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We study HI and metal-line absorption around $z\approx2$ star-forming galaxies by comparing an analysis of data from the Keck Baryonic Structure Survey to mock spectra generated from the EAGLE cosmological, hydrodynamical simulations. We…

Astrophysics of Galaxies · Physics 2017-08-09 Monica L. Turner , Joop Schaye , Robert A. Crain , Gwen Rudie , Charles C. Steidel , Allison Strom , Tom Theuns

We use the recent detection of He II absorption at $z=2.2-2.6$ in the line of sight of the quasar HS1700+64 to put bounds on the sources of ionization. We find that given the uncertainty in $\tauhgp$ and the model of absorption in the…

Astrophysics · Physics 2015-06-24 Shiv K. Sethi , Biman B. Nath

Cross-correlating the Planck High Frequency Instrument (HFI) maps against quasars from the Sloan Digital Sky Survey (SDSS) DR7, we estimate the intensity distribution of the Cosmic Infrared Background (CIB) over the redshift range 0 < z <…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-05 Samuel J. Schmidt , Brice Ménard , Ryan Scranton , Christopher B. Morrison , Mubdi Rahman , Andrew M. Hopkins

We have observed a sample of 14 nearby ($z \sim 0.03$) star-forming blue compact galaxies in the rest-frame far-UV ($\sim1150-2200 \AA$) using the Cosmic Origins Spectrograph on the Hubble Space Telescope. We have also generated a grid of…

Astrophysics of Galaxies · Physics 2015-06-03 Erika Zetterlund , Emily M. Levesque , Claus Leitherer , Charles W. Danforth

We report results from the third in a series of nebular abundance studies of emission-line galaxies from the KPNO International Spectroscopic Survey (KISS). Galaxies with coarse metallicity estimates of 12 + log(O/H) less than 8.2 dex were…

Astrophysics · Physics 2009-11-10 Janice C. Lee , John J. Salzer , Jason Melbourne

The first measurement of the diffuse background spectrum at 0.8-1.7 $\mu \rm{m}$ from the CIBER experiment has revealed a significant excess of the cosmic infrared background (CIB) radiation compared to the theoretically expected spectrum.…

High Energy Physics - Phenomenology · Physics 2019-01-04 Oleg E. Kalashev , Alexander Kusenko , Edoardo Vitagliano

We present the abundances of Li, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Zn, Sr, Y, Zr, and Ba in a wide metallicity range ($-2.8 \le$ [Fe/H] $\le -1.5$). Using the differential technique allowed us to obtain an unprecedented low…

Solar and Stellar Astrophysics · Physics 2017-12-06 Henrique Reggiani , Jorge Meléndez , Chiaki Kobayashi , Amanda Karakas , Vinicius Placco

Using Hubble Space Telescope ultraviolet and ground-based optical spectroscopy, we measure the C/O and N/O ratios of three metal-poor galaxies with similar metallicity but differing N/O. The C/O ratios estimated from C III] lambda1909 and…

Astrophysics · Physics 2009-10-30 Henry A. Kobulnicky , Evan D. Skillman

The circumgalactic medium (CGM) serves as a baryon reservoir that connects galaxies to the intergalactic medium and fuels star formation. The spatial distribution of the metal-enriched cool CGM has not yet been directly revealed at cosmic…

We study metal line absorption of CIV, CII, SiIV, and NV at redshifts z=3.5 to z=2 within the framework of a cosmological model for the Lyman alpha forest, comparing the results of numerical simulations to recent observations by Songaila &…

Astrophysics · Physics 2009-10-30 Uffe Hellsten , Romeel Dave , Lars Hernquist , David H. Weinberg , Neal Katz

The discovery of the Cosmic Infrared Background (CIB) in 1996, together with recent cosmological surveys from the mid-infrared to the millimeter have revolutionized our view of star formation at high redshifts. It has become clear, in the…

Astrophysics · Physics 2007-05-23 G. Lagache , H. Dole , J. -L. Puget

We present improved synthesis models of the evolving spectrum of the UV/X-ray diffuse background, updating and extending our previous results. Five new main components are added to our radiative transfer code CUBA: (1) the sawtooth…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Francesco Haardt , Piero Madau

A detailed spectroscopic study, from lambda 3700 A to 1 um, was performed for a sample of 34 HII galaxies in order to derive fundamental parameters for their HII regions and ionizing sources, as well as gaseous metal abundances. All the…

Astrophysics · Physics 2009-11-11 C. Kehrig , J. M. Vilchez , E. Telles , F. Cuisinier , E. Perez-Montero

The cosmic infrared background (CIB) provides a fundamental observational constraint on the star-formation history of galaxies over cosmic history. We estimate the contribution to the CIB from catalogued galaxies in the COSMOS field by…

We analyzed the CI lines associated with the damped Ly-alpha system observed at zabs = 1.15 in the spectrum of HE 0515-4414 to derive the 12C/13C ratio. The spectrum was obtained by means of the UV-Visual Echelle Spectrograph (UVES) at the…

Astrophysics · Physics 2009-11-11 S. A. Levshakov , M. Centurion , P. Molaro , M. V. Kostina

Measurements of the UV-continuum slopes provide valuable information on the physical properties of galaxies forming in the early universe, probing the dust reddening, age, metal content, and even the escape fraction. While constraints on…

We investigate the implications of the intergalactic opacity for the evolution of the cosmic UV luminosity density and its sources. Our main constraint is our measurement of the Lya forest opacity at redshifts 2<z<4.2 from 86…

Astrophysics · Physics 2009-11-13 C