7.

  12. Lyman alpha SMM/UVSP absolute calibration and geocoronal correction

    Science.gov (United States)

    Fontenla, Juan M.; Reichmann, Edwin J.

    1987-01-01

    Lyman alpha observations from the Ultraviolet Spectrometer Polarimeter (UVSP) instrument of the Solar Maximum Mission (SMM) spacecraft were analyzed and provide instrumental calibration details. Specific values of the instrument quantum efficiency, Lyman alpha absolute intensity, and correction for geocoronal absorption are presented.

  13. The visibility of Lyman Alpha Emitters during reionization

    CERN Document Server

    Dayal, Pratika; Ferrara, Andrea

    2010-01-01

    We present the first Lyman Alpha Emitter (LAE) study that combines: (i) cosmological SPH simulations run using GADGET-2, (ii) radiative transfer simulations (CRASH), and (iii) a previously developed LAE model. This complete LAE model accounts for the intrinsic LAE Lyman Alpha/continuum luminosity, dust enrichment and Lyman Alpha transmission through the intergalactic medium (IGM), to quantify the effects of reionization, dust and velocity fields on the Lyman Alpha and UV Luminosity Functions (LF). We find that a model neglecting dust sorely fails to reproduce either the slope or the magnitude of the observed Lyman Alpha and UV LFs. Clumped dust is required to simultaneously fit the observed UV and Lyman Alpha LFs, such that the intrinsic Lyman Alpha-to-continuum luminosity is enhanced by a factor f_alpha/f_c ~ 1.5 (3.7) excluding (including) peculiar velocities. The higher value including velocity fields arises since LAEs reside in large potential wells and inflows decrease their Lyman Alpha transmission. For...

  14. Genetic parameters and crossbreeding effects of fat deposition and fatty acid profiles in Iberian pig lines.

    Science.gov (United States)

    Ibáñez-Escriche, N; Magallón, E; Gonzalez, E; Tejeda, J F; Noguera, J L

    2016-01-01

    The aim of this study was to estimate the genetic and environmental parameters and crossbreeding effects on fatty acid and fat traits in the Iberian pig. Our final goal is to explore target selection traits and define crossbreeding strategies. The phenotypes were obtained under intensive management from 470 animals in a diallelic experiment involving Retinto, Torbiscal, and Entrepelado lines. The data set was composed of backfat thickness at the fourth rib (BFT), intramuscular fat (IMF) in the longissimus thoracis (LT), and the fatty acid profile for IMF and subcutaneous fat (SCF) traits. Data were analyzed through a Bayesian bivariate animal model by using a reparameterization of Dickerson's model. The results obtained showed an important genetic determinism for all traits analyzed with heritability ranging from 0.09 to 0.67. The common environment litter effect also had an important effect on IMF (0.34) and its fatty acid composition (0.06-0.53) at slaughter. The additive genetic correlation between BFT and IMF (additive genetic correlation [] = 0.31) suggested that it would be possible to improve lean growth independent of the IMF with an appropriate selection index. Furthermore, the high additive genetic correlation ( = 0.68) found between MUFA tissues would seem to indicate that either the LT or SCF could be used as the reference tissue for MUFA selection. The relevance of the crossbreeding parameters varied according to the traits analyzed. Backfat thickness at the fourth rib and the fatty acid profile of the IMF showed relevant differences between crosses, mostly due to line additive genetic effects associated with the Retinto line. On the contrary, those for IMF crosses were probably mainly attributable to heterosis effects. Particularly, heterosis effects were relevant for the Retinto and Entrepelado crosses (approximately 16% of the trait), which could be valuable for a crossbreeding system involving these lines.

  15. K$\\alpha$ iron line profile from accretion disks around regular and singular exotic compact objects

    CERN Document Server

    Bambi, Cosimo

    2013-01-01

    The nature of the super-massive black hole candidates in galactic nuclei can be tested by analyzing the profile of the K$\\alpha$ iron line observed in their X-ray spectrum. In this paper, we consider the possibility that the spacetime in the immediate vicinity of these objects may be described by some non vacuum exact solutions of Einstein's equations resulting as the end-state of gravitational collapse. The vacuum far away portion of the spacetime is described by the Schwarzschild metric, while the interior part may be either regular or have a naked singularity at the center. The iron line generated around this class of objects has specific features, which can be used to distinguish such objects from Kerr black holes. In particular, their iron line cannot have the characteristic low-energy tail of the line generated from accretion disks around fast-rotating Kerr black holes. We can thus conclude that the super-massive black hole candidates whose spin parameter has been estimated to be close to 1 assuming the...

  16. Derivation and transcriptional profiling analysis of pluripotent stem cell lines from rat blastocysts

    Institute of Scientific and Technical Information of China (English)

    Chunliang Li; Ying Yang; Junjie Gu; Yu Ma; Ying Jin

    2009-01-01

    Embryonic stem (ES) cells are derived from blastocyst-stage embryos. Their unique properties of self-renewal and pluripotency make them an attractive tool for basic research and a potential cell resource for therapy. ES cells of mouse and human have been successfully generated and applied in a wide range of research. However, no genuine ES cell lines have been obtained from rat to date. In this study, we identified pluripotent cells in early rat embryos using specific antibodies against markers of pluripotent stem cells. Subsequently, by modifying the culture medium for rat blastocysts, we derived pluripotent rat ES-llke cell lines, which expressed pluripotency markers and formed embryoid bodies (EBs) in vitro. Importantly, these rat ES-like cells were able to produce teratomas. Both EBs and teratomas contained tissues from all three embryonic germ layers, in addition, from the rat ES-like cells, we derived a rat primitive endoderm (PrE) cell line. Furthermore, we conducted transcriptional profiling of the rat ES-like cells and identified the unique molecular signature of the rat pluripotent stem cells. Our analysis demonstrates that multiple signaling pathways, including the BMP, Activin and roTOR pathways, may be involved in keeping the rat ES-like cells in an undifferentiated state. The cell lines and information obtained in this study will accelerate our understanding of the molecular regulation underlying pluripotency and guide us in the appropriate manipulation of ES cells from a particular species.

  17. A Tie2-driven BAC-TRAP transgenic line for in vivo endothelial gene profiling.

    Science.gov (United States)

    Santhosh, Devi; Huang, Zhen

    2016-03-01

    Recent technological innovations including bacterial artificial chromosome-based translating ribosome affinity purification (BAC-TRAP) have greatly facilitated analysis of cell type-specific gene expression in vivo, especially in the nervous system. To better study endothelial gene expression in vivo, we have generated a BAC-TRAP transgenic mouse line where the L10a ribosomal subunit is tagged with EGFP and placed under the control of the endothelium-specific Tie2 (Tek) promoter. We show that transgene expression in this line is widely, but specifically, detected in endothelial cells in several brain regions throughout pre- and postnatal development, as well as in other organs. We also show that this line results in highly significant enrichment of endothelium-specific mRNAs from brain tissues at different stages. This BAC-TRAP line therefore provides a useful genetic tool for in vivo endothelial gene profiling under various developmental, physiological, and pathological conditions. genesis 54:136-145, 2016. © 2016 Wiley Periodicals, Inc.

  18. THE GENE EXPRESSION PROFILE OF HIGHLY METASTATIC HUMAN OVARIAN CANCER CELL LINE BY GENE CHIP

    Institute of Scientific and Technical Information of China (English)

    吕桂泉; 许沈华; 牟瀚舟; 朱赤红; 羊正炎; 高永良; 楼洪坤; 刘祥麟; 杨文; 程勇

    2001-01-01

    To study the gene expression of high metastatic human ovarian carcinoma cell line (HO-8910PM) and to screen for novel metastasis- associated genes by cDNA microarray. Methods: The cDNA was retro-transcribed from equal quantity mRNA derived from tissues of highly metastatic ovarian carcinoma cell line and normal ovarian, and was labeled with Cy5 and Cy3 fluorescence as probes. The mixed probes were hybridized with BioDoor 4096 double dot human whole gene chip. The chip was scanned by scanArray 3000 laser scanner. The acquired image was analyzed by ImaGene 3.0 software. Results: By applying the cDNA microarray we found: A total of 323 genes whose expression level were 3 times higher or lower in HO-8910PM cell than normal ovarian epithelium cell were screened out, with 71 higher and 252 lower respectively. Among these 10 were new genes. 67 genes showed expression difference bigger than 6 times between HO-8910PM cell and normal ovarian epithelium cell, among these genes 12 were higher, 55 lower, and two new genes were found. Conclusion: cDNA microarray technique is effective in screening the differentially expressed genes between human ovarian cancer cell line (HO-8910PM) and normal ovarian epithelium cell. Using the cDNA microarray to analyze of human ovarian cancer cell line gene expression profile difference will help the gene diagnosis, treatment and protection.

  19. Demonstration of Current Profile Shaping using Double Dog-Leg Emittance Exchange Beam Line at Argonne Wakefield Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Gwanghui [Argonne, HEP; Cho, Moo-Hyun [POSTECH; Conde, Manoel [Argonne, HEP; Doran, Darrell [Argonne, HEP; Gai, Wei [Argonne, HEP; Jing, Chunguang [Euclid Techlabs, Solon; Kim, Kwang-Je [Argonne, HEP; Liu, Wanming [Argonne, HEP; Namkung, Won [POSTECH; Piot, Philippe [Northern Illinois U.; Power, John [Argonne, HEP; Sun, Yin-E [Argonne, HEP; Whiteford, Charles [Argonne, HEP; Wisniewski, Eric [Argonne, HEP; Zholents, Alexander [Argonne, HEP

    2016-06-01

    Emittance exchange (EEX) based longitudinal current profile shaping is the one of the promising current profile shaping technique. This method can generate high quality arbitrary current profiles under the ideal conditions. The double dog-leg EEX beam line was recently installed at the Argonne Wakefield Accelerator (AWA) to explore the shaping capability and confirm the quality of this method. To demonstrate the arbitrary current profile generation, several different transverse masks are applied to generate different final current profiles. The phase space slopes and the charge of incoming beam are varied to observe and suppress the aberrations on the ideal profile. We present current profile shaping results, aberrations on the shaped profile, and its suppression.

  20. The galactic unclassified B[e] star HD 50138 III. The short-term line profile variability of its photospheric lines

    CERN Document Server

    Fernandes, Marcelo Borges; Nickeler, Dieter H; De Cat, Peter; Lampens, Patricia; Pereira, Claudio Bastos; Oksala, Mary E

    2012-01-01

    HD 50138 presents the B[e] phenomenon, but its nature is not clear yet. This star is known to present spectral variations, which have been associated with outbursts and shell phases. We analyze the line profile variability of HD 50138 and its possible origin, which provide possible hints to its evolutionary stage, so far said to be close to the end of (or slightly beyond) the main sequence. New high-resolution spectra of HD 50138 obtained with the HERMES spectrograph over several nights (five of them consecutively) were analyzed, allowing us to confirm short-term line profile variability. Our new data show short-term variations in the photospheric lines. On the other hand, purely circumstellar lines (such as [O I] lines) do not show such rapid variability. The rotational velocity of HD 50138, V_rot = 90.3 +- 4.3 km/s, and the rotation period, P = 3.64 +- 1.16 d, were derived from the He II 4026A photospheric line. Based on the moment method, we confirm that the origin of this short-term line profile variabili...

  1. Numerical Evaluation of Parameter Correlation in the Hartmann-Tran Line Profile

    Science.gov (United States)

    Adkins, Erin M.; Reed, Zachary; Hodges, Joseph T.

    2017-06-01

    The partially correlated quadratic, speed-dependent hard-collision profile (pCqSDHCP), for simplicity referred to as the Hartmann-Tran profile (HTP), has been recommended as a generalized lineshape for high resolution spectroscopy. The HTP parameterizes complex collisional effects such as Dicke narrowing, speed dependent narrowing, and correlations between velocity-changing and dephasing collisions, while also simplifying to simpler profiles that are widely used, such as the Voigt profile. As advanced lineshape profiles are adopted by more researchers, it is important to understand the limitations that data quality has on the ability to retrieve physically meaningful parameters using sophisticated lineshapes that are fit to spectra of finite signal-to-noise ratio. In this work, spectra were simulated using the HITRAN Application Programming Interface (HAPI) across a full range of line parameters. Simulated spectra were evaluated to quantify the precision with which fitted lineshape parameters can be determined at a given signal-to-noise ratio, focusing on the numerical correlation between the retrieved Dicke narrowing frequency and the velocity-changing and dephasing collisions correlation parameter. Tran, H., N. Ngo, and J.-M. Hartmann, Journal of Quantitative Spectroscopy and Radiative Transfer 2013. 129: p. 89-100. Tennyson, et al., Pure Appl. Chem. 2014, 86: p. 1931-1943. Kochanov, R.V., et al., Journal of Quantitative Spectroscopy and Radiative Transfer 2016. 177: p. 15-30. Tran, H., N. Ngo, and J.-M. Hartmann, Journal of Quantitative Spectroscopy and Radiative Transfer 2013. 129: p. 199-203.

  2. First results from Faint Infrared Grism Survey (FIGS): first simultaneous detection of Lyman-{\\alpha} emission and Lyman break from a galaxy at z=7.51

    CERN Document Server

    Tilvi, V; Malhotra, S; Finkelstein, S L; Rhoads, J E; Windhorst, R; Grogin, N A; Koekemoer, A; Zakamska, N; Ryan, R; Christensen, L; Hathi, N; Pharo, J; Joshi, B; Yang, H; Gronwall, C; Cimatti, A; Walsh, J; OConnell, R; Straughn, A; Ostlin, G; Rothberg, B; Livermore, R C; Hibon, P; Gardner, Jonathan P

    2016-01-01

    Galaxies at high redshifts provide a valuable tool to study cosmic dawn, and therefore it is crucial to reliably identify these galaxies. Here, we present an unambiguous and first simultaneous detection of both the Lyman-\\alpha emission and the Lyman break from a z = 7.512+/- 0.004 galaxy, observed in the Faint Infrared Grism Survey (FIGS). These spectra, taken with G102 grism on Hubble Space Telescope (HST), show a significant emission line detection (6{\\sigma}) in multiple observational position angles (PA), with total integrated Ly{\\alpha} line flux of 1.06+/- 0.12 e10-17erg s-1cm-2. The line flux is nearly a factor of four higher than the previous MOSFIRE spectroscopic observations of faint Ly{\\alpha} emission at {\\lambda} = 1.0347{\\mu}m, yielding z = 7.5078+/- 0.0004. This is consistent with other recent observations implying that ground-based near-infrared spectroscopy underestimates total emission line fluxes, and if confirmed, can have strong implications for reionization studies that are based on gro...

  3. Cell Line Derived 5-FU and Irinotecan Drug-Sensitivity Profiles Evaluated in Adjuvant Colon Cancer Trial Data

    DEFF Research Database (Denmark)

    Buhl, Ida Kappel; Gerster, Sarah; Delorenzi, Mauro

    2016-01-01

    patients who benefitted from the addition of irinotecan to 5-FU, we used gene expression profiles based on cell lines and clinical tumor material. These profiles were applied to expression data obtained from pretreatment formalin fixed paraffin embedded (FFPE) tumor tissue from 636 stage III colon cancer...

  4. Modification of SOL profiles and fluctuations with line-average density and divertor flux expansion in TCV

    DEFF Research Database (Denmark)

    Vianello, N.; Tsui, C.; Theiler, C.

    2017-01-01

    that this modification does not influence neither the detachment density threshold, nor the development of a flat SOL density profile which instead depends strongly on the increase of the core line average density. The modification of the SOL upstream profile, with the appearance of what is generally called a density...

  5. The 3D scanner prototype utilize object profile imaging using line laser and octave software

    Science.gov (United States)

    Nurdini, Mugi; Manunggal, Trikarsa Tirtadwipa; Samsi, Agus

    2016-11-01

    Three-dimensional scanner or 3D Scanner is a device to reconstruct the real object into digital form on a computer. 3D Scanner is a technology that is being developed, especially in developed countries, where the current 3D Scanner devices is the advanced version with a very expensive prices. This study is basically a simple prototype of 3D Scanner with a very low investment costs. 3D Scanner prototype device consists of a webcam, a rotating desk system controlled by a stepper motor and Arduino UNO, and a line laser. Objects that limit the research is the object with same radius from its center point (object pivot). Scanning is performed by using object profile imaging by line laser which is then captured by the camera and processed by a computer (image processing) using Octave software. On each image acquisition, the scanned object on a rotating desk rotated by a certain degree, so for one full turn multiple images of a number of existing side are finally obtained. Then, the profile of the entire images is extracted in order to obtain digital object dimension. Digital dimension is calibrated by length standard, called gage block. Overall dimensions are then digitally reconstructed into a three-dimensional object. Validation of the scanned object reconstruction of the original object dimensions expressed as a percentage error. Based on the results of data validation, horizontal dimension error is about 5% to 23% and vertical dimension error is about +/- 3%.

  6. Modelling chromospheric line profiles as diagnostics of velocity fields in {\\omega} Centauri red giant stars

    CERN Document Server

    Vieytes, M; Cacciari, C; Origlia, L; Pancino, E

    2010-01-01

    Context. Mass loss of ~0.1-0.3 M$_{\\odot}$ from Population II red giant stars (RGB) is a requirement of stellar evolution theory in order to account for several observational evidences in globular clusters. Aims. The aim of this study is to detect the presence of outward velocity fields, which are indicative of mass outflow, in six luminous red giant stars of the stellar cluster {\\omega} Cen. Methods. We compare synthetic line profiles computed using relevant model chromospheres to observed profiles of the H{\\alpha} and Ca II K lines. The spectra were taken with UVES (R=45,000) and the stars were selected so that three of them belong to the metal-rich population and three to the metal-poor population, and sample as far down as 1 to 2.5 magnitudes fainter than the respective RGB tips. Results. We do indeed reveal the presence of low-velocity outward motions in four of our six targets, without any apparent correlation with astrophysical parameters. Conclusions. This provides direct evidence that outward velocit...

  7. A CpG island hypermethylation profile of primary colorectal carcinomas and colon cancer cell lines

    Directory of Open Access Journals (Sweden)

    Rognum Torleiv O

    2004-10-01

    Full Text Available Abstract Background Tumor cell lines are commonly used as experimental tools in cancer research, but their relevance for the in vivo situation is debated. In a series of 11 microsatellite stable (MSS and 9 microsatellite unstable (MSI colon cancer cell lines and primary colon carcinomas (25 MSS and 28 MSI with known ploidy stem line and APC, KRAS, and TP53 mutation status, we analyzed the promoter methylation of the following genes: hMLH1, MGMT, p16INK4a (CDKN2A α-transcript, p14ARF (CDKN2A β-transcript, APC, and E-cadherin (CDH1. We compared the DNA methylation profiles of the cell lines with those of the primary tumors. Finally, we examined if the epigenetic changes were associated with known genetic markers and/or clinicopathological variables. Results The cell lines and primary tumors generally showed similar overall distribution and frequencies of gene methylation. Among the cell lines, 15%, 50%, 75%, 65%, 20% and 15% showed promoter methylation for hMLH1, MGMT, p16INK4a, p14ARF, APC, and E-cadherin, respectively, whereas 21%, 40%, 32%, 38%, 32%, and 40% of the primary tumors were methylated for the same genes. hMLH1 and p14ARF were significantly more often methylated in MSI than in MSS primary tumors, whereas the remaining four genes showed similar methylation frequencies in the two groups. Methylation of p14ARF, which indirectly inactivates TP53, was seen more frequently in tumors with normal TP53 than in mutated samples, but the difference was not statistically significant. Methylation of p14ARF and p16INK4a was often present in the same primary tumors, but association to diploidy, MSI, right-sided location and female gender was only significant for p14ARF. E-cadherin was methylated in 14/34 tumors with altered APC further stimulating WNT signaling. Conclusions The present study shows that colon cancer cell lines are in general relevant in vitro models, comparable with the in vivo situation, as the cell lines display many of the same

  8. Strong H I Lyman-α variations from an 11 Gyr-old host star: a planetary origin?

    Science.gov (United States)

    Bourrier, V.; Ehrenreich, D.; Allart, R.; Wyttenbach, A.; Semaan, T.; Astudillo-Defru, N.; Gracia-Berná, A.; Lovis, C.; Pepe, F.; Thomas, N.; Udry, S.

    2017-06-01

    Kepler-444 provides a unique opportunity to probe the atmospheric composition and evolution of a compact system of exoplanets smaller than the Earth. Five planets transit this bright K star at close orbital distances, but they are too small for their putative lower atmosphere to be probed at optical/infrared wavelengths. We used the Space Telescope Imaging Spectrograph instrument on board the Hubble Space Telescope to search for the signature of the planet's upper atmospheres at six independent epochs in the Lymanline. We detect significant flux variations during the transits of both Kepler-444 e and f ( 20%), and also at a time when none of the known planets was transiting ( 40%). Variability in the transition region and corona of the host star might be the source of these variations. Yet, their amplitude over short timescales ( 2-3 h) is surprisingly strong for this old (11.2 ± 1.0 Gyr) and apparently quiet main-sequence star. Alternatively, we show that the in-transit variations could be explained by absorption from neutral hydrogen exospheres trailing the two outer planets (Kepler-444 e and f). They would have to contain substantial amounts of water to replenish hydrogen exospheres such as these, which would reveal them to be the first confirmed ocean planets. The out-of-transit variations, however, would require the presence of an as-yet-undetected Kepler-444 g at larger orbital distance, casting doubt on the planetary origin scenario. Using HARPS-N observations in the sodium doublet, we derived the properties of two interstellar medium clouds along the line of sight toward Kepler-444. This allowed us to reconstruct the stellar Lymanline profile and to estimate the extreme-UV (XUV) irradiation from the star, which would still allow for a moderate mass loss from the outer planets after 11.2 Gyr. Follow-up of the system at XUV wavelengths will be required to assess this tantalizing possibility.

  9. On the origins of C IV absorption profile diversity in broad absorption line quasars

    CERN Document Server

    Baskin, Alexei; Hamann, Fred

    2015-01-01

    There is a large diversity in the C IV broad absorption line (BAL) profile among BAL quasars (BALQs). We quantify this diversity by exploring the distribution of the C IV BAL properties, FWHM, maximum depth of absorption and its velocity shift ($v_{\\rm md}$), using the SDSS DR7 quasar catalogue. We find the following: (i) Although the median C IV BAL profile in the quasar rest-frame becomes broader and shallower as the UV continuum slope ($\\alpha_{\\rm UV}$ at 1700-3000 A) gets bluer, the median individual profile in the absorber rest-frame remains identical, and is narrow (FWHM = 3500 km/s) and deep. Only 4 per cent of BALs have FWHM > 10,000 km/s. (ii) As the He II emission equivalent-width (EW) decreases, the distributions of FWHM and $v_{\\rm md}$ extend to larger values, and the median maximum depth increases. These trends are consistent with theoretical models in which softer ionizing continua reduce overionization, and allow radiative acceleration of faster BAL outflows. (iii) As $\\alpha_{\\rm UV}$ become...

  10. Asymmetric profiles and prewetting lines in the filling of planar slits with Ne.

    Science.gov (United States)

    Sartarelli, Salvador A; Szybisz, Leszek

    2013-05-23

    The filling of slits with identical planar walls is investigated in the frame of the density functional theory. For this kind of slit, the confining potential is symmetric with respect to its central plane. Closed and open systems are studied by applying, respectively, the canonical and grand canonical ensembles (CE and GCE). Results obtained for the confinement of fluid Ne by alkaline surfaces are reported. The behavior of these systems is analyzed by varying the strength of the Ne-substrate attraction, the temperature T, and the coverage Γ(l). It is assumed that the one-body density of the fluid, ρ(r), is uniform along the (x, y) planes parallel to the walls, becoming a function of the coordinate z perpendicular to those planes. Two sorts of solutions are found for the density profile: (i) symmetric ones that follow the left-right symmetry of the potential exerted by the walls and (ii) asymmetric ones that break the symmetry of the slit. The pores are wide enough for determining prewetting (PW) lines and wetting and critical PW temperatures, i.e., T(w) and T(cpw), from the analysis of symmetric solutions provided by both the CE and GCE schemes. Asymmetric species are examined in detail for T > T(w). It is shown that for a given Ne-substrate pair at a fixed T both the CE and GCE frames yield only one asymmetric 2-fold degenerate stable profile (formed by a "thin" wetting film at one wall and a "thick" wetting film at the other) coexisting with two symmetric profiles (formed by "thin" or "thick" wetting films at the two walls), while the remaining asymmetric states are at best metastable. This feature occurs along PW lines and disappears at T(cpw).

  11. Diagnosing the reionization of the universe - The absorption spectrum of the intergalactic medium and Lyman alpha clouds

    Science.gov (United States)

    Giroux, Mark L.; Shapiro, Paul R.

    1991-01-01

    The thermal and ionization evolution of a uniform intergalactic medium composed of H and He and undergoing reionization is studied. The diagnosis of the metagalactic ionizing radiation background at z of about three using metal line ratios for Lyman limit quasar absorption line systems is addressed. The use of the He II Gunn-Peterson effect to diagnose the reionization source and/or nature of the Hy-alpha forest clouds is considered.

  12. Autoantibody profiling of patients with primary biliary cirrhosis using a multiplexed line-blot assay.

    Science.gov (United States)

    Villalta, Danilo; Sorrentino, Maria Concetta; Girolami, Elia; Tampoia, Marilina; Alessio, Maria Grazia; Brusca, Ignazio; Daves, Massimo; Porcelli, Brunetta; Barberio, Giuseppina; Bizzaro, Nicola

    2015-01-01

    To evaluate the autoantibody profile in patients with primary biliary cirrhosis (PBC) using a new multiplexed line-blot assay specifically designed for the diagnosis of autoimmune liver diseases. Sera of 58 consecutive PBC patients and 191 disease controls (144 with autoimmune liver diseases other than PBC, and 67 with non-autoimmune chronic liver diseases) were tested by both the multiplexed line-blot Autoimmune Liver Disease Profile 2 (ALD2) and by IIF on HEp-2 cells and on rat kidney/liver/stomach tissues. ALD2 contains the following PBC-associated antigens: AMA-M2, natively purified from bovine heart; M2-E3, a recombinant fusion protein including the E2 subunits of PDC, BCOADC and OGDC; sp100, PML and gp210 recombinant proteins. With the ALD2 assay, a positive reaction to AMA-M2, M2-E3, sp100, PML and gp210 in PBC patients was observed in 77.6%, 84.5%, 34.5%, 15.1% and 18.9%, respectively, of the PBC sera. The overall sensitivity and specificity for PBC were 98.3% and 93.7%. Using IIF, positivity rates to AMA, and to antinuclear autoantibodies with membranous/rim-like and multiple nuclear dot patterns were 86.2%, 8.6% and 22.4%, respectively. The overall sensitivity and specificity for PBC of the IIF method were 86.2% and 97.9%, respectively. The ALD2 line-blot showed a good diagnostic accuracy for PBC and a higher sensitivity than the IIF method to detect sp100 and gp210 autoantibodies. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Interstellar H I and H_2 in the Magellanic Clouds: An Expanded Sample Based on UV Absorption-Line Data

    CERN Document Server

    Welty, Daniel E; Wong, Tony

    2011-01-01

    We have determined column densities of H I and/or H_2 for sight lines in the Magellanic Clouds from archival HST and FUSE spectra of H I Lyman-alpha and H_2 Lyman-band absorption. Together with some similar data from the literature, we now have absorption-based N(H I) and/or N(H_2) for 285 LMC and SMC sight lines (114 with a detection or limit for both species) -- enabling more extensive, direct, and accurate determinations of molecular fractions, gas-to-dust ratios, and elemental depletions in these two nearby, low-metallicity galaxies. For sight lines where the N(H I) estimated from 21 cm emission is significantly higher than the value derived from Lyman-alpha absorption (presumably due to emission from gas beyond the target stars), integration of the 21 cm profile only over the velocity range seen in Na I or H_2 absorption generally yields much better agreement. Conversely, N(21 cm) can be lower than N(Ly-alpha) by factors of 2--3 in some LMC sight lines -- suggestive of small-scale structure within the 21...

  14. Analysis on Energy Conversion of Screw Centrifugal Pump in Impeller Domain Based on Profile Lines

    Directory of Open Access Journals (Sweden)

    Hui Quan

    2013-01-01

    Full Text Available In order to study the power capability of impeller and energy conversion mechanism of screw centrifugal pump, the methods of theoretical analysis and numerical simulation by computational fluid dynamics theory (CFD were adopted, specifically discussing the conditions of internal flow such as velocity, pressure, and concentration. When the medium is sand-water two-phase flow and dividing the rim of the lines and wheel lines of screw centrifugal pump to segments to analyze energy conversion capabilities which along the impeller profile lines with the dynamic head and hydrostatic head changer, the results show that the energy of fluid of the screw centrifugal pump is provided by helical segment, and the helical segment of the front of the impeller has played the role of multilevel increasing energy; the sand-water two phases move at different speeds because the different force field and the impeller propeller and centrifugal effect. As liquid phase is the primary phase, the energy conversion is mainly up to the change of liquid energy, the solid phase flows under the wrapped action of liquid, and solid energy is carried out through liquid indirectly.

  15. Distorted cyclotron line profile in Cep X-4 as observed by NuSTAR

    CERN Document Server

    Fuerst, F; Miyasaka, H; Bhalerao, V; Bachetti, M; Boggs, S E; Christensen, F E; Craig, W W; Grinberg, V; Hailey, C J; Harrison, F A; Kennea, J A; Rahoui, F; Stern, D; Tendulkar, S P; Tomsick, J A; Walton, D J; Wilms, J; Zhang, W W

    2015-01-01

    We present spectral analysis of NuSTAR and Swift observations of Cep X-4 during its outburst in 2014. We observed the source once during the peak of the outburst and once during the decay, finding good agreement in the spectral shape between the observations. We describe the continuum using a powerlaw with a Fermi-Dirac cutoff at high energies. Cep X-4 has a very strong cyclotron resonant scattering feature (CRSF) around 30 keV. A simple absorption-like line with a Gaussian optical depth or a pseudo-Lorentzian profile both fail to describe the shape of the CRSF accurately, leaving significant deviations at the red side of the line. We characterize this asymmetry with a second absorption feature around 19 keV. The line energy of the CRSF, which is not influenced by the addition of this feature, shows a small but significant positive luminosity dependence. With luminosities between (1-6)e36 erg/s, Cep X-4 is below the theoretical limit where such a correlation is expected. This behavior is similar to Vela X-1 a...

  16. DISTORTED CYCLOTRON LINE PROFILE IN CEP X-4 AS OBSERVED BY NuSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Fürst, F.; Miyasaka, H.; Harrison, F. A.; Tendulkar, S. P.; Walton, D. J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Pottschmidt, K. [CRESST, Department of Physics, and Center for Space Science and Technology, UMBC, Baltimore, MD 21250 (United States); Bhalerao, V. [Inter-University Center for Astronomy and Astrophysics, Ganeshkhind, Pune 411007 (India); Bachetti, M. [Osservatorio Astronomico di Cagliari, I-09047 Selargius (Italy); Boggs, S. E.; Craig, W. W.; Tomsick, J. A. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space, National Space Institute, Technical University of Denmark, DK-2800 Lyngby (Denmark); Grinberg, V. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics, Cambridge, MA 02139 (United States); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Kennea, J. A. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Rahoui, F. [European Southern Observatory, D-85748 Garching bei München (Germany); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wilms, J. [Dr. Karl-Remeis-Sternwarte and ECAP, University of Erlangen-Nuremberg, D-96049 Bamberg (Germany); Zhang, W. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2015-06-20

    We present spectral analysis of Nuclear Spectroscopic Telescope Array and Swift observations of Cep X-4 during its outburst in 2014. We observed the source once during the peak of the outburst and once during the decay, finding good agreement in the spectral shape between the observations. We describe the continuum using a power law with a Fermi–Dirac cutoff at high energies. Cep X-4 has a very strong cyclotron resonant scattering feature (CRSF) around 30 keV. A simple absorption-like line with a Gaussian optical depth or a pseudo-Lorentzian profile both fail to describe the shape of the CRSF accurately, leaving significant deviations at the red side of the line. We characterize this asymmetry with a second absorption feature around 19 keV. The line energy of the CRSF, which is not influenced by the addition of this feature, shows a small but significant positive luminosity dependence. With luminosities between (1–6) × 10{sup 36} erg s{sup −1}, Cep X-4 is below the theoretical limit where such a correlation is expected. This behavior is similar to Vela X-1 and we discuss parallels between the two systems.

  17. Inhomogeneous speed effects on H2 vibrational line profiles in ternary mixtures

    Science.gov (United States)

    Joubert, P.; Bruet, X.; Bonamy, J.; Robert, D.; Chaussard, F.; Saint-Loup, R.; Berger, H.

    2000-12-01

    A study of speed inhomogeneous broadening of the hydrogen vibrational line profiles in the collisional regime for ternary mixtures is reported. The Q(1) line of H2 in H2-Ar-N2, H2-He-Ar, and H2-He-N2 mixtures is investigated by high resolution stimulated Raman spectroscopy for various concentrations and temperatures. A model, successfully used for binary mixtures, is extended to ternary mixtures. An excellent agreement is obtained between theory and experiment for H2-Ar-N2, by using the collisional parameters previously obtained from binary mixtures study. For H2-He-Ar and H2-He-N2, H2-He collisions play a "hardening" effect in the H2 soft speed memory mechanism for H2-Ar or H2-N2. The present experimental results allow us, via the frame of our model, to determine the "hardness" parameter values for H2-He (inaccessible from binary mixtures data) and to get an accurate description of the spectral line shape. This study should be useful for hydrogen coherent anti-Stokes Raman spectroscopy thermometry in H2/air flames at high pressure through its possible extension to the H2-N2-H2O system.

  18. The Masses of Lyman Break Galaxies

    Science.gov (United States)

    Primack, Joel R.; Wechsler, Risa H.; Somerville, Rachel S.

    Data on galaxies at high redshift, identified by the Lyman-break photometric technique, can teach us about how galaxies form and evolve. The stellar masses and other properties of such Lyman break galaxies (LBGs) depend sensitively on the details of star formation. In this paper we consider three different star formation prescriptions, and use semi-analytic methods applied to the now-standard ΛCDM theory of hierarchical structure formation to show how these assumptions about star formation affect the predicted masses of the stars in these galaxies and the masses of the dark matter halos that host them. We find that, within the rather large uncertainties, recent estimates of the stellar masses of LBGs from multi-color photometry are consistent with the predictions of all three models. However, the estimated stellar masses are more consistent with the predictions of two of the models in which star formation is accelerated at high redshifts z ≳ 3, and of these models the one in which many of the LBGs are merger-driven starbursts is also more consistent with indications that many high redshift galaxies are gas rich. The clustering properties of LBGs have put some constraints on the masses of their host halos, but due to similarities in the halo occupation of the three models we consider and degeneracies between model parameters, current constraints are not yet sufficient to distinguish between realistic models.

  19. The Masses of Lyman Break Galaxies

    CERN Document Server

    Primack, Joel R; Somerville, R S; Primack, Joel R.; Wechsler, Risa H.; Somerville, Rachel S.

    2001-01-01

    Data on galaxies at high redshift, identified by the Lyman-break photometric technique, can teach us about how galaxies form and evolve. The stellar masses and other properties of such Lyman break galaxies (LBGs) depend sensitively on the details of star formation. In this paper we consider three different star formation prescriptions, and use semi-analytic methods applied to the now-standard $\\Lambda$CDM theory of hierarchical structure formation to show how these assumptions about star formation affect the predicted masses of the stars in these galaxies and the masses of the dark matter halos that host them. We find that, within the rather large uncertainties, recent estimates of the stellar masses of LBGs from multi-color photometry are consistent with the predictions of all three models. However, the estimated stellar masses are more consistent with the predictions of two of the models in which star formation is accelerated at high redshifts $z\\gsim3$, and of these models the one in which many of the LBGs...

  20. GHRS Observations of the Lyman $\\alpha$ Forest

    CERN Document Server

    Morris, S L

    1996-01-01

    I review the results obtained using the GHRS on low redshift Lyman alpha absorbers. Until the advent of HST and the GHRS, the existence of such absorbers was doubted. The confirmation of their existence, in one of the first GHRS GTO team results to be published, must rank as one of the HSTs most interesting results. The GHRS resolution allows us to probe equivalent widths well below those detectable with the FOS, and has led to a number of interesting new questions. One example is the apparent disagreement between the GHRS result that there are many Lyman alpha absorbers which are not associated with luminous galaxies, and FOS studies which suggest that all such absorbers have a nearby galaxy causing them. This almost certainly shows that the equivalent width (or column density) range reachable by the GHRS includes gas from a wide range of causes, and not only the halos of luminous galaxies. With these data, we are seeing the debris left over from Galaxy formation, material flung out from galaxy interactions ...

  1. Molecular hydrogen in Lyman Alpha Emitters

    CERN Document Server

    Vallini, Livia; Ferrara, Andrea

    2012-01-01

    We present a physically motivated model to estimate the molecular hydrogen (H2) content of high-redshift (z~5.7,6.6) Lyman Alpha Emitters (LAEs) extracted from a suite of cosmological simulations. We find that the H2 mass fraction, (f_H2), depends on three main LAE physical properties: (a) star formation rate, (b) dust mass, and (c) cold neutral gas mass. At z~5.7, the value of f_H2 peaks and ranges between 0.5-0.9 for intermediate mass LAEs with stellar mass M_* ~ 10^{9-10} solar mass, decreasing for both smaller and larger galaxies. However, the largest value of the H2 mass is found in the most luminous LAEs. These trends also hold at z\\sim6.6, although, due to a lower dust content, f_H2(z=6.6)\\sim0.5 f_H2(z=5.7) when averaged over all LAEs; they arise due to the interplay between the H2 formation/shielding controlled by dust and the intensity of the ultraviolet (UV) Lyman-Werner photo-dissociating radiation produced by stars. We then predict the carbon monoxide (CO) luminosities for such LAEs and check tha...

  2. Observations and Simulations of the Na i D1 Line Profiles in an M-class Solar Flare

    Science.gov (United States)

    Kuridze, D.; Mathioudakis, M.; Christian, D. J.; Kowalski, A. F.; Jess, D. B.; Grant, S. D. T.; Kawate, T.; Simões, P. J. A.; Allred, J. C.; Keenan, F. P.

    2016-12-01

    We study the temporal evolution of the Na i D1 line profiles in the M3.9 flare SOL2014-06-11T21:03 UT, using observations at high spectral resolution obtained with the Interferometric Bidimensional Spectrometer instrument on the Dunn Solar Telescope combined with radiative hydrodynamic simulations. Our results show a significant increase in the intensities of the line core and wings during the flare. The analysis of the line profiles from the flare ribbons reveals that the Na i D1 line has a central reversal with excess emission in the blue wing (blue asymmetry). We combine RADYN and RH simulations to synthesize Na i D1 line profiles of the flaring atmosphere and find good agreement with the observations. Heating with a beam of electrons modifies the radiation field in the flaring atmosphere and excites electrons from the ground state 3s 2S to the first excited state 3p 2P, which in turn modifies the relative population of the two states. The change in temperature and the population density of the energy states make the sodium line profile revert from absorption into emission. Furthermore, the rapid changes in temperature break the pressure balance between the different layers of the lower atmosphere, generating upflow/downflow patterns. Analysis of the simulated spectra reveals that the asymmetries of the Na i D1 flare profile are produced by the velocity gradients in the lower solar atmosphere.

  3. Lyman-Werner UV escape fractions from primordial haloes

    Science.gov (United States)

    Schauer, Anna T. P.; Whalen, Daniel J.; Glover, Simon C. O.; Klessen, Ralf S.

    2015-12-01

    Population III (Pop III) stars can regulate star formation in the primordial Universe in several ways. They can ionize nearby haloes, and even if their ionizing photons are trapped by their own haloes, their Lyman-Werner (LW) photons can still escape and destroy H2 in other haloes, preventing them from cooling and forming stars. LW escape fractions are thus a key parameter in cosmological simulations of early reionization and star formation but have not yet been parametrized for realistic haloes by halo or stellar mass. To do so, we perform radiation hydrodynamical simulations of LW UV escape from 9-120 M⊙ Pop III stars in 105-107 M⊙ haloes with ZEUS-MP. We find that photons in the LW lines (i.e. those responsible for destroying H2 in nearby systems) have escape fractions ranging from 0 to 85 per cent. No LW photons escape the most massive halo in our sample, even from the most massive star. Escape fractions for photons elsewhere in the 11.18-13.6 eV energy range, which can be redshifted into the LW lines at cosmological distances, are generally much higher, being above 60 per cent for all but the least massive stars in the most massive haloes. We find that shielding of H2 by neutral hydrogen, which has been neglected in most studies to date, produces escape fractions that are up to a factor of 3 smaller than those predicted by H2 self-shielding alone.

  4. Lyman alpha emission in starburst galaxies

    Science.gov (United States)

    Kunth, Daniel

    1999-07-01

    We propose to perform a deep study of Ly-alpha emission and destruction in 3 star-forming galaxies. These objects have been already observed with the GHRS and exhibit a variety of situations, with Ly-alpha showing P Cyg profiles, secondary emissions or even a deep damped absorption line with no emission. They also span a range of intrinsic properties: IZW18 is a gas-rich, metal deficient dust free dwarf galaxy, Haro 2 has a simple morphology while IRAS 08339+6517 is a luminous IRAS starburst galaxy with more dust and complex Ly- alpha profile. The use of STIS will allow for the first time to study the geometrical/kinematical configuration of the ionized and neutral gas across the galaxies nuclear regions and pin point the effects of porosity and the kinematical structure of the ISM, that may play the key roles {in addition to dust} in the detectability of the line. This study will have important impact for cosmology since Ly-alpha emitters are nowaday found at high-re dshift. We strongly emphasize that since Ly-alpha is primarely a diagnostic of the ISM, a full understanding of how the ISM and Ly-alpha are related is a necessary step before we can hope to correlate Ly-alpha to the cosmic star-formation rate. Our results will be interpreted against the model of superbubble evolution developed with G. Tenorio Tagle.

  5. Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts

    Science.gov (United States)

    Blondin, Stéphane; Dessart, Luc; Leibundgut, Bruno; Branch, David; Höflich, Peter; Tonry, John L.; Matheson, Thomas; Foley, Ryan J.; Chornock, Ryan; Filippenko, Alexei V.; Sollerman, Jesper; Spyromilio, Jason; Kirshner, Robert P.; Wood-Vasey, W. Michael; Clocchiatti, Alejandro; Aguilera, Claudio; Barris, Brian; Becker, Andrew C.; Challis, Peter; Covarrubias, Ricardo; Davis, Tamara M.; Garnavich, Peter; Hicken, Malcolm; Jha, Saurabh; Krisciunas, Kevin; Li, Weidong; Miceli, Anthony; Miknaitis, Gajus; Pignata, Giuliano; Prieto, Jose Luis; Rest, Armin; Riess, Adam G.; Salvo, Maria Elena; Schmidt, Brian P.; Smith, R. Chris; Stubbs, Christopher W.; Suntzeff, Nicholas B.

    2006-03-01

    Using archival data of low-redshift (zdatabases) Type Ia supernovae (SNe Ia) and recent observations of high-redshift (0.161.7] SNe Ia, which are also subluminous. In addition, we give the first direct evidence in two high-z SN Ia spectra of a double-absorption feature in Ca II λ3945, an event also observed, although infrequently, in low-redshift SN Ia spectra (6 out of 22 SNe Ia in our local sample). Moreover, echoing the recent studies of Dessart & Hillier in the context of Type II supernovae (SNe II), we see similar P Cygni line profiles in our large sample of SN Ia spectra. First, the magnitude of the velocity location at maximum profile absorption may underestimate that at the continuum photosphere, as observed, for example, in the optically thinner line S II λ5640. Second, we report for the first time the unambiguous and systematic intrinsic blueshift of peak emission of optical P Cygni line profiles in SN Ia spectra, by as much as 8000 km s-1. All the high-z SNe Ia analyzed in this paper were discovered and followed up by the ESSENCE collaboration and are now publicly available. Based in part on observations obtained at the Cerro Tololo Inter-American Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under cooperative agreement with the National Science Foundation (NSF); the European Southern Observatory, Chile (ESO program 170.A-0519) the Gemini Observatory, which is operated by AURA under a cooperative agreement with the NSF on behalf of the Gemini partnership (the NSF [United States], the Particle Physics and Astronomy Research Council [United Kingdom], the National Research Council [Canada], CONICYT [Chile], the Australian Research Council [Australia], CNPq [Brazil], and CONICET [Argentina]) (programs GN-2002B-Q-14, GN-2003B-Q-11, and GS-2003B-Q-11) the Magellan Telescopes at Las Campanas Observatory; the MMT Observatory, a joint facility of the Smithsonian Institution and the University of

  6. The Reionization and Galaxy Evolution Probed by z=7 Lyman Alpha Emitters

    CERN Document Server

    Ota, Kazuaki; Kashikawa, Nobunari; Shimasaku, Kazuhiro; Kobayashi, Masakazu A R; Totani, Tomonori; Nagashima, Masahiro; Morokuma, Tomoki; Furusawa, Hisanori; Hattori, Takashi; Matsuda, Yuichi; Hashimoto, Tetsuya; Ouchi, Masami

    2007-01-01

    We made a narrowband NB973 (bandwidth of 200A at 9755A) imaging of the Subaru Deep Field (SDF) and found two z=7 Lyman alpha emitter (LAE) candidates down to NB973=24.9. Carrying out deep follow-up spectroscopy, we identified one of them as a real z=6.96 LAE. This has shown that galaxy formation was in progress just 750 Myr after the Big Bang. Meanwhile, the Lyman alpha line luminosity function of LAE is known to decline from z=5.7 to 6.6 in the SDF. L* at z=6.6 is 40-60% of that at z=5.7. We also confirm that the number density of z=7 LAE is only 17% of the density at z=6.6 comparing the latest SDF LAE samples. This series of significant decreases in LAE density with increasing redshift can be the result of galaxy evolution during these epochs. However, using the UV continuum luminosity functions of LAEs, those of Lyman break galaxies, and a LAE evolution model based on the hierarchical clustering, we find that galaxy evolution alone cannot explain all the decrease in density. This extra density deficit can ...

  7. The Lyman-alpha Reference Sample: I. Survey outline and first results for Markarian 259

    CERN Document Server

    Östlin, Göran; Duval, Florent; Sandberg, Andreas; Rivera-Thorsen, Thoger; Marquart, Thomas; Orlitova, Ivana; Adamo, Angela; Melinder, Jens; Guaita, Lucia; Atek, Hakim; Cannon, John M; Gruyters, Pieter; Herenz, Edmund Christian; Kunth, Daniel; Laursen, Peter; Mas-Hesse, J Miguel; Micheva, Genoveva; Pardy, Hector Oti-Floranes Stephen A; Roth, Martin M; Schaerer, Daniel; Verhamme, Anne

    2014-01-01

    The Lyman-alpha reference sample (LARS) is a program with the Hubble Space Telescope (HST) that provides a sample of local universe laboratory galaxies in which to study the astrophysics of the visibility and strength of the Lyman-alpha (Lya) line of hydrogen. This article presents an overview of the survey, its selection function and HST imaging observations. The sample was selected from the GALEX+SDSS catalogue at z=0.028-0.19, in order to allow Lya to be captured with combinations of long pass filters in the Solar Blind Channel (SBC) of HST/ACS. In addition, LARS utilises Halpha and Hbeta narrow, and U, B, i broad-band imaging with ACS and WFC3. In order to study galaxies in which large numbers of Lya photons are produced we demanded an Halpha equivalent width > 100{\\AA}. The sample of 14 galaxies covers far UV (FUV) luminosities that overlaps with those of high-z Lya emitters and Lyman Break Galaxies (LBGs). We present the reduction steps used to obtain the Lya images, including our LARS eXtraction softwa...

  8. A Spectroscopic Search for Leaking Lyman Continuum at z~0.7

    CERN Document Server

    Bridge, Carrie R; Siana, Brian; Scarlata, Claudia; Conselice, Christopher J; Ferguson, Henry C; Brown, Thomas M; Salvato, Mara; Rudie, Gwen C; de Mello, Duilia F; Colbert, James; Gardner, Jonathan P; Giavalisco, Mauro; Armus, Lee

    2010-01-01

    We present the results of rest-frame, UV slitless spectroscopic observations of a sample of 32 z~0.7 Lyman break galaxy (LBG) analogs in the COSMOS field. The spectroscopic search was performed with the Solar Blind Channel (SBC) on Hubble Space Telescope. We report the detection of leaking Lyman continuum (LyC) radiation from an AGN-starburst composite. While we find no direct detections of LyC emission in the remainder of our sample, we achieve individual lower limits (3 sigma) of the observed non-ionizing UV to LyC flux density ratios, f_{nu}(1500A)/f_{nu}(830A) of 20 to 204 (median of 73.5) and 378.7 for the stack. Assuming an intrinsic Lyman break of 3.4 and an intergalactic medium (IGM) transmission of LyC photons along the line of sight to the galaxy of 85% we report an upper limit for the relative escape fraction in individual galaxies of 0.02 - 0.19 and a stacked 3 sigma upper limit of 0.01. We find no indication of a relative escape fraction near unity as seen in some LBGs at z~3. Our UV spectra achi...

  9. High-resolution H-band spectroscopy of Be stars with SDSS-III/apogee. I. New Be stars, line identifications, and line profiles

    Energy Technology Data Exchange (ETDEWEB)

    Chojnowski, S. Drew; Majewski, Steven R.; Hall, Matthew; Beaton, Rachael; Burton, Adam; Damke, Guillermo; Wilson, John [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Whelan, David G. [Department of Physics, Austin College, 900 N. Grand Ave., Sherman, TX 75090 (United States); Wisniewski, John P. [Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Shetrone, Matthew [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400 Austin, Texas 78712-1205 (United States); Eikenberry, Steve [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Hasselquist, Sten; Holtzman, Jon A.; Brewington, Howard; Brinkmann, J. [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); Mészáros, Szabolcs [ELTE Gothard Astrophysical Observatory, 1H-9704 Szombathely, Szent Imre herceg st. 112 (Hungary); Nidever, David [Department of Astronomy, University of Michigan, 830 Dennison, 500 Church St., Ann Arbor, MI 48109-1042 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Zasowski, Gail [Department of Physics and Astronomy, Johns Hopkins University, Bloomberg Center for Physics and Astronomy, Room 366, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Bizyaev, Dmitry, E-mail: drewski@virginia.edu [Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); and others

    2015-01-01

    The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has amassed the largest ever collection of multi-epoch, high-resolution (R∼22,500), H-band spectra for B-type emission line (Be) stars. These stars were targeted by APOGEE as telluric standard stars and subsequently identified via visual inspection as Be stars based on H i Brackett series emission or shell absorption in addition to otherwise smooth continua and occasionally non-hydrogen emission features. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to increase the total number of known Be stars by ∼6%. Because the H band is relatively unexplored compared to other wavelength regimes, we focus here on identification of the H-band lines and analysis of the emission peak velocity separations (Δv{sub p}) and emission peak intensity ratios (V/R) of the usually double-peaked H i and non-hydrogen emission lines. H i Br11 emission is found to preferentially form in the circumstellar disks at an average distance of ∼2.2 stellar radii. Increasing Δv{sub p} toward the weaker Br12–Br20 lines suggests these lines are formed interior to Br11. By contrast, the observed IR Fe ii emission lines present evidence of having significantly larger formation radii; distinctive phase lags between IR Fe ii and H i Brackett emission lines further supports that these species arise from different radii in Be disks. Several emission lines have been identified for the first time including C i 16895, a prominent feature in the spectra for almost a fifth of the sample and, as inferred from relatively large Δv{sub p} compared to the Br11–Br20, a tracer of the inner regions of Be disks. Emission lines at 15760 Å and 16781 Å remain unidentified, but usually appear along with and always have similar line profile morphology to Fe ii 16878. Unlike the typical metallic lines observed for Be stars in the optical, the H-band metallic lines, such as Fe ii 16878, never exhibit any

  10. The high-ion content and kinematics of low-redshift Lyman limit systems

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Andrew J.; Tumlinson, Jason; Bordoloi, Rongmon [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Lehner, Nicolas; Howk, J. Christopher [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Tripp, Todd M.; Katz, Neal [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Prochaska, J. Xavier; Werk, Jessica K. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); O' Meara, John M. [Department of Physics, Saint Michael' s College, One Winooski Park, Colchester, VT 05439 (United States); Oppenheimer, Benjamin D. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Davé, Romeel, E-mail: afox@stsci.edu [University of the Western Cape, Robert Sobukwe Road, Bellville 7535 (South Africa)

    2013-12-01

    We study the high-ion content and kinematics of the circumgalactic medium around low-redshift galaxies using a sample of 23 Lyman limit systems (LLSs) at 0.08 < z < 0.93 observed with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. In Lehner et al., we recently showed that low-z LLSs have a bimodal metallicity distribution. Here we extend that analysis to search for differences between the high-ion and kinematic properties of the metal-poor and metal-rich branches. We find that metal-rich LLSs tend to show higher O VI columns and broader O VI profiles than metal-poor LLSs. The total H I line width (Δv {sub 90} statistic) in LLSs is not correlated with metallicity, indicating that the H I kinematics alone cannot be used to distinguish inflow from outflow and gas recycling. Among the 17 LLSs with O VI detections, all but two show evidence of kinematic sub-structure, in the form of O VI-H I centroid offsets, multiple components, or both. Using various scenarios for how the metallicities in the high-ion and low-ion phases of each LLS compare, we constrain the ionized hydrogen column in the O VI phase to lie in the range log N(H II) ∼ 17.6-20. The O VI phase of LLSs is a substantial baryon reservoir, with M(high-ion) ∼ 10{sup 8.5-10.9} (r/150 kpc){sup 2} M {sub ☉}, similar to the mass in the low-ion phase. Accounting for the O VI phase approximately doubles the contribution of low-z LLSs to the cosmic baryon budget.

  11. Mid-Infrared [NeII] and [NeIII] Emission Line Profiles in Starbursts and AGN

    Science.gov (United States)

    Samsonyan, A. L.

    2016-09-01

    Line profiles and velocities of the [CII] 157μm line observed with the Herschel PACS instrument are compared to high resolution [NeII] 12.81μm and [NeIII] 15.55μm emission lines observed with the Spitzer Infrared Spectrograph (IRS). We are analysing spectra of at least 400 galaxies having both IRS high resolution and Herschel PACS [CII] line profiles that are available from the public archives. The goal of the work is the comparison of emission line velocity profiles and fluxes to locate and understand differences in the origins of [CII] compared to the mid-infrared Neon lines. Line velocities and widths are carefully measured, and errors are analyzed to determine if there is any kinematic evidence for [CII] arising from clouds not visible in the mid-infrared emission lines. This will give an answer to two questions: 1. Is there evidence that [CII] is more diffuse, distributed throughout galaxies, than the mid infrared starburst indicators [NeII] and [NeIII]?; 2. Is there evidence for specific, very dusty clouds of [CII] with so much extinction that the [CII] can be seen but the [NeII] and [NeIII] is not seen?

  12. Fundamental Parameter Method Applied to X-Ray Line Profile Analysis

    Directory of Open Access Journals (Sweden)

    Florica Matei

    2016-11-01

    Full Text Available Crystallite size strain effect the mechanical, electric, magnetic and optical properties of many kind of the nanomaterials. The effects of the finite crystallite size and lattice strain can be very well observed as the deformation in the shape of the X-ray line profile (XRLP. In this contribution we have used the fundamental parameter (FP [1,2] method to evaluate the nanostructure materials assuming a theoretical model of experimental XRLP.  In this contribution we have used various distribution functions such as normal, lognormal, Gumbel, Maxwell and Student. The best values of the crystallite size of nanostructued materials are chosen by analysis of root mean squares of residuals and by correlation matrix of the fit parameters. The entire procedure was implemented in the GnuPlot script.

  13. Radial velocities of giant stars: an investigation of line profile variations

    Energy Technology Data Exchange (ETDEWEB)

    Hekker, S; Snellen, I A G [Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden (Netherlands); Aerts, C [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Quirrenbach, A; Reffert, S [ZAH, Landessternwarte Heidelberg, Koenigstuhl 12, D-69117 Heidelberg (Germany); Mitchell, D S [California Polytechnic State University, San Luis Obispo, CA 93407 (United States)], E-mail: saskia@strw.leidenuniv.nl

    2008-10-15

    Since 1999, a radial velocity survey of 179 red giant stars is ongoing at Lick Observatory with a one month cadence. At present{approx}20-100 measurements have been collected per star with an accuracy of 5 to 8 ms{sup -1}. Of the stars monitored, 145 (80%) show radial velocity (RV) variations at a level >20 ms{sup -1}, of which 43 exhibit significant periodicities. Here, we investigate the mechanism causing the observed radial velocity variations. Firstly, we search for a correlation between the radial velocity amplitude and an intrinsic parameter of the star, in this case surface gravity (logg). Secondly, we investigate line profile variations and compare these with theoretical predictions.

  14. Multi-omic profiling of MYCN-amplified neuroblastoma cell-lines

    Directory of Open Access Journals (Sweden)

    Erik Dassi

    2015-12-01

    Full Text Available Neuroblastoma is the most common pediatric cancer, arising from the neural crest cells of the sympathetic nervous system. Its most aggressive subtype, characterized by the amplification of the MYCN oncogene, has a dismal prognosis and no effective treatment is available. Understanding the alterations induced by the tumor on the various layers of gene expression is therefore important for a complete characterization of this neuroblastoma subtype and for the discovery of new therapeutic opportunities. Here we describe the profiling of 13 MYCN-amplified neuroblastoma cell lines at the genome (copy number, transcriptome, translatome and miRome levels (GEO series GSE56654, GSE56552 and GSE56655. We provide detailed experimental and data analysis procedures by means of which we derived the results described in [1].

  15. Genome-wide nucleosome occupancy and DNA methylation profiling of four human cell lines

    Directory of Open Access Journals (Sweden)

    Aaron L. Statham

    2015-03-01

    Full Text Available DNA methylation and nucleosome positioning are two key mechanisms that contribute to the epigenetic control of gene expression. During carcinogenesis, the expression of many genes is altered alongside extensive changes in the epigenome, with repressed genes often being associated with local DNA hypermethylation and gain of nucleosomes at their promoters. However the spectrum of alterations that occur at distal regulatory regions has not been extensively studied. To address this we used Nucleosome Occupancy and Methylation sequencing (NOMe-seq to compare the genome-wide DNA methylation and nucleosome occupancy profiles between normal and cancer cell line models of the breast and prostate. Here we describe the bioinformatic pipeline and methods that we developed for the processing and analysis of the NOMe-seq data published by (Taberlay et al., 2014 [1] and deposited in the Gene Expression Omnibus with accession GSE57498.

  16. Social Profiles and Social Behaviour and Attitudes towards Gaming and On-Line Gaming in Spain

    Directory of Open Access Journals (Sweden)

    Francisco Javier RUIZ MARTÍNEZ

    2011-12-01

    Full Text Available For the last two decades our world has experienced increasing globalization linked to the revolution in Information and Communication Technologies (ICT leading to new business spheres escaping from the traditional Nation-State control. The gaming business is one of these areas and has recorded a notable increase in profits in the last decade: gambling, betting and network games constitute some of the main issues developed by ICT companies located beyond State control. The action of the States is focusing on the formulation of new public policies that allow them to control these activities. But first a deep social description of gaming is needed to know which actors are involved in this field of activities, which is the profile of the gamer and what kind of social attitudes are carried out by users and companies taking part of the business. This article focuses on the social profiles and the social behaviour and attitudes towards gaming in Spain, and specially in the transition from traditional gaming to on line gaming.

  17. Observations and simulations of the Na I D1 line profiles in an M-class solar flare

    CERN Document Server

    Kuridze, D; Christian, D J; Kowalski, A F; Jess, D B; Grant, S D T; Kawate, T; Simões, P J A; Allred, J C; Keenan, F P

    2016-01-01

    We study the temporal evolution of the Na I D1 line profiles in the M3.9 flare SOL2014-06-11T21:03 UT, using high spectral resolution observations obtained with the IBIS instrument on the Dunn Solar Telescope combined with radiative hydrodynamic simulations. Our results show a significant increase in line core and wing intensities during the flare. The analysis of the line profiles from the flare ribbons reveal that the Na I D1 line has a central reversal with excess emission in the blue wing (blue asymmetry). We combine RADYN and RH simulations to synthesise Na I D1 line profiles of the flaring atmosphere and find good agreement with the observations. Heating with a beam of electrons modifies the radiation field in the flaring atmosphere and excites electrons from the ground state $\\mathrm{3s~^2S}$ to the first excited state $\\mathrm{3p~^2P}$, which in turn modifies relative population of the two states. The change in temperature and the population density of the energy states make the sodium line profile re...

  18. Extracellular matrix proteins expression profiling in chemoresistant variants of the A2780 ovarian cancer cell line.

    Science.gov (United States)

    Januchowski, Radosław; Zawierucha, Piotr; Ruciński, Marcin; Nowicki, Michał; Zabel, Maciej

    2014-01-01

    Ovarian cancer is the leading cause of death among gynaecological malignancies. Extracellular matrix (ECM) can affect drug resistance by preventing the penetration of the drug into cancer cells and increased resistance to apoptosis. This study demonstrates alterations in the expression levels of ECM components and related genes in cisplatin-, doxorubicin-, topotecan-, and paclitaxel-resistant variants of the A2780 ovarian cancer cell line. Affymetrix Gene Chip Human Genome Array Strips were used for hybridisations. The genes that had altered expression levels in drug-resistant sublines were selected and filtered by scatter plots. The genes that were up- or downregulated more than fivefold were selected and listed. Among the investigated genes, 28 genes were upregulated, 10 genes were downregulated, and two genes were down- or upregulated depending on the cell line. Between upregulated genes 12 were upregulated very significantly--over 20-fold. These genes included COL1A2, COL12A1, COL21A1, LOX, TGFBI, LAMB1, EFEMP1, GPC3, SDC2, MGP, MMP3, and TIMP3. Four genes were very significantly downregulated: COL11A1, LAMA2, GPC6, and LUM. The expression profiles of investigated genes provide a preliminary insight into the relationship between drug resistance and the expression of ECM components. Identifying correlations between investigated genes and drug resistance will require further analysis.

  19. Gene Expression Profile of Multiple Myeloma Cell Line Treated by Arsenic Trioxide

    Institute of Scientific and Technical Information of China (English)

    WANG Mengchang; LIU Shaanxi; LIU Pengbo

    2007-01-01

    cDNA microarray was used to compare the gone expression profiles of multiple myeloma cell line RPMI8226 24 h before and after treatment with arsenic trioxide. Two eDNA probes were prepared by mRNA reverse transcription of both arsenic trioxide-treated and untreated RPMI8226 cells. The probes were labeled with Cy3 and Cy5 fluorescence dyes separately, hybridized with cDNA microarray representing 4096 different human genes, and scanned for fluorescence intensity. The differences in gene expression were calculated on the basis of the ratios of signal intensity of treated and untreated samples. The up- and down-regulated genes were screened through the analysis of gene expression ratios. The results showed that 273 genes were differentially altered at mRNA level, 121 genes were up-regulated and 152 were down-regulated. It is concluded that the treatment with arsenic trioxide can induce a variety of gene changes in RPMI8226 cell line. Many genes may be involved in the pathogenesis of multiple myeloma. ALK-1 and TXNIP genes may play an impor- tant role in the apoptosis and partial differentiation of RPMI8226 cells.

  20. Gene expression profiling and gene copy-number changes in malignant mesothelioma cell lines.

    Science.gov (United States)

    Zanazzi, Claudia; Hersmus, Remko; Veltman, Imke M; Gillis, Ad J M; van Drunen, Ellen; Beverloo, H Berna; Hegmans, Joost P J J; Verweij, Marielle; Lambrecht, Bart N; Oosterhuis, J Wolter; Looijenga, Leendert H J

    2007-10-01

    Malignant mesothelioma (MM) is an asbestos-induced tumor that acquires aneuploid DNA content during the tumorigenic process. We used instable MM cell lines as an in vitro model to study the impact of DNA copy-number changes on gene expression profiling, in the course of their chromosomal redistribution process. Two MM cell lines, PMR-MM2 (early passages of in vitro culture) and PMR-MM7 (both early and late passages of in vitro culture), were cytogenetically characterized. Genomic gains and losses were precisely defined using microarray-based comparative genomic hybridization (array-CGH), and minimal overlapping analysis led to the identification of the common unbalanced genomic regions. Using the U133Plus 2.0 Affymetrix gene chip array, we analyzed PMR-MM7 early and late passages for genome-wide gene expression, and correlated the differentially expressed genes with copy-number changes. The presence of a high number of genetic imbalances occurring from early to late culture steps reflected the tendency of MM cells toward genomic instability. The selection of specific chromosomal abnormalities observed during subsequent cultures demonstrated the spontaneous evolution of the cancer cells in an in vitro environment. MM cell lines were characterized by copy-number changes associated with the TP53 apoptotic pathway already present at the first steps of in vitro culture. Prolonged culture led to acquisition of additional chromosomal copy-number changes associated with dysregulation of genes involved in cell adhesion, regulation of mitotic cell cycle, signal transduction, carbohydrate metabolism, motor activity, glycosaminoglycan biosynthesis, protein binding activity, lipid transport, ATP synthesis, and methyltransferase activity.

  1. Observed Faraday Effects in Damped Lyman-Alpha Absorbers and Lyman Limit Systems: The Magnetised Environment of Galactic Building Blocks at Redshift=2

    CERN Document Server

    Farnes, J S; Gaensler, B M; Haverkorn, M; O'Sullivan, S P; Curran, S J

    2016-01-01

    Protogalactic environments are typically identified using quasar absorption lines, and these galactic building blocks can manifest as Damped Lyman-Alpha Absorbers (DLAs) and Lyman Limit Systems (LLSs). We use radio observations of Faraday effects to test whether DLAs and LLSs host a magnetised medium, by combining DLA and LLS detections throughout the literature with 1.4 GHz polarization data from the NRAO VLA Sky Survey (NVSS). We obtain a control, a DLA, and a LLS sample consisting of 114, 19, and 27 lines-of-sight respectively - all of which are polarized at $\\ge8\\sigma$ to ensure Rician bias is negligible. Using a Bayesian framework, we are unable to detect either coherent or random magnetic fields in DLAs: the regular coherent magnetic fields within the DLAs must be $\\le2.8$ $\\mu$G, and the lack of depolarization is consistent with the weakly magnetised gas in DLAs being non-turbulent and quiescent. However, we find mild suggestive evidence that LLSs have coherent magnetic fields: after controlling for t...

  2. Giant Lyman-Alpha Nebulae in the Illustris Simulation

    CERN Document Server

    Gronke, Max

    2016-01-01

    Several `giant' Lyman-$\\alpha$ (Ly$\\alpha$) nebulae with extent $\\gtrsim 300\\,$kpc and observed Ly$\\alpha$ luminosity of $\\gtrsim 10^{44}\\,{\\rm erg}\\,{\\rm s}^{-1}\\,{\\rm cm}^{-2}\\,{\\rm arcsec}^{-2}$ have recently been detected, and it has been speculated that their presence hints at a substantial cold gas reservoir in small cool clumps not resolved in modern hydro-dynamical simulations. We use the Illustris simulation to predict the Ly$\\alpha$ emission emerging from large halos ($M > 10^{11.5}M_{\\odot}$) at $z\\sim 2$ and thus test this model. We consider both AGN and star driven ionization, and compared the simulated surface brightness maps, profiles and Ly$\\alpha$ spectra to a model where most gas is clumped below the simulation resolution scale. We find that while the cold clumps boost the Ly$\\alpha$ luminosity especially in the outer regions of the halo -- as expected by previous work -- with Illustris no additional clumping is necessary to explain the extents and luminosities of the `giant Ly$\\alpha$ nebul...

  3. Lyman Continuum Emission from Galaxies at z~3.4

    CERN Document Server

    Steidel, C C; Adelberger, K L

    2000-01-01

    We report the detection of significant Lyman continuum flux in the composite spectrum of 29 Lyman break galaxies (LBGs) with redshifts = 3.40+/-0.09. After correction for opacity due to intervening absorption using a new composite QSO spectrum evaluated at the same redshift, the ratio of emergent flux density at 1500 \\AA in the rest frame to that in the Lyman continuum is L(1500)/L(900) = 4.6 +/- 1.0. If the relative intensity of the inferred escaping Lyman continuum radiation is typical of LBGs at z ~ 3 (the galaxies in this sample are drawn from the bluest quartile of LBG spectral energy distributions due to known selection effects), then observed LBGs produce about 5 times more H-ionizing photons per unit co-moving volume than QSOs at z ~ 3. The associated contribution to the metagalactic ionizing radiation field is J_{\

  4. Stellar Mass Function of Lyman Break Galaxies: Theoretical Perspective

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Liang; HUANG Yong-Qing; LIU Nian-Hua; LAI Zhen-Quan; SHU Cheng-Gang

    2006-01-01

    @@ Adopting the observational distributions of star formation rates and half-light radii of Lyman break galaxies (LBGs) in the rest frame UV, we investigate empirically the predicted stellar mass function for LBGs.

  5. Molecular profiling of breast cancer cell lines defines relevant tumor models and provides a resource for cancer gene discovery.

    Directory of Open Access Journals (Sweden)

    Jessica Kao

    Full Text Available BACKGROUND: Breast cancer cell lines have been used widely to investigate breast cancer pathobiology and new therapies. Breast cancer is a molecularly heterogeneous disease, and it is important to understand how well and which cell lines best model that diversity. In particular, microarray studies have identified molecular subtypes-luminal A, luminal B, ERBB2-associated, basal-like and normal-like-with characteristic gene-expression patterns and underlying DNA copy number alterations (CNAs. Here, we studied a collection of breast cancer cell lines to catalog molecular profiles and to assess their relation to breast cancer subtypes. METHODS: Whole-genome DNA microarrays were used to profile gene expression and CNAs in a collection of 52 widely-used breast cancer cell lines, and comparisons were made to existing profiles of primary breast tumors. Hierarchical clustering was used to identify gene-expression subtypes, and Gene Set Enrichment Analysis (GSEA to discover biological features of those subtypes. Genomic and transcriptional profiles were integrated to discover within high-amplitude CNAs candidate cancer genes with coordinately altered gene copy number and expression. FINDINGS: Transcriptional profiling of breast cancer cell lines identified one luminal and two basal-like (A and B subtypes. Luminal lines displayed an estrogen receptor (ER signature and resembled luminal-A/B tumors, basal-A lines were associated with ETS-pathway and BRCA1 signatures and resembled basal-like tumors, and basal-B lines displayed mesenchymal and stem/progenitor-cell characteristics. Compared to tumors, cell lines exhibited similar patterns of CNA, but an overall higher complexity of CNA (genetically simple luminal-A tumors were not represented, and only partial conservation of subtype-specific CNAs. We identified 80 high-level DNA amplifications and 13 multi-copy deletions, and the resident genes with concomitantly altered gene-expression, highlighting known and

  6. Caustics and Caustic-Diffraction in Laser Shadowgraphy of a Sessile Drop and Identification of Profile Near Contact Line

    Science.gov (United States)

    Zhang, Neng-Li; Chao, David F.

    2003-01-01

    This paper presents an optical method based on the caustics and caustic-difraction in laser shadowgaphy of a sessile drop to identify and estimate the drop profile near the contact line. A parallel laser beam passes through a liquid sessile drop placed on a transparent substrate to produce a shadowgraphic image of the drop on the screen far from the substrate. Along the inflection line of the drop the Gaussian curvature of the wavefront deformed by the drop vanishes, and therefore the inflection line gives caustics in the far field of the wave, which can be seen on the screen. The neighboring light rays at both sides of the inflection line interfere with each other to form interference fringes at the inner side of the caustics. According to the pattern of the caustics, the drop-profile shape can be identified and estimated.

  7. The morphologies of breast cancer cell lines in three-dimensionalassays correlate with their profiles of gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Paraic A.; Lee, Genee Y.; Myers, Connie A.; Neve, RichardM.; Semeiks, Jeremy R.; Spellman, Paul T.; Lorenz, Katrin; Lee, Eva H.; Barcellos-Hoff, Mary Helen; Petersen, Ole W.; Gray, Joe W.; Bissell, MinaJ.

    2007-01-31

    3D cell cultures are rapidly becoming the method of choice for the physiologically relevant modeling of many aspects of non-malignant and malignant cell behavior ex vivo. Nevertheless, only a limited number of distinct cell types have been evaluated in this assay to date. Here we report the first large scale comparison of the transcriptional profiles and 3D cell culture phenotypes of a substantial panel of human breast cancer cell lines. Each cell line adopts a colony morphology of one of four main classes in 3D culture. These morphologies reflect, at least in part, the underlying gene expression profile and protein expression patterns of the cell lines, and distinct morphologies were also associated with tumor cell invasiveness and with cell lines originating from metastases. We further demonstrate that consistent differences in genes encoding signal transduction proteins emerge when even tumor cells are cultured in 3D microenvironments.

  8. Diagnostic Power of Broad Emission Line Profiles in Searches for Binary Supermassive Black Holes: Comparison of Models with Observations

    Science.gov (United States)

    Nguyen, Khai; Bogdanovic, Tamara; Eracleous, Michael; Runnoe, Jessie C.; Sigurdsson, Steinn

    2017-01-01

    Motivated by observational searches for sub-parsec supermassive black hole binaries (SBHBs) we develop a semi-analytic model to describe the spectral emission line signatures of these systems. We are particularly interested in modeling the profiles of the broad emission lines, which have been used as a tool to search for SBHBs. The goal of this work is to test one of the leading models of binary accretion flows in the literature: SBHB in a circumbinary disk. In this context, 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 that forms a common envelope about a gravitationally bound binary. Our first generation model shows that emission line profiles tend to have different statistical properties depending on the semi-major axis, mass ratio, eccentricity of the binary, and the alignment of the triple-disk system, and can in principle be used to constrain the statistical distribution of these parameters. We present the results of a second generation model, which improves upon the treatment of radiative transfer by taking into account the effect of line-driven winds on the properties of the model emission line profiles. This improvement allows a preliminary comparison of the model profiles with the observed SBHB candidates and AGN population in general.

  9. Line profiles of water for the photon dominated region and embedded sources in the S140 region

    CERN Document Server

    Poelman, D R

    2006-01-01

    A radiative transfer method for the treatment of molecular lines is presented. We apply this method to previous SWAS and ISO observations of water vapor in the source S140 in order to make models to plan for, and to interpret, HIFI data. Level populations are calculated with the use of a three-dimensional (multi-zone) escape probability method and with a long characteristic code that uses Monte Carlo techniques with fixed directions. Homogeneous and inhomogeneous models are used to compute the differences between water line profiles across the S140 region. We find that when an outflow or infall velocity field with a gradient of a few kms^{-1} is adopted, line profiles with a FWHM of 6 kms^{-1} are found, in agreement with observations. Inhomogeneous models are favoured to produce a single-peaked line profile. When zooming in on smaller regions within the PDR, the shapes of the line profiles start to differ due to the different temperature and density distributions there. The embedded sources are traced by hig...

  10. Physiological basis and transcriptional profiling of three salt-tolerant mutant lines of rice

    Directory of Open Access Journals (Sweden)

    Concha Domingo

    2016-09-01

    Full Text Available Salinity is a complex trait that affects growth and productivity in many crops, including rice. Mutation induction, a useful tool to generate salt tolerant plants, enables the analysis of plants with similar genetic background, facilitating the understanding of the salt tolerance mechanisms. In this work, we generated three salt tolerant mutant lines by irradiation of a salt-sensitive cultivar plants and screened M2 plants at seedling stage in the presence of high salinity. These three lines, SaT20, SaS62 and SaT58, showed different responses to salinity, but exhibited similar phenotype to wild type plants, except SaT20 that displayed shorter height when grown in the absence of salt. Under salt conditions, all three mutants and the parental line showed similar reduction in yield, although relevant differences in other physiological parameters, such as Na+ accumulation in healthy leaves of SaT20, were registered. Microarray analyses of gene expression profiles in roots revealed the occurrence of common and specific responses in the mutants. The three mutants showed up-regulation of responsive genes, the activation of oxido-reduction process and the inhibition of ion transport. The participation of jasmonate in the plant response to salt was evident by down-regulation of a gene coding for a jasmonate O-methyltransferase. Genes dealing with lipid transport and metabolism were, in general, up-regulated except in SaS62, that also exhibited down-regulation of genes involved in ion transport and Ca2+ signal transduction. The two most tolerant varieties, SaS62 and SaT20, displayed lower levels of transcripts involved in K+ uptake. The physiological study and the description of the expression analysis evidenced that the three lines showed different responses to salt: SaT20 showed a high Na+ content in leaves, SaS62 presented an inhibition of lipid metabolism and ion transport and SaT58 differs in both features in the response to salinity. The analysis of

  11. Integrative fitting of absorption line profiles with high accuracy, robustness, and speed

    Science.gov (United States)

    Skrotzki, Julian; Habig, Jan Christoph; Ebert, Volker

    2014-08-01

    The principle of the integrative evaluation of absorption line profiles relies on the numeric integration of absorption line signals to retrieve absorber concentrations, e.g., of trace gases. Thus, it is a fast and robust technique. However, previous implementations of the integrative evaluation principle showed shortcomings in terms of accuracy and the lack of a fit quality indicator. This has motivated the development of an advanced integrative (AI) fitting algorithm. The AI fitting algorithm retains the advantages of previous integrative implementations—robustness and speed—and is able to achieve high accuracy by introduction of a novel iterative fitting process. A comparison of the AI fitting algorithm with the widely used Levenberg-Marquardt (LM) fitting algorithm indicates that the AI algorithm has advantages in terms of robustness due to its independence from appropriately chosen start values for the initialization of the fitting process. In addition, the AI fitting algorithm shows speed advantages typically resulting in a factor of three to four shorter computational times on a standard personal computer. The LM algorithm on the other hand retains advantages in terms of a much higher flexibility, as the AI fitting algorithm is restricted to the evaluation of single absorption lines with precomputed line width. Comparing both fitting algorithms for the specific application of in situ laser hygrometry at 1,370 nm using direct tunable diode laser absorption spectroscopy (TDLAS) suggests that the accuracy of the AI algorithm is equivalent to that of the LM algorithm. For example, a signal-to-noise ratio of 80 and better typically yields a deviation of TDLAS hygrometry at the aerosol and cloud chamber aerosol interactions and dynamics in the atmosphere (AIDA)—a unique large-scale facility to study atmospheric processes. The robustness of the AI fitting algorithm has been validated for typical AIDA conditions encompassing strong transmission fluctuations

  12. Physiological Basis and Transcriptional Profiling of Three Salt-Tolerant Mutant Lines of Rice

    Science.gov (United States)

    Domingo, Concha; Lalanne, Eric; Catalá, María M.; Pla, Eva; Reig-Valiente, Juan L.; Talón, Manuel

    2016-01-01

    Salinity is a complex trait that affects growth and productivity in many crops, including rice. Mutation induction, a useful tool to generate salt tolerant plants, enables the analysis of plants with similar genetic background, facilitating the understanding of the salt tolerance mechanisms. In this work, we generated three salt tolerant mutant lines by irradiation of a salt-sensitive cultivar plants and screened M2 plants at seedling stage in the presence of high salinity. These three lines, SaT20, SaS62, and SaT58, showed different responses to salinity, but exhibited similar phenotype to wild type plants, except SaT20 that displayed shorter height when grown in the absence of salt. Under salt conditions, all three mutants and the parental line showed similar reduction in yield, although relevant differences in other physiological parameters, such as Na+ accumulation in healthy leaves of SaT20, were registered. Microarray analyses of gene expression profiles in roots revealed the occurrence of common and specific responses in the mutants. The three mutants showed up-regulation of responsive genes, the activation of oxido-reduction process and the inhibition of ion transport. The participation of jasmonate in the plant response to salt was evident by down-regulation of a gene coding for a jasmonate O-methyltransferase. Genes dealing with lipid transport and metabolism were, in general, up-regulated except in SaS62, that also exhibited down-regulation of genes involved in ion transport and Ca2+ signal transduction. The two most tolerant varieties, SaS62 and SaT20, displayed lower levels of transcripts involved in K+ uptake. The physiological study and the description of the expression analysis evidenced that the three lines showed different responses to salt: SaT20 showed a high Na+ content in leaves, SaS62 presented an inhibition of lipid metabolism and ion transport and SaT58 differs in both features in the response to salinity. The analysis of these salt

  13. Lyman Alpha Signatures from Direct Collapse Black Holes

    CERN Document Server

    Dijkstra, Mark; Sobral, David

    2016-01-01

    `Direct collapse black holes' (DCBHs) provide possible seeds for supermassive black holes that exist at redshifts as high as z~7. We study Lyman Alpha (Lya) radiative transfer through simplified representations of the DCBH-scenario. We find that gravitational heating of the collapsing cloud gives rise to a Lya cooling luminosity of up to ~ 1e38(M_gas/1e6 Msun)^2 erg/s. The Lya production rate can be significantly larger during the final stages of collapse, but collisional deexcitation efficiently suppresses the emerging Lya flux. Photoionization by a central source boosts the Lya luminosity to L~1e43(M_BH/1e6 M_sun) erg/s during specific evolutionary stages of the cloud, where M_BH denotes the mass of the black hole powering this source. We predict that the width and velocity off-set of the Lya spectral line range from a few tens to few thousands km/s, depending sensitively on the evolutionary state of the cloud. We also compare our predictions to observations of CR7 (Sobral et al. 2015), a luminous Lya emitt...

  14. Lyman-Werner UV Escape Fractions from Primordial Halos

    CERN Document Server

    Schauer, Anna T P; Glover, Simon C O; Klessen, Ralf S

    2015-01-01

    Population III stars can regulate star formation in the primordial Universe in several ways. They can ionize nearby halos, and even if their ionizing photons are trapped by their own halos, their Lyman-Werner (LW) photons can still escape and destroy H$_2$ in other halos, preventing them from cooling and forming stars. LW escape fractions are thus a key parameter in cosmological simulations of early reionization and star formation but have not yet been parametrized for realistic halos by halo or stellar mass. To do so, we perform radiation hydrodynamical simulations of LW UV escape from 9--120 M$_{\\odot}$ Pop III stars in $10^5$ to $10^7$ M$_{\\odot}$ halos with ZEUS-MP. We find that photons in the LW lines (i.e. those responsible for destroying H$_{2}$ in nearby systems) have escape fractions ranging from 0% to 85%. No LW photons escape the most massive halo in our sample, even from the most massive star. Escape fractions for photons elsewhere in the 11.18--13.6~eV energy range, which can be redshifted into t...

  15. The Metallicity evolution of Damped Lyman-$\\alpha$ systems

    CERN Document Server

    Savaglio, S; Stiavelli, M

    1999-01-01

    We have collected absorption line measurements of 70 Damped Lyman-alpha (DLA) systems, mostly coming from high resolution data, to investigate the chemical evolution of galaxies in the redshift interval 0.0 < z < 4.4. In doing that, we have adopted the most general approach used so far, i.e. the dust depletion corrections are obtained by comparing the element abundances with four depletion patterns observed in the Milky Way. The best solution, obtained through chi^2 minimization, gives as output parameters the global DLA metallicity and the dust-to-metals ratio. Clear evolution of the metallicity vs. redshift is found, with average values going from ~1/30 solar at z~4.1 to dispersion around the average regression is significantly larger than the errors (i.e. ~0.45 dex average dispersion relative to ~0.14 dex error), indicating that the class of DLAs include objects with a range of evolutionary histories and/or initial conditions, such as total mass, formation time, matter spatial distribution, etc. We a...

  16. Origin of the Lyman excess in early-type stars

    CERN Document Server

    Cesaroni, R; Beltrán, M T; Molinari, S; Olmi, L; Treviño-Morales, S P

    2016-01-01

    Ionized regions around early-type stars are believed to be well-known objects, but until recently, our knowledge of the relation between the free-free radio emission and the IR emission has been observationally hindered by the limited angular resolution in the far-IR. The advent of Herschel has now made it possible to obtain a more precise comparison between the two regimes, and it has been found that about a third of the young HII regions emit more Lyman continuum photons than expected, thus presenting a Lyman excess. With the present study we wish to distinguish between two scenarios that have been proposed to explain the existence of the Lyman excess: (i) underestimation of the bolometric luminosity, or (ii) additional emission of Lyman-continuum photons from an accretion shock. We observed an outflow (SiO) and an infall (HCO+) tracer toward a complete sample of 200 HII regions, 67 of which present the Lyman excess. Our goal was to search for any systematic difference between sources with Lyman excess and ...

  17. Gene expression profiles deciphering leaf senescence variation between early- and late-senescence cotton lines.

    Directory of Open Access Journals (Sweden)

    Xiangqiang Kong

    Full Text Available Leaf senescence varies greatly among genotypes of cotton (Gossypium hirsutium L, possibly due to the different expression of senescence-related genes. To determine genes involved in leaf senescence, we performed genome-wide transcriptional profiling of the main-stem leaves of an early- (K1 and a late-senescence (K2 cotton line at 110 day after planting (DAP using the Solexa technology. The profiling analysis indicated that 1132 genes were up-regulated and 455 genes down-regulated in K1 compared with K2 at 110 DAP. The Solexa data were highly consistent with, and thus were validated by those from real-time quantitative PCR (RT-PCR. Most of the genes related to photosynthesis, anabolism of carbohydrates and other biomolecules were down-regulated, but those for catabolism of proteins, nucleic acids, lipids and nutrient recycling were mostly up-regulated in K1 compared with K2. Fifty-one differently expressed hormone-related genes were identified, of which 5 ethylene, 3 brassinosteroid (BR, 5 JA, 18 auxin, 8 GA and 1 ABA related genes were up-regulated in K1 compared with K2, indicating that these hormone-related genes might play crucial roles in early senescence of K1 leaves. Many differently expressed transcription factor (TF genes were identified and 11 NAC and 8 WRKY TF genes were up-regulated in K1 compared with K2, suggesting that TF genes, especially NAC and WRKY genes were involved in early senescence of K1 leaves. Genotypic variation in leaf senescence was attributed to differently expressed genes, particularly hormone-related and TF genes.

  18. An extreme, blueshifted iron line profile in the Narrow Line Seyfert 1 PG 1402+261; an edge-on accretion disk or highly ionized absorption?

    CERN Document Server

    Reeves, J N; Turner, T J

    2004-01-01

    We report on a short XMM-Newton observation of the radio-quiet Narrow Line Seyfert 1 PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6-9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad (FWHM velocity of 110000 km/s) iron K-shell emission line. The line centroid energy at 7.3 keV appears blue-shifted with respect to the iron Kalpha emission band between 6.4-6.97 keV, while the blue-wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of >60 deg is required to model the extreme blue-wing of the line. Furthermore the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG 1402+261 above 2 keV is dominated by the pure-reflection component from the disk, while little or none of the direct hard power-law is observed. Alternatively the spectrum above 2 keV may instead b...

  19. Measurements of Spatial Line Emission Profiles in the Main Scrape-Off Layer of the DIII-D Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Groth, M; Ellis, R; Brooks, N; Fenstermacher, M; Lasnier, C; Meyer, W; Moller, J

    2009-06-05

    A video camera system is described that measures the spatial distribution of visible line emission emitted from the main scrape-off layer (SOL) of plasmas in the DIII-D tokamak. A wide-angle lens installed on an equatorial port and an in-vessel mirror which intercepts part of the lens view provide simultaneous tangential views of the SOL on the low-field and high-field sides of the plasma's equatorial plane. Tomographic reconstruction techniques are used to calculate the 2-D poloidal profiles from the raw data, and 1-D poloidal profiles simulating chordal views of other optical diagnostics from the 2-D profiles. The 2-D profiles can be compared with SOL plasma simulations; the 1-D profiles with measurements from spectroscopic diagnostics. Sample results are presented which elucidate carbon transport in plasmas with toroidally uniform injection of methane and argon transport in disruption mitigation experiments with massive gas jet injection.

  20. Authentication of newly established human esophageal squamous cell carcinoma cell line (YM-1) using short tandem repeat (STR) profiling method.

    Science.gov (United States)

    Ayyoob, Khosravi; Masoud, Khoshnia; Vahideh, Kazeminejad; Jahanbakhsh, Asadi

    2016-03-01

    Cross-contamination during or early after establishment of a new cell line could result in the worldwide spread of a misidentified cell line. Therefore, newly established cell lines need to be authenticated by a reference standard method. This study was conducted to investigate the authenticity of a newly established epithelial cell line of human esophageal squamous cell carcinoma (ESCC) called YM-1 using short tandem repeat (STR) DNA profiling method. Primary human ESCC epithelial cells were cultured from the fresh tumor tissue of an adult female patient. Growth characteristics and epithelial originality of YM-1 cells were studied. Genomic DNA was isolated from YM-1 cells harvested at passage 22 and ESCC donor tumor sample on two different days to prevent probable DNA contamination. STR profiling was performed using AmpFℓSTR® Identifiler® Plus PCR Amplification Kit. To address whether YM-1 cells undergo genetic alteration as the passage number increases, STR profiling was performed again on harvested cells at passage 51. YM-1 cells grew as a monolayer with a population doubling time of 40.66 h. Epithelial originality of YM-1 cells was confirmed using ICC/IF staining of cytokeratins AE1/AE3. The STR profile of the ESCC donor tumor sample was the same with YM-1 cells at passage 22. However, STR profile of the donor tumor sample showed an off-ladder (OL) allele in their D7S820 locus. Also, re-profiling of YM-1 cells at passage 51 showed a loss of heterozygosity (LOH) at D18S51 locus. This suggests that long-term culture of cell lines may alter their DNA profile. Comparison of the DNA fingerprinting results in DSMZ, and ATCC STR profiling databases confirmed unique identity of YM-1 cell line. This study provides an easy, fast, and reliable procedure for authentication of newly established cell lines, which helps in preventing the spread of misidentified cells and improving the reproducibility and validity of experiments, consequently.

  1. A connection between extremely strong Damped Lyman-alpha Systems and Lyman-alpha Emitting Galaxies at small impact parameters

    CERN Document Server

    Noterdaeme, P; Paris, I; Cai, Z; Finley, H; Ge, J; Pieri, M M; York, D G

    2014-01-01

    We present a study of ~100 high redshift (z~2-4) extremely strong damped Lyman-alpha systems (ESDLA, with N(HI)>0.5x10^22 cm^-2) detected in quasar spectra from the Baryon Oscillation Spectroscopic Survey SDSS-III DR11. We study the neutral hydrogen, metal, and dust content of this elusive population of absorbers and confirm our previous finding that the high column density end of the N(HI) frequency distribution has a relatively shallow slope with power-law index -3.6, similar to what is seen from 21-cm maps in nearby galaxies. The stacked absorption spectrum indicates a typical metallicity ~1/20th solar, similar to the mean metallicity of the overall DLA population. The relatively small velocity extent of the low-ionisation lines suggests that ESDLAs do not arise from large-scale flows of neutral gas. The high column densities involved are in turn more similar to what is seen in DLAs associated with gamma-ray burst afterglows (GRB-DLAs), which are known to occur close to star forming regions. This indicates...

  2. Genetic profiling reveals an alarming rate of cross-contamination among human cell lines used in China.

    Science.gov (United States)

    Ye, Fang; Chen, Chuguang; Qin, Jian; Liu, Jie; Zheng, Congyi

    2015-10-01

    Cell lines are widely used as in vitro model systems in biologic and medical research. However, much of the research has been invalidated by the unwitting use of false cell lines. A significant proportion of the research involving human cell lines was initiated in China. Paradoxically, the cell lines used in China have never been authenticated. Here, we present a comprehensive survey of cross-contamination in 380 samples from 113 independent sources in China using short tandem repeat profiling methods. High levels of cross-contamination were uncovered (95 of 380, 25%). Notable false cell lines (e.g., KB and WISH) are still actively used under their false identity and tissue attributions. Most strikingly, 85.51% of lines established in China were misidentified (59 of 69) and accounted for over half of the misidentifications (59 of 95, 62.11%). Further, 93.22% of the contaminants in cell lines established in laboratories of China were HeLa cells or a possible hybrid of HeLa with an unknown cell line. Results from these misidentified lines have been published in thousands of potentially erroneous articles and may have distorted the findings visible to the scientific community. False lines have been used in drug screening, potentially leading to unusable or even harmful therapeutic strategies. We also noted the causes of contamination and provided suggestions for remediation.

  3. Chromatic line-profile tomography to reveal exoplanetary atmospheres: application to HD 189733b

    CERN Document Server

    Borsa, Francesco; Poretti, Ennio

    2016-01-01

    Transmission spectroscopy can be used to constrain the properties of exoplanetary atmospheres. During a transit, the light blocked from the atmosphere of the planet leaves an imprint in the light coming from the star. This has been shown for many exoplanets with different techniques, with both photometry and spectroscopy. We aim at testing chromatic line-profile tomography as a new tool to investigate exoplanetary atmospheres. The signal imprinted on the cross-correlation function (CCF) by a planet transiting its star is dependent on the planet-to-star radius ratio. We want to verify if the precision reachable on the CCF obtained from a subset of the spectral orders of the HARPS spectrograph is enough to discriminate the radius of a planet at different wavelengths. Methods. We analyze HARPS archival data of three transits of HD 189733b. We divide the HARPS spectral range in 7 broadbands, calculating for each band the ratio between the area of the out-of-transit CCF and the area of the signal imprinted by the ...

  4. PROJECT VeSElkA: ANALYSIS OF BALMER LINE PROFILES OF SLOWLY ROTATING CHEMICALLY PECULIAR STARS

    Energy Technology Data Exchange (ETDEWEB)

    Khalack, V.; LeBlanc, F., E-mail: khalack.viktor@umoncton.ca [Département de Physique et d’Astronomie, Université de Moncton, Moncton, N.-B., E1A 3E9 (Canada)

    2015-07-15

    We present results for the estimation of gravity, effective temperature, and radial velocity of poorly studied chemically peculiar stars recently observed with the spectropolarimeter Echelle SpectroPolarimetric Device for Observations of Stars at the Canada–France–Hawaii Telescope in the frame of the Vertical Stratification of Element Abundances project. The effective temperature and surface gravity values are determined for the very first time for four of the stars from our sample (HD 23878, HD 83373, HD 95608, and HD 164584). Grids of stellar atmosphere models with the corresponding fluxes have been calculated using version 15 of the PHOENIX code for effective temperatures in the range of 5000–15,000 K, for the logarithm of surface gravities in the range of 3.0–4.5 and for the metallicities from −1.0 to +1.5. We used these fluxes to fit the Balmer line profiles employing the code FITSB2 that produces estimates of the effective temperature, gravity, and radial velocity for each star. When possible, our results are compared to those previously published. The physical characteristics of 16 program stars are discussed with the future aim to study the abundance anomalies of chemical species and the possible vertical abundance stratification in their stellar atmosphere.

  5. Project VeSElkA: Analysis of Balmer line profiles in slowly rotating chemically peculiar stars

    CERN Document Server

    Khalack, Viktor

    2015-01-01

    We present results for the estimation of gravity, effective temperature, and radial velocity of poorly studied chemically peculiar stars recently observed with the spectropolarimeter Echelle SpectroPolarimetric Device for Observations of Stars at the Canada-France-Hawaii Telescope in the frame of the Vertical Stratification of Element Abundances project. The effective temperature and surface gravity values are determined for the very first time for four of the stars from our sample (HD23878, HD83373, HD95608, and HD164584). Grids of stellar atmosphere models with the corresponding fluxes have been calculated using version 15 of the PHOENIX code for effective temperatures in the range of 5000-15,000 K, for the logarithm of surface gravities in the range of 3.0-4.5 and for the metallicities from -1.0 to +1.5. We used these fluxes to fit the Balmer line profiles employing the code FITSB2 that produces estimates of the effective temperature, gravity, and radial velocity for each star. When possible, our results a...

  6. Models of Five Absorption Line Systems Along the Line of Sight Toward PG0117+213

    CERN Document Server

    Masiero, J R; Ding, J; Churchill, C W; Kacprzak, G G

    2005-01-01

    We present our investigation into the physical conditions of the gas in five intervening quasar absorption line systems along the line of sight toward the quasar PG 0117+213, with redshifts of z=0.57, z=0.72, z=1.04, z=1.32 and z=1.34. Photoionization modeling of HST, Keck I, and Palomar data, using the code Cloudy, is employed to derive densities and metallicities of the multiple phases of gas required to fit the absorption profile for each system. We discuss the implications of these models for galaxy evolution, including the interpretation of ``CIV deficiency'' and damped Lyman alpha absorbers (DLAs), and the relationships between galaxy morphology, galaxy luminosity, and absorption signature.

  7. Expression profiling of colon cancer cell lines and colon biopsies: Towards a screening system for potential cancer-preventive compounds

    NARCIS (Netherlands)

    Erk, van M.J.; Krul, C.A.M.; Caldenhoven, E.; Stierum, R.H.; Peters, W.H.; Woutersen, R.A.; Ommen, van B.

    2005-01-01

    Interest in mechanisms of colon cancer prevention by food compounds is strong and research in this area is often performed with cultured colon cancer cells. In order to assess utility for screening of potential cancer-preventive (food) compounds, expression profiles of 14 human cell lines derived

  8. Expression profiling of colon cancer cell lines and colon biopsies: towards a screening system for potential cancer-preventive compounds.

    NARCIS (Netherlands)

    Erk, M.J. van; Krul, C.A.; Caldenhoven, E.; Stierum, R.H.; Peters, W.H.M.; Woutersen, R.A.; Ommen, B.

    2005-01-01

    Interest in mechanisms of colon cancer prevention by food compounds is strong and research in this area is often performed with cultured colon cancer cells. In order to assess utility for screening of potential cancer-preventive (food) compounds, expression profiles of 14 human cell lines derived

  9. Transcriptomic profile of two canine mammary cancer cell lines with different proliferative and anti-apoptotic potential

    NARCIS (Netherlands)

    Krol, M.; Skierski, J.; Rao, N.A.; Hellmen, E.; Mol, J.A.; Motyl, T.

    2009-01-01

    J Physiol Pharmacol. 2009 May;60 Suppl 1:95-106. Transcriptomic profile of two canine mammary cancer cell lines with different proliferative and anti-apoptotic potential. Krol M, Pawlowski KM, Skierski J, Rao NA, Hellmen E, Mol JA, Motyl T. Department of Physiological Sciences, Faculty of Veterinary

  10. Expression profiling of colon cancer cell lines and colon biopsies: Towards a screening system for potential cancer-preventive compounds

    NARCIS (Netherlands)

    Erk, van M.J.; Krul, C.A.M.; Caldenhoven, E.; Stierum, R.H.; Peters, W.H.; Woutersen, R.A.; Ommen, van B.

    2005-01-01

    Interest in mechanisms of colon cancer prevention by food compounds is strong and research in this area is often performed with cultured colon cancer cells. In order to assess utility for screening of potential cancer-preventive (food) compounds, expression profiles of 14 human cell lines derived fr

  11. Expression profiling of colon cancer cell lines and colon biopsies: towards a screening system for potential cancer-preventive compounds.

    NARCIS (Netherlands)

    Erk, M.J. van; Krul, C.A.; Caldenhoven, E.; Stierum, R.H.; Peters, W.H.M.; Woutersen, R.A.; Ommen, B.

    2005-01-01

    Interest in mechanisms of colon cancer prevention by food compounds is strong and research in this area is often performed with cultured colon cancer cells. In order to assess utility for screening of potential cancer-preventive (food) compounds, expression profiles of 14 human cell lines derived fr

  12. Indirect Evidence for Escaping Ionizing Photons in Local Lyman Break Galaxy Analogs

    CERN Document Server

    Alexandroff, Rachael; Borthakur, Sanchayeeta; Overzier, Roderik; Leitherer, Claus

    2015-01-01

    A population of early star-forming galaxies is the leading candidate for the re-ionization of the universe. It is still unclear what conditions and physical processes would enable a significant fraction of the ionizing photons to escape from these gas-rich galaxies. In this paper we present the results of the analysis of HST COS far-UV spectroscopy plus ancillary multi-waveband data of a sample of 22 low-redshift galaxies that are good analogs to typical star-forming galaxies at high-redshift. We measure three parameters that provide indirect evidence of the escape of ionizing radiation: (1) the residual intensity in the cores of saturated interstellar low-ionization absorption-lines. (2) The relative amount of blue-shifted Lyman alpha line emission, and (3) the relative weakness of the [SII] optical emission lines. We use these diagnostics to rank-order our sample in terms of likely leakiness, noting that a direct measure of escaping Lyman continuum has recently been made for one of the leakiest members of o...

  13. Theoretical Emission-Line Profiles of Active Galactic Nuclei and the Unified Model. I. The Face-on Torus

    Science.gov (United States)

    Quintilio, R.; Viegas, S. M.

    1997-01-01

    Theoretical emission-line profiles are obtained for active galactic nuclei (AGNs) taking into account the presence of an obscuring torus around the central energy source. For the sake of simplicity, the torus is represented by a cylindrical shell characterized by the inner and outer radius and the opening angle. In this paper we discuss the results with angle of sight equal to 0, i.e., for a face-on torus. Different line profiles are obtained following the torus parameters. The line profiles may show more than one peak and bumps, depending on the torus dimensions. The main parameter determining the number of peaks or bumps is the opening angle. Thus, the observed line shape may be a good indicator of the torus characteristics. As an example, the fit to the observed [O III] λ5007 emission line of NGC 4151 is presented. The model reproduces the FWHM and the asymmetrical bumps observed. Partially supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) under Grant 92/4335-9.

  14. Identification of differential gene expression profiles of radioresistant lung cancer cell line established by fractionated ionizing radiation in vitro

    Institute of Scientific and Technical Information of China (English)

    XU Qing-yong; GAO Yuan; LIU Yan; YANG Wei-zhi; XU Xiang-ying

    2008-01-01

    Background Radiotherapy plays a critical role in the management of non-small cell lung cancer (NSCLC). This study was conducted to identify gene expression profiles of acquired radioresistant NSCLC cell line established by fractionated ionizing radiation (FIR) by cDNA microarray.Methods The human lung adenocarcinoma cell line Anip973 was treated with high energy X-ray to receive 60 Gy in 4 Gy fractions. The radiosensitivity of Anip973R and its parental line were measured by clonogenic assay. Gene expression profiles of Anip973R and its parental line were analyzed using cDNA microarray consisting of 21 522 human genes.Identified partly different expressive genes were validated by quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR).Results Fifty-nine upregulated and 43 downregulated genes were identified to radio-resistant Anip973R. Up-regulated genes were associated with DNA damage repair (DDB2), extracellular matrix (LOX), cell adhesion (CDH2), and apoptosis (CRYAB). Down-regulated genes were associated with angiogenesis (GBP-1), immune response (CD83), and calcium signaling pathway (TNNC1). Subsequent validation of selected eleven genes (CD24, DDB2, IGFBP3, LOX,CDH2, CRYAB, PROCR, ANXA1 DCN, GBP-1 and CD83) by Q-RT-PCR was consistent with microarray analysis.Conclusions Fractionated ionizing radiation can lead to the development of radiation resistance. Altered gene profiles of radioresistant cell line may provide new insights into mechanisms underlying clinical radioresistance for NSCLC.

  15. Performance Characterization of UV Science Cameras Developed for the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)

    Science.gov (United States)

    Champey, Patrick; Kobayashi, Ken; Winebarger, Amy; Cirtin, Jonathan; Hyde, David; Robertson, Bryan; Beabout, Brent; Beabout, Dyana; Stewart, Mike

    2014-01-01

    The NASA Marshall Space Flight Center (MSFC) has developed a science camera suitable for sub-orbital missions for observations in the UV, EUV and soft X-ray. Six cameras will be built and tested for flight with the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP), a joint National Astronomical Observatory of Japan (NAOJ) and MSFC sounding rocket mission. The goal of the CLASP mission is to observe the scattering polarization in Lyman-alpha and to detect the Hanle effect in the line core. Due to the nature of Lyman-alpha polarization in the chromosphere, strict measurement sensitivity requirements are imposed on the CLASP polarimeter and spectrograph systems; science requirements for polarization measurements of Q/I and U/I are 0.1% in the line core. CLASP is a dual-beam spectro-polarimeter, which uses a continuously rotating waveplate as a polarization modulator, while the waveplate motor driver outputs trigger pulses to synchronize the exposures. The CCDs are operated in frame-transfer mode; the trigger pulse initiates the frame transfer, effectively ending the ongoing exposure and starting the next. The strict requirement of 0.1% polarization accuracy is met by using frame-transfer cameras to maximize the duty cycle in order to minimize photon noise. Coating the e2v CCD57-10 512x512 detectors with Lumogen-E coating allows for a relatively high (30%) quantum efficiency at the Lyman-$\\alpha$ line. The CLASP cameras were designed to operate with =10 e- /pixel/second dark current, = 25 e- read noise, a gain of 2.0 and =0.1% residual non-linearity. We present the results of the performance characterization study performed on the CLASP prototype camera; dark current, read noise, camera gain and residual non-linearity.

  16. X-ray Spectroscopy of the Radiation-Driven Winds of Massive Stars: Line Profile and Line Ratio Diagnostics

    CERN Document Server

    Cohen, David H

    2009-01-01

    Massive stars drive powerful, supersonic winds via the radiative momentum associated with the thermal UV emission from their photospheres. Shock phenomena are ubiquitous in these winds, heating them to millions, and sometimes tens of millions, of degrees. The emission line spectra from the shock-heated plasma provide powerful diagnostics of the winds' physical conditions, which in turn provide constraints on models of wind shock heating. Here I show how x-ray line transfer is affected by photoelectric absorption in the partially ionized component of the wind and how it can be modeled to determine the astrophysically important mass-loss rates of these stellar winds. I also discuss how photoexcitation out of metastable excited levels of helium-like ions can provide critical information about the location of the hot plasma in magnetically channeled massive star winds.

  17. Solar Flare Termination Shock and Synthetic Emission Line Profiles of the Fe xxi 1354.08 Å Line

    Science.gov (United States)

    Guo, Lijia; Li, Gang; Reeves, Kathy; Raymond, John

    2017-09-01

    Solar flares are among the most energetic phenomena that occur in the solar system. In the standard solar flare model, a fast mode shock, often referred to as the flare termination shock (TS), can exist above the loop-top source of hard X-ray emissions. The existence of the TS has been recently related to spectral hardening of a flare’s hard X-ray spectra at energies >300 keV. Observations of the Fe xxi 1354.08 Å line during solar flares by the Interface Region Imaging Spectrograph (IRIS) spacecraft have found significant redshifts with >100 km s‑1, which is consistent with a reconnection downflow. The ability to detect such a redshift with IRIS suggests that one may be able to use IRIS observations to identify flare TSs. Using a magnetohydrodynamic simulation to model magnetic reconnection of a solar flare and assuming the existence of a TS in the downflow of the reconnection plasma, we model the synthetic emission of the Fe xxi 1354.08 line in this work. We show that the existence of the TS in the solar flare may manifest itself in the Fe xxi 1354.08 Å line.

  18. Space Telescope Imaging Spectrograph Observations of High-Velocity Interstellar Absorption-Line Profiles in the Carina Nebula

    Science.gov (United States)

    Walborn, Nolan R.; Danks, Anthony C.; Vieira, Gladys; Landsman, Wayne B.

    2002-06-01

    An atlas of ultraviolet interstellar absorption-line profiles toward four stars in the Carina Nebula is presented. The observations have been made with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, with a resolving power of 114,000. Low-ionization, high-ionization, and excited-state lines from a wide array of chemical species are included. Extensive measurements of radial velocities, velocity dispersions, and column densities of individual components in these profiles are also given. The unprecedented capabilities of STIS reveal many more velocity components than previously known; most of the high-velocity components in previous observations with the International Ultraviolet Explorer are now resolved into multiple subcomponents, and even higher velocities are seen. The great range of line strengths available permits the detection of the low-velocity components in the weakest lines, and progressively higher velocities in stronger lines (in which the low-velocity components become completely blended). The weak and high-ionization lines trace global structure in the H II region, while the strong low-ionization lines show intricate high-velocity structure that likely originates relatively near to the O stars observed. The extreme velocities found in the low-ionization lines toward these four stars are -388 and +127 km s-1, with 23-26 resolved components in each. Some components in different stars may be related, but many are different in each line of sight. A remarkably well-defined Routly-Spitzer effect is found in this region. Temporal variations toward one star observed twice have already been reported. These measurements will be used in subsequent astrophysical analyses to further constrain the origins of the phenomena. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract

  19. - X (1)Sigma(+)((g)) (v ''=0) Lyman bands in H-2 and HD

    NARCIS (Netherlands)

    Hollenstein, U.; Reinhold, E.M.; Lange, de C.A.; Ubachs, W.M.G.

    2006-01-01

    - X (1)Sigma(+) (v" = 0) Lyman bands in HD are presented using a narrow bandwidth vacuum ultraviolet laser system combined with an accurate frequency calibration. These measurements complete the recently published data on the Lyman frequency transitions of Philip.

  20. Hepatic drug metabolizing profile of Flinders Sensitive Line rat model of depression.

    Science.gov (United States)

    Kotsovolou, Olga; Ingelman-Sundberg, Magnus; Lang, Matti A; Marselos, Marios; Overstreet, David H; Papadopoulou-Daifoti, Zoi; Johanson, Inger; Fotopoulos, Andrew; Konstandi, Maria

    2010-08-16

    The Flinders Sensitive Line (FSL) rat model of depression exhibits some behavioral, neurochemical, and pharmacological features that have been reported in depressed patients and has been very effective in screening antidepressants. Major factor that determines the effectiveness and toxicity of a drug is the drug metabolizing capacity of the liver. Therefore, in order to discriminate possible differentiation in the hepatic drug metabolism between FSL rats and Sprague-Dawley (SD) controls, their hepatic metabolic profile was investigated in this study. The data showed decreased glutathione (GSH) content and glutathione S-transferase (GST) activity and lower expression of certain major CYP enzymes, including the CYP2B1, CYP2C11 and CYP2D1 in FSL rats compared to SD controls. In contrast, p-nitrophenol hydroxylase (PNP), 7-ethoxyresorufin-O-dealkylase (EROD) and 16alpha-testosterone hydroxylase activities were higher in FSL rats. Interestingly, the wide spread environmental pollutant benzo(alpha)pyrene (B(alpha)P) induced CYP1A1, CYP1A2, CYP2B1/2 and ALDH3c at a lesser extend in FSL than in SD rats, whereas the antidepressant mirtazapine (MIRT) up-regulated CYP1A1/2, CYP2C11, CYP2D1, CYP2E1 and CYP3A1/2, mainly, in FSL rats. The drug also further increased ALDH3c whereas suppressed GSH content in B(alpha)P-exposed FSL rats. In conclusion, several key enzymes of the hepatic biotransformation machinery are differentially expressed in FSL than in SD rats, a condition that may influence the outcome of drug therapy. The MIRT-induced up-regulation of several drug-metabolizing enzymes indicates the critical role of antidepressant treatment that should be always taken into account in the designing of treatment and interpretation of insufficient pharmacotherapy or drug toxicity.

  1. Direct Method Gas Phase Oxygen Abundances of 4 Lyman Break Analogs

    CERN Document Server

    Brown, Jonathan S; Pogge, Richard W

    2014-01-01

    We measure the gas-phase oxygen abundances in 4 Lyman Break Analogs (LBAs) using auroral emission lines to derive direct abundances. The direct method oxygen abundances of these objects are generally consistent with the empirically-derived strong-line method values, confirming that these objects are low oxygen abundance outliers from the Mass-Metallicity (MZ) relation defined by star forming SDSS galaxies. We find slightly anomalous excitation conditions (Wolf-Rayet features) that could potentially bias the empirical estimates towards high values if caution is not exercised in the selection of the strong-line calibration used. The high rate of star formation and low oxygen abundance of these objects is consistent with the predictions of the Fundamental Metallicity Relation (FMR), in which the infall of relatively unenriched gas simultaneously triggers an episode of star formation and dilutes ISM of the host galaxy.

  2. Observations of Ha Line Profiles in Be Stars Using 45 cm Cassegrain Telescope at Arthur C Clarke Institute

    Science.gov (United States)

    Gunasekera, S.; Adassuriya, J.; Medagangoda, N. I.

    2008-12-01

    H-alpha line profiles of 13 Be starts (mv d6.9) were observed using 45 cm Cassegrain telescope at the Arthur C Clarke Institute, Sri Lanka during the period of August 2005 to March 2006. High resolution spectra of these Be stars were obtained using 1200 lines/mm reflective grating in first order with resolution R=λ/Δλ=76800 and linear spectral dispersion 0.31 Å per pixel at 6563 Å in order to find out line parameters such as equivalent width, full width at half-maxima, V/R ratios etc. A study of the correlations between different pairs of parameters was obtained and compared with previous analysis to see the behavior of circumstellar disk. We found a good correlation (0.8) between FWHM and v sin i and strong correlation (0.96) between the Ip/Ic and the equivalent width. The drastic changes of the V/R ratio in profiles HR5941 and HR6712 imply the circumstellar disk is more likely an elliptical shape and undergoes slow apsidal motion. The inclination angles (i) were estimated for each star using the theoretical vsin i values and assuming star rotates in 0.8Vc and are matched with the structure of the line profiles.

  3. Comparisons between direct and inverse approaches in problems of recovering the true profile of a spectral line

    CERN Document Server

    Mijovic, S

    2003-01-01

    Computer-supported techniques are introduced in the evaluation of experimental data and obtaining the real profile of spectral lines. The direct and inverse approaches were used. The MINUIT program from the packets of CERN's library was used to solve direct problems. Tikhonov's regularization method was also applied to solve the same problems in an inverse manner. Model functions were introduced to check the applicability limitation of these methods and make a comparison between them as well. The advantages and disadvantages of these approaches were shown. The procedures were applied to the measured profiles of He II's spectral lines in a pulsed low-pressure arc. The chosen lines are He II Paschen-alpha (468.6 nm) in the visible region and Balmer-beta (121.5 nm) in the VUV spectral region. The range of experimental errors was determined where both approaches have given reliable results. It was found that we can obtain the real profile of He II 468.6 nm and He II 121.5 nm spectral lines, using the regularizati...

  4. The ESO UVES Advanced Data Products Quasar Sample - VI. Sub-Damped Lyman-$\\alpha$ Metallicity Measurements and the Circum-Galactic Medium

    CERN Document Server

    Quiret, S; Zafar, T; Kulkarni, V P; Jenkins, E D; Milliard, B; Rahmani, H; Popping, A; Sandhya, R M; Turnshek, D A; Monier, E M

    2016-01-01

    The Circum-Galactic Medium (CGM) can be probed through the analysis of absorbing systems in the line-of-sight to bright background quasars. We present measurements of the metallicity of a new sample of 15 sub-damped Lyman-$\\alpha$ absorbers (sub-DLAs, defined as absorbers with 19.0 < log N(H I) < 20.3) with redshift 0.584 < $\\rm z_{abs}$ < 3.104 from the ESO Ultra-Violet Echelle Spectrograph (UVES) Advanced Data Products Quasar Sample (EUADP). We combine these results with other measurements from the literature to produce a compilation of metallicity measurements for 92 sub-DLAs as well as a sample of 362 DLAs. We apply a multi-element analysis to quantify the amount of dust in these two classes of systems. We find that either the element depletion patterns in these systems differ from the Galactic depletion patterns or they have a different nucleosynthetic history than our own Galaxy. We propose a new method to derive the velocity width of absorption profiles, using the modeled Voigt profile feat...

  5. Lenses in the forest: cross--correlation of the Lyman-alpha flux with CMB lensing

    Energy Technology Data Exchange (ETDEWEB)

    Vallinotto, Alberto; /Paris, Inst. Astrophys. /Fermilab; Das, Sudeep; /Princeton U. Observ. /Princeton U.; Spergel, David N.; /Princeton U. Observ. /APC, Paris; Viel, Matteo; /Trieste Observ. /INFN, Trieste

    2009-03-01

    We present a theoretical estimate for a new observable: the cross-correlation between the Lyman-{alpha}-flux fluctuations in quasar (QSO) spectra and the convergence of the cosmic microwave background (CMB) as measured along the same line-of-sight. As a first step toward the assessment of its detectability, we estimate the signal-to-noise ratio using linear theory. Although the signal-to-noise is small for a single line-of-sight and peaks at somewhat smaller redshifts than those probed by the Lyman-{alpha} forest, we estimate a total signal-to-noise of 9 for cross-correlating QSO spectra of SDSSIII with Planck and 20 for cross-correlating with a future polarization based CMB experiment. The detection of this effect would be a direct measure of the neutral hydrogen-matter cross-correlation and could provide important information on the growth of structures at large scales in a redshift range which is still poorly probed by observations.

  6. The impact of feedback from galaxy formation on the Lyman-alpha transmitted flux

    CERN Document Server

    Viel, Matteo; Booth, Craig M

    2012-01-01

    The forest of Lyman-alpha absorption lines seen in the spectra of distant quasars has become an important probe of the distribution of matter in the Universe. We use large, hydrodynamical simulations from the OWLS project to investigate the effect of feedback from galaxy formation on the probability distribution function and the power spectrum of the Lyman-alpha transmitted flux. While metal-line cooling is unimportant, both galactic outflows from massive galaxies driven by active galactic nuclei and winds from low-mass galaxies driven by supernovae have a substantial impact on the flux statistics. At redshift z=2.25, the effects on the flux statistics are of a similar magnitude as the statistical uncertainties of published data sets. The changes in the flux statistics are not due to differences in the temperature-density relation of the photo-ionised gas. Instead, they are caused by changes in the density distribution and in the fraction of hot, collisionally ionised gas. It may be possible to disentangle as...

  7. The primordial deuterium abundance of the most metal-poor damped Lyman-alpha system

    CERN Document Server

    Cooke, Ryan; Nollett, Kenneth M; Jorgenson, Regina

    2016-01-01

    We report the discovery and analysis of the most metal-poor damped Lyman-alpha (DLA) system currently known, which also displays the Lyman series absorption lines of neutral deuterium. The average [O/H] abundance of this system is [O/H] = -2.804 +/- 0.015, which includes an absorption component with [O/H] = -3.07 +/- 0.03. Despite the unfortunate blending of many weak D I absorption lines, we report a precise measurement of the deuterium abundance of this system. Using the six highest quality and self-consistently analyzed measures of D/H in DLAs, we report tentative evidence for a subtle decrease of D/H with increasing metallicity. This trend must be confirmed with future high precision D/H measurements spanning a range of metallicity. A weighted mean of these six independent measures provides our best estimate of the primordial abundance of deuterium, 10^5 (D/H)_P = 2.547 +/- 0.033 (log_10 (D/H)_P = -4.5940 +/- 0.0056). We perform a series of detailed Monte Carlo calculations of Big Bang nucleosynthesis (BB...

  8. The Keck+Magellan Survey for Lyman Limit Absorption III: Sample Definition and Column Density Measurements

    CERN Document Server

    Prochaska, J Xavier; Fumagalli, Michele; Bernstein, Rebecca A; Burles, Scott M

    2015-01-01

    We present an absorption-line survey of optically thick gas clouds -- Lyman Limit Systems (LLSs) -- observed at high dispersion with spectrometers on the Keck and Magellan telescopes. We measure column densities of neutral hydrogen NHI and associated metal-line transitions for 157 LLSs at z=1.76-4.39 restricted to 10^17.3 < NHI < 10^20.3. An empirical analysis of ionic ratios indicates an increasing ionization state of the gas with decreasing NHI and that the majority of LLSs are highly ionized, confirming previous expectations. The Si^+/H^0 ratio spans nearly four orders-of-magnitude, implying a large dispersion in the gas metallicity. Fewer than 5% of these LLSs have no positive detection of a metal transition; by z~3, nearly all gas that is dense enough to exhibit a very high Lyman limit opacity has previously been polluted by heavy elements. We add new measurements to the small subset of LLS (~5-10) that may have super-solar abundances. High Si^+/Fe^+ ratios suggest an alpha-enhanced medium whereas ...

  9. Damped and sub-damped Lyman-alpha absorbers in z > 4 QSOs

    CERN Document Server

    Guimaraes, Rodney; De Carvalho, Reinaldo Ramos; Djorgovski, George; Noterdaeme, Pasquier; Castro, Sandra; Poppe, Paulo Da Rocha; Aghaee, Ali

    2009-01-01

    We present the results of a survey for damped (DLA, log N(H I) > 20.3) and sub-damped Lyman-? systems (19.5 2.55 along the lines-of-sight to 77 quasars with emission redshifts in the range 4 19.5 are detected of which 40 systems are damped Lyman-? systems for an absorption length of ?X = 378. About half of the lines of sight of this homogeneous survey have never been investigated for DLAs. We study the evolution with redshift of the cosmological density of the neutral gas and ?nd, consis- tently with previous studies at similar resolution, that ?DLA,H I decreases at z > 3.5. The overall cosmological evolution of ?HI shows a peak around this redshift. The H I column density distribution for log N(H I) ? 20.3 is ?tted, consistently with previous surveys, with a single power-law of index ? ? -1.8$\\pm$0.25. This power-law overpredicts data at the high-end and a second, much steeper, power-law (or a gamma function) is needed. There is a ?attening of the function at lower H I column densities with an index of ? ?...

  10. An Extreme, Blueshifted Iron-Line Profile in the Narrow-Line Seyfert 1 PG 1402+261: An Edge-on Accretion Disk or Highly Ionized Absorption?

    Science.gov (United States)

    Reeves, J. N.; Porquet, D.; Turner, T. J.

    2004-11-01

    We report on a short XMM-Newton observation of the radio-quiet narrow-line Seyfert 1 galaxy PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6 and 9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad (FWHM velocity of 110,000 km s-1) iron K-shell emission line. The line centroid energy at 7.3 keV appears blueshifted with respect to the iron Kα emission band between 6.4 and 6.97 keV, while the blue wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of >60° is required to model the extreme blue wing of the line. Furthermore, the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG 1402+261 above 2 keV is dominated by the pure-reflection component from the disk, while little or none of the direct hard power law is observed. Alternatively, the spectrum above 2 keV may be explained by an ionized absorber, if the column density is sufficiently high (NH>3×1023 cm-2) and if the matter is ionized enough to produce a deep (τ~1) iron K-shell absorption edge at 9 keV. This absorber could originate in a large column density, high-velocity outflow, perhaps similar to those that appear to be observed in several other high accretion rate active galactic nuclei. Further observations, especially at higher spectral resolution, are required to distinguish between the accretion disk reflection and outflow scenarios.

  11. APPLICATION OF THE MOMENT METHODS TO ANALYSIS OF X-RAY DIFFRACTION LINE PROFILE FOR PA1010-BMI SYSTEM

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hongfang; YU Li; ZHANG Lihua; MO Zhishen; MU Zhongchen

    1995-01-01

    Pure X-ray diffraction profiles have been analysed for polyamide 1010 and PA1010-BMI system by means of multipeak fitting resolution of X-ray diffraction. The methods of variance and fourth moment have been applied to determine the particle size and strain values for the paracrystalline materials. The results indicated that both variance and fourth moment of X-ray diffraction line profile yielded approximately the same values of the particle size and the strain. The particle sizes of (100) reflection have been found to decrease with increasing BMI content, whereas the strain values increased.

  12. Molecule survival in magnetized protostellar disk winds. II. Predicted H2O line profiles versus Herschel/HIFI observations

    CERN Document Server

    Yvart, W; Forets, G Pineau des; Ferreira, J

    2016-01-01

    We investigate whether the broad wings of H2O emission identified with Herschel towards low-mass Class 0 and Class 1 protostars may be consistent with an origin in a dusty MHD disk wind, and the constraints it would set on the underlying disk properties. We present synthetic H2O line profiles predictions for a typical MHD disk wind solution with various values of disk accretion rate, stellar mass, extension of the launching area, and view angle. We compare them in terms of line shapes and intensities with the HIFI profiles observed by the WISH Key Program. We find that a dusty MHD disk wind launched from 0.2--0.6 AU AU to 3--25 AU can reproduce to a remarkable degree the observed shapes and intensities of the broad H2O component, both in the fundamental 557 GHz line and in more excited lines. Such a model also readily reproduces the observed correlation of 557 GHz line luminosity with envelope density, if the infall rate at 1000 AU is 1--3 times the disk accretion rate in the wind ejection region. It is also ...

  13. Broadening of the Spectral Atomic Lines Analysis in High Density Argon Corona Plasma by Using Voigt Profile

    Science.gov (United States)

    Nur, M.; Bonifaci, N.; Denat, A.; Atrazhev, V. M.

    2015-06-01

    Studies of spectrum emission from high density argon plasma corona has been done. The analysis of the boardening of spectral atomic lines of Ar-I profile has been curried out by using an empirical approximation based on a Voigt profile. Full-width at half-maximum (FWHM) of the spectral-lines of 763.5 nm has been determined from atmospheric pressure until liquid state. The study liquid argon was curried out in a variation of temperature from K to 151.2 K and hydrostatics pressure from 2.1 MPa to 6.4 MPa. These pressure gives the densities N∞ (i.e. density very far from ionization zone) a variation from 1.08 1022 to 2.11 1022 cm-3. FWHM of Voigt approximation (Wv) of the line 763,5 nm of 'Ar I for: the emission lamp very low pressure (Wv = 0,160 nm) and our corona discharge at a pressure of MPa (Wv = 0,67 nm) and at a pressure of 9,5 MPa (Wv = 1,16 nm). In gas, corona plasma has been generated from 0.1 MPa to 9.5 MPa. We found that the broadening spectral line increase by increasing densities both for. the spectral-lines of 763.5 nm and 696.5 nm. We concluded that broadening of spectrum cause of Van der Waals force.

  14. The puzzle of the lyman continuum polarization of qsos

    Directory of Open Access Journals (Sweden)

    Gregory A. Shields

    2001-01-01

    Full Text Available Mediante espectropolarimetr a reciente de cuasares se ha encontrado un sor- prendente incremento en la polarizaci on del cont nuo de Lyman en varios objetos. Discutimos algunos intentos recientes para explicar este hecho, que incluyen el papel de la absorci on de Lyman en PG 1222+228. Presentamos nuevos resultados te oricos que involucran dispersi on por electrones en una corona caliente o en un viento por encima de un disco de acreci on, y la polarizaci on que resulta del efecto relativista de la radiaci on que regresa. Potencialemente estos mecanismos pueden alcanzar niveles de polarizaci on observables en longitudes de onda cortas, pero ninguno logra ex- plicar cuantitativamente los incrementos en la polarizaci on del cont nuo de Lyman. Se requiere urgentemente mayor capacidad para llevar a cabo espectropolarimetr a en el ultravioleta desde sat elites para esclarecer este fen omeno.

  15. Lyman-alpha Emission From Cosmic Structure I: Fluorescence

    CERN Document Server

    Kollmeier, Juna A; Davé, Romeel; Gould, Andrew; Katz, Neal; Miralda-Escudé, Jordi; Weinberg, David H

    2009-01-01

    We present predictions for the fluorescent Lyman-alpha emission signature arising from photoionized, optically thick structures in Smoothed Particle Hydrodynamic (SPH) cosmological simulations of a Lambda-CDM universe using a Monte Carlo Lyman-alpha radiative transfer code. We calculate the expected Lyman-alpha image and 2-dimensional spectra for gas exposed to a uniform ultraviolet ionizing background as well as gas exposed additionally to the photoionizing radiation from a local quasar, after correcting for the self-shielding of hydrogen. As a test of our numerical methods and for application to current observations, we examine simplified analytic structures that are uniformly or anisotropically illuminated. We compare these results with recent observations. We discuss future observing campaigns on large telescopes and realistic strategies for detecting fluorescence owing to the ambient metagalactic ionization and in regions close to bright quasars. While it will take hundreds of hours on the current genera...

  16. Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

    CERN Document Server

    Schee, Jan

    2016-01-01

    We study optical effects in quintessential Kerr black hole spacetimes corresponding to the limiting case of the equation-of-state parameter $\\omega_{q}=-1/3$ of the quintessence. In dependence on the dimensionless quintessential field parameter $c$, we determine the black hole silhouette and the spectral line profiles of Keplerian disks generated in this special quintessential Kerr geometry, representing an extension of the general modifications of the Kerr geometry introduced recently by Ghasemi-Nodehi and Bambi \\cite{Gha-Bam:2016:EPJC:}. We demonstrate that due to the influence of the parameter $c$, the silhouette is almost homogeneously enlarged, and the spectral line profiles are redshifted with almost conserved shape.

  17. Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

    Energy Technology Data Exchange (ETDEWEB)

    Schee, Jan; Stuchlik, Zdenek [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Centre for Theoretical Physics and Astrophysics, Opava (Czech Republic)

    2016-11-15

    We study optical effects in quintessential Kerr black hole spacetimes corresponding to the limiting case of the equation-of-state parameter ω{sub q} = -1/3 of the quintessence. In dependence on the dimensionless quintessential field parameter c, we determine the black hole silhouette and the spectral line profiles of Keplerian disks generated in this special quintessential Kerr geometry, representing an extension of the general modifications of the Kerr geometry introduced recently by Ghasemi-Nodehi and Bambi (Eur. Phys. J. C 56:290, 2016). We demonstrate that due to the influence of the parameter c, the silhouette is almost homogeneously enlarged, and the spectral line profiles are redshifted with almost conserved shape. (orig.)

  18. Iris si iv line profiles: An indication for the plasmoid instability during small-scale magnetic reconnection on the sun

    CERN Document Server

    Innes, Davina; Huang, YiMin; Bhattacharjee, Amitava

    2015-01-01

    Our understanding of the process of fast reconnection has undergone a dramatic change in the last 10 years driven, in part, by the availability of high-resolution numerical simulations that have consistently demonstrated the break-up of current sheets into magnetic islands, with reconnection rates that become independent of Lundquist number, challenging the belief that fast magnetic reconnection in flares proceeds via the Petschek mechanism that invokes pairs of slow-mode shocks connected to a compact diffusion region. The reconnection sites are too small to be resolved with images but these reconnection mechanisms, Petschek and the plasmoid instability, have reconnection sites with very different density and velocity structures and so can be distinguished by high-resolution line-profiles observations. Using IRIS spectroscopic observations we obtain a survey of typical line profiles produced by small-scale events thought to be reconnection sites on the Sun. Slit-jaw images are used to investigate the plasma h...

  19. Comparative assessment of maize lines produced by different breeding methods using both microbiological and metabolic profiling tools

    CSIR Research Space (South Africa)

    Barros, E

    2006-02-01

    Full Text Available , F; NMR-based metabolomic study of transgenic maize. Phytochemistry (2004), 65: 3187-3198 2. Rabie, CJ; Lübben, A; Marais, GJ; and Jansen van Vuuren, H (1997) Enumeration of fungi in barley. International Journal of Food Microbiology, 35, 117... Biosciences includes the evaluation of different South African and European maize lines, using microbiological and mycotoxin analysis, as well as metabolic profiling through NMR (Nuclear Magnetic Resonance) analysis. This study shows the results obtained...

  20. A Low-Profile Dual-Band Micro-strip Antenna Having Open-Circuited Strip-line-Stub

    OpenAIRE

    長谷川, 孝明; 羽石, 操

    1986-01-01

    Copyright notice. c1986 IEICE All rights reserved. "A Low-Profile Dual-Band Micro-strip Antenna Having Open-Circuited Strip-line-Stub"Misao HANEISHI, Hidekazu SUGA, Takaaki HASEGAWA.The Transactions of the Institute of Electronics and Communication Engineers of Japan. Section E, English, 1986. Vol. E69 No.11 pp. 1165-1166 許諾No.07RB0055.

  1. Gene-specific DNA methylation profiles and LINE-1 hypomethylation are associated with myocardial infarction risk

    NARCIS (Netherlands)

    Guarrera, Simonetta; Fiorito, Giovanni; Onland-Moret, N Charlotte; Russo, Alessia; Agnoli, Claudia; Allione, Alessandra; Di Gaetano, Cornelia; Mattiello, Amalia; Ricceri, Fulvio; Chiodini, Paolo; Polidoro, Silvia; Frasca, Graziella; Verschuren, Monique W M; Boer, Jolanda M A; Iacoviello, Licia; van der Schouw, Yvonne T; Tumino, Rosario; Vineis, Paolo; Krogh, Vittorio; Panico, Salvatore; Sacerdote, Carlotta; Matullo, Giuseppe

    2015-01-01

    BACKGROUND: DNA methylation profiles are responsive to environmental stimuli and metabolic shifts. This makes DNA methylation a potential biomarker of environmental-related and lifestyle-driven diseases of adulthood. Therefore, we investigated if white blood cells' (WBCs) DNA methylation profiles ar

  2. Estimation of Mass-Loss Rates from Emission Line Profiles in the UV Spectra of Cool Stars

    Science.gov (United States)

    Carpenter, K. G.; Robinson, R. D.; Harper, G. M.

    1999-01-01

    The photon-scattering winds of cool, low-gravity stars (K-M giants and supergiants) produce absorption features in the strong chromospheric emission lines. This provides us with an opportunity to assess important parameters of the wind, including flow and turbulent velocities, the optical depth of the wind above the region of photon creation, and the star's mass-loss rate. We have used the Lamers et al. Sobolev with Exact Integration (SEI) radiative transfer code along with simple models of the outer atmospheric structure to compute synthetic line profiles for comparison with the observed line profiles. The SEI code has the advantage of being computationally fast and allows a great number of possible wind models to be examined. We therefore use it here to obtain initial first-order estimates of the wind parameters. More sophisticated, but more time-consuming and resource intensive calculations will be performed at a later date, using the SEI-deduced wind parameters as a starting point. A comparison of the profiles over a range of wind velocity laws, turbulence values, and line opacities allows us to constrain the wind parameters, and to estimate the mass-loss rates. We have applied this analysis technique (using lines of Mg II, 0 I, and Fe II) so far to four stars: the normal K5-giant alpha Tau, the hybrid K-giant gamma Dra, the K5 supergiant lambda Vel, and the M-giant gamma Cru. We present in this paper a description of the technique, including the assumptions which go into its use, an assessment of its robustness, and the results of our analysis.

  3. Fast inversion of Zeeman line profiles using central moments. II. Stokes V moments and determination of vector magnetic fields

    Science.gov (United States)

    Mein, P.; Uitenbroek, H.; Mein, N.; Bommier, V.; Faurobert, M.

    2016-06-01

    Context. In the case of unresolved solar structures or stray light contamination, inversion techniques using four Stokes parameters of Zeeman profiles cannot disentangle the combined contributions of magnetic and nonmagnetic areas to the observed Stokes I. Aims: In the framework of a two-component model atmosphere with filling factor f, we propose an inversion method restricting input data to Q , U, and V profiles, thus overcoming ambiguities from stray light and spatial mixing. Methods: The V-moments inversion (VMI) method uses shifts SV derived from moments of V-profiles and integrals of Q2, U2, and V2 to determine the strength B and inclination ψ of a magnetic field vector through least-squares polynomial fits and with very few iterations. Moment calculations are optimized to reduce data noise effects. To specify the model atmosphere of the magnetic component, an additional parameter δ, deduced from the shape of V-profiles, is used to interpolate between expansions corresponding to two basic models. Results: We perform inversions of HINODE SOT/SP data for inclination ranges 0 <ψ< 60° and 120 <ψ< 180° for the 630.2 nm Fe i line. A damping coefficient is fitted to take instrumental line broadening into account. We estimate errors from data noise. Magnetic field strengths and inclinations deduced from VMI inversion are compared with results from the inversion codes UNNOFIT and MERLIN. Conclusions: The VMI inversion method is insensitive to the dependence of Stokes I profiles on the thermodynamic structure in nonmagnetic areas. In the range of Bf products larger than 200 G, mean field strengths exceed 1000 G and there is not a very significant departure from the UNNOFIT results because of differences between magnetic and nonmagnetic model atmospheres. Further improvements might include additional parameters deduced from the shape of Stokes V profiles and from large sets of 3D-MHD simulations, especially for unresolved magnetic flux tubes.

  4. A systematic study of Lyman-Alpha transfer through outflowing shells: Model parameter estimation

    CERN Document Server

    Gronke, Max; Dijkstra, Mark

    2015-01-01

    Outflows promote the escape of Lyman-$\\alpha$ (Ly$\\alpha$) photons from dusty interstellar media. The process of radiative transfer through interstellar outflows is often modelled by a spherically symmetric, geometrically thin shell of gas that scatters photons emitted by a central Ly$\\alpha$ source. Despite its simplified geometry, this `shell model' has been surprisingly successful at reproducing observed Ly$\\alpha$ line shapes. In this paper we perform automated line fitting on a set of noisy simulated shell model spectra, in order to determine whether degeneracies exist between the different shell model parameters. While there are some significant degeneracies, we find that most parameters are accurately recovered, especially the HI column density ($N_{\\rm HI}$) and outflow velocity ($v_{\\rm exp}$). This work represents an important first step in determining how the shell model parameters relate to the actual physical properties of Ly$\\alpha$ sources. To aid further exploration of the parameter space, we ...

  5. Studying Lyman-alpha escape and reionization in Green Pea galaxies

    Science.gov (United States)

    Yang, Huan; Malhotra, Sangeeta; Rhoads, James E.; Gronke, Max; Leitherer, Claus; Wofford, Aida; Dijkstra, Mark

    2017-01-01

    Green Pea galaxies are low-redshift galaxies with extreme [OIII]5007 emission line. We built the first statistical sample of Green Peas observed by HST/COS and used them as analogs of high-z Lyman-alpha emitters to study Ly-alpha escape and Ly-alpha sizes. Using the HST/COS 2D spectra, we found that Ly-alpha sizes of Green Peas are larger than the UV continuum sizes. We found many correlations between Ly-alpha escape fraction and galactic properties -- dust extinction, Ly-alpha kinematic features, [OIII]/[OII] ratio, and gas outflow velocities. We fit an empirical relation to predict Ly-alpha escape fraction from dust extinction and Ly-alpha red-peak velocity. In the JWST era, we can use this relation to derive the IGM HI column density along the line of sight of each high-z Ly-alpha emitter and probe the reionization process.

  6. Adaptive Optics Imaging of Low-redshift Damped Lyman-alpha Quasar Absorbers

    CERN Document Server

    Chun, M R; Kulkarni, V P; Takamiya, M; Chun, Mark R.; Gharanfoli, Soheila; Kulkarni, Varsha P.; Takamiya, Marianne

    2005-01-01

    We have carried out a high angular resolution near-infrared imaging study of the fields of 6 quasars with 7 strong absorption line systems at z < 0.5, using the Hokupa'a adaptive optics system and the QUIRC near-infrared camera on the Gemini-North telescope. These absorption systems include 4 classical damped Lyman-alpha absorbers (DLAs), 2 sub-DLAs, and one Lyman-limit system. Images were obtained in the H or K' filters with FWHM between 0.2"-0.5" with the goal of detecting the absorbing galaxies and identifying their morphologies. Features are seen at projected separations of 0.5"-16.0" from the quasars and all of the fields show features at less than 2" separation. We find candidate absorbers in all of the seven systems. With the assumption that some of these are associated with the absorbers, the absorbers are low luminosity < 0.1 L*_H or L*_K; we do not find any large bright candidate absorbers in any of our fields. Some fields show compact features that are too faint for quantitative morphology, b...

  7. Absorption signatures of warm-hot gas at low redshift: Broad Lyman-Alpha Absorbers

    CERN Document Server

    Tepper-García, Thorsten; Schaye, Joop; Booth, Craig M; Vecchia, Claudio Dalla; Theuns, Tom

    2012-01-01

    We investigate the physical state of HI absorbing gas at low redshift (z=0.25) using a subset of cosmological, hydrodynamic simulations from the OWLS project, focusing in particular on broad (b_HI > 40 km/s) Lyman-Alpha absorbers (BLAs), which are believed to originate in shock-heated gas in the Warm-Hot Intergalactic Medium (WHIM). Our fiducial model, which includes radiative cooling by heavy elements and feedback by supernovae and active galactic nuclei, predicts that by z=0.25 nearly 60 per cent of the gas mass ends up at densities and temperatures characteristic of the WHIM and we find that half of this fraction is due to outflows. The standard HI observables (distribution of HI column densities N_HI, distribution of Doppler parameters b_HI, b_HI - N_HI correlation) and the BLA line number density predicted by our simulations are in remarkably good agreement with observations. BLAs arise in gas that is hotter, more highly ionised and more enriched than the gas giving rise to typical Lyman-Alpha forest abs...

  8. Detection of HI in Emission in the Lyman Alpha Emitting Galaxy Haro 11

    CERN Document Server

    Pardy, Stephen A; Östlin, Göran; Hayes, Matthew; Bergvall, Nils

    2016-01-01

    We present the first robust detection of HI 21 cm emission in the blue compact galaxy Haro 11 using the 100m Robert C. Byrd Green Bank Telescope (GBT). Haro 11 is a luminous blue compact galaxy with emission in both Lyman Alpha and the Lyman continuum. We detect (5.1 $\\pm$ 0.7 $\\times$10$^8$) M$_{\\odot}$ of HI gas at an assumed distance of 88 Mpc, making this galaxy HI deficient compared to other local galaxies with similar optical properties. Given this small HI mass, Haro 11 has an elevated M$_{H2}$/M$_{HI}$ ratio and a very low gas fraction compared to most local galaxies, and contains twice as much mass in ionized hydrogen as in neutral hydrogen. The HI emission has a linewidth of 71 kms$^{-1}$ and is offset 60 kms$^{-1}$ redward of the optical line center. It is undergoing a starburst after a recent merger which has elevated the star formation rate, and will deplete the gas supply in $<$ 0.2 Gyr. Although this starburst has elevated the SFR compared to galaxies with similar HI masses and linewidths, H...

  9. Enhanced direct collapse due to Lyman {\\alpha} feedback

    CERN Document Server

    Johnson, Jarrett L

    2016-01-01

    We assess the impact of trapped Lyman {\\alpha} cooling radiation on the formation of direct collapse black holes (DCBHs). We apply a one-zone chemical and thermal evolution model, accounting for the photodetachment of H$^-$ ions, precursors to the key coolant H$_{\\rm 2}$, by Lyman {\\alpha} photons produced during the collapse of a cloud of primordial gas in an atomic cooling halo at high redshift. We find that photodetachment of H$^-$ by trapped Lyman {\\alpha} photons can lower the level of the H$_{\\rm 2}$-dissociating background radiation field required for DCBH formation substantially, dropping the critical flux by up to an order of magnitude. This translates into a large increase in the expected number density of DCBHs in the early Universe, and implies that DCBHs may be the seeds for the BHs residing in the centers of a significant fraction of galaxies today. We find that detachment of H$^-$ by Lyman {\\alpha} has the strongest impact on the critical flux for the relatively high background radiation temper...

  10. The nature of proximate damped Lyman α systems

    NARCIS (Netherlands)

    Ellison, S.L.; Prochaska, J.X.; Hennawi, J.; Lopez, S.; Usher, C.; Wolfe, A.M.; Russell, D.M.; Benn, C.R.

    2010-01-01

    We present high-resolution echelle spectra of seven proximate damped Lyman α (PDLA) systems. The relative velocity separation of each PDLA from the background quasar is ΔV < 3000 km s−1. Combining our sample with a further nine PDLAs from the literature we compare the chemical properties of the prox

  11. Broadband distortion modeling in Lyman-$\\alpha$ forest BAO fitting

    CERN Document Server

    Blomqvist, Michael; Bautista, Julian E; Ariño, Andreu; Busca, Nicolás G; Miralda-Escudé, Jordi; Slosar, Anže; Font-Ribera, Andreu; Margala, Daniel; Schneider, Donald P; Vazquez, Jose A

    2015-01-01

    In recent years, the Lyman-$\\alpha$ absorption observed in the spectra of high-redshift quasars has been used as a tracer of large-scale structure by means of the three-dimensional Lyman-$\\alpha$ forest auto-correlation function at redshift $z\\simeq 2.3$, but the need to fit the quasar continuum in every absorption spectrum introduces a broadband distortion that is difficult to correct and causes a systematic error for measuring any broadband properties. We describe a $k$-space model for this broadband distortion based on a multiplicative correction to the power spectrum of the transmitted flux fraction that suppresses power on scales corresponding to the typical length of a Lyman-$\\alpha$ forest spectrum. Implementing the distortion model in fits for the baryon acoustic oscillation (BAO) peak position in the Lyman-$\\alpha$ forest auto-correlation, we find that the fitting method recovers the input values of the linear bias parameter $b_{F}$ and the redshift-space distortion parameter $\\beta_{F}$ for mock dat...

  12. Oxygen sensitivity of krypton and Lyman-alpha hygrometers

    NARCIS (Netherlands)

    Dijk, van A.; Kohsiek, W.; Bruin, de H.A.R.

    2003-01-01

    The oxygen sensitivity of krypton and Lyman-¿ hygrometers is studied. Using a dewpoint generator and a controlled nitrogen/oxygen flow the extinction coefficients of five hygrometers associated with the third-order Taylor expansion of the Lambert¿Beer law around reference conditions for oxygen and f

  13. Exploring 21CM - Lyman Alpha Emitter Synergies for SKA

    NARCIS (Netherlands)

    Dayal, Pratika; Hutter, Anne; Müller, Volker; Trott, C. M.

    2017-01-01

    We study the signatures of reionization and ionizing properties of the early galaxies in the cross-correlations between the 21cm emission from the spin-flip transition of neutral hydrogen (H I ) and the underlying galaxy population, in particular a sub-population of galaxies visible as Lyman Alpha E

  14. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  15. Comparison of Return Stroke Current Profiles for Transmission-Line-Type and Traveling-Current-Source-Type Models

    Directory of Open Access Journals (Sweden)

    J.O. Adepitan

    2012-05-01

    Full Text Available The study is aimed at determining the dependence of the current along a channel on the model used, assuming the same base current. We compared three transmission-line-type models, namely: Transmission Line (TL, Modified Transmission Line with Linear decay, Modified Transmission Line with Exponential decay and two traveling-current-source-type models: Bruce-Golde (BG and Traveling Current Source (TCS models. The current profiles along the channel at different heights predicted by these models are presented and discussed. Comparison is based on the assumption that all the models have the same base current. It was found that at low heights and within a time window frame of 15 :s, the currents of the transmission-line-type models predict a zero value at one time or the other with a maximum turning point following some 1:s after. A linear relationship is predicted between the current peak and the channel height. A discontinuity of current peak was observed at high heights. No zero value of current was recorded in case of TCS both at low and high channel heights.

  16. PROFILES AND PREFERENCES OF ON-LINE MILLENIAL SHOPPERS IN BULGARIA

    Directory of Open Access Journals (Sweden)

    Patricia R. Loubeau

    2014-05-01

    Full Text Available This research seeks to develop a better understanding of the factors affecting on-line purchasing behavior among Generation Y (Gen Y consumers in Bulgaria. Also called millenials and born between the mid-1970s and late 1990s, this generation is especially active on-line and will be a dominant influence shaping e-commerce. An empirical study was conducted based on a written survey of a sample consisting of 367 high school and university students in Bulgaria. The most important reason why Bulgarian young people shop on-line is the pursuit of unique products not locally available, followed by convenience and better pricing, and their favorite category of internet purchases is “Apparel and Accessories.” Bulgarian millennials are using the internet to shop for trendy fashion and to obtain a variety of brands that are unavailable locally. Like other regions of the world, concern about financial transactions security is a major barrier limiting the willingness to shop on-line in Bulgaria. Unlike other markets where on-line music purchases are growing, high levels of digital piracy in Bulgaria strongly discourage Bulgarian students from purchasing music on-line. One limitation of this study arises because of its reliance on a convenience sample of students from medium sized cities in Southern Bulgaria. Further research employing stratified random sampling across Bulgaria is needed to assess whether the findings are broadly generalizable for the Gen Y population.

  17. Systematic Blueshift of Line Profiles in the Type IIn Supernova 2010jl: Evidence for Post-Shock Dust Formation?

    CERN Document Server

    Smith, Nathan; Filippenko, Alexei V; Cooper, Michael C; Matheson, Thomas; Bian, Fuyan; Weiner, Benjamin J; Comerford, Julia M

    2011-01-01

    Type IIn SNe show spectral evidence for strong interaction between their blast wave and dense circumstellar material (CSM) around the progenitor star. SN2010jl was the brightest core-collapse SN in 2010, and it was a Type IIn explosion with strong CSM interaction. Andrews et al. recently reported evidence for an IR excess in SN2010jl, indicating either new dust formation or the heating of CSM dust in an IR echo. Here we report multi-epoch spectra of SN2010jl that reveal the tell-tale signature of new dust formation: emission-line profiles becoming systematically more blueshifted as the red side of the line is blocked by increasing extinction. The effect is seen clearly in the intermediate-width (400--4000 km/s) component of H$\\alpha$ beginning roughly 30d after explosion. Moreover, we present near-IR spectra demonstrating that the asymmetry in the hydrogen-line profiles is wavelength dependent, appearing more pronounced at shorter wavelengths. This evidence suggests that new dust grains had formed quickly in ...

  18. High Redshift Lyman-α Hunt

    DEFF Research Database (Denmark)

    Kochiashvili, Ia

    constitute the backbone of thisthesis, I investigated the nature of almost 100 emission-line galaxies selected with thenarrow-band selection method. These candidates can be: galaxies with Hα emissionlines at redshift z ∼ 0.6, [Oiii]/Hβ emission-line galaxies at redshift z ∼ 1.15 and [Oii]emitters at z ∼ 1...

  19. Quantitative profiling of housekeeping and Epstein-Barr virus gene transcription in Burkitt lymphoma cell lines using an oligonucleotide microarray

    Directory of Open Access Journals (Sweden)

    Niggli Felix K

    2006-06-01

    Full Text Available Abstract Background The Epstein-Barr virus (EBV is associated with lymphoid malignancies, including Burkitt's lymphoma (BL, and can transform human B cells in vitro. EBV-harboring cell lines are widely used to investigate lymphocyte transformation and oncogenesis. Qualitative EBV gene expression has been extensively described, but knowledge of quantitative transcription is lacking. We hypothesized that transcription levels of EBNA1, the gene essential for EBV persistence within an infected cell, are similar in BL cell lines. Results To compare quantitative gene transcription in the BL cell lines Namalwa, Raji, Akata, Jijoye, and P3HR1, we developed an oligonucleotide microarray chip, including 17 housekeeping genes, six latent EBV genes (EBNA1, EBNA2, EBNA3A, EBNA3C, LMP1, LMP2, and four lytic EBV genes (BZLF1, BXLF2, BKRF2, BZLF2, and used the cell line B95.8 as a reference for EBV gene transcription. Quantitative polymerase chain reaction assays were used to validate microarray results. We found that transcription levels of housekeeping genes differed considerably among BL cell lines. Using a selection of housekeeping genes with similar quantitative transcription in the tested cell lines to normalize EBV gene transcription data, we showed that transcription levels of EBNA1 were quite similar in very different BL cell lines, in contrast to transcription levels of other EBV genes. As demonstrated with Akata cells, the chip allowed us to accurately measure EBV gene transcription changes triggered by treatment interventions. Conclusion Our results suggest uniform EBNA1 transcription levels in BL and that microarray profiling can reveal novel insights on quantitative EBV gene transcription and its impact on lymphocyte biology.

  20. Metabolism and fatty acid profile in fat and lean rainbow trout lines fed with vegetable oil: effect of carbohydrates.

    Directory of Open Access Journals (Sweden)

    Biju Sam Kamalam

    Full Text Available The present study investigated the effect of dietary carbohydrates on metabolism, with special focus on fatty acid bioconversion and flesh lipid composition in two rainbow trout lines divergently selected for muscle lipid content and fed with vegetable oils. These lines were chosen based on previously demonstrated potential differences in LC-PUFA synthesis and carbohydrate utilization. Applying a factorial study design, juvenile trout from the lean (L and the fat (F line were fed vegetable oil based diets with or without gelatinised starch (17.1% for 12 weeks. Blood, liver, muscle, intestine and adipose tissue were sampled after the last meal. Feed intake and growth was higher in the L line than the F line, irrespective of the diet. Moderate postprandial hyperglycemia, strong induction of hepatic glucokinase and repressed glucose-6-phosphatase transcripts confirmed the metabolic response of both lines to carbohydrate intake. Further at the transcriptional level, dietary carbohydrate in the presence of n-3 LC-PUFA deficient vegetable oils enhanced intestinal chylomicron assembly, disturbed hepatic lipid metabolism and importantly elicited a higher response of key desaturase and elongase enzymes in the liver and intestine that endorsed our hypothesis. PPARγ was identified as the factor mediating this dietary regulation of fatty acid bioconversion enzymes in the liver. However, these molecular changes were not sufficient to modify the fatty acid composition of muscle or liver. Concerning the genotype effect, there was no evidence of substantial genotypic difference in lipid metabolism, LC-PUFA synthesis and flesh fatty acid profile when fed with vegetable oils. The minor reduction in plasma glucose and triglyceride levels in the F line was linked to potentially higher glucose and lipid uptake in the muscle. Overall, these data emphasize the importance of dietary macro-nutrient interface in evolving fish nutrition strategies.

  1. Lyman-alpha Absorption from Heliosheath Neutrals

    CERN Document Server

    Wood, B E; Linsky, J L; Malama, Y G; Wood, Brian E.; Izmodenov, Vladislav V.; Linsky, Jeffrey L.; Malama, Yury G.

    2006-01-01

    We assess what information HST observations of stellar Ly-alpha lines can provide on the heliosheath, the region of the heliosphere between the termination shock and heliopause. To search for evidence of heliosheath absorption, we conduct a systematic inspection of stellar Ly-alpha lines reconstructed after correcting for ISM absorption (and heliospheric/astrospheric absorption, if present). Most of the stellar lines are well centered on the stellar radial velocity, as expected, but the three lines of sight with the most downwind orientations relative to the ISM flow (Chi1 Ori, HD 28205, and HD 28568) have significantly blueshifted Ly-alpha lines. Since it is in downwind directions where heliosheath absorption should be strongest, the blueshifts are almost certainly caused by previously undetected heliosheath absorption. We make an initial comparison between the heliosheath absorption and the predictions of a pair of heliospheric models. A model with a complex multi-component treatment of plasma within the he...

  2. Drug sensitivity and drug resistance profiles of human intrahepatic cholangiocarcinoma cell lines

    Institute of Scientific and Technical Information of China (English)

    Nisana Tepsiri; Liengchai Chaturat; Banchob Sripa; Wises Namwat; Sopit Wongkham; Vajarabhongsa Bhudhisawasdi; Wichittra Tassaneeyakul

    2005-01-01

    AIM: To study the effect of a number of chemotherapeutic drugs on five human intrahepatic cholangiocarcinoma (CCA) cell lines. The expressions of genes that have been proposed to influence the resistance of chemotherapeutic drugs including thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), glutathione-S-transferase P1 (GSTP1), multidrug resistance protein (MDR1) and multidrug resistance-associated proteins (MRPs) were also determined.METHODS: Five human CCA cell lines (KKU-100, KKU M055, KKU-M156, KKU-M214 and KKU-OCA17) weretreated with various chemotherapeutic drugs and growth inhibition was determined by 3-(4,5-dimethylthiazol-2-yl)5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Semi-quantitative levels of gene expression were determined by a reverse transcriptase polymerase chain reaction (RT-PCR). Results of IC50 values and the ratios of gene expression were analyzed by linear regression to predict their relationship. RESULTS: Among five CCA cell lines, KKU-M055 was the most sensitive cell line towards all chemotherapeutic drugs investigated, particularly taxane derivatives with IC50 values of 0.02-3 nmol/L, whereas KKU-100 was apparently the least sensitive cell line. When compared to other chemotherapeutic agents, doxorubicin and pirarubicin showed the lowest IC50 values (<5 μmol/L) in all five CCA cell lines. Results from RT-PCR showed that TS, MRP1, MRP3 and GSTP1 were highly expressed in these five CCA cell lines while DPD and MRP2 were only moderately expressed. It should be noted that MDR1 expression was detected only in KKU-OCA17 cell lines. A strong correlation was only found between the level of MRP3 expression and the IC50 values of etoposide, doxorubicin and pirarubicin (r = 0.86-0.98, ,P<0.05). CONCLUSION: Sensitivity to chemotherapeutic agents is not associated with the histological type of CCA. Choosing of the appropriate chemotherapeutic regimen for the treatment of CCA requires knowledge of drug

  3. Hodgkin Lymphoma Cell Lines Are Characterized by a Specific miRNA Expression Profile

    NARCIS (Netherlands)

    Gibcus, Johan H.; Tan, Lu Ping; Harms, Geert; Schakel, Rikst Nynke; de Jong, Debora; Blokzijl, T.; Moller, Peter; Poppema, Sibrand; Kroesen, Bart-Jan; van den Berg, Anke

    Hodgkin lymphoma (HL) is derived from preapoptotic germinal center B cells, although a general loss of B cell phenotype is noted. Using quantitative reverse transcription-polymerase chain reaction and miRNA microarray, we determined the microRNA (miRNA) profile of HL and compared this with the

  4. The Lyman Continuum Escape Fraction of the Cosmic Horseshoe: A Test of Indirect Estimates

    Science.gov (United States)

    Vasei, Kaveh; Siana, Brian; Shapley, Alice E.; Quider, Anna M.; Alavi, Anahita; Rafelski, Marc; Steidel, Charles C.; Pettini, Max; Lewis, Geraint F.

    2016-11-01

    High-redshift star-forming galaxies are likely responsible for the reionization of the universe, yet direct detection of their escaping ionizing (Lyman continuum [LyC]) photons has proven to be extremely challenging. In this study, we search for escaping LyC of the Cosmic Horseshoe, a gravitationally lensed, star-forming galaxy at z = 2.38 with a large magnification of ∼24. Transmission at wavelengths of low-ionization interstellar absorption lines in the rest-frame ultraviolet suggests a patchy, partially transparent interstellar medium. This makes it an ideal candidate for direct detection of the LyC. We obtained a 10-orbit Hubble near-UV image using the Wide Field Camera 3 (WFC3)/UVIS F275W filter that probes wavelengths just below the Lyman limit at the redshift of the Horseshoe in an attempt to detect escaping LyC radiation. After fully accounting for the uncertainties in the opacity of the intergalactic medium (IGM) and accounting for the charge transfer inefficiency in the WFC3 CCDs, we find a 3σ upper limit for the relative escape fraction of {f}{esc,{rel}}\\lt 0.08. This value is a factor of five lower than the value (0.4) predicted by the 40% transmission in the low-ion absorption lines. Though possible, it is unlikely that the nondetection is due to a high-opacity line of sight through the IGM (\\lt 20% chance). We discuss several possible causes for the discrepancy between the escape fraction and the covering fraction and consider the implications for future attempts at both direct LyC detection and indirect estimates of the escape fraction.

  5. Neonatal Cytokine Profile in the Airway Mucosal Lining Fluid Is Skewed by Maternal Atopy

    DEFF Research Database (Denmark)

    Folsgaard, Nilofar V.; Chawes, Bo L.; Rasmussen, Morten A.;

    2012-01-01

    on the cytokines and chemokines in the upper airway mucosal lining fluid of healthy neonates. Objectives: To study parental atopic imprinting on the cytokines and chemokines in the upper airway mucosal lining fluid of healthy neonates. Methods: Eighteen cytokines and chemokines were quantified in nasal mucosal...... lining fluid in 309 neonates from the novel unselected Copenhagen Prospective Study on Asthma in Childhood (COPSAC) birth cohort. Measurements and Main Results: Maternal, but not paternal, atopic status (asthma, hay fever, or eczema with or without sensitization) was associated with general down......-regulation of all 18 mediators assessed by principal component analysis (overall P = 0.015). Conclusions: Maternal atopy, but not paternal atopy, showed a strong linkage with a suppressed mucosal cytokine and chemokine signature in asymptomatic neonates, suggesting imprinting by the maternal milieu in utero...

  6. Vortex line density in counterflowing He II with laminar and turbulent normal fluid velocity profiles

    CERN Document Server

    Baggaley, A W

    2013-01-01

    Superfluid helium is an intimate mixture of a viscous normal fluid, with continuous vorticity, and an inviscid superfluid, where vorticity is constrained to thin, stable topological defects. One mechanism to generate turbulence in this system is through the application of a heat flux, so called thermal counterflow. Of particular interest is how turbulence in the superfluid responds to both a laminar and turbulent normal fluid in the presence of walls. We model superfluid vortex lines as reconnecting space curves with fixed circulation, and consider both laminar (Poiseuille) and turbulent normal fluid flows in a channel configuration. Using high resolution numerical simulations we show that turbulence in the normal fluid sustains a notably higher vortex line density than a laminar flow with the same mean flow rate. We exam Vinen's relation, $\\sqrt{L}=\\gamma v_{ns}$, between the steady state vortex line density $L$ and the counterflow velocity $v_{ns}$. Our results support the hypothesis that transition to turb...

  7. Temporal Variation of Ca–K Line Profile of the Sun during the Solar Cycle 22 and 23

    Indian Academy of Sciences (India)

    G. Sindhuja; Jagdev Singh

    2015-03-01

    We obtained the Ca–K line profile of the Sun as a star since 1969 at the Kodaikanal Observatory (KO) and analysis of the data showed the need to delineate the role of different chromospheric features to the variations of solar irradiance. We, therefore, initiated a new methodology to make observations of Ca–K line profiles of the Sun as a function of latitude and integrated over the longitude on a daily basis since 1986. We have collected the data for about thousand days, spread over two solar cycles. Earlier data (before 1997) were recorded on the photographic film and later data using the CCD detector. The photographic film data were digitized and analysed along with the data obtained from CCD camera. From these data, we computed K1 and K2 widths for the Sun as a star, using all the observed line profiles as a function of latitude. In addition, we have analyzed the spectra of the whole Sun as a star obtained on some days and compared it with the results obtained from latitude spectra of the same day. The K1 and K2 widths of the Sun as a star derived from the KO data are compared with values determined from the observations made at other observatories to compare results from the new methodology of observations adopted by us and the earlier techniques. The average values of K1 width during the minimum period. of solar cycle 23 are smaller than those during the minimum period of cycle 22. Day-to-day variations in the K1 and K2 widths and plage areas may imply that irradiance variations occur not only due to large-scale solar activity, but also because of variations in some of the three types of network in quiet regions of the Sun. The variation in intensity of the plages can also cause day-to-day variations in widths.

  8. Stacking Spectra in Protoplanetary Disks: Detecting Intensity Profiles from Hidden Molecular Lines in HD 163296

    Science.gov (United States)

    Yen, Hsi-Wei; Koch, Patrick M.; Liu, Hauyu Baobab; Puspitaningrum, Evaria; Hirano, Naomi; Lee, Chin-Fei; Takakuwa, Shigehisa

    2016-12-01

    We introduce a new stacking method in Keplerian disks that (1) enhances signal-to-noise ratios (S/Ns) of detected molecular lines and (2) makes visible otherwise-undetectable weak lines. Our technique takes advantage of the Keplerian rotational velocity pattern. It aligns spectra according to their different centroid velocities at their different positions in a disk and stacks them. After aligning, the signals are accumulated in a narrower velocity range as compared to the original line width without alignment. Moreover, originally correlated noise becomes decorrelated. Stacked and aligned spectra thus have a higher S/N. We apply our method to Atacama Large Millimeter/Submillimeter Array (ALMA) archival data of DCN (3-2), DCO+ (3-2), N2D+ (3-2), and H2CO (3{}{0,3}-2{}{0,2}), (3{}{2,2}-2{}{2,1}), and (3{}{2,1}-2{}{2,0}) in the protoplanetary disk around HD 163296. As a result, (1) the S/Ns of the originally detected DCN (3-2), DCO+ (3-2), H2CO (3{}{0,3}-2{}{0,2}), and N2D+ (3-2) lines are boosted by a factor of ≳4-5 at their spectral peaks, implying one order of magnitude shorter integration times to reach the original S/N; and (2) the previously undetectable spectra of the H2CO (3{}{2,2}-2{}{2,1}) and (3{}{2,1}-2{}{2,0}) lines are materialized at more than 3σ. These dramatically enhanced S/Ns allow us to measure intensity distributions in all lines with high significance. The principle of our method can be applied not only to Keplerian disks but also to any systems with ordered kinematic patterns.

  9. PROFILES AND PREFERENCES OF ON-LINE MILLENIAL SHOPPERS IN BULGARIA

    OpenAIRE

    Loubeau, Patricia R.; Robert Jantzen; Elitsa Alexander

    2014-01-01

    This research seeks to develop a better understanding of the factors affecting on-line purchasing behavior among Generation Y (Gen Y) consumers in Bulgaria. Also called millenials and born between the mid-1970s and late 1990s, this generation is especially active on-line and will be a dominant influence shaping e-commerce. An empirical study was conducted based on a written survey of a sample consisting of 367 high school and university students in Bulgaria. The most important reason why Bulg...

  10. Comparison of lung cancer cell lines representing four histopathological subtypes with gene expression profiling using quantitative real-time PCR

    Directory of Open Access Journals (Sweden)

    Kawaguchi Makoto

    2010-01-01

    Full Text Available Abstract Background Lung cancers are the most common type of human malignancy and are intractable. Lung cancers are generally classified into four histopathological subtypes: adenocarcinoma (AD, squamous cell carcinoma (SQ, large cell carcinoma (LC, and small cell carcinoma (SC. Molecular biological characterization of these subtypes has been performed mainly using DNA microarrays. In this study, we compared the gene expression profiles of these four subtypes using twelve human lung cancer cell lines and the more reliable quantitative real-time PCR (qPCR. Results We selected 100 genes from public DNA microarray data and examined them by DNA microarray analysis in eight test cell lines (A549, ABC-1, EBC-1, LK-2, LU65, LU99, STC 1, RERF-LC-MA and a normal control lung cell line (MRC-9. From this, we extracted 19 candidate genes. We quantified the expression of the 19 genes and a housekeeping gene, GAPDH, with qPCR, using the same eight cell lines plus four additional validation lung cancer cell lines (RERF-LC-MS, LC-1/sq, 86-2, and MS-1-L. Finally, we characterized the four subtypes of lung cancer cell lines using principal component analysis (PCA of gene expression profiling for 12 of the 19 genes (AMY2A, CDH1, FOXG1, IGSF3, ISL1, MALL, PLAU, RAB25, S100P, SLCO4A1, STMN1, and TGM2. The combined PCA and gene pathway analyses suggested that these genes were related to cell adhesion, growth, and invasion. S100P in AD cells and CDH1 in AD and SQ cells were identified as candidate markers of these lung cancer subtypes based on their upregulation and the results of PCA analysis. Immunohistochemistry for S100P and RAB25 was closely correlated to gene expression. Conclusions These results show that the four subtypes, represented by 12 lung cancer cell lines, were well characterized using qPCR and PCA for the 12 genes examined. Certain genes, in particular S100P and CDH1, may be especially important for distinguishing the different subtypes. Our results

  11. Measurement of storage time, estimation of ion number and study of absorption line profile in a Paul trap

    Indian Academy of Sciences (India)

    Soumen Bhattacharyya; Anita Gupta; S G Nakhate; Pushpa M Rao

    2006-12-01

    Europium (Eu+) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu+ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions. The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both experimentally and theoretically.

  12. Effects of Magnetic Coupling on Profile of Emission Lines and Images of an Accretion Disc Around a Black Hole

    Institute of Scientific and Technical Information of China (English)

    MA Ren-Yi; WANG Ding-Xiong; LEI Wei-Hua; YAO Guo-Zheng

    2004-01-01

    @@ The profiles of emission lines and images of an accretion disc around a black hole (BH) are simulated by considering the effects of the magnetic coupling (MC) of a central BH with the disc. The MC effects are discussed for both slow- and fast-spinning BHs, and the following results are obtained. Firstly, the width of the emission lines and the brightness of the disc are reduced and augmented for slow- and fast-spinning BHs, respectively. Secondly,the image of the disc becomes dimmer and brighter near the inner edge of the disc for slow- and fast-spinning BHs, respectively. It turns out that all these results arise from the MC effects on the position of the dominant emission region of the accretion disc.

  13. Adaptive Optics Imaging of Lyman Break Galaxies as Progenitors of Spheroids in the Local Universe

    CERN Document Server

    Akiyama, M; Kobayashi, N; Ohta, K; Iwata, I

    2007-01-01

    In order to reveal the stellar mass distribution of z~3 galaxies, we are conducting deep imaging observations of U-dropout Lyman Break Galaxies (LBGs) with Adaptive Optics (AO) systems in K-band, which corresponds to rest-frame V-band of z~3 galaxies. The results of the Subaru intensive-program observations with AO36/NGS/IRCS indicate that 1) the K-band peaks of some of the LBGs brighter than K=22.0 mag show significant offset from those in the optical images, 2) the z~3 Mv* LBGs and serendipitously observed Distant Red Galaxies (DRGs) have flat profiles similar to disk galaxies in the local universe (i.e., Sersic with n2 systems among the luminous z~3 LBGs and DRGs, and their strong spatial clustering, we infer that the dense n2 spheroids of nearby galaxies through relaxations due to major merger events.

  14. DNA Methylation Profiles of Protease Nexin 1 (SERPINE2) Gene in Human Cell Lines

    Institute of Scientific and Technical Information of China (English)

    Shan Gao; Peter A. Andreasen

    2011-01-01

    Objective: To investigated whether epigenetic mechanisms contribute to the variable expression of variable protease nexin1(PN-1) encoded by the SERPINE2 gene in different cell types. Methods: Working with 5 human cell lines, we determined the CpG methylation status within two CpG islands in the SERPINE2 gene by bisulphate sequencing and the PN-1 mRNA level by Q-RT PCR. Results: A CpG island spanning the transcription initiation site showed little methylation in 3 of the cell lines and substantial methylation in 2 of the cell lines. A CpG island covering the translation starting site showed full methylation in all investigated cell lines. Methylation within the CpG island was not randomly distributed, but showed accumulation at specific sites. However, we were not able to distinguish any patterns which related the methylation frequency to the gene expression level. Inhibition of CpG methylation with 5-aza-2′-deoxycytidine led to a several fold increase in PN-1 mRNA levels, but based on the results on CpG methylation in the CpG island spanning the transcript, the effect is most likely indirect. Conclusion: We have carefully mapped the CpG methylation pattern in two CpG islands in the 5′ part of the SERPINE2 gene without finding any obvious inverse correlation between methylation frequency and expression level.

  15. Stacking Spectra in Protoplanetary Disks: Detecting Intensity Profiles from Hidden Molecular Lines in HD 163296

    CERN Document Server

    Yen, Hsi-Wei; Liu, Hauyu Baobab; Puspitaningrum, Evaria; Hirano, Naomi; Lee, Chin-Fei; Takakuwa, Shigehisa

    2016-01-01

    We introduce a new stacking method in Keplerian disks that (1) enhances signal-to-noise ratios (S/N) of detected molecular lines and (2) that makes visible otherwise undetectable weak lines. Our technique takes advantage of the Keplerian rotational velocity pattern. It aligns spectra according to their different centroid velocities at their different positions in a disk and stacks them. After aligning, the signals are accumulated in a narrower velocity range as compared to the original line width without alignment. Moreover, originally correlated noise becomes de-correlated. Stacked and aligned spectra, thus, have a higher S/N. We apply our method to ALMA archival data of DCN (3-2), DCO+ (3-2), N2D+ (3-2), and H2CO (3_0,3-2_0,2), (3_2,2-2_2,1), and (3_2,1-2_2,0) in the protoplanetary disk around HD 163296. As a result, (1) the S/N of the originally detected DCN (3-2), DCO+ (3-2), and H2CO (3_0,3-2_0,2) and N2D+ (3-2) lines are boosted by a factor of >4-5 at their spectral peaks, implying one order of magnitud...

  16. Effect of D-allose on prostate cancer cell lines: phospholipid profiling by nanoflow liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Jeong, Rae Ung; Lim, Sangsoo; Kim, Myoung Ok; Moon, Myeong Hee

    2011-08-01

    D-Allose, a rare, naturally occurring monosaccharide, is known to exert anti-proliferative effects on cancer cells. The effects of D-allose on the cellular membranes of hormone-refractory prostate cancer cell line (DU145), hormone-sensitive prostate cancer cell line (LNCaP), and normal prostate epithelial cells (PrEC) were studied at the molecular level by phospholipid (PL) profiling using a shotgun lipidomic method. The molecular structures of 85 PL species including 23 phosphatidylcholines, 12 phosphatidylethanolamines (PEs), 11 phosphatidylserines (PSs), 16 phosphatidylinositols, 9 phosphatidic acids (PAs), and 14 phosphatidylglycerols (PGs) were identified by data-dependent collision-induced dissociation of nanoflow liquid chromatography-tandem mass spectrometry, and the PL amounts were quantified. The addition of D-allose to prostate cancer cell lines during their growth phases had negligible or decreased effects on the relative regulation of PL species, but several new PS molecules (two for DU145 and three for LNCaP) emerged. In contrast, experiments on the PrEC cell line revealed that some high abundant species (14:0/14:0-PE, 16:2/16:0-PG, and 20:6/18:1-PA) showed significant increases in concentration. These findings support a mechanism for the anti-proliferative effect of D-allose on prostate cancer cell lines that involves the induction of programmed cell death since PS molecules are known to induce apoptosis. Principal component analysis was carried out to examine differences in PL distributions among the three cell lines promoted by D-allose.

  17. The Lyman-alpha forest of a Lyman Break Galaxy VLT Spectra of MS1512-cB58 at z=2.724

    CERN Document Server

    Savaglio, S; Padovani, P

    2001-01-01

    The high redshift galaxy MS1512-cB58 (z=2.724, m_V=20.64) has been observed with the very efficient high resolution echelle spectrograph VLT/UVES. Although this is a very challenging observational program for a Southern hemisphere telescope (the galaxy is located at +36 deg declination), high resolution spectra (FWHM ~ 26 km/s) have revealed, with unprecedented detail along a galaxy sight line, the Lyman-alpha forest due to intervening clouds in the intergalactic medium (IGM). The mean depression D_A due to IGM absorption blueward of the galaxy Ly-alpha wavelength and the number density dn/dz of Ly-alpha clouds have been compared with equivalent results obtained for QSO sight lines at similar redshifts. Our results indicate a possible excess of absorption close to the galaxy. The mean depression at ~ 150 h_65^-1 Mpc comoving (Omega_m=0.3, Omega_Lambda=0.7) from the galaxy is D_A=0.36+/-0.03, to be compared with 0.22+/-0.04, expected from a best fit to QSO sight lines. In the same region (z=2.610), the number ...

  18. Reconstructing the velocity dispersion profiles from the line-of-sight kinematic data in disc galaxies

    Science.gov (United States)

    Marchuk, A. A.; Sotnikova, N. Y.

    2017-03-01

    We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio σz/σR remains constant along the profile or along several pieces of the profile. The method was tested on two galaxies from the sample of other authors and for the first time applied to three lenticular galaxies NGC 1167, NGC 3245 and NGC 4150, as well as to one Sab galaxy NGC 338. We found that for galaxies with a high inclination (i >55° - 60°) it is difficult or rather impossible to extract the information about SVE, while for galaxies at an intermediate inclination the procedure of extracting is successful. For NGC 1167 we managed to reconstruct SVE, provided that the value of σz/σR is piecewise constant. We found σz/σR = 0.7 for the inner parts of the disc and σz/σR = 0.3 for the outskirts. We also obtained a rigid constraint on the value of the radial velocity dispersion σR for highly inclined galaxies, and tested the result using the asymmetric-drift equation, provided that the gas rotation curve is available.

  19. MiRNA Profiles in Lymphoblastoid Cell Lines of Finnish Prostate Cancer Families.

    Directory of Open Access Journals (Sweden)

    Daniel Fischer

    Full Text Available Heritable factors are evidently involved in prostate cancer (PrCa carcinogenesis, but currently, genetic markers are not routinely used in screening or diagnostics of the disease. More precise information is needed for making treatment decisions to distinguish aggressive cases from indolent disease, for which heritable factors could be a useful tool. The genetic makeup of PrCa has only recently begun to be unravelled through large-scale genome-wide association studies (GWAS. The thus far identified Single Nucleotide Polymorphisms (SNPs explain, however, only a fraction of familial clustering. Moreover, the known risk SNPs are not associated with the clinical outcome of the disease, such as aggressive or metastasised disease, and therefore cannot be used to predict the prognosis. Annotating the SNPs with deep clinical data together with miRNA expression profiles can improve the understanding of the underlying mechanisms of different phenotypes of prostate cancer.In this study microRNA (miRNA profiles were studied as potential biomarkers to predict the disease outcome. The study subjects were from Finnish high risk prostate cancer families. To identify potential biomarkers we combined a novel non-parametrical test with an importance measure provided from a Random Forest classifier. This combination delivered a set of nine miRNAs that was able to separate cases from controls. The detected miRNA expression profiles could predict the development of the disease years before the actual PrCa diagnosis or detect the existence of other cancers in the studied individuals. Furthermore, using an expression Quantitative Trait Loci (eQTL analysis, regulatory SNPs for miRNA miR-483-3p that were also directly associated with PrCa were found.Based on our findings, we suggest that blood-based miRNA expression profiling can be used in the diagnosis and maybe even prognosis of the disease. In the future, miRNA profiling could possibly be used in targeted screening

  20. A search for Lyman Break Galaxies at z>8 in the NICMOS Parallel Imaging Survey

    CERN Document Server

    Henry, A L; Colbert, J W; Siana, B; Teplitz, H I; McCarthy, P; Yan, L; Henry, Alaina L.; Malkan, Matthew A.; Colbert, James W.; Siana, Brian; Teplitz, Harry I.; Carthy, Patrick Mc

    2007-01-01

    We have selected 14 J-dropout Lyman Break Galaxy (LBG) candidates with J110 - H160 > 2.5 from the NICMOS Parallel Imaging Survey. This survey consists of 135 square arcminutes of imaging in 228 independent sight lines, reaching average 5 sigma sensitivities of J110 = 25.8 and H160 = 25.6 (AB). Distinguishing these candidates from dust reddened star forming galaxies at z ~ 2-3 is difficult, and will require longer wavelength observations. We consider the likelihood that any J-dropout LBGs exist in this survey, and find that if L*(z=9.5) is significantly brighter than L*(z=6) (a factor of four), then a few J-dropout LBGs are likely. A similar increase in luminosity has been suggested by Eyles et al. and Yan et al., but the magnitude of this increase is uncertain.

  1. Statistical properties of damped Lyman-alpha systems from Sloan Digital Sky Survey DR12

    CERN Document Server

    Bird, Simeon; Ho, Shirley

    2016-01-01

    We present new estimates for the statistical properties of damped Lyman-$\\alpha$ absorbers (DLAs). We compute the column density distribution function at $z>2$, the line density, $\\mathrm{d}N/\\mathrm{d}X$, and the neutral hydrogen density, $\\Omega_\\mathrm{DLA}$. Our estimates are derived from the DLA catalogue of \\cite{Garnett:2016}, which uses the SDSS--III DR12 quasar spectroscopic survey. This catalogue provides a probability that a given spectrum contains a DLA, allowing us to use even the noisiest data without biasing our results and thus substantially increase our sample size. We measure a non-zero column density distribution function at $95\\%$ confidence for all column densities $N_\\mathrm{HI} 4$. We show that our results are insensitive to the signal-to-noise ratio of the spectra, but that there is a residual dependence on quasar redshift for $z<2.5$, which may be due to remaining systematics in our analysis.

  2. A metallicity-spin temperature relation in damped Lyman-$\\alpha$ systems

    CERN Document Server

    Kanekar, Nissim; Briggs, Frank H; Chengalur, Jayaram N

    2009-01-01

    We report evidence for an anti-correlation between spin temperature $T_s$ and metallicity [Z/H], detected at $3.6 \\sigma$ significance in a sample of 26 damped Lyman-$\\alpha$ absorbers (DLAs) at redshifts $0.09 1.7$ have low metallicities, [Z/H] $< -1$, implying that the HI in high-$z$ DLAs is predominantly warm. The anti-correlation between $T_s$ and [Z/H] is consistent with the presence of a mass-metallicity relation in DLAs, suggested by the tight correlation between DLA metallicity and the kinematic widths of metal lines. Most high-$z$ DLAs are likely to arise in galaxies with low masses ($M_{\\rm vir} < 10^{10.5} M_\\odot$), low metallicities ([Z/H]$< -1$, and low cold gas fractions.

  3. Cosmochemistry, cosmology and fundamental constants: High-resolution spectroscopy of damped Lyman-alpha systems

    CERN Document Server

    Quast, R; Smette, A; Garcet, O; Ledoux, C; López, S; Wisotzki, L

    2004-01-01

    Spectroscopy of QSO absorption lines provides essential observational input for the study of nucleosynthesis and chemical evolution of galaxies at high redshift. But new observations may indicate that present chemical abundance data are biased due to deficient spectral resolution and unknown selection effects: Recent high-resolution spectra reveal the hitherto unperceived chemical nonuniformity of molecular hydrogen-bearing damped Lyman-alpha (DLA) systems, and the novel H/ESO DLA survey produces compelling evidence for faint QSOs being attenuated by dust. We present a revised analysis of the molecular hydrogen-bearing DLA complex toward HE 0515-4414 showing nonuniform differential depletion of chemical elements onto dust grains, and introduce to the H/ESO DLA survey and its implications. Conclusively, we aim at starting an unbiased chemical abundance database established on high-resolution spectroscopic observations. New data to probe the temperature-redshift relation predicted by standard cosmology and to t...

  4. Profiling flavonoid cytotoxicity in human breast cancer cell lines: determination of structure-function relationships.

    Science.gov (United States)

    Yadegarynia, Sina; Pham, Anh; Ng, Alex; Nguyen, Duong; Lialiutska, Tetiana; Bortolazzo, Anthony; Sivryuk, Valentin; Bremer, Martina; White, J Brandon

    2014-05-01

    Flavonoids have been shown to be cytotoxic to cancer cells. However, the mechanism of cytotoxicity has not been clearly defined. It has previously been reported that HER2/ERBB2, the estrogen receptor, progesterone receptor, and p53 were required for flavonoid induced cytotoxicity in breast cancer cell lines. We have used a panel of breast cancer cell lines, known to contain as well as be deficient in these signaling pathways, to screen fourteen different flavonoids. Comparing the cytotoxicity for all flavonoids allows us to determine if a structure-functional relationship exists between cytotoxicity and flavonoid, and if a particular signaling pathway is required for cytotoxicity. We show that several flavonoids are cytotoxic to all cell lines including primary mammary epithelial cells tested. The cytotoxic flavonoids are also able to inhibit Mitochondrial Outer Membrane Permeability while at the same time stimulate ATP levels whereas the non-cytotoxic flavonoids are not able to do this. We also show that both cytotoxic and non-cytotoxic flavonoids can transverse the cell membrane to enter MDA-MB-231 cells at different levels. Finally, all flavonoids regardless of their cytotoxicity were able to induce some form of cell cycle arrest. We conclude that for flavonoids to be strongly cytotoxic, they must possess the 2,3-double bond in the C-ring and we believe the cytotoxicity occurs through mitochondrial poisoning in both cancer and normal cells.

  5. Genomic profiling in CEPH cell lines distinguishes between the camptothecins and indenoisoquinolines.

    Science.gov (United States)

    Watson, Venita Gresham; Hardison, Nicholas E; Harris, Tyndall; Motsinger-Reif, Alison; McLeod, Howard L

    2011-10-01

    We have attempted to use a familial genetics strategy to study mechanisms of topoisomerase 1 (Top1) inhibition. Investigations have steadily been chipping away at the pathways involved in cellular response following Top1 inhibition for more than 20 years. Our system-wide approach, which phenotypes a collection of genotyped human cell lines for sensitivity to compounds and interrogates all genes and molecular pathways simultaneously. Previously, we characterized the in vitro sensitivity of 15 families of Centre d'Etude Polymorphisme Humain (CEPH) cell lines (n = 142) to 9 camptothecin analogues. Linkage analysis revealed a pattern of 7 quantitative trait loci (QTL) shared by all of the camptothecins. To identify which, if any, QTLs are related to the general mechanism of Top1 inhibition or should be considered camptothecin specific, we characterized the in vitro sensitivity of the same panel of CEPH cell lines to the indenisoquinolones, a structurally distinct class of Top1 inhibitors. Four QTLs on chromosomes 1, 5, 11, and 16 were shared by both the camptothecins and the indenoisoquinolines and are considered associated with the general mechanism of Top1 inhibition. The remaining 3 QTLs (chromosomes 6 and 20) are considered specific to camptothecin-induced cytotoxicity. Finally, 8 QTLs were identified, which were unique to the indenoisoquinolines.

  6. An Abel transform for deriving line-of-sight wind profiles from LEO-LEO infrared laser occultation measurements

    Science.gov (United States)

    Syndergaard, S.; Kirchengast, G.

    2016-03-01

    We have developed a formula for the retrieval of the line-of-sight (l.o.s.) wind speed from future low Earth orbit (LEO) satellite-to-satellite infrared laser occultation measurements. The formula involves an Abelian integral transform akin to the Abel transform widely used for deriving refractive index from bending angle in Global Navigation Satellite System radio occultation measurements. Besides the Abelian integral transform, the formula is derived from a truncated series expansion of the volume absorption coefficient as a function of frequency and includes a simple absorption-line-asymmetry correction term. A first-order formulation (referred to as the standard formula) is complemented by higher-order terms that can be used for high-accuracy computations. Under the assumptions of spherical symmetry and perfect knowledge of spectroscopy, the residual l.o.s. wind error from using the standard formula rather than the high-accuracy formula is assessed to be small compared to that anticipated from measurement errors in a real experiment. Applying the new formula just in standard form to future infrared laser transmission profiles would therefore enable the retrieval of l.o.s. stratospheric wind profiles with an accuracy limited mainly by measurement errors, residual spectroscopic errors, and deviations from spherical symmetry.

  7. Correlation of antinuclear antibody immunofluorescence patterns with immune profile using line immunoassay in the Indian scenario

    Directory of Open Access Journals (Sweden)

    Sebastian Wendy

    2010-07-01

    Full Text Available Background: Immunity status, individual response to disease and types of antibodies produced are well known to vary from person to person, place to place and probably from population to population. A broad spectrum of specific auto antibodies that have so far been associated with specific rheumatic diseases, as noted in Western literature, has been well taken as a reference standard all over the world. There is neither research work nor any data correlating the auto antibodies and their antinuclear antibody (ANA patterns with the immunoprofile in the Indian population to date. Aims: To understand a definite association between ANA patterns and specific antibodies in the serum in the Indian study population and to document similarities / differences with the West. Settings and Design: This prospective and retrospective double blind study was undertaken on the South Indian population referred for ANA testing by Indirect Immunofluorescence method and by immunoline methods. Materials and Methods: Serum samples of patients from a random South Indian population who sought medical help for rheumatic disease were subjected for ANA testing by indirect immunofluorescence (IIF method and line immunoassay during the study period of 27 months. Serum samples were processed in dilution of 1:100 using HEp - 2010 / liver biochip (Monkey (EUROIMMUN AG. The serum samples which were further processed for line immunoassay were treated in 1:100 dilution on nylon strips coated with recombinant and purified antigens as discrete lines with plastic backing (EUROIMMUN AG coated with antigens nRNP / Sm, Sm, SSA, Ro-52, SSB, Scl-70, PM-Scl, PCNA, Jo-1, CENP-B, dsDNA, nucleosomes, histones, ribosomal protein-P, anti-mitochondrial antibodies (AMA-M2 along with a control band. The analysis was done by comparing the intensity of the reaction with positive control line by image analysis. Results: The antinuclear antibody indirect immunofluorescence (ANA - IIF patterns obtained

  8. New interpretations of extraterrestrial Lyman-alpha observations.

    Science.gov (United States)

    Blum, P. W.; Fahr, H. J.

    1972-01-01

    The solar Lyman-alpha radiation pressure affects the orbits and the velocities of the interstellar particles entering the solar system. This leads to enhanced particle losses in the heliosphere, since particles spend a longer time crossing it. This causes a stronger decrease of the density with decreasing distances from the sun than had been calculated without accounting for the radiation pressure. Furthermore, the emission pattern of the solar Lyman-alpha radiation is anisotropic and rotates with the sun in a 27-day period. This causes a temporal change in the location of the intensity extrema. At the same time it produces hydrogen density anisotropies with extrema deviating in their directions from those which had been calculated without consideration of the radiation pressure.

  9. The Environmental Impact of Lyman-break Galaxies

    CERN Document Server

    Tasker, E J; Bryan, Greg L.; Tasker, Elizabeth J.

    2006-01-01

    We perform cosmological simulations of galaxies forming at z=3 using the hydrodynamics grid code, Enzo. By selecting the largest galaxies in the volume to correspond to Lyman-break galaxies, we construct observational spectra of the HI flux distribution around these objects, as well as column densities of CIV and OVI throughout a refined region. We successfully reproduce the most recent observations of the mean HI flux in the close vicinity of Lyman-break galaxies but see no evidence for the proximity effect in earlier observations. While our galaxies do return metals to the IGM, their quantity and volume appears to be somewhat less than observed. We conclude that either we do not adequately resolve galactic winds, or that at least some of the intergalactic metal enrichment is by early epoch objects whose mass is smaller than our minimum resolved halo mass.

  10. Atmospheric profiling via satellite to satellite occultations near water and ozone absorption lines for weather and climate

    Science.gov (United States)

    Kursinski, E. R.; Ward, D.; Otarola, A. C.; McGhee, J.; Stovern, M.; Sammler, K.; Reed, H.; Erickson, D.; McCormick, C.; Griggs, E.

    2016-05-01

    Significantly reducing weather and climate prediction uncertainty requires global observations with substantially higher information content than present observations provide. While GPS occultations have provided a major advance, GPS observations of the atmosphere are limited by wavelengths chosen specifically to minimize interaction with the atmosphere. Significantly more information can be obtained via satellite to satellite occultations made at wavelengths chosen specifically to characterize the atmosphere. Here we describe such a system that will probe cm- and mmwavelength water vapor absorption lines called the Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS). Profiling both the speed and absorption of light enables ATOMMS to profile temperature, pressure and humidity simultaneously, which GPS occultations cannot do, as well as profile clouds and turbulence. We summarize the ATOMMS concept and its theoretical performance. We describe field measurements made with a prototype ATOMMS instrument and several important capabilities demonstrated with those ground based measurements including retrieving temporal variations in path-averaged water vapor to 1%, in clear, cloudy and rainy conditions, up to optical depths of 17, remotely sensing turbulence and determining rain rates. We conclude with a vision of a future ATOMMS low Earth orbiting satellite constellation designed to take advantage of synergies between observational needs for weather and climate, ATOMMS unprecedented orbital remote sensing capabilities and recent cubesat technological innovations that enable a constellation of dozens of very small spacecraft to achieve many critical, but as yet unfulfilled, monitoring and forecasting needs.

  11. Characterization of the glycosylation profile of the human breast cancer cell line, MDA-231, and a bone colonizing variant.

    Science.gov (United States)

    Carcel-Trullols, Jaime; Stanley, Joseph S; Saha, Rinku; Shaaf, Saeid; Bendre, Manali S; Monzavi-Karbassi, Behjatolah; Suva, Larry J; Kieber-Emmons, Thomas

    2006-05-01

    The mechanisms that guide organ-specific metastases are not fully established. The aberrant expression of carbohydrates may play a fundamental role in defining the molecular mechanisms for metastases to distant organs and facilitate positive interactions within the target organ. The purpose of the present study was to determine the glycomic profile of a variant of the MDA-MB-231 breast cancer cell line that colonizes the bone and to ascribe mechanistic functions mediated by carbohydrates that might correlate with clinical bone metastases. The carbohydrate expression profiles of osteolytic MDA-MET breast cancer cells and non-osteolytic parental MDA-MB-231 cells were determined. MDA-MET cells were derived from MDA-MB-231 cells by in vivo selection of metastatic bone lesions following intracardiac inoculation. The two related breast cancer cell lines expressed distinct carbohydrate profiles; MDA-MET cells displayed an increased expression of alpha (2,6) linked sialic acid, N-beta1-6 GlcNAc, and sialylated Lewis-A antigen, and decreased expression of Galbeta1,3GalNAc as detected using a combination of lectins and anti-carbohydrate antibodies. Microarray analysis demonstrated an increased expression of glycosyltransferase genes, correlative for the distinct glycomic phenotype. The altered glycomic phenotypes of MDA-MET cells include effects on the differential binding to bone marrow endothelial cells, enhanced ECM binding and an increase in invasive potential. These data suggest that the glycomic phenotype of MDA-MET cells is associated with a select set of accumulated functions that collectively impact on the bone metastases and bone colonization capacity of breast cancer cells.

  12. The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)

    Science.gov (United States)

    Ishikawa, Shin-nosuke; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N..; Ishikawa, R.; Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Hara, H.; hide

    2014-01-01

    To Understand energy release process in the Sun including solar flares, it is essentially important to measure the magnetic field of the atmosphere of the Sun. Magnetic field measurement of the upper layers (upper chromosphere and above) was technically difficult and not well investigated yet. Upper chromosphere and transition region magnetic field measurement by Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP) sounding rocket to be launched in 2015. The proposal is already selected and developments of the flight components are going.

  13. High Redshift Lyman-α Hunt

    DEFF Research Database (Denmark)

    Kochiashvili, Ia

    . Significant differences between the two selectionmethods have been found. The colour-colour selection method, tends to pick galaxieswith high colour excess and can leave some strong emission-line candidates with relativelylower colour excess out of the sample. The populations of selected galaxies can also...

  14. In Situ Characterizing Membrane Lipid Phenotype of Human Lung Cancer Cell Lines Using Mass Spectrometry Profiling

    OpenAIRE

    2016-01-01

    Abnormal lipid metabolisms are closely associated with cancers. In this study, mass spectrometry was employed to in situ investigate the associations of membrane lipid phenotypes of six human lung cancer cell lines (i.e., A549, H1650, H1975 from adenocarcinoma, H157 and H1703 from squamous cell carcinomas, and H460 from a large cell carcinoma) with cancer cell types and finally total 230 lipids were detected. Based these 230 lipids, partial least-square discriminant analysis indicated that fi...

  15. NICMOS Snapshot Survey of Damped Lyman Alpha Quasars

    CERN Document Server

    Colbert, J W; Colbert, James W.; Malkan, Matthew A.

    2001-01-01

    We image 19 quasars with 22 damped Lyman alpha (DLA) systems using the F160W filter and the Near-Infrared Camera and Multiobject Spectrograph aboard the Hubble Space Telescope, in both direct and coronagraphic modes. We reach 5 sigma detection limits of ~H=22 in the majority of our images. We compare our observations to the observed Lyman-break population of high-redshift galaxies, as well as Bruzual & Charlot evolutionary models of present-day galaxies redshifted to the distances of the absorption systems. We predict H magnitudes for our DLAs, assuming they are producing stars like an L* Lyman-break galaxy (LBG) at their redshift. Comparing these predictions to our sensitivity, we find that we should be able to detect a galaxy around 0.5-1.0 L* (LBG) for most of our observations. We find only one new possible candidate, that near LBQS0010-0012. This scarcity of candidates leads us to the conclusion that most DLA systems are not drawn from a normal LBG luminosity function nor a local galaxy luminosity fun...

  16. Lyman Break Galaxies and the Reionization of the Intergalactic Medium

    CERN Document Server

    Ferguson, H C; Papovich, C; Ferguson, Henry C.; Dickinson, Mark; Papovich, Casey

    2002-01-01

    Near-infrared observations of Lyman-break galaxies at redshifts z~3 are beginning to provide constraints on ages, star-formation histories, dust content, metallicities, and stellar masses. At present, uncertainties of more than an order of magnitude are typical for many of these parameters. It is nonetheless interesting to ask what the stellar-population models imply for the existence and luminosities of Lyman-break galaxies at higher redshift. To this end we examine the inferred star-formation rates in two well-studied samples of galaxies as a function of redshift out to z = 10 for various best-fit and limiting cases. Taken at face value, the generally young ages (typically 10^8 +- 0.5 yr) of the z = 3 Lyman break galaxies imply that their stars were not present much beyond z=4. By z = 6 the cosmic star-formation rate from the progenitors of these galaxies is less than 10% of star-formation rate at z=3 +- 0.5, even for maximally-old models, provided the derivative of the star-formation rate SFR(t) is monoton...

  17. Suppression subtractive hybridization profiles of radial growth phase and metastatic melanoma cell lines reveal novel potential targets

    Directory of Open Access Journals (Sweden)

    Espreafico Enilza M

    2008-01-01

    Full Text Available Abstract Background Melanoma progression occurs through three major stages: radial growth phase (RGP, confined to the epidermis; vertical growth phase (VGP, when the tumor has invaded into the dermis; and metastasis. In this work, we used suppression subtractive hybridization (SSH to investigate the molecular signature of melanoma progression, by comparing a group of metastatic cell lines with an RGP-like cell line showing characteristics of early neoplastic lesions including expression of the metastasis suppressor KISS1, lack of αvβ3-integrin and low levels of RHOC. Methods Two subtracted cDNA collections were obtained, one (RGP library by subtracting the RGP cell line (WM1552C cDNA from a cDNA pool from four metastatic cell lines (WM9, WM852, 1205Lu and WM1617, and the other (Met library by the reverse subtraction. Clones were sequenced and annotated, and expression validation was done by Northern blot and RT-PCR. Gene Ontology annotation and searches in large-scale melanoma expression studies were done for the genes identified. Results We identified 367 clones from the RGP library and 386 from the Met library, of which 351 and 368, respectively, match human mRNA sequences, representing 288 and 217 annotated genes. We confirmed the differential expression of all genes selected for validation. In the Met library, we found an enrichment of genes in the growth factors/receptor, adhesion and motility categories whereas in the RGP library, enriched categories were nucleotide biosynthesis, DNA packing/repair, and macromolecular/vesicular trafficking. Interestingly, 19% of the genes from the RGP library map to chromosome 1 against 4% of the ones from Met library. Conclusion This study identifies two populations of genes differentially expressed between melanoma cell lines from two tumor stages and suggests that these sets of genes represent profiles of less aggressive versus metastatic melanomas. A search for expression profiles of melanoma in

  18. Profiling polyphenols of two diploid strawberry (Fragaria vesca) inbred lines using UHPLC-HRMS(n.).

    Science.gov (United States)

    Sun, Jianghao; Liu, Xianjin; Yang, Tianbao; Slovin, Janet; Chen, Pei

    2014-03-01

    Phenolic compounds in the fruits of two diploid strawberries (Fragaria vesca f. semperflorens) inbred lines-Ruegen F7-4 (a red-fruited genotype) and YW5AF7 (a yellow-fruited genotype) were characterised using ultra-high-performance liquid chromatography coupled with tandem high-resolution mass spectrometry (UHPLC-HRMS(n)). The changes of anthocyanin composition during fruit development and between Ruegen F7-4 and YW5AF7 were studied. About 67 phenolic compounds, including taxifolin 3-O-arabinoside, glycosides of quercetin, kaempferol, cyanidin, pelargonidin, peonidin, ellagic acid derivatives, and other flavonols were identified in these two inbred lines. Compared to the regular octoploid strawberry, unique phenolic compounds were found in F. vesca fruits, such as taxifolin 3-O-arabinoside (both) and peonidin 3-O-malonylglucoside (Ruegen F7-4). The results provide the basis for comparative analysis of polyphenolic compounds in yellow and red diploid strawberries, as well as with the cultivated octoploid strawberries.

  19. Radiation pressure force emission line profiles and black hole mass in active galactic nuclei

    CERN Document Server

    Netzer, H

    2010-01-01

    We present a new analysis of the motion of broad line region (BLR) clouds in active galactic nuclei (AGNs) taking into account the combined influence of gravity and radiation pressure force. We calculate cloud orbits under a large range of conditions and include the effect of a changing column density as a function of location. The dependence of radiation pressure force on the level of ionization and the column density are accurately computed. The main results are: a. The mean cloud location r(BLR) and the line widths (FWHMs) are combined in such a way that the simple virial mass estimate, r{BLR} FWHM^2/G, gives a reasonable approximation to the black hole mass M even when radiation pressure force is important. The reason is that L/M rather than L is the main parameter affecting the planar cloud motion. b. Reproducing the observed mean radius, FWHM and intensity of H-beta and CIV 1549 requires at least two different populations of clouds. c. The cloud location is a function of both L^{1/2} and L/M. Given this...

  20. Protein Profile of Human Lung Squamous Carcinoma Cell Line NCI-H226

    Institute of Scientific and Technical Information of China (English)

    HAO ZHANG; NA LI; YUE CHEN; LING-YUN HUANG; YI-CHING WANG; GANG FANG; DA-CHENG HE; XUE-YUAN XIAO

    2007-01-01

    Objective To construct a database of human lung squamous carcinoma cell line NCI-H226 and to facilitate discovery of novel subtypes markers of lung cancer. Method Proteomic technique was used to analyze human lung squamous carcinoma cell line NCI-H226. The proteins of the NCI-H226 cells were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. Results The results showed that a good reproducibility of the 2-D gel pattern was attained. The position deviation of matched spots among three 2-D gels was 1.95±0.53 mm in the isoelectric focusing direction,and 1.73±0.45 mm in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis direction. One hundred and twenty-seven proteins, including enzymes, signal transduction proteins, structure proteins, transport proteins, etc. were characterized, of which, 29 identified proteins in NCI-H226 cells were reported for the first time to be involved in lung cancer carcinogenesis.Conclusion The information obtained from this study could provide some valuable clues for further study on the carcinogenetic mechanism of different types of lung cancer, and may help us to discover some potential subtype-specific biomarkers of lung cancer.

  1. Low-Profile Fully-Printed Multifrequency Monopoles Loaded with Complementary Metamaterial Transmission Line

    Directory of Open Access Journals (Sweden)

    Xue Li

    2015-04-01

    Full Text Available The design of a new class of multifrequency monopoles by loading a set of resonant-type complementary metamaterial transmission lines (CMTL is firstly presented. Two types of CMTL elements are comprehensively explored: the former is the epsilon negative (ENG one by loading complementary split ring resonators (CSRRs with different configurations on the signal strip, whereas the latter is the double negative (DNG one by incorporating the CSRRs and capacitive gaps. In both cases, the CMTLs are considered with different number of unit cells. By cautiously controlling the geometrical parameters of element structure, five antenna prototypes coving different communication standards (GSM, UMTS, DMB and WiMAX are designed, fabricated and measured. Numerical and experimental results illustrate that the zeroth-order resonance frequencies of the ENG and DNG monopoles are in desirable consistency. Moreover, of all operating frequencies the antennas exhibit fairly good impedance matching performances better than -10dB and quasi-omnidirectional radiation patterns.

  2. CONTINUUM INTENSITY AND [O i] SPECTRAL LINE PROFILES IN SOLAR 3D PHOTOSPHERIC MODELS: THE EFFECT OF MAGNETIC FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Fabbian, D.; Moreno-Insertis, F., E-mail: damian@iac.es, E-mail: fmi@iac.es [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain)

    2015-04-01

    The importance of magnetic fields in three-dimensional (3D) magnetoconvection models of the Sun’s photosphere is investigated in terms of their influence on the continuum intensity at different viewing inclination angles and on the intensity profile of two [O i] spectral lines. We use the RH numerical radiative transfer code to perform a posteriori spectral synthesis on the same time series of magnetoconvection models used in our publications on the effect of magnetic fields on abundance determination. We obtain a good match of the synthetic disk-center continuum intensity to the absolute continuum values from the Fourier Transform Spectrometer (FTS) observational spectrum; the match of the center-to-limb variation synthetic data to observations is also good, thanks, in part, to the 3D radiation transfer capabilities of the RH code. The different levels of magnetic flux in the numerical time series do not modify the quality of the match. Concerning the targeted [O i] spectral lines, we find, instead, that magnetic fields lead to nonnegligible changes in the synthetic spectrum, with larger average magnetic flux causing both of the lines to become noticeably weaker. The photospheric oxygen abundance that one would derive if instead using nonmagnetic numerical models would thus be lower by a few to several centidex. The inclusion of magnetic fields is confirmed to be important for improving the current modeling of the Sun, here in particular in terms of spectral line formation and of deriving consistent chemical abundances. These results may shed further light on the still controversial issue regarding the precise value of the solar oxygen abundance.

  3. Small RNA Profiles of the Rice PTGMS Line Wuxiang S Reveal miRNAs Involved in Fertility Transition.

    Science.gov (United States)

    Zhang, Hongyuan; Hu, Jihong; Qian, Qian; Chen, Hao; Jin, Jing; Ding, Yi

    2016-01-01

    MicroRNAs (miRNAs) play key roles in the regulation of plant growth and developmental processes. In this study, RNA-seq was used to examine the expression profiles of miRNAs in a novel, photo-thermosensitive genic male sterile (PTGMS) rice line, Wuxiang S (WXS), during fertility transition. A total of 497 known miRNAs and 273 novel miRNAs were identified. In a differential expression analysis, 26 miRNAs exhibited significant differential expression between WXS (Sterile, S) and WXS (Fertile, F). Some of these miRNAs were validated by quantitative real-time PCR. Among these miRNAs, 11 showed decreased expression levels, and 15 showed increased expression levels in WXS (S) compared to WXS (F). Some of these miRNAs, such as osa-miR156a-j, osa-miR164d, and osa-miR528, were shown to be negatively correlated with their targets. These targets have previously been reported to be related to pollen development and male sterility, suggesting that these miRNAs may be involved in the regulation of pollen development in the rice PTGMS line WXS. Furthermore, miRNA-mediated editing events were also observed. In this study, a possible model for the control of signaling pathways during the process of fertility transition in the rice PTGMS line WXS by miRNAs was developed. These findings contribute to our understanding of the roles of miRNAs during anther development in PTGMS lines in rice.

  4. Polyphenolic Profile and Targeted Bioactivity of Methanolic Extracts from Mediterranean Ethnomedicinal Plants on Human Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Antonino Pollio

    2016-03-01

    Full Text Available The methanol extracts of the aerial part of four ethnomedicinal plants of Mediterranean region, two non-seed vascular plants, Equisetum hyemale L. and Phyllitis scolopendrium (L. Newman, and two Spermatophyta, Juniperus communis L. (J. communis and Cotinus coggygria Scop. (C. coggygria, were screened against four human cells lines (A549, MCF7, TK6 and U937. Only the extracts of J. communis and C. coggygria showed marked cytotoxic effects, affecting both cell morphology and growth. A dose-dependent effect of these two extracts was also observed on the cell cycle distribution. Incubation of all the cell lines in a medium containing J. communis extract determined a remarkable accumulation of cells in the G2/M phase, whereas the C. coggygria extract induced a significant increase in the percentage of G1 cells. The novelty of our findings stands on the observation that the two extracts, consistently, elicited coherent effects on the cell cycle in four cell lines, independently from their phenotype, as two of them have epithelial origin and grow adherent and two are lymphoblastoid and grow in suspension. Even the expression profiles of several proteins regulating cell cycle progression and cell death were affected by both extracts. LC-MS investigation of methanol extract of C. coggygria led to the identification of twelve flavonoids (compounds 1–11, 19 and eight polyphenols derivatives (12–18, 20, while in J. communis extract, eight flavonoids (21–28, a α-ionone glycoside (29 and a lignin (30 were found. Although many of these compounds have interesting individual biological activities, their natural blends seem to exert specific effects on the proliferation of cell lines either growing adherent or in suspension, suggesting potential use in fighting cancer.

  5. Recovery of acetylene absorption line profile basing on tunable diode laser spectroscopy with intensity modulation and photoacoustic spectroscopy

    Science.gov (United States)

    Li, Li; Thursby, Graham; Stewart, George; Arsad, Norhana; Uttamchandani, Deepak; Culshaw, Brian; Wang, Yiding

    2010-04-01

    A novel and direct absorption line recovery technique based on tunable diode laser spectroscopy with intensity modulation is presented. Photoacoustic spectroscopy is applied for high sensitivity, zero background and efficient acoustic enhancement at a low modulation frequency. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used for generating laser intensity modulation (without wavelength modulation) through the external reflection. The MEMS mirror with 10μm thick structure material layer and 100nm thick gold coating is formed as a circular mirror of 2mm diameter attached to an electrothermal actuator and is fabricated on a chip that is wire-bonded and placed on a PCB holder. Low modulation frequency is adopted (since the resonant frequencies of the photoacoustic gas cell and the electrothermal actuator are different) and intrinsic high signal amplitude characteristics in low frequency region achieved from measured frequency responses for the MEMS mirror and the gas cell. Based on the property of photoacoustic spectroscopy and Beer's law that detectable sensitivity is a function of input laser intensity in the case of constant gas concentration and laser path length, a Keopsys erbium doped fibre amplifier (EDFA) with opto-communication C band and high output power up to 1W is chosen to increase the laser power. High modulation depth is achieved through adjusting the MEMS mirror's reflection position and driving voltage. In order to scan through the target gas absorption line, the temperature swept method is adopted for the tunable distributed feed-back (DFB) diode laser working at 1535nm that accesses the near-infrared vibration-rotation spectrum of acetylene. The profile of acetylene P17 absorption line at 1535.39nm is recovered ideally for ~100 parts-per-million (ppm) acetylene balanced by nitrogen. The experimental signal to noise ratio (SNR) of absorption line recovery for 500mW laser power was ~80 and hence the

  6. Polyphenolic Profile and Targeted Bioactivity of Methanolic Extracts from Mediterranean Ethnomedicinal Plants on Human Cancer Cell Lines.

    Science.gov (United States)

    Pollio, Antonino; Zarrelli, Armando; Romanucci, Valeria; Di Mauro, Alfredo; Barra, Federica; Pinto, Gabriele; Crescenzi, Elvira; Roscetto, Emanuela; Palumbo, Giuseppe

    2016-03-23

    The methanol extracts of the aerial part of four ethnomedicinal plants of Mediterranean region, two non-seed vascular plants, Equisetum hyemale L. and Phyllitis scolopendrium (L.) Newman, and two Spermatophyta, Juniperus communis L. (J. communis) and Cotinus coggygria Scop. (C. coggygria), were screened against four human cells lines (A549, MCF7, TK6 and U937). Only the extracts of J. communis and C. coggygria showed marked cytotoxic effects, affecting both cell morphology and growth. A dose-dependent effect of these two extracts was also observed on the cell cycle distribution. Incubation of all the cell lines in a medium containing J. communis extract determined a remarkable accumulation of cells in the G2/M phase, whereas the C. coggygria extract induced a significant increase in the percentage of G1 cells. The novelty of our findings stands on the observation that the two extracts, consistently, elicited coherent effects on the cell cycle in four cell lines, independently from their phenotype, as two of them have epithelial origin and grow adherent and two are lymphoblastoid and grow in suspension. Even the expression profiles of several proteins regulating cell cycle progression and cell death were affected by both extracts. LC-MS investigation of methanol extract of C. coggygria led to the identification of twelve flavonoids (compounds 1-11, 19) and eight polyphenols derivatives (12-18, 20), while in J. communis extract, eight flavonoids (21-28), a α-ionone glycoside (29) and a lignin (30) were found. Although many of these compounds have interesting individual biological activities, their natural blends seem to exert specific effects on the proliferation of cell lines either growing adherent or in suspension, suggesting potential use in fighting cancer.

  7. Gene expression profile differences in high and low metastatic human ovarian cancer cell lines by gene chip

    Institute of Scientific and Technical Information of China (English)

    许沈华; 牟瀚舟; 吕桂泉; 朱赤红; 羊正炎; 高永良; 楼洪坤; 刘祥麟; 程勇; 杨文

    2002-01-01

    Objectives To study the difference between gene expressions of high (H0-8910PM) and low (HO-8910) metastatic human ovarian carcinoma cell lines and screen novel associated genes by cDNA microarray. Methods cDNA retro-transcribed from equal quantities of mRNA derived from high and low metastatic tumor cells or normal ovarian tissues were labeled with Cy5 and Cy3 fluorescein as probes. The mixed probe was hybridized with two pieces of BioDoor 4096 double dot human whole gene chip and scanned with a ScanArray 3000 laser scanner. The acquired image was analyzed by ImaGene 3.0 software. Results A total of 355 genes with expression levels more than 3 times larger were found by comparing the HO-8910 cell with normal ovarian epithelial cells. A total of 323 genes with expression levels more than 3 times larger in HO-8910PM cells compared to normal ovarian epithelium cells were also detected. A total of 165 genes whose expression levels were more than two times those of HO-8910PM cells compared to their mother cell line (HO-8910) were detected. Twenty-one genes with expression levels >3 times were found from comparison of these two tumor cell lines.Conclusions cDNA microarray techniques are effective in screening differential gene expression between two human ovarian cancer cell lines (H0-8910PM; HO-8910) and normal ovarian epithelial cells. These genes may be related to the genesis and development of ovarian carcinoma. Analysis of the human ovarian cancer gene expression profile with cDNA microarray may help in gene diagnosis, treatment and prevention.

  8. From Mirrors to Windows: Lyman-Alpha Radiative Transfer in a Very Clumpy Medium

    CERN Document Server

    Gronke, Max; McCourt, Michael; Oh, S Peng

    2016-01-01

    Lyman-Alpha (Ly$\\alpha$) is the strongest emission line in the Universe and is frequently used to detect and study the most distant galaxies. Because Lya is a resonant line, photons typically scatter prior to escaping; this scattering process complicates the interpretation of Ly$\\alpha$ spectra, but also encodes a wealth of information about the structure and kinematics of neutral gas in the galaxy. Modeling the Ly$\\alpha$ line therefore allows us to study tiny-scale features of the gas, even in the most distant galaxies. Curiously, observed Ly$\\alpha$ spectra can be modeled successfully with very simple, homogeneous geometries (such as an expanding, spherical shell), whereas more realistic, multiphase geometries often fail to reproduce the observed spectra. This seems paradoxical since the gas in galaxies is known to be multiphase. In this Letter, we show that spectra emerging from extremely clumpy geometries with many clouds along the line of sight converge to the predictions from simplified, homogeneous mo...

  9. An FE Based On-line Model for the Prediction of Work Roll Thermal Profile in Hot Strip Rolling

    Science.gov (United States)

    Choi, Ji Won; Lee, Jung Hyeung; Sun, Cheng Gang; Hwang, Sang Moo

    2010-06-01

    Prediction and control of the thermal deformation of the work roll is vital for enhancing product quality in hot strip and plate rolling. In this paper, we present an on-line model for the prediction of the work roll thermal profile. The model is developed on the basis of an integrated finite element model for the coupled analysis of heat transfer and deformation occurring at the bite zone, to rigorously take into account the effect of various rolling parameters on the thermal behavior of the work roll. The validity of the model is demonstrated through comparison with measurements made in an industrial hot strip mill. Also, an emphasis is given to the examination the effect of some selected rolling parameters in an actual production environment.

  10. A CORRELATION BETWEEN Lyα SPECTRAL LINE PROFILE AND REST-FRAME UV MORPHOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Vivian U; Hemmati, Shoubaneh; Darvish, Behnam; Mobasher, Bahram; Nayyeri, Hooshang; Mallery, Ryan [Department of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Spinrad, Hyron, E-mail: vivianu@ucr.edu [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2015-12-10

    We explore the relationship between the spectral shape of the Lyα emission and the UV morphology of the host galaxy using a sample of 304 Lyα-emitting BVi-dropouts at 3 < z < 7 in the Great Observatories Origins Deep Survey and Cosmic Evolution Survey fields. Using our extensive reservoir of high-quality Keck DEIMOS spectra combined with Hubble Space Telescope WFC3 data, we measure the Lyα line asymmetries for individual galaxies and compare them to axial ratios measured from observed J- and H-band (restframe UV) images. We find that the Lyα skewness exhibits a large scatter at small elongation (a/b < 2), and this scatter decreases as the axial ratio increases. Comparison of this trend to radiative transfer models and various results from the literature suggests that these high-redshift Lyα emitters are not likely to be intrinsically round and symmetric disks, but they probably host galactic outflows traced by Lyα emitting clouds. The ionizing sources are centrally located, and the optical depth is a good indicator of the absorption and scattering events on the escape path of Lyα photons from the source. Our results find no evidence of evolution in Lyα asymmetry or axial ratio with look-back time.

  11. A Correlation Between Ly{\\alpha} Spectral Line Profile and Rest-Frame UV Morphology

    CERN Document Server

    U, Vivian; Darvish, Behnam; Mobasher, Bahram; Nayyeri, Hooshang; Dickinson, Mark; Stern, Daniel; Spinrad, Hyron; Mallery, Ryan

    2015-01-01

    We explore the relationship between the spectral shape of the Ly{\\alpha} emission and the UV morphology of the host galaxy using a sample of 304 Ly{\\alpha}-emitting BV i-dropouts at 3 < z < 7 in the GOODS and COSMOS fields. Using our extensive reservoir of high-quality Keck DEIMOS spectra combined with HST WFC3 data, we measure the Ly{\\alpha} line asymmetries for individual galaxies and compare them to axial ratios measured from observed J- and H-band (restframe UV) images. We find that the Ly{\\alpha} skewness exhibits a large scatter at small elongation (a/b < 2), and this scatter decreases as axial ratio increases. Comparison of this trend to radiative transfer models and various results from literature suggests that these high-redshift Ly{\\alpha} emitters are not likely to be intrinsically round and symmetric disks, but they probably host galactic outflows traced by Ly{\\alpha} emitting clouds. The ionizing sources are centrally located, with the optical depth a good indicator of the absorption and...

  12. Microstructure and texture of electrodeposited Ni–ZrC composite coatings investigated by Rietveld XRD line profile analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhongquan; Jiang, Chuanhai, E-mail: jiangchuanhai211@163.com; Fu, Peng; Cai, Fei; Ma, Naiheng

    2015-03-25

    Highlights: • Microstructure of Ni–ZrC electrodeposits is studied by Rietveld refinement. • Rietveld refinement software is used to simulate the pole figures of Ni–ZrC. • The RTC, simulated and measured pole figures are coincident with each other. • Influence of current density on the texture of Ni–ZrC is studied. - Abstract: Rietveld X-ray diffraction (XRD) line profile analysis method was used to investigate the influence of applied current density on the microstructure and texture of the electrodeposited Ni–ZrC composite coatings. Crystallite size, microstrain, distribution of crystallite size, dislocation density, crystalline preferred orientation (texture), and ZrC particles content of the Ni–ZrC coatings were obtained from the Rietveld XRD line profile analysis. The results show that the crystallite size of Ni–ZrC coating increases, the microstrain and dislocation density decrease with the increasing of the current density. And the distribution of crystallite size is less uniform at higher current density. The pole figures simulated by Rietveld analysis software are coincident with the measured pole figures of Ni–ZrC coatings. The calculated relative texture coefficient (RTC) values, the simulated and measured pole figures of the coatings all illustrate that the texture of Ni–ZrC coating is modified from weak (2 2 0) to strong (2 0 0) texture with the increasing of applied current density. The microstructure evolution of Ni–ZrC composites is ascribed to the change of applied current density and ZrC content in the coatings.

  13. IDENTIFIKASI PROFIL DASAR LAUT MENGGUNAKAN INSTRUMEN SIDE SCAN SONAR DENGAN METODE BEAM PATTERN DISCRETE-EQUI-SPACED UNSHADED LINE ARRAY

    Directory of Open Access Journals (Sweden)

    Muhammad Zainuddin Lubis

    2017-05-01

    Full Text Available Laut Punggur merupakan laut yang terletak di Batam, Kepulauan Riau yang mempunyai beragam habitat objek,dan bentuk struktur bawah laut yang memiliki dinamika laut yang sangat tinggi. Side scan sonar (SSS merupakan instrumen pengembangan sistem sonar yang mampu menunjukkan dalam gambar dua dimensional permukaan dasar laut dengan kondisi kontur, topografi, dan target secara bersamaan. Metode Beam Pattern Discrete-Equi-Spaced Unshaded Line Array digunakan untuk menghitung beam pattern dua dimensi yang tergantung pada sudut dari gelombang suara yang masuk dari sumbu array yang diterima tergantung pada sudut di mana sinar suara pada array. Penelitian ini dilakukan pada Desember 2016 di laut Punggur,Batam, Kepulauan Riau-Indonesia, dengan koordinat 104 ° 08,7102 E dan 1° 03,2448 N sampai 1 ° 03.3977 N dan 104 ° 08,8133 E, menggunakan instrumen Side Scan Sonar C-Max CM2 Tow fish dengan frekuensi 325 kHz. Hasil yang diperoleh dari perekaman terdapat 7 target, dan Beam pattern dari metode Beam Discrete-Equi-Spaced Unshaded Line Array target 4 memiliki nilai tertinggi pada directivity Pattern yaitu 21.08 dB. Hasil model beam pattern ini memiliki nilai pusat pada incidence angle (o terhadap Directivity pattern (dB tidak berada di nilai 0 ataupun pada pusat beam pattern yang dihasilkan pada target 6 dengan nilai incident angle -1.5 o dan 1.5o mengalami penurunan hingga -40 dB. Karakteristik sedimen dasar perairan di laut punggur ditemukan lebih banyak pasir. Hasil metode Beam Discrete-Equi-Spaced Unshaded Line Array ditemukan bangkai kapal tenggelam.Kata Kunci: Side Scan Sonar, Beam Pattern Discrete-Equi-Spaced Unshaded Line Array, Incidence angle, Directivity pattern IDENTIFICATION OF SEABED PROFILE USING SIDE SCAN SONAR INSTRUMENT WITH PATTERN DISCRETE-EQUI-SPACED UNSHADED LINE ARRAY METHODRiau Islands is an island that has a variety of habitat objects, and forms of submarine structures that have a very high ocean dynamics, Punggur Sea is the sea

  14. Profiling the progression of cancer: separation of microsomal proteins in MCF10 breast epithelial cell lines using nonporous chromatophoresis.

    Science.gov (United States)

    O'Neil, Kimberly A; Miller, Fred R; Barder, Timothy J; Lubman, David M

    2003-07-01

    The heterogeneity of cellular protein expression has stimulated development of separations targeting smaller groups of related proteins rather than entire proteomes. The following work describes the development of a technique for the characterization of membrane subproteomes from five different breast epithelial cell lines. Intact membrane proteins are separated by hydrophobicity in the first dimension using nonporous reversed-phase high-performance liquid chromatography (RP-HPLC) to generate unique chromatographic profiles. Fractions of eluent are further separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to create distinct banding patterns. This hybrid liquid phase/gel phase method circumvents issues of membrane protein precipitation and provides a simple strategy aimed at isolating and characterizing a traditionally underrepresented protein class. Membrane protein profiles are created that discriminate between microsomal fractions of breast epithelial cells in different stages of neoplastic progression. Proteins are subsequently identified using matrix-assisted laser desorption/ionization - mass spectrometry (MALDI-MS) mass fingerprinting and MALDI-quadrupole time of flight - tandem mass spectrometry (QTOF-MS/MS) peptide sequencing. Furthermore, as this strategy preserves intact protein structure, further characterization can be performed on proteins producing mass fingerprint spectra and fragmentation spectra that did not result in database protein identifications. The coupling of nonporous RP-HPLC with SDS-PAGE provides a useful alternative to two-dimensional PAGE (2-D-PAGE) for membrane protein analysis.

  15. Profile of Exosomal and Intracellular microRNA in Gamma-Herpesvirus-Infected Lymphoma Cell Lines

    Science.gov (United States)

    Hoshina, Shiho; Sekizuka, Tsuyoshi; Kataoka, Michiyo; Hasegawa, Hideki; Hamada, Hiromichi; Kuroda, Makoto; Katano, Harutaka

    2016-01-01

    Exosomes are small vesicles released from cells, into which microRNAs (miRNA) are specifically sorted and accumulated. Two gamma-herpesviruses, Kaposi sarcoma-associated herpesvirus (KSHV) and Epstein—Barr virus (EBV), encode miRNAs in their genomes and express virus-encoded miRNAs in cells and exosomes. However, there is little information about the detailed distribution of virus-encoded miRNAs in cells and exosomes. In this study, we thus identified virus- and host-encoded miRNAs in exosomes released from KSHV- or EBV-infected lymphoma cell lines and compared them with intracellular miRNAs using a next-generation sequencer. Sequencing analysis demonstrated that 48% of the annotated miRNAs in the exosomes from KSHV-infected cells originated from KSHV. Human mir-10b-5p and mir-143-3p were much more highly concentrated in exosomes than in cells. Exosomes contained more nonexact mature miRNAs that did not exactly match those in miRBase than cells. Among the KSHV-encoded miRNAs, miRK12-3-5p was the most abundant exact mature miRNA in both cells and exosomes that exactly matched those in miRBase. Recently identified EXOmotifs, nucleotide motifs that control the loading of miRNAs into exosomes were frequently found within the sequences of KSHV-encoded miRNAs, and the presence of the EXOmotif CCCT or CCCG was associated with the localization of miRNA in exosomes in KSHV-infected cells. These observations suggest that specific virus-encoded miRNAs are sorted by EXOmotifs and accumulate in exosomes in virus-infected cells. PMID:27611973

  16. High-definition DNA methylation profiles from breast and ovarian carcinoma cell lines with differing doxorubicin resistance.

    Directory of Open Access Journals (Sweden)

    Michael Boettcher

    Full Text Available Acquired drug resistance represents a frequent obstacle which hampers efficient chemotherapy of cancers. The contribution of aberrant DNA methylation to the development of drug resistant tumor cells has gained increasing attention over the past decades. Hence, the objective of the presented study was to characterize DNA methylation changes which arise from treatment of tumor cells with the chemotherapeutic drug doxorubicin. DNA methylation levels from CpG islands (CGIs linked to twenty-eight genes, whose expression levels had previously been shown to contribute to resistance against DNA double strand break inducing drugs or tumor progression in different cancer types were analyzed. High-definition DNA methylation profiles which consisted of methylation levels from 800 CpG sites mapping to CGIs around the transcription start sites of the selected genes were determined. In order to investigate the influence of CGI methylation on the expression of associated genes, their mRNA levels were investigated via qRT-PCR. It was shown that the employed method is suitable for providing highly accurate methylation profiles, comparable to those obtained via clone sequencing, the gold standard for high-definition DNA methylation studies. In breast carcinoma cells with acquired resistance against the double strand break inducing drug doxorubicin, changes in methylation of specific cytosines from CGIs linked to thirteen genes were detected. Moreover, similarities between methylation profiles obtained from breast and ovarian carcinoma cell lines with acquired doxorubicin resistance were found. The expression levels of a subset of analyzed genes were shown to be linked to the methylation levels of the analyzed CGIs. Our results provide detailed DNA methylation information from two separate model systems for acquired doxorubicin resistance and suggest the occurrence of similar methylation changes in both systems upon exposure to the drug.

  17. The lack of intense Lyman~alpha in ultradeep spectra of z=7 candidates in GOODS-S: imprint of reionization?

    CERN Document Server

    Fontana, A; Pentericci, L; Castellano, M; Giavalisco, M; Grazian, A; Boutsia, K; Cristiani, S; Dickinson, M; Giallongo, E; Maiolino, M; Moorwood, A; Santini, P

    2010-01-01

    We present ultradeep optical spectroscopy obtained with FORS2 on VLT of seven Lyman-break galaxy (LBG) candidates at z>6.5 selected in the GOODS-S field from Hawk-I/VLT and WFC3/HST imaging. For one galaxy we detect a low significance emission line (S/N10 is ~ 2%, and that of observing only one galaxy out of seven with S/N=5 is ~4%, but these can be as small as ~1E-3, depending on the details of the EW distribution. We conclude that either a significant fraction of the candidates is not at high redshift or that some physical mechanism quenches the Lyman alpha emission emerging from the galaxies at z>6.5, abruptly reversing the trend of the increasing fraction of strong emitters with increasing redshift observed up to z~ 6.5. We discuss the possibility that an increasingly neutral intergalactic medium is responsible for such quenching.

  18. Searching double-peaked emission line profiles in the spectra of galaxies through the symmetry of the cross-correlation function

    CERN Document Server

    Garcia-Lorenzo, B

    2012-01-01

    The presence of double-peaked/multicomponent emission line profiles in spectra of galaxies is commonly done by visual inspection. However, the identification of complex emission line profiles by eye is unapproachable for large databases such as the Sloan Digital Sky Survey (SDSS) or the integral field spectroscopy surveys of galaxies (e.g. CALIFA or MaNGA). We describe a quick method involving the cross-correlation technique for detecting the presence of complex (double-peaked or multiple components) profiles in the spectra of galaxies, deriving simultaneously a first estimation of the velocity dispersions and radial velocities of the dominant gaseous component. We illustrate the proposed procedure with the well-known complex [OIII]4959,5007 profiles of the central region of NGC1068.

  19. The effect of dust geometry on the Lyman-alpha output of galaxies

    CERN Document Server

    Scarlata, C; Teplitz, H I; Panagia, N; Hayes, M; Siana, B; Rau, A; Francis, P; Caon, A; Pizzella, A; Bridge, C

    2009-01-01

    We present the optical spectroscopic follow-up of 31 z=0.3 Lyman-alpha (Lya) emitters, previously identified by Deharveng et al. (2008). We find that 17% of the Lya emitters have line ratios that require the hard ionizing continuum produced by an AGN. The uniform dust screen geometry traditionally used in studies similar to ours is not able to simultaneously reproduce the observed high Lya/Halpha and Halpha/Hbeta line ratios. We consider different possibilities for the geometry of the dust around the emitting sources. We find that also a uniform mixture of sources and dust does not reproduce the observed line ratios. Instead, these are well reproduced by a clumpy dust screen. This more realistic treatment of the geometry results in extinction corrected (Lya/Halpha)_C values consistent with Case B recombination theory, whereas a uniform dust screen model would imply values (Lya/Halpha)_C higher than 8.7. Our analysis shows that there is no need to invoke "ad-hoc" multi phase media in which the Lya photons only...

  20. HST/ACS Lyman alpha imaging of the nearby starburst ESO338-IG04

    CERN Document Server

    Hayes, M; Mas-Hesse, J M; Kunth, D; Leitherer, C; Petrosian, A

    2005-01-01

    ESO338-IG04 is a well known, local, luminous Blue Compact Galaxy. It has a complex morphology and contains a central young starburst with compact young star clusters. The galaxy was imaged using HST/ACS in the Lyman alpha line and continuum. Using the Starburst99 synthetic spectra and other imaging data from HST/WFPC2 we developed a technique that allows us to make the first photometrically valid continuum subtraction for the LYa line. Our results are in qualitative agreement with the models of LYa escape being regulated by kinematical properties of the interstellar medium. The line-only image shows LYa in both emission and absorption. Notably, emission is seen from central bright young clusters and is in spatial agreement with the features present in a longslit spectrum taken with HST/STIS. Diffuse LYa emission regions are seen surrounding the central starburst where photons escape after one or more resonant scatterings in HI. These regions dominate the total LYa output. Photometry reveals a total LYa flux o...

  1. Chemical abundances of damped Lyman alpha systems in the XQ-100 survey

    CERN Document Server

    Berg, T A M; Sanchez-Ramirez, R; Prochaska, J X; Lopez, S; D'Odorico, V; Becker, G; Christensen, L; Cupani, G; Denney, K; Worsek, G

    2016-01-01

    The XQ-100 survey has provided high signal-noise spectra of 100 redshift 3-4.5 quasars with the X-Shooter spectrograph. The metal abundances for 13 elements in the 41 damped Lyman alpha systems (DLAs) identified in the XQ-100 sample are presented, and an investigation into abundances of a variety of DLA classes is conducted. The XQ-100 DLA sample contains five DLAs within 5000 km/s of their host quasar (proximate DLAs; PDLAs) as well as three sightlines which contain two DLAs within 10,000 km/s of each other along the same line-of-sight (multiple DLAs; MDLAs). Combined with previous observations in the literature, we demonstrate that PDLAs with logN(HI)21.0. These abundance discrepancies are independent of their line-of-sight velocity separation from the host quasar, and the velocity width of the metal lines (v90). Contrary to previous studies, MDLAs show no difference in [alpha/Fe] relative to single DLAs matched in metallicity and redshift. In addition, we present follow-up UVES data of J0034+1639, a sightl...

  2. The Low Redshift Lyman $\\alpha$ Forest in Cold Dark Matter Cosmologies

    CERN Document Server

    Davé, R; Katz, N; Weinberg, D H; Davé, Romeel; Hernquist, Lars; Katz, Neal; Weinberg, David

    1999-01-01

    We study the physical origin of the low-redshift Lyman alpha forest in hydrodynamic simulations of four CDM cosmologies. Our main conclusions are insensitive to the cosmological model but depend on our assumption that the UV background declines at low redshift. We find that the expansion of the universe drives rapid evolution of dN/dz (the number of absorbers per unit z) at z > 1.7, but that at lower redshift the fading of the UV background counters the influence of expansion, leading to slow evolution. At every redshift, weaker lines come primarily from moderate fluctuations of the diffuse, unshocked IGM, and stronger lines originate in shocked or radiatively cooled gas of higher overdensity. However, the neutral hydrogen column density associated with structures of fixed overdensity drops as the universe expands, so an absorber at z = 0 is dynamically analogous to an absorber with neutral hydrogen column density 10 to 50 times higher at z = 2-3. We find no clear distinction between lines arising in "galaxy ...

  3. Direct Method Gas-phase Oxygen Abundances of Four Lyman Break Analogs

    Science.gov (United States)

    Brown, Jonathan S.; Croxall, Kevin V.; Pogge, Richard W.

    2014-09-01

    We measure the gas-phase oxygen abundances in four Lyman break analogs using auroral emission lines to derive direct abundances. The direct method oxygen abundances of these objects are generally consistent with the empirically derived strong-line method values, confirming that these objects are low oxygen abundance outliers from the mass-metallicity (MZ) relation defined by star forming Sloan Digital Sky Survey galaxies. We find slightly anomalous excitation conditions (Wolf-Rayet features) that could potentially bias the empirical estimates toward high values if caution is not exercised in the selection of the strong-line calibration. The high rate of star formation and low oxygen abundance of these objects is consistent with the predictions of the fundamental metallicity relation, in which the infall of relatively unenriched gas simultaneously triggers an episode of star formation and dilutes the interstellar medium of the host galaxy. Based on data acquired using the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; the Ohio State University, and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia.

  4. The Lyman β forest as a cosmic thermometer

    Energy Technology Data Exchange (ETDEWEB)

    Iršič, Vid [The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34151 Trieste (Italy); Viel, Matteo, E-mail: virsic@ictp.it, E-mail: viel@oats.inaf.it [INAF - Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-34143 Trieste (Italy)

    2014-12-01

    We present a comprehensive analysis of high resolution hydrodynamic simulations in terms of Lyman α and Lyman β one dimensional flux power spectra P{sub αα} and P{sub ββ}). In particular, we focus on the behaviour that the flux auto-power spectra and cross-power spectra P{sub αβ}) display when the intergalactic medium (IGM) thermal history is changed in a range of values that bracket a reference model, while cosmological parameters are kept fixed to best fit the cosmic microwave background data. We present empirical fits that describe at the sub-percent level the dependence of the power spectra on the thermal parameters. At the largest scales, the power spectra show a constant bias between each other that is set by the parameters describing the IGM thermal state. The cross-power spectrum has an oscillatory pattern and crosses zero at a scale which depends on T{sub 0}, the IGM temperature at the mean density, for reasonable values of the power-law index γ of the IGM temperature-density relation T=T{sub 0}(1+δ){sup γ-1}). By performing a Fisher matrix analysis, we find that the power spectrum P{sub ββ} is more sensitive to the thermal history than P{sub αα} alone, due to the fact that it probes denser regions than Lyman α. When we combine the power and cross spectra the constraints on γ can be improved by a factor ∼ 4, while the constraints on T{sub 0} improve by a factor of ∼ 2. We address the role of signal-to-noise and resolution by mocking realistic observations and we conclude that the framework presented in this work can significantly improve the knowledge of the IGM thermal state, which will in turn guarantee better constraints on IGM-derived cosmological parameters.

  5. Emission lines from rotating proto-stellar jets with variable velocity profiles. I. Three-dimensional numerical simulation of the non-magnetic case

    CERN Document Server

    Cerqueira, A H; Raga, A C; Vasconcelos, M J; De Colle, F

    2005-01-01

    Using the Yguazu-a three-dimensional hydrodynamic code, we have computed a set of numerical simulations of heavy, supersonic, radiatively cooling jets including variabilities in both the ejection direction (precession) and the jet velocity (intermittence). In order to investigate the effects of jet rotation on the shape of the line profiles, we also introduce an initial toroidal rotation velocity profile, in agreement with some recent observational evidence found in jets from T Tauri stars which seems to support the presence of a rotation velocity pattern inside the jet beam, near the jet production region. Since the Yguazu-a code includes an atomic/ionic network, we are able to compute the emission coefficients for several emission lines, and we generate line profiles for the H, [O I]6300, [S II]6716 and [N II]6548 lines. Using initial parameters that are suitable for the DG Tau microjet, we show that the computed radial velocity shift for the medium-velocity component of the line profile as a function of di...

  6. Theoretical quasar emission-line ratios. VII - Energy-balance models for finite hydrogen slabs

    Science.gov (United States)

    Hubbard, E. N.; Puetter, R. C.

    1985-01-01

    The present energy balance calculations for finite, isobaric, hydrogen-slab quasar emission line clouds incorporate probabilistic radiative transfer (RT) in all lines and bound-free continua of a five-level continuum model hydrogen atom. Attention is given to the line ratios, line formation regions, level populations and model applicability results obtained. H lines and a variety of other considerations suggest the possibility of emission line cloud densities in excess of 10 to the 10th/cu cm. Lyman-beta/Lyman-alpha line ratios that are in agreement with observed values are obtained by the models. The observed Lyman/Balmer ratios can be achieved with clouds whose column depths are about 10 to the 22nd/sq cm.

  7. Evidence for Black Hole Growth in Local Analogs to Lyman Break Galaxies

    Science.gov (United States)

    Jia, Jianjun; Ptak, Andrew; Heckman, Timothy M.; Overzier, Roderik A.; Hornschemeier, Ann; LaMassa, Stephanie M.

    2011-01-01

    We have used XMM-Newton to observe six Lyman break analogs (LBAs): members of the rare population of local galaxies that have properties that are very similar to distant Lyman break galaxies. Our six targets were specifically selected because they have optical emission-line properties that are intermediate between starbursts and Type 2 (obscured) active galactic nuclei (AGNs). Our new X-ray data provide an important diagnostic of the presence of an AGN. We find X-ray luminosities of order 10(sup 42) erg per second and ratios of X-ray to far-IR lummositles that are higher than values in pure starburst galaxies by factors ranging from approximately 3 to 30. This strongly suggests the presence of an AGN in at least some of the galaxies. The ratios of the luminosities of the hard (2-10 keV) X-ray to [O III] emission line are low by about an order of magnitude compared with Type 1 AGN, but are consistent with the broad range seen in Type 2 AGN. Either the AGN hard X-rays are significantly obscured or the [O III] emission is dominated by the starburst. We searched for an iron emission line at approximately 6.4 ke V, which is a key feature of obscured AGNs, but only detected emission at the approximately 2sigma level. Finally, we find that the ratios of the mid-infrared (24 micrometer) continuum to [O III]lambda 5007 luminosities in these LBAs are higher than the values for Type 2 AGN by an average of 0.8 dex. Combining all these clues, we conclude that an AGN is likely to be present, but that the bolometric luminosity is produced primarily by an intense starburst. If these black holes are radiating at the Eddington limit, their masses would lie in the range of 10(sup 5) - 10(sup 6) solar mass. These objects may offer ideal local laboratories to investigate the processes by which black holes grew in the early universe.

  8. Jovian Equatorial H Lyman-alpha and the Ionosphere

    Science.gov (United States)

    Ballester, Gilda E.

    An excess of H Ly alpha emission has been a persistent feature in Jupiter's equatorial upper atmosphere since its discovery in 1978. This Ly alpha 'bulge' was found by high-resolution IUE observations to be due to broadening of the Jovian line increasing the resonant scattering of the solar Ly alpha, rather than from a local enhancement in the H density. The line broadening implies that the H column at the bulge is disturbed by a localized, non-thermal process, and two mechanisms have been proposed to explain this: one by the generation of turbulence from strong thermospheric winds or jets meeting at the bulge region and originating in the active Jovian auroral zones, the other involving a superthermal population of H atoms produced by a process analogous to the equatorial anomaly and tropical arcs on the Earth. Some line broadening was also observed in the off-bulge region while modelling of the usual bulge profile does not predict this behavior, but these observations may have been performed at a time of an unusually large extension of the bulge. We propose to make a series of high-dispersion observations (of improved S/N) for a detailed longitudinal study of the line profile which would be of benefit independently of the particular bulge conditions (to be determined with low-dispersion exposures). In addition, new insight will be gained with simultaneous ground-based observations of the newly discovered global ionospheric H3+ emissions. These emissions are diagnostic of the ionospheric temperature and ion density, and have already shown very particular characteristics in the H Ly alpha bulge region. Coordinated observations of the whole longitudinal range should therefore set new constraints on the mechanisms operating in the Jovian equatorial upper atmosphere.

  9. Lyman-alpha Forests cool Warm Dark Matter

    CERN Document Server

    Baur, Julien; Yèche, Christophe; Magneville, Christophe; Viel, Matteo

    2015-01-01

    The free-streaming of keV-scale particles impacts structure growth on scales that are probed by the Lyman-alpha forest of distant quasars. Using an unprecedentedly large sample of medium-resolution QSO spectra from the ninth data release of SDSS, along with a state-of-the-art set of hydrodynamical simulations to model the Lyman-alpha forest in the non-linear regime, we issue the tightest bounds to date on pure dark matter particles: $m_X \\gtrsim 4.35 \\: \\rm{keV}$ (95% CL) for early decoupled thermal relics such as a hypothetical gravitino, and its corresponding bound for a non-resonantly produced right-handed neutrino $m_s \\gtrsim 31.7 \\: \\rm{keV}$ (95% CL). Thanks to SDSS-III data featuring smaller uncertainties and covering a larger redshift range than SDSS-I data, our bounds improve upon those established by previous works and are further at odds with a purely non-resonantly produced sterile neutrino as dark matter.

  10. The Lyman-beta forest as a cosmic thermometer

    CERN Document Server

    Iršič, Vid

    2014-01-01

    We present a comprehensive analysis of high resolution hydrodynamic simulations in terms of Lyman-alpha and Lyman-beta one dimensional flux power spectra ($P_{\\alpha\\alpha}$ and $P_{\\beta\\beta}$). In particular, we focus on the behaviour that the flux auto-power spectra and cross-power spectra ($P_{\\alpha\\beta}$) display when the intergalactic medium (IGM) thermal history is changed in a range of values that bracket a reference model, while cosmological parameters are kept fixed to best fit the cosmic microwave background data. We present empirical fits that describe at the sub-percent level the dependence of the power spectra on the thermal parameters. At the largest scales, the power spectra show a constant bias between each other that is set by the parameters describing the IGM thermal state. The cross-power spectrum has an oscillatory pattern and crosses zero at a scale which depends on $T_0$, the IGM temperature at the mean density, for reasonable values of the power-law index $\\gamma$ of the IGM tempera...

  11. Lyman-alpha Forest Constraints on Decaying Dark Matter

    CERN Document Server

    Wang, Mei-Yu; Peter, Annika H G; Zentner, Andrew R; Purcell, Chris W

    2013-01-01

    We present an analysis of high-resolution N-body simulations of decaying dark matter cosmologies focusing on the statistical properties of the transmitted Lyman-alpha forest flux in the high-redshift intergalactic medium. In this type of model a dark matter particle decays into a slightly less massive stable dark matter daughter particle and a comparably light particle. The small mass splitting provides a non-relativistic kick velocity V_k to the daughter particle resulting in free-streaming and subsequent damping of small-scale density fluctuations. Current Lyman-alpha forest power spectrum measurements probe comoving scales up to ~ 2-3 h^-1 Mpc at redshifts z ~ 2-4, providing one of the most robust ways to probe cosmological density fluctuations on relatively small scales. The suppression of structure growth due to the free-streaming of dark matter daughter particles also has a significant impact on the neutral hydrogen cloud distribution, which traces the underlying dark matter distribution well at high re...

  12. Semi-empirical AGN detection threshold in spectral synthesis studies of Lyman-continuum-leaking early-type galaxies

    CERN Document Server

    Cardoso, Leandro S M; Papaderos, Polychronis

    2016-01-01

    Various lines of evidence suggest that the cores of a large portion of early-type galaxies (ETGs) are virtually evacuated of warm ionised gas. This implies that the Lyman-continuum (LyC) radiation produced by an assumed active galactic nucleus (AGN) can escape from the nuclei of these systems without being locally reprocessed into nebular emission, which would prevent their reliable spectroscopic classification as Seyfert galaxies with standard diagnostic emission-line ratios. The spectral energy distribution (SED) of these ETGs would then lack nebular emission and be essentially composed of an old stellar component and the featureless power-law (PL) continuum from the AGN. A question that arises in this context is whether the AGN component can be detected with current spectral population synthesis in the optical, specifically, whether these techniques effectively place an AGN detection threshold in LyC-leaking galaxies. To quantitatively address this question, we took a combined approach that involves spectr...

  13. Altered expression profiles of microRNAs in a stable hepatitis B virus-expressing cell line

    Institute of Scientific and Technical Information of China (English)

    LIU Yan; ZHAO Jian-Jun; WANG Chun-mei; LI Mian-yang; HAN Ping; WANG Lin; CHENG Yong-qian; Fabien Zoulim; MA Xu; XU Dong-ping

    2009-01-01

    Background MicroRNAs (miRNAs) are highly conserved small non-coding RNAs of 18-25 nucleotides (nt) that mediate post-transcriptional gene regulation. Hepatitis B virus (HBV) can cause either acute or chronic hepatitis B, and is a high risk factor for liver cirrhosis and hepatocellular carcinoma. Some mammalian viruses have been shown to modulate the expression of host cellular miRNAs. However, interactions between the HBV and the host cellular miRNAs are largely unknown. Methods miRNA microarray and Northern blotting analysis were used to compare the expression profile of cellular miRNAs of a stable HBV-expressing cell line HepG2.2.15 and its parent cell line HepG2. mRNA microarray assay and the miRanda program were used to predict the miRNA targets. A flow cytometric assay was further used to investigate the expression of human leukocyte antigen (HLA)-A. Results Eighteen miRNAs were differentially expressed between the two cell lines. Among them, eleven were up-regulated and seven were down-regulated in HepG2.2.15 cells. Northern blotting analysis confirmed that the expression of miR-181a, miR-181b, miR-200b and miR-146a were up-regulated and the expression of miR-15a was down-regulated, which was in consistent with the results of the microarray analysis. Furthermore, some putative miRNA targets were predicted and verified to be linked with mRNA expression. The 3'-UTR of HLA-A gene had one partially complementary site for miR-181a and miR-181a might down-regulate the expression of HLA-A. Conclusion HBV replication modulates the expression of host cellular miRNAs, which may play a role in the pathogenesis of HBV-related liver diseases.

  14. Transcriptome Profiling of Caco-2 Cancer Cell Line following Treatment with Extracts from Iodine-Biofortified Lettuce (Lactuca sativa L..

    Directory of Open Access Journals (Sweden)

    Aneta A Koronowicz

    Full Text Available Although iodization of salt is the most common method used to obtain iodine-enriched food, iodine deficiency disorders are still a global health problem and profoundly affect the quality of human life. Iodine is required for the synthesis of thyroid hormones, which are crucial regulators of human metabolism, cell growth, proliferation, apoptosis and have been reported to be involved in carcinogenesis. In this study, for the first time, we evaluated the effect of iodine-biofortified lettuce on transcriptomic profile of Caco-2 cancer cell line by applying the Whole Human Genome Microarray assay. We showed 1326 differentially expressed Caco-2 transcripts after treatment with iodine-biofortified (BFL and non-fortified (NFL lettuce extracts. We analysed pathways, molecular functions, biological processes and protein classes based on comparison between BFL and NFL specific genes. Iodine, which was expected to act as a free ion (KI-NFL or at least in part to be incorporated into lettuce macromolecules (BFL, differently regulated pathways of numerous transcription factors leading to different cellular effects. In this study we showed the inhibition of Caco-2 cells proliferation after treatment with BFL, but not potassium iodide (KI, and BFL-mediated induction of mitochondrial apoptosis and/or cell differentiation. Our results showed that iodine-biofortified plants can be effectively used by cells as an alternative source of this trace element. Moreover, the observed differences in action of both iodine sources may suggest a potential of BFL in cancer treatment.

  15. Transcriptome Profiling of Caco-2 Cancer Cell Line following Treatment with Extracts from Iodine-Biofortified Lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Koronowicz, Aneta A; Kopeć, Aneta; Master, Adam; Smoleń, Sylwester; Piątkowska, Ewa; Bieżanowska-Kopeć, Renata; Ledwożyw-Smoleń, Iwona; Skoczylas, Łukasz; Rakoczy, Roksana; Leszczyńska, Teresa; Kapusta-Duch, Joanna; Pysz, Mirosław

    2016-01-01

    Although iodization of salt is the most common method used to obtain iodine-enriched food, iodine deficiency disorders are still a global health problem and profoundly affect the quality of human life. Iodine is required for the synthesis of thyroid hormones, which are crucial regulators of human metabolism, cell growth, proliferation, apoptosis and have been reported to be involved in carcinogenesis. In this study, for the first time, we evaluated the effect of iodine-biofortified lettuce on transcriptomic profile of Caco-2 cancer cell line by applying the Whole Human Genome Microarray assay. We showed 1326 differentially expressed Caco-2 transcripts after treatment with iodine-biofortified (BFL) and non-fortified (NFL) lettuce extracts. We analysed pathways, molecular functions, biological processes and protein classes based on comparison between BFL and NFL specific genes. Iodine, which was expected to act as a free ion (KI-NFL) or at least in part to be incorporated into lettuce macromolecules (BFL), differently regulated pathways of numerous transcription factors leading to different cellular effects. In this study we showed the inhibition of Caco-2 cells proliferation after treatment with BFL, but not potassium iodide (KI), and BFL-mediated induction of mitochondrial apoptosis and/or cell differentiation. Our results showed that iodine-biofortified plants can be effectively used by cells as an alternative source of this trace element. Moreover, the observed differences in action of both iodine sources may suggest a potential of BFL in cancer treatment.

  16. Monitoring gradient profile on-line in micro- and nano-high performance liquid chromatography using conductivity detection.

    Science.gov (United States)

    Zhang, Min; Chen, Apeng; Lu, Joann J; Cao, Chengxi; Liu, Shaorong

    2016-08-19

    In micro- or nano-flow high performance liquid chromatography (HPLC), flow-splitters and gradient elutions are commonly used for reverse phase HPLC separations. When a flow splitter was used at a high split-ratio (e.g., 1000:1 or higher), the actual gradient may deviate away from the programmed gradient. Sometimes, mobile phase concentrations can deviate by as much as 5%. In this work, we noticed that the conductivity (σ) of a gradient decreased with the increasing organic-solvent fraction (φ). Based on the relationship between σ and φ, a method was developed for monitoring gradient profile on-line to record any deviations in these HPLC systems. The conductivity could be measured by a traditional conductivity detector or a capacitively coupled contactless conductivity detector (C(4)D). The method was applied for assessing the performance of an electroosmotic pump (EOP) based nano-HPLC. We also observed that σ value of the gradient changed with system pressure; a=0.0175ΔP (R(2)=0.964), where a is the percentage of the conductivity increase and ΔP is the system pressure in bar. This effect was also investigated.

  17. X-ray diffraction line profile analysis for defect study in Zr–2.5% Nb material

    Indian Academy of Sciences (India)

    K Kapoor; D Lahiri; S V R Rao; T Sanyal; B P Kashyap

    2004-02-01

    The microstructure characterization by X-ray line profile analysis is possible for determination of dislocation density, micro-strain within grains due to dislocation and average coherent domain size (subgrain) within the grain. This study presents the X-ray diffraction peaks shape analysis and their broadening with different thermal treatments in Zr–2.5% Nb pressure tube material. The peak shape is analysed using Fourier transformation and information about coherent domain size, micro-strain and dislocation density could be obtained from the Fourier coefficients of the peak. Analysis of broadening of the peaks by integral breadth method also gives the coherent domain size, dislocation density and micro-strain present in the material. The results from the X-ray techniques are comparable to those obtained from direct observation of transmission electron microscopy. The measured yield strength increases with dislocation density. An empirical relationship is obtained for the yield strength from the dislocation density of the material. The measured strength is in agreement with the one calculated from dislocation density.

  18. Protein profiles reveal diverse responsive signaling pathways in kernels of two maize inbred lines with contrasting drought sensitivity.

    Science.gov (United States)

    Yang, Liming; Jiang, Tingbo; Fountain, Jake C; Scully, Brian T; Lee, Robert D; Kemerait, Robert C; Chen, Sixue; Guo, Baozhu

    2014-01-01

    Drought stress is a major factor that contributes to disease susceptibility and yield loss in agricultural crops. To identify drought responsive proteins and explore metabolic pathways involved in maize tolerance to drought stress, two maize lines (B73 and Lo964) with contrasting drought sensitivity were examined. The treatments of drought and well water were applied at 14 days after pollination (DAP), and protein profiles were investigated in developing kernels (35 DAP) using iTRAQ (isobaric tags for relative and absolute quantitation). Proteomic analysis showed that 70 and 36 proteins were significantly altered in their expression under drought treatments in B73 and Lo964, respectively. The numbers and levels of differentially expressed proteins were generally higher in the sensitive genotype, B73, implying an increased sensitivity to drought given the function of the observed differentially expressed proteins, such as redox homeostasis, cell rescue/defense, hormone regulation and protein biosynthesis and degradation. Lo964 possessed a more stable status with fewer differentially expressed proteins. However, B73 seems to rapidly initiate signaling pathways in response to drought through adjusting diverse defense pathways. These changes in protein expression allow for the production of a drought stress-responsive network in maize kernels.

  19. Protein Profiles Reveal Diverse Responsive Signaling Pathways in Kernels of Two Maize Inbred Lines with Contrasting Drought Sensitivity

    Directory of Open Access Journals (Sweden)

    Liming Yang

    2014-10-01

    Full Text Available Drought stress is a major factor that contributes to disease susceptibility and yield loss in agricultural crops. To identify drought responsive proteins and explore metabolic pathways involved in maize tolerance to drought stress, two maize lines (B73 and Lo964 with contrasting drought sensitivity were examined. The treatments of drought and well water were applied at 14 days after pollination (DAP, and protein profiles were investigated in developing kernels (35 DAP using iTRAQ (isobaric tags for relative and absolute quantitation. Proteomic analysis showed that 70 and 36 proteins were significantly altered in their expression under drought treatments in B73 and Lo964, respectively. The numbers and levels of differentially expressed proteins were generally higher in the sensitive genotype, B73, implying an increased sensitivity to drought given the function of the observed differentially expressed proteins, such as redox homeostasis, cell rescue/defense, hormone regulation and protein biosynthesis and degradation. Lo964 possessed a more stable status with fewer differentially expressed proteins. However, B73 seems to rapidly initiate signaling pathways in response to drought through adjusting diverse defense pathways. These changes in protein expression allow for the production of a drought stress-responsive network in maize kernels.

  20. Quality properties and expression profiling of protein disulfide isomerase genes during grain development of three spring wheat near isogenic lines

    Directory of Open Access Journals (Sweden)

    Dong Liwei

    2016-01-01

    Full Text Available Three wheat glutenin near isogenic lines (NILs CB037A, CB037B and CB037C were used to investigate their quality properties and the transcriptional expression profiles of PDI gene family during grain development. Our purpose is to understand the relationships between the dynamic expression of different PDI genes and glutenin allelic compositions related to gluten quality. The results showed that glutenin allelic variations had no significant effects on main agronomic traits and yield performance, but resulted in clear gluten quality changes. CB037B with 5+10 subunits had higher glutenin macropolymer (GMP content and better breadmaking quality than CB037A with 2+12 while the lack of Glu-B3h encoding one abundant B-subunit in CB037C significantly reduced GMP content, dough strength and breadmaking quality. The dynamic expression patterns of eight protein disulfide isomerase (PDI genes during grain development detected by quantitative real-time polymerase chain reaction (qRT-PCR showed the close correlations between higher expression levels of PDI3-1, PDI5-1 and PDI8-1 and the presence of 5+10 subunits. Meanwhile, Glu-B3h silence resulted in significant decrease of expression levels of five PDI genes (PDI3-1, PDI5-1, PDI6-1, PDI7-2 and PDI8-1, suggesting the vital roles of certain PDI genes in glutenin and GMP synthesis and gluten quality formation.

  1. MODELING THE Fe K LINE PROFILES IN TYPE I ACTIVE GALACTIC NUCLEI WITH A COMPTON-THICK DISK WIND

    Energy Technology Data Exchange (ETDEWEB)

    Tatum, M. M.; Turner, T. J. [Department of Physics, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Sim, S. A. [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Miller, L. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Reeves, J. N.; Patrick, A. R. [Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Long, K. S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2012-06-20

    We have modeled a small sample of Seyfert galaxies that were previously identified as having simple X-ray spectra with little intrinsic absorption. The sources in this sample all contain moderately broad components of Fe K-shell emission and are ideal candidates for testing the applicability of a Compton-thick accretion disk wind model to active galactic nucleus (AGN) emission components. Viewing angles through the wind allow the observer to see the absorption signature of the gas, whereas face-on viewing angles allow the observer to see the scattered light from the wind. We find that the Fe K emission line profiles are well described with a model of a Compton-thick accretion disk wind of solar abundances, arising tens to hundreds of gravitational radii from the central black hole. Further, the fits require a neutral component of Fe K{alpha} emission that is too narrow to arise from the inner part of the wind, and likely comes from a more distant reprocessing region. Our study demonstrates that a Compton-thick wind can have a profound effect on the observed X-ray spectrum of an AGN, even when the system is not viewed through the flow.

  2. Application of a Continued-Fraction-Based Theory to Line-Profile in Mn-Doped GaN Film

    Science.gov (United States)

    Park, Jung-Il; Lee, Hyeong-Rag; Lee, Su-Ho

    2012-05-01

    Starting with the Kubo formalism and using the projection operator technique (POT) introduced by Kawabata, the optical quantum transition line-profiles (QTLPs) formula for a Mn-doped wurtzite GaN film was derived as a function of temperature at a frequency of 9.49 GHz (X-band), on the basis of continued fraction representation (CFR) which is a counterpart of the conventional series expansion (CSE). Utilizing this formula we obtained the fine-structure parameter a - F = 9.4 ×10-4 cm-1 and fitting parameter ζ= 4.1. The optical quantum transition half-widths (QTHWs) obtained with the use of these parameters agrees quite well with the existing experimental result in the temperature region T > 20 K. The QTHWs increase with increasing temperature due to the interaction of electrons with optical phonons. Thus, the present technique is considered to be more convenient to explain the resonant system as in the case of other optical transition problems.

  3. Ionized Gas in Damped Lyman Alpha Protogalaxies II. Comparison Between Models and the Kinematic Data

    CERN Document Server

    Wolfe, A M; Wolfe, Arthur M.

    2000-01-01

    We test semi-analytic models for galaxy formation with accurate kinematic data of damped Lyman alpha protogalaxies (DLAs) presented in the companion paper I. The models envisage centrifugally supported exponential disks at the centers of dark matter halos which are filled with ionized gas undergoing radial infall to the disks. The halo masses are drawn from cross-section weighted mass distributions predicted by CDM cosmogonies, or by the null hypothesis (TF model) that the dark matter mass distribution has not evolved since z ~ 3. In our models, C IV absorption lines detected in DLAs arise in infalling ionized clouds while the low-ion absorption lines arise from neutral gas in the disks. Using Monte Carlo methods we find: (a) The CDM models are incompatible with the low-ion statistics at more than 99% confidence whereas some TF models cannot be excluded at more than 88% confidence. (b) Both CDM and TF models agree with the observed distribution of C IV velocity widths. (c) The CDM models generate differences ...

  4. HeII emission in Lyman-alpha nebulae: AGN or cooling radiation?

    CERN Document Server

    Scarlata, C; Teplitz, H I; Bridge, C; Francis, P; Palunas, P; Siana, B; Williger, G M; Woodgate, B

    2009-01-01

    We present a study of an extended Lyman-alpha (Lya) nebula located in a known overdensity at z~2.38. The data include multiwavelength photometry covering the rest-frame spectral range from 0.1 to 250um, and deep optical spectra of the sources associated with the extended emission. Two galaxies are associated with the Lya nebula. One of them is a dust enshrouded AGN, while the other is a powerful starburst, forming stars at >~600 Msol/yr. We detect the HeII emission line at 1640A in the spectrum of the obscured AGN, but detect no emission from other highly ionized metals (CIV or NV) as is expected from an AGN. One scenario that simultaneously reproduces the width of the detected emission lines, the lack of CIV emission, and the geometry of the emitting gas, is that the HeII and the Lya emission are the result of cooling gas that is being accreted on the dark matter halo of the two galaxies, Ly1 and Ly2. Given the complexity of the environment associated with our Lya nebula it is possible that various mechanism...

  5. Quasar-Lyman $\\alpha$ Forest Cross-Correlation from BOSS DR11 : Baryon Acoustic Oscillations

    CERN Document Server

    Font-Ribera, Andreu; Busca, Nicolas; Miralda-Escudé, Jordi; Ross, Nicholas P; Slosar, Anže; Aubourg, Éric; Bailey, Stephen; Bhardwaj, Vaishali; Bautista, Julian; Beutler, Florian; Bizyaev, Dmitry; Blomqvist, Michael; Brewington, Howard; Brinkmann, Jon; Brownstein, Joel R; Carithers, Bill; Dawson, Kyle S; Delubac, Timothée; Ebelke, Garrett; Eisenstein, Daniel J; Ge, Jian; Kinemuchi, Karen; Lee, Khee-Gan; Malanushenko, Viktor; Malanushenko, Elena; Marchante, Moses; Margala, Daniel; Muna, Demitri; Myers, Adam D; Noterdaeme, Pasquier; Oravetz, Daniel; Palanque-Delabrouille, Nathalie; Pâris, Isabelle; Petitjean, Patrick; Pieri, Matthew M; Rossi, Graziano; Schneider, Donald P; Simmons, Audrey; Viel, Matteo; Yeche, Christophe; York, Donald G

    2013-01-01

    We measure the large-scale cross-correlation of quasars with the Lyman alpha forest absorption, using over 164,000 quasars from Data Release 11 of the SDSS-III Baryon Oscillation Spectroscopic Survey. We extend the previous study of roughly 60,000 quasars from Data Release 9 to larger separations, allowing a measurement of the Baryonic Acoustic Oscillation (BAO) scale along the line of sight $c/(H(z=2.36) ~ r_s) = 9.0 \\pm 0.3$ and across the line of sight $D_A(z=2.36)~ / ~ r_s = 10.8 \\pm 0.4$, consistent with CMB and other BAO data. Using the best fit value of the sound horizon from Planck data ($r_s=147.49 Mpc$), we can translate these results to a measurement of the Hubble parameter of $H(z=2.36) = 226 \\pm 8 km/s$ and of the angular diameter distance of $D_A(z=2.36) = 1590 \\pm 60 Mpc$. The measured cross-correlation function and an update of the code to fit the BAO scale (baofit) are made publicly available.

  6. Nonparametric 3D map of the IGM using the Lyman-alpha forest

    CERN Document Server

    Cisewski, Jessi; Freeman, Peter E; Genovese, Christopher R; Khandai, Nishikanta; Ozbek, Melih; Wasserman, Larry

    2014-01-01

    Visualizing the high-redshift Universe is difficult due to the dearth of available data; however, the Lyman-alpha forest provides a means to map the intergalactic medium at redshifts not accessible to large galaxy surveys. Large-scale structure surveys, such as the Baryon Oscillation Spectroscopic Survey (BOSS), have collected quasar (QSO) spectra that enable the reconstruction of HI density fluctuations. The data fall on a collection of lines defined by the lines-of-sight (LOS) of the QSO, and a major issue with producing a 3D reconstruction is determining how to model the regions between the LOS. We present a method that produces a 3D map of this relatively uncharted portion of the Universe by employing local polynomial smoothing, a nonparametric methodology. The performance of the method is analyzed on simulated data that mimics the varying number of LOS expected in real data, and then is applied to a sample region selected from BOSS. Evaluation of the reconstruction is assessed by considering various feat...

  7. An 80-kpc Lyman-alpha halo around a high redshift type-2 QSO

    CERN Document Server

    Smith, Daniel J B; Simpson, Chris; Martinez-Sansigre, Alejo

    2008-01-01

    We announce the discovery of an extended emission line region associated with a high redshift type-2 QSO. The halo, which was discovered in our new wide-field narrow-band survey, resides at z = 2.85 in the Spitzer First Look Survey region and is extended over ~80 kpc. Deep VLBI observations imply that approximately 50 per cent of the radio emission is extended on scales > 200pc. The inferred AGN luminosity is sufficient to ionize the extended halo, and the optical emission is consistent with being triggered coevally with the radio source. The Lyman-alpha halo is as luminous as those found around high redshift radio galaxies, however the active nucleus is several orders of magnitude less luminous at radio wavelengths than those FRIIs more commonly associated with extended emission line regions. AMS05 appears to be a high-redshift analogue to the radio-quiet quasar E1821+643 which is core dominated but which also exhibits extended FRI-like structure and contains an optically powerful AGN. We also find evidence ...

  8. The Luminosity Function of Lyman alpha Emitters at Redshift z=7.7

    CERN Document Server

    Tilvi, Vithal; Hibon, Pascale; Malhotra, Sangeeta; Wang, Junxian; Veilleux, Sylvain; Swaters, Rob; Probst, Ron; Krug, Hannah; Finkelstein, Steven L; Dickinson, Mark

    2010-01-01

    Lyman alpha (Lya) emission lines should be attenuated in a neutral intergalactic medium (IGM). Therefore the visibility of Lya emitters at high redshifts can serve as a valuable probe of reionization at about the 50% level. We present an imaging search for z=7.7 Lya emitting galaxies using an ultra-narrowband filter (filter width= 9A) on the NEWFIRM imager at the Kitt Peak National Observatory. We found four candidate Lya emitters in a survey volume of 1.4 x 10^4 Mpc^3, with a line flux brighter than 6x10^-18 erg/cm^2/s (5 sigma in 2" aperture). We also performed a detailed Monte-Carlo simulation incorporating the instrumental effects to estimate the expected number of Lya emitters in our survey, and found that we should expect to detect one Lya emitter, assuming a non-evolving Lya luminosity function (LF) between z=6.5 and z=7.7. Even if one of the present candidates is spectroscopically confirmed as a z~8 Lya emitter, it would indicate that there is no significant evolution of the Lya LF from z=3.1 to z~8. ...

  9. Nebular emission and the Lyman continuum photon escape fraction in CALIFA early-type galaxies

    CERN Document Server

    Papaderos, P; Vilchez, J M; Kehrig, C; Lehnert, M D; Ziegler, B; Sanchez, S F; Husemann, B; Monreal-Ibero, A; Garcia-Benito, R; Bland-Hawthorn, J; Coritjo, C; de Lorenzo-Caceres, A; del Olmo, A; Falcon-Barroso, J; Galbany, L; Iglesias-Paramo, J; Lopez-Sanchez, A R; Marquez, I; Molla, M; Mast, D; van de Ven, G; Wisotzki, L

    2013-01-01

    We use deep integral field spectroscopy data from the CALIFA survey to study the warm interstellar medium (WIM) of 32 nearby early-type galaxies (ETGs). We propose a tentative subdivision of our sample ETGs into two groups, according to their Ha equivalent width (EW) and Lyman continuum (LyC) photon escape fraction (PLF). Type i ETGs show nearly constant EWs and a PLF~0, suggesting that photoionization by post-AGB stars is the main driver of their faint extranuclear nebular emission. Type ii ETGs are characterized by very low, outwardly increasing EWs, and a PLF as large as ~0.9 in their centers. Such properties point to a low, and inwardly decreasing WIM density and/or volume filling factor. We argue that, because of extensive LyC photon leakage, emission-line luminosities and EWs are reduced in type ii ETG nuclei by at least one order of magnitude. Consequently, the line weakness of these ETGs is by itself no compelling evidence for their containing merely "weak" (sub-Eddington accreting) active galactic nu...

  10. Optical Alignment of the Chromospheric Lyman-Alpha SpectroPolarimeter using Sophisticated Methods to Minimize Activities under Vacuum

    Science.gov (United States)

    Giono, G.; Katsukawa, Y.; Ishikawa, R.; Narukage, N.; Kano, R.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.; Winebarger, A.; Kobayashi, K.

    2016-01-01

    The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a sounding-rocket instrument developed at the National Astronomical Observatory of Japan (NAOJ) as a part of an international collaboration. The in- strument main scientific goal is to achieve polarization measurement of the Lyman-alpha line at 121.56 nm emitted from the solar upper-chromosphere and transition region with an unprecedented 0.1% accuracy. For this purpose, the optics are composed of a Cassegrain telescope coated with a "cold mirror" coating optimized for UV reflection and a dual-channel spectrograph allowing for simultaneous observation of the two orthogonal states of polarization. Although the polarization sensitivity is the most important aspect of the instrument, the spatial and spectral resolutions of the instrument are also crucial to observe the chromospheric features and resolve the Ly- pro les. A precise alignment of the optics is required to ensure the resolutions, but experiments under vacuum conditions are needed since Ly-alpha is absorbed by air, making the alignment experiments difficult. To bypass this issue, we developed methods to align the telescope and the spectrograph separately in visible light. We will explain these methods and present the results for the optical alignment of the CLASP telescope and spectrograph. We will then discuss the combined performances of both parts to derive the expected resolutions of the instrument, and compare them with the flight observations performed on September 3rd 2015.

  11. Properties of High Equivalent Width Lyman-α Emitting Galaxies at Redshifts Between 2.5 and 3.5

    Science.gov (United States)

    Baptista, Brian J.; Bonfield, D.; Grady, C.; Lindler, D.; Mufson, S.; Woodgate, B.

    2012-01-01

    Lyman-α emitting galaxies (LAEs) have been studied for the last decade, yet there are few observations of high equivalent width (EW) objects. The emission mechanisms that drive high EW LAEs, though studied for the last decade, still are not well understood. Since only small numbers have been discovered, it is unknown whether these high EW LAEs make up a population that is undergoing a peculiar stage of galactic evolution, or simply just a more vigorous version of star formation coupled with a clumpy ISM. We have developed a broadband selection technique to effectively increase the number of known LAEs, to build a bigger sample of high EW LAEs. While these high EW LAEs are less numerous than typical LAEs, we are able to probe much larger volumes than blind narrowband or spectroscopic searches. Using photometry from the Deep 2 and 3 fields from the CFHT-Legacy Survey, we have spectroscopically confirmed 63 LAEs with redshifts between 2.5 and 3.5 using the WIYN/Hydra multi-object spectrograph. These LAEs exhibit narrow Lyman-α emission, and show no other line emission to our spectroscopic flux limits. Using UV continuum fitting techniques in conjunction with our spectroscopic data, we have calculated equivalent widths, star formation rates, internal reddening, and escape fractions for our program galaxies. Of the 63 LAEs that we discovered, 29 show EWs that are in excess of 100 Å in the rest frame.

  12. Spectroscopy of z ~ 7 candidate galaxies: Using Lyman-alpha to constrain the neutral fraction of hydrogen in the high-redshift universe

    CERN Document Server

    Caruana, Joseph; Wilkins, Stephen M; Stanway, Elizabeth R; Lorenzoni, Silvio; Jarvis, Matt J; Elbert, Holly

    2013-01-01

    Following our previous spectroscopic observations of $z>7$ galaxies with Gemini/GNIRS and VLT/XSHOOTER, which targeted a total of 8 objects, we present here our results from a deeper and larger VLT/FORS2 spectroscopic sample of Wide Field Camera 3 selected $z>7$ candidate galaxies. With our FORS2 setup we cover the 737-1070nm wavelength range, enabling a search for Lyman-$\\alpha$ in the redshift range spanning 5.06 - 7.80. We target 22 $z$-band dropouts and find no evidence of Lyman-$\\alpha$ emission. The upper limits on Lyman-$\\alpha$ flux and the broad-band magnitudes are used to constrain the rest-frame Equivalent Widths for this line emission. We analyse our FORS2 observations in combination with our previous GNIRS and XSHOOTER observations, and suggest that a simple model where the fraction of high rest-frame Equivalent Width emitters follows the trend seen at $z=3-6.5$ is inconsistent with our non-detections at $z\\sim7.8$ at the 96\\% confidence level. This may indicate that a significant neutral HI frac...

  13. Hubble Space Telescope Imaging of Lyman Alpha Emission at z=4.4

    CERN Document Server

    Finkelstein, Steven L; Windhorst, Rogier A; Ryan, Russell E; Hathi, Nimish P; Finkelstein, Keely D; Anderson, Jay; Grogin, Norman A; Koekemoer, Anton M; Malhotra, Sangeeta; Mutchler, Max; Rhoads, James E; McCarthy, Patrick J; O'Connell, Robert W; Balick, Bruce; Bond, Howard E; Calzetti, Daniela; Disney, Michael J; Dopita, Michael A; Frogel, Jay A; Hall, Donald N B; Holtzman, Jon A; Kimble, Randy A; Luppino, Gerard; Paresce, Francesco; Saha, Abhijit; Silk, Joseph I; Trauger, John T; Walker, Alistair R; Whitmore, Bradley C; Young, Erick T

    2010-01-01

    We present the highest redshift detections of resolved Lyman alpha emission, using Hubble Space Telescope/ACS F658N narrowband-imaging data taken in parallel with the Wide Field Camera 3 Early Release Science program in the GOODS CDF-S. We detect Lyman alpha emission from three spectroscopically confirmed z = 4.4 Lyman alpha emitting galaxies (LAEs), more than doubling the sample of LAEs with resolved Lyman alpha emission. Comparing the light distribution between the rest-frame ultraviolet continuum and narrowband images, we investigate the escape of Lyman alpha photons at high redshift. While our data do not support a positional offset between the Lyman alpha and rest-frame ultraviolet (UV) continuum emission, the half-light radii in two out of the three galaxies are significantly larger in Lyman alpha than in the rest-frame UV continuum. This result is confirmed when comparing object sizes in a stack of all objects in both bands. Additionally, the narrowband flux detected with HST is significantly less than...

  14. Mars Ozone Absorption Line Shapes from Infrared Heterodyne Spectra Applied to GCM-Predicted Ozone Profiles and to MEX/SPICAM Column Retrievals

    Science.gov (United States)

    Fast, Kelly E.; Kostiuk, T.; Annen, J.; Hewagama, T.; Delgado, J.; Livengood, T. A.; Lefevre, F.

    2008-01-01

    We present the application of infrared heterodyne line shapes of ozone on Mars to those produced by radiative transfer modeling of ozone profiles predicted by general circulation models (GCM), and to contemporaneous column abundances measured by Mars Express SPICAM. Ozone is an important tracer of photochemistry Mars' atmosphere, serving as an observable with which to test predictions of photochemistry-coupled GCMs. Infrared heterodyne spectroscopy at 9.5 microns with spectral resolving power >1,000,000 is the only technique that can directly measure fully-resolved line shapes of Martian ozone features from the surface of the Earth. Measurements were made with Goddard Space Flight Center's Heterodyne instrument for Planetary Wind And Composition (HIPWAC) at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii on February 21-24 2008 UT at Ls=35deg on or near the MEX orbital path. The HIPWAC observations were used to test GCM predictions. For example, a GCM-generated ozone profile for 60degN 112degW was scaled so that a radiative transfer calculation of its absorption line shape matched an observed HIPWAC absorption feature at the same areographic position, local time, and season. The RMS deviation of the model from the data was slightly smaller for the GCM-generated profile than for a line shape produced by a constant-with-height profile, even though the total column abundances were the same, showing potential for testing and constraining GCM ozone-profiles. The resulting ozone column abundance from matching the model to the HIPWAC line shape was 60% higher than that observed by SPICAM at the same areographic position one day earlier and 2.5 hours earlier in local time. This could be due to day-to-day, diurnal, or north polar region variability, or to measurement sensitivity to the ozone column and its distribution, and these possibilities will be explored. This work was supported by NASA's Planetary Astronomy Program.

  15. Mars Ozone Absorption Line Shapes from Infrared Heterodyne Spectra Applied to GCM-Predicted Ozone Profiles and to MEX/SPICAM Column Retrievals

    Science.gov (United States)

    Fast, Kelly E.; Kostiuk, T.; Annen, J.; Hewagama, T.; Delgado, J.; Livengood, T. A.; Lefevre, F.

    2008-01-01

    We present the application of infrared heterodyne line shapes of ozone on Mars to those produced by radiative transfer modeling of ozone profiles predicted by general circulation models (GCM), and to contemporaneous column abundances measured by Mars Express SPICAM. Ozone is an important tracer of photochemistry Mars' atmosphere, serving as an observable with which to test predictions of photochemistry-coupled GCMs. Infrared heterodyne spectroscopy at 9.5 microns with spectral resolving power >1,000,000 is the only technique that can directly measure fully-resolved line shapes of Martian ozone features from the surface of the Earth. Measurements were made with Goddard Space Flight Center's Heterodyne instrument for Planetary Wind And Composition (HIPWAC) at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii on February 21-24 2008 UT at Ls=35deg on or near the MEX orbital path. The HIPWAC observations were used to test GCM predictions. For example, a GCM-generated ozone profile for 60degN 112degW was scaled so that a radiative transfer calculation of its absorption line shape matched an observed HIPWAC absorption feature at the same areographic position, local time, and season. The RMS deviation of the model from the data was slightly smaller for the GCM-generated profile than for a line shape produced by a constant-with-height profile, even though the total column abundances were the same, showing potential for testing and constraining GCM ozone-profiles. The resulting ozone column abundance from matching the model to the HIPWAC line shape was 60% higher than that observed by SPICAM at the same areographic position one day earlier and 2.5 hours earlier in local time. This could be due to day-to-day, diurnal, or north polar region variability, or to measurement sensitivity to the ozone column and its distribution, and these possibilities will be explored. This work was supported by NASA's Planetary Astronomy Program.

  16. Damped and sub-damped Lyman-α absorbers in z > 4 QSOs

    Science.gov (United States)

    Guimarães, R.; Petitjean, P.; de Carvalho, R. R.; Djorgovski, S. G.; Noterdaeme, P.; Castro, S.; Poppe, P. C. Da R.; Aghaee, A.

    2009-12-01

    We present the results of a survey of damped (DLA, log~N(H i)>20.3) and sub-damped Lyman-α systems (19.5 2.55 along the lines-of-sight to 77 quasars with emission redshifts in the range 419.5 were detected of which 40 systems are damped Lyman-α systems for an absorption length of Δ X = 378. About half of the lines of sight of this homogeneous survey have never been investigated for DLAs. We study the evolution with redshift of the cosmological density of the neutral gas and find, consistent with previous studies at similar resolution, that ΩDLA, H_I decreases at z>3.5. The overall cosmological evolution of Ω_HI shows a peak around this redshift. The H i column density distribution for log N(H i)≥20.3 is fitted, consistent with previous surveys, with a single power-law of index α ˜ -1.8 ±0.25. This power-law overpredicts data at the high-end and a second, much steeper, power-law (or a gamma function) is needed. There is a flattening of the function at lower H i column densities with an index of α ˜ -1.4 for the column density range log N(H i)=19.5-21. The fraction of H i mass in sub-DLAs is of the order of 30%. The H i column density distribution does not evolve strongly from z˜ 2.5 to z˜ 4.5. The observations reported here were obtained with the W. M. Keck Observatory, which is operated by the California Association for Research in Astronomy, a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. Tables 1, 2 and Appendices are only available in electronic form at http://www.aanda.org

  17. Minimally Parametric Constraints on the Primordial Power Spectrum from Lyman-alpha

    CERN Document Server

    Bird, Simeon

    2010-01-01

    Current analyses of the Lyman-alpha forest assume that the primordial power spectrum of density perturbations obeys a simple power law, a strong theoretical assumption which should be tested. Employing a large suite of numerical simulations which drop this assumption, we reconstruct the shape of the primordial power spectrum using Lyman-alpha data from the Sloan Digital Sky Survey (SDSS). Our method combines a minimally parametric framework with cross-validation, a technique used to avoid over-fitting the data. Future work will involve predictions for the upcoming Baryon Oscillation Sky Survey (BOSS), which will provide new Lyman-alpha data with vastly decreased statistical errors.

  18. Dynamic microRNA profiles of hepatic differentiated human umbilical cord lining-derived mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Lina Cui

    Full Text Available Despite the extensive hepatic differentiation potential of human umbilical cord lining-derived mesenchymal stem cells (hUC-MSC, little is known about the molecular mechanisms of hUC-MSC differentiation. At the post-transcriptional level, microRNAs are key players in the control of cell fate determination during differentiation. In this study, we aimed to identify microRNAs involved in the hepatic differentiation of hUC-MSCs. After successfully isolating hUC- MSCs, we induced hepatocyte formation in vitro with growth factors. After 26 days of induction, hUC-MSCs could express hepatocyte-specific genes, synthesize urea and glycogen and uptake low-density lipoprotein. Cellular total RNA from hUC-MSCs and hepatic differentiated hUC-MSCs was collected at 7 time points, including 2 days, 6 days, 10 days, 14 days, 22 days and 26 days, for microRNA microarray analysis. Dynamic microRNA profiles were identified that did not overlap or only partially overlapped with microRNAs reported to be involved in human liver development, hepatocyte regeneration or hepatic differentiation of liver-derived progenitor cells. A total of 61 microRNAs among 1205 human and 144 human viral microRNAs displayed consistent changes and were altered at least 2-fold between hUC-MSCs and hepatic differentiated hUC-MSCs. Among these microRNAs, 25 were over-expressed; this over-expression occurred either gradually or increased sharply and was maintained at a high level. A total of 36 microRNAs were under-expressed, with an expression pattern similar to that of the over-expressed microRNAs. The expression of the altered expressed microRNAs was also confirmed by quantitative reverse-transcription polymerase chain reaction. We also found that microRNAs involved in hepatic differentiation were not enriched in hepatocyte or hepatocellular carcinoma cells and can potentially target liver-enriched transcription factors and genes. The elucidation of the microRNA profile during the hepatic

  19. Effect of cultivation line and peeling on food composition, taste characteristic, aroma profile, and antioxidant activity of Shiikuwasha (Citrus depressa Hayata) juice.

    Science.gov (United States)

    Asikin, Yonathan; Fukunaga, Hibiki; Yamano, Yoshimasa; Hou, De-Xing; Maeda, Goki; Wada, Koji

    2014-09-01

    Shiikuwasha (Citrus depressa Hayata) juice from four main cultivation lines subjected to two peeling practices (with or without peeling) were discriminated in terms of quality attributes, represented by sugar and organic acid composition, taste characteristic, aroma profile, and antioxidant activity. Shiikuwasha juice from these lines had diverse food compositions; 'Izumi kugani' juice had lower acidity but contained more ascorbic acid than that of other cultivation lines. The composition of volatile aroma components was influenced by fruit cultivation line, whereas its content was affected by peeling process (20.26-53.73 mg L(-1) in whole juice versus 0.82-1.58 mg L(-1) in flesh juice). Peeling also caused Shiikuwasha juice to be less astringent and acidic bitter and to lose its antioxidant activity. Moreover, the total phenolic and ascorbic acid content of Shiikuwasha juice positively influenced its antioxidant activity. Each fruit cultivation line had a distinct food composition, taste characteristic, and aroma profile. Peeling in Shiikuwasha juice production might reduce aftertaste, and thus might improve its palatability. Comprehensive information on the effect of cultivation line and peeling on quality attributes will be useful for Shiikuwasha juice production, and can be applied to juice production of similar small citrus fruits. © 2014 Society of Chemical Industry.

  20. The response of the H geocorona between 3 and 8 Re to geomagnetic disturbances studied using TWINS stereo Lyman-α data

    Science.gov (United States)

    Zoennchen, Jochen H.; Nass, Uwe; Fahr, Hans J.; Goldstein, Jerry

    2017-02-01

    Circumterrestrial Lyman-α column brightness observations from 3-8 Earth radii (Re) have been used to study temporal density variations in the exospheric neutral hydrogen as response to geomagnetic disturbances of different strength, i.e., Dst peak values between -26 and -147 nT. The data used were measured by the two Lyman-α detectors (LAD1/2) onboard both TWINS satellites between the solar minimum of 2008 and near the solar maximum of 2013. The solar Lyman-α flux at 121.6 nm is resonantly scattered near line center by exospheric H atoms and measured by the TWINS LADs. Along a line of sight (LOS), the scattered LOS-column intensity is proportional to the LOS H column density, assuming optically thin conditions above 3 Re. In the case of the eight analyzed geomagnetic storms we found a significant increase in the exospheric Lyman-α flux between 9 and 23 % (equal to the same increase in H column density ΔnH) compared to the undisturbed case short before the storm event. Even weak geomagnetic storms (e.g., Dst peak values ≥ -41 nT) under solar minimum conditions show increases up to 23 % of the exospheric H densities. The strong H density increase in the observed outer exosphere is also a sign of an enhanced H escape flux during storms. For the majority of the storms we found an average time shift of about 11 h between the time when the first significant dynamic solar wind pressure peak (pSW) hits the Earth and the time when the exospheric Lyman-α flux variation reaches its maximum. The results show that the (relative) exospheric density reaction of ΔnH have a tendency to decrease with increasing peak values of Dst index or the Kp index daily sum. Nevertheless, a simple linear correlation between ΔnH and these two geomagnetic indices does not seem to exist. In contrast, when recovering from the peak back to the undisturbed case, the Kp index daily sum and the ΔnH essentially show the same temporal recovery.

  1. Neutral Hydrogen and Its Emission Lines in the Solar Corona

    Science.gov (United States)

    Vial, Jean-Claude; Chane-Yook, Martine

    2016-12-01

    Since the Lyman-α rocket observations of Gabriel ( Solar Phys. 21, 392, 1971), it has been realized that the hydrogen (H) lines could be observed in the corona and that they offer an interesting diagnostic for the temperature, density, and radial velocity of the coronal plasma. Moreover, various space missions have been proposed to measure the coronal magnetic and velocity fields through polarimetry in H lines. A necessary condition for such measurements is to benefit from a sufficient signal-to-noise ratio. The aim of this article is to evaluate the emission in three representative lines of H for three different coronal structures. The computations have been performed with a full non-local thermodynamic-equilibrium (non-LTE) code and its simplified version without radiative transfer. Since all collisional and radiative quantities (including incident ionizing and exciting radiation) are taken into account, the ionization is treated exactly. Profiles are presented at two heights (1.05 and 1.9 solar radii, from Sun center) in the corona, and the integrated intensities are computed at heights up to five solar radii. We compare our results with previous computations and observations ( e.g. Lα from Ultraviolet Coronal Spectrometer) and find a rough (model-dependent) agreement. Since the Hα line is a possible candidate for ground-based polarimetry, we show that in order to detect its emission in various coronal structures, it is necessary to use a very narrow (less than 2 Å wide) bandpass filter.

  2. Sample variance and Lyman-alpha forest transmission statistics

    CERN Document Server

    Rollinde, Emmanuel; Schaye, Joop; Pâris, Isabelle; Petitjean, Patrick

    2012-01-01

    We compare the observed probability distribution function of the transmission in the \\HI\\ Lyman-alpha forest, measured from the UVES 'Large Programme' sample at redshifts z=[2,2.5,3], to results from the GIMIC cosmological simulations. Our measured values for the mean transmission and its PDF are in good agreement with published results. Errors on statistics measured from high-resolution data are typically estimated using bootstrap or jack-knife resampling techniques after splitting the spectra into chunks. We demonstrate that these methods tend to underestimate the sample variance unless the chunk size is much larger than is commonly the case. We therefore estimate the sample variance from the simulations. We conclude that observed and simulated transmission statistics are in good agreement, in particular, we do not require the temperature-density relation to be 'inverted'.

  3. An excess of damped Lyman alpha galaxies near QSOs

    CERN Document Server

    Russell, D M; Ellison, S L; Benn, Chris R.; Ellison, Sara L.; Russell, David M.

    2006-01-01

    We present a sample of 33 damped Lyman alpha systems (DLAs) discovered in the Sloan Digital Sky Survey (SDSS) whose absorption redshifts (z_abs) are within 6000 km/s of the QSO's systemic redshift (z_sys). Our sample is based on 731 2.5 = 2e20 cm^-2. The derived number density of DLAs per unit redshift, n(z), within v < 6000 km/s is higher (3.5 sigma significance) by almost a factor of 2 than that of intervening absorbers observed in the SDSS DR3, i.e. there is evidence for an overdensity of galaxies near the QSOs. This provides a physical motivation for excluding DLAs at small velocity separations in surveys of intervening 'field' DLAs. In addition, we find that the overdensity of proximate DLAs is independent of the radio-loudness of the QSO, consistent with the environments of radio-loud and radio-quiet QSOs being similar.

  4. Expression profiles of miRNAs in human pancreatic cancer cell lines%胰腺癌细胞系中miRNAs的表达分析

    Institute of Scientific and Technical Information of China (English)

    Shineng Zhang; Haijun Zuo; Zhong Yu; Fengting Huang; Wa Zhong

    2009-01-01

    Objective:To analyze initially the differences of miRNAs expression profiles in human pancreatic cencer cell lines by microarray technique.Methods:A total of 743 probes were designed according to lhe known miRNAs sequences of human,mice,and rats.miRNAs microarray was manufactured and its credibility was verified.Total RNAs were extracted and miRNAs were separated from human pancreatic cancer cell lines(SW1990,Capan-2.BxPC-3,Aspc-1,and Panc 1)and immortal human pancreatic duct epithelial cell line H6C7.They were labeled with T4 RNA ligase.then were hybridized with microarray.Through array scan and analysis,miRNAs expression profiles in pancreatic cancer were obtained.The results were verified by Northern blotting and RT-PCR.Results:A totsl of 63 miRNAs related to pancreatic cancer were found to be differentially expressed in 5 pancreatic cancer cell lines.including 25 down-regulated and 38 up-regulated miRNAs.Expres- sions of mir-21 and let-7 were also confirmed.Conclusion:The results suggested that miRNAs expression profiles could befound in pancreatic cancer cells.

  5. The Lyman alpha reference sample. II. Hubble space telescope imaging results, integrated properties, and trends

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, Matthew; Östlin, Göran; Duval, Florent; Sandberg, Andreas; Guaita, Lucia; Melinder, Jens; Rivera-Thorsen, Thøger [Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Adamo, Angela [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Schaerer, Daniel [Université de Toulouse, UPS-OMP, IRAP, F-31000 Toulouse (France); Verhamme, Anne; Orlitová, Ivana [Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, CH-1290 Versoix (Switzerland); Mas-Hesse, J. Miguel; Otí-Floranes, Héctor [Centro de Astrobiología (CSIC-INTA), Departamento de Astrofísica, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Cannon, John M.; Pardy, Stephen [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Atek, Hakim [Laboratoire dAstrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Kunth, Daniel [Institut d' Astrophysique de Paris, UMR 7095, CNRS and UPMC, 98 bis Bd Arago, F-75014 Paris (France); Laursen, Peter [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Herenz, E. Christian, E-mail: matthew@astro.su.se [Leibniz-Institut für Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

    2014-02-10

    We report new results regarding the Lyα output of galaxies, derived from the Lyman Alpha Reference Sample, and focused on Hubble Space Telescope imaging. For 14 galaxies we present intensity images in Lyα, Hα, and UV, and maps of Hα/Hβ, Lyα equivalent width (EW), and Lyα/Hα. We present Lyα and UV radial light profiles and show they are well-fitted by Sérsic profiles, but Lyα profiles show indices systematically lower than those of the UV (n ≈ 1-2 instead of ≳ 4). This reveals a general lack of the central concentration in Lyα that is ubiquitous in the UV. Photometric growth curves increase more slowly for Lyα than the far ultraviolet, showing that small apertures may underestimate the EW. For most galaxies, however, flux and EW curves flatten by radii ≈10 kpc, suggesting that if placed at high-z only a few of our galaxies would suffer from large flux losses. We compute global properties of the sample in large apertures, and show total Lyα luminosities to be independent of all other quantities. Normalized Lyα throughput, however, shows significant correlations: escape is found to be higher in galaxies of lower star formation rate, dust content, mass, and nebular quantities that suggest harder ionizing continuum and lower metallicity. Six galaxies would be selected as high-z Lyα emitters, based upon their luminosity and EW. We discuss the results in the context of high-z Lyα and UV samples. A few galaxies have EWs above 50 Å, and one shows f{sub esc}{sup Lyα} of 80%; such objects have not previously been reported at low-z.

  6. Rapid line-profile variability of H-alpha and H-beta in the A-type shell star HD 163296

    Science.gov (United States)

    Pogodin, M. A.

    1994-02-01

    The results of the H-alpha and H-beta line profile investigation of an A0-shell star HD 163296 are presented. 47 high-resolution CCD spectra (35 for H-alpha and 12 for H-beta) were obtained on July 15-20, 1991 and on July 24-27, 1992. A considerable profile variability is found on time scales from one hour to a few days. The main properties of the night-to-night variations are strong change in shape of the entire line profile with the exception of the primary PCyg-absorption which remains relatively constant both in strength and in position. Two types of extremely rapid variations (tau approximately equal hours) are discovered: (a) positional shift of sharp spectral bumps, and (b) monotonous flux variations of different parts of a profile during a night. A qualitative explanation in the framework of the model for an envelope containing an active non-stable region formed by an equatorially concentrated stellar wind and an external cool shell is proposed for the observed variability. Some reasons for the extremely rapid profile changes are considered.

  7. The Column Density Distribution of the Low-Redshift Lyman-Alpha Forest in Illustris

    CERN Document Server

    Gurvich, Alex; Bird, Simeon

    2016-01-01

    We investigate the low-redshift Lyman-alpha forest column density distribution in the Illustris simulation. We show that Illustris reproduces observations extremely well in the column density range 10^12.5-10^14.5 cm^-2, relevant for the "photon underproduction crisis." We attribute this to the inclusion of AGN feedback, which changes the gas distribution so as to mimic the effect of extra photons, as well as the use of the Faucher-Giguere (2009) ultra-violet background, which is more ionizing at z=0.1 than the Haardt & Madau (2012) background previously considered. We show that the difference between simulations run with smoothed particle hydrodynamics and simulations using a moving mesh is small in this column density range. We further consider the effect of supernova feedback, Voigt profile fitting and finite resolution, all of which we show to be small. Finally, we identify a discrepancy between our simulations and observations at column densities 10^14-10^16 cm^-2, where Illustris produces too few ab...

  8. RNA-seq profiles of immune related genes in the spleen of Necrotic enteritis-afflicted chicken lines

    Science.gov (United States)

    The study aimed to compare the Necrotic enteritis (NE)-induced transcriptome differences in the spleen of two highly inbred White Leghorn chicken lines, line 6.3 that is Marek’s Disease (MD) resistant and line 7.2 that is MD susceptible. Induction of NE in the chickens was achieved by co-infection ...

  9. Stratospheric and mesospheric pressure-temperature profiles from rotational analysis of CO2 lines in atmospheric trace molecule spectroscopy/ATLAS 1 infrared solar occultation spectra

    Science.gov (United States)

    Stiller, G. P.; Gunson, M. R.; Lowes, L. L.; Abrams, M. C.; Raper, O. F.; Farmer, C. B.; Zander, R.; Rinsland, C. P.

    1995-01-01

    A simple, classical, and expedient method for the retrieval of atmospheric pressure-temperature profiles has been applied to the high-resolution infrared solar absorption spectra obtained with the atmospheric trace molecule spectroscopy (ATMOS) instrument. The basis for this method is a rotational analysis of retrieved apparent abundances from CO2 rovibrational absorption lines, employing existing constituent concentration retrieval software used in the analysis of data returned by ATMOS. Pressure-temperature profiles derived from spectra acquired during the ATLAS 1 space shuttle mission of March-April 1992 are quantitatively evaluated and compared with climatological and meteorological data as a means of assessing the validity of this approach.

  10. Mapping High-Velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    Science.gov (United States)

    France, Kevin; McCray, Richard; Fransson, Claes; Larsson, Josefin; Frank, Kari A.; Burrows, David N.; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger A.; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S.; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01

    We present new Hubble Space Telescope images of high-velocity H-alpha and Lyman-alpha emission in the outer debris of SN 1987A. The H-alpha images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H-alpha imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals (-7,500 < V(sub obs) < -2,800 km/s) and (1,000 < V(sub obs) < 7,500 km/s), ?M(sub H) = 1.2 × 10(exp -3) M/ y. We also present the first Lyman-alpha imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Lyman-alpha and X-ray emission, we observe that the majority of the high-velocity Lyman-alpha emission originates interior to the equatorial ring. The observed Lyman-alpha/H-alpha photon ratio, R(L-alpha/H-alpha) approx. = 17, is significantly higher than the theoretically predicted ratio of approx. = 5 for neutral atoms crossing the reverse shock front. We attribute this excess to Lyman-alpha emission produced by X-ray heating of the outer debris. The spatial orientation of the Lyman-alpha and X-ray emission suggests that X-ray heating of the outer debris is the dominant Lyman-alpha production mechanism in SN 1987A at this phase in its evolution.

  11. Lyman alpha emitting galaxies at high redshift: Direct detection of young galaxies in a young universe

    Science.gov (United States)

    Dawson, Steven Arthur

    An early result of galaxy formation theory was the prediction that the copious ionizing radiation produced in nascent galaxies undergoing their first starbursts should in turn produce a strong Lya emission line. We report on our efforts to detect and characterize primeval galaxies by searching for this expected Lya signature with two observational techniques: serendipitous slit spectroscopy, and narrowband imaging selection. In Part I, we describe our serendipitous slit spectroscopy survey of the Hubble Deep Field and its environs, which resulted in a catalog of 74 spectroscopic redshifts spanning 0.10 5. Follow-up observations at higher resolution resulted in the additional serendipitous detection of a strong Lya-emitting galaxy at z = 5.190 (ES1). At the time of its discovery, ES1 was one of only nine known galaxies at z > 5, and was the sixth most distant known galaxy. The unprecedented spectral purity of the observation offers evidence for a galaxy-scale outflow with a. velocity of v > 300 km s -1 , consistent with wind speeds observed in powerful local starbursts (typically 10 2 to 10 3 km s -1 ), and with simulations of the late- stage evolution of Lya emission in star-forming systems. Our final serendipitous detection is the remarkable source CXOHDFN J123635.6+621424, which is both the highest redshift known spiral galaxy, and a rare example of a high redshift, hard X-ray-emitting Type II AGN. Significantly, all of these results were acquired with no direct allocation of telescope time. In Part II, we report on our implementation of narrowband imaging selection, with which we traded redshift coverage for survey volume, focusing on the systematic study of galaxies at a particular epoch in favor of chasing that rare, most-distant object. This effort resulted in a catalog of 76 z [approximate] 4.5 Lya-emitting galaxies spectroscopically-confirmed in campaigns of Keck/LRIS and Keck/DEIMOS follow-up observations to candidates selected in the Large Area Lyman

  12. The physical properties of z>2 Lyman limit systems: new constraints for feedback and accretion models

    CERN Document Server

    Fumagalli, Michele; Prochaska, J Xavier

    2015-01-01

    We study the physical properties of a homogeneous sample of 157 optically-thick absorption line systems at redshifts ~1.8-4.4, selected from a high-dispersion spectroscopic survey of Lyman limit systems (LLSs). By means of multiple ionisation models and Bayesian techniques, we derive the posterior probability distribution functions for the density, metallicity, temperature, and dust content of the absorbing gas. We find that z>2 LLSs are highly ionised with ionisation parameters between -32 are characterised by a broad unimodal distribution over >4 orders of magnitude, with a peak at log Z/Zsun~-2. LLSs are metal poor, significantly less enriched than DLAs, with ~70% of the metallicity PDF below log Z/Zsun19 rapidly evolves with redshift, with a ten-fold increase between z~2.1-3.6 (~1.5 Gyr). Based on this sample, we find that LLSs at z=2.5-3.5 account for ~15% of all the metals produced by UV-selected galaxies. The implications for theories of cold gas accretion and metal ejection from galaxies are also disc...

  13. Star Formation in the First Galaxies I: Collapse Delayed by Lyman-Werner Radiation

    CERN Document Server

    Safranek-Shrader, Chalence; Federrath, Christoph; Dubey, Anshu; Milosavljevic, Milos; Bromm, Volker

    2012-01-01

    We investigate the process of metal-free star formation in the first galaxies with a high-resolution cosmological simulation. We consider the cosmologically motivated scenario in which a strong molecule-destroying Lyman-Werner (LW) background inhibits effective cooling in low-mass haloes, delaying star formation until the collapse or more massive haloes. Only when molecular hydrogen (H2) can self-shield from LW radiation, which requires a halo capable of cooling by atomic line emission, will star formation be possible. To follow the formation of multiple gravitationally bound objects, at high gas densities we introduce sink particles which accrete gas directly from the computational grid. We find that in a 1 Mpc^3 (comoving) box, runaway collapse first occurs in a 3x10^7 M_sun dark matter halo at z~12 assuming a background intensity of J21=100. Due to a runaway increase in the H2 abundance and cooling rate, a self-shielding, supersonically turbulent core develops abruptly with ~10^4 M_sun in cold gas availabl...

  14. C, N, O Abundances in the Most Metal-Poor Damped Lyman alpha Systems

    CERN Document Server

    Pettini, Max; Steidel, Charles C; Chaffee, Fred H

    2007-01-01

    This study focuses on some of the most metal-poor damped Lyman alpha absorbers known in the spectra of high redshift QSOs, using new and archival observations obtained with UV-sensitive echelle spectrographs on the Keck and VLT telescopes. The weakness and simple velocity structure of the absorption lines in these systems allows us to measure the abundances of several elements, and in particular those of C, N, and O, a group that is difficult to study in DLAs of more typical metallicities. We find that when the oxygen abundance is less than about 1/100 of solar, the C/O ratio in high redshift DLAs and sub-DLAs matches that of halo stars of similar metallicity and shows higher values than expected from galactic chemical evolution models based on conventional stellar yields. Furthermore, there are indications that at these low metallicities the N/O ratio may also be above simple expectations and may exhibit a minimum value, as proposed by Centurion and her collaborators in 2003. Both results can be interpreted ...

  15. Statistical properties of damped Lyman-alpha systems from Sloan Digital Sky Survey DR12

    Science.gov (United States)

    Bird, Simeon; Garnett, Roman; Ho, Shirley

    2017-04-01

    We present new estimates for the statistical properties of damped Lyman-α absorbers (DLAs). We compute the column density distribution function at z > 2, the line density, dN/dX, and the neutral hydrogen density, ΩDLA. Our estimates are derived from the DLA catalogue of Garnett et al. (2016), which uses the Sloan Digital Sky Survey III Data Release 12 (SDSS-III DR12) quasar spectroscopic survey. This catalogue provides a probability that a given spectrum contains a DLA. It allows us to use even the noisiest data without biasing our results and thus substantially increases our sample size. We measure a non-zero column density distribution function at 95 per cent confidence for all column densities N_H I 4. We show that our results are insensitive to the signal-to-noise ratio of the spectra, but that there is a residual dependence on quasar redshift for z < 2.5, which may be due to remaining systematics in our analysis.

  16. A Multiply-Imaged z $\\sim$ 6.3 Lyman Alpha Emitter candidate behind Abell 2261

    CERN Document Server

    Rydberg, Claes-Erik; Zackrisson, Erik; Melinder, Jens; Whalen, Daniel J; Klessen, Ralf S; Gonzalez, Juan; Östlin, Göran; Carollo, Daniela

    2016-01-01

    While the Lyman-$\\alpha$ ($\\mathrm{Ly}\\alpha$) emission line serves as an important tool in the study of galaxies at $z\\lesssim 6$, finding Ly$\\alpha$ emitters (LAE) at significantly higher redshifts has been more challenging, probably because of the increasing neutrality of the intergalactic medium above $z\\sim6$. Galaxies with extremely high rest-frame Ly$\\alpha$ equivalent widths, EW(Ly$\\alpha$) $\\gtrsim 150$ \\AA{}, at $z>6$ are good candidates for Ly$\\alpha$ follow-up observations, and can stand out in multiband imaging surveys because of their unusual colors. We have conducted a photometric search for such objects in the Cluster Lensing And Supernova survey with Hubble (CLASH), and report here the identification of three likely gravitationally-lensed images of a single LAE candidate at $z\\sim6.3$, behind the galaxy cluster Abell 2261($z = 0.225$). In the process, we also measured with Keck/MOSFIRE the first spectroscopic redshift of a multiply-imaged galaxy behind Abell 2261, at $z = 3.337$. This allows ...

  17. Discovery of Ubiquitous Fast Propagating Intensity Disturbances by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)

    Science.gov (United States)

    Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando, T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.; Ishikawa, S.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.; Auchere, F.; Bueno, J. Trujillo; Ramos, A. Asensio; Stepan, J.; Belluzzi, L.; Sainz, R. Manso; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.

    2016-01-01

    High cadence observations by the slit-jaw (SJ) optics system of the sounding rocket experiment known as the Chromospheric Lyman Alpha SpectroPolarimeter (CLASP) reveal ubiquitous intensity disturbances that recurrently propagate in one or both of the chromosphere or transition region at a speed much higher than the sound speed. The CLASP/SJ instrument provides a time series of 2D images taken with broadband filters centered on the Ly(alpha) line at a 0.6 s cadence. The fast propagating intensity disturbances are detected in the quiet Sun and in an active region, and at least 20 events are clearly detected in the field of view of 527'' x 527'' during the 5-minute observing time. The apparent speeds of the intensity disturbances range from 150 to 350 km/s, and they are comparable to the local Alfven speed in the transition region. The intensity disturbances tend to propagate along bright elongated structures away from areas with strong photospheric magnetic fields. This suggests that the observed propagating intensity disturbances are related to the magnetic canopy structures. The maximum distance traveled by the intensity disturbances is of about 10'', and the widths are a few arcseconds, which is almost determined by the pixel size of 1.''03. The timescale of each intensity pulse is shorter than 30 s. One possible explanation of the fast propagating intensity disturbances observed by CLASP is magneto-hydrodynamic fast mode waves.

  18. Properties of High-Redshift Lyman Alpha Clouds II. Statistical Properties of the Clouds

    CERN Document Server

    Press, W H; Press, William H.; Rybicki, George B.

    1993-01-01

    Curve of growth analysis, applied to the Lyman series absorption ratios deduced in our previous paper, yields a measurement of the logarithmic slope of distribution of \\Lya\\ clouds in column density $N$. The observed exponential distribution of the clouds' equivalent widths $W$ is then shown to require a broad distribution of velocity parameters $b$, extending up to 80 km s$^{-1}$. We show how the exponential itself emerges in a natural way. An absolute normalization for the differential distribution of cloud numbers in $z$, $N$, and $b$ is obtained. By detailed analysis of absorption fluctuations along the line of sight we are able to put upper limits on the cloud-cloud correlation function $\\xi$ on several megaparsec length scales. We show that observed $b$ values, if thermal, are incompatible, in several different ways, with the hypothesis of equilibrium heating and ionization by a background UV flux. Either a significant component of $b$ is due to bulk motion (which we argue against on several grounds), o...

  19. The evolution of neutral gas in damped Lyman $\\alpha$ systems from the XQ-100 survey

    CERN Document Server

    Sánchez-Ramírez, R; Prochaska, J X; Berg, T A M; López, S; D'Odorico, V; Becker, G D; Christensen, L; Cupani, G; Denney, K D; Pâris, I; Worseck, G; Gorosabel, J

    2015-01-01

    We present a sample of 38 intervening Damped Lyman $\\alpha$ (DLA) systems identified towards 100 $z>3.5$ quasars, observed during the XQ-100 survey. The XQ-100 DLA sample is combined with major DLA surveys in the literature. The final combined sample consists of 742 DLAs over a redshift range approximately $1.6 < z_{\\rm abs} < 5.0$. We develop a novel technique for computing $\\Omega_{\\rm HI}^{\\rm DLA}$ as a continuous function of redshift, and we thoroughly assess and quantify the sources of error therein, including fitting errors and incomplete sampling of the high column density end of the column density distribution function. There is a statistically significant redshift evolution in $\\Omega_{\\rm HI}^{\\rm DLA}$ ($\\geq 3 \\sigma$) from $z \\sim 2$ to $z \\sim$ 5. In order to make a complete assessment of the redshift evolution of $\\Omega_{\\rm HI}$, we combine our high redshift DLA sample with absorption surveys at intermediate redshift and 21cm emission line surveys of the local universe. Although $\\Omeg...

  20. Constraints on the gas masses of low-z damped Lyman-$\\alpha$ systems

    CERN Document Server

    Mazumdar, Parichay; Prochaska, J Xavier

    2014-01-01

    We report a deep search for redshifted HI 21 cm emission from three damped and sub-damped Lyman-$\\alpha$ absorbers (DLAs) at $z \\approx 0.1$ with the Green Bank Telescope (GBT). No evidence for a redshifted HI 21 cm emission signal was obtained in the GBT spectra of two absorbers, with the data on the third rendered unusable by terrestrial interference. The non-detections of HI 21 cm emission yield strong constraints on the HI masses of the associated galaxies, M$_{\\rm HI} < 2.3 \\times 10^9 \\times (\\Delta V/100)^{1/2}$ M$_\\odot$ for the sub-DLA at $z = 0.0830$ towards J1553+3548, and M$_{\\rm HI} < 2.7 \\times 10^9 \\times (\\Delta V/100)^{1/2}$ M$_\\odot$ for the DLA at $z = 0.0963$ towards J1619+3342, where $\\Delta V$ is the HI 21 cm line width, in km s$^{-1}$. This continues the trend of low HI masses found in all low-$z$ DLAs and sub-DLAs that have been searched for redshifted HI 21 cm emission. Low-redshift absorbers with relatively low HI column densities, $\\lesssim few \\times 10^{20}$ cm$^{-2}$, thus ...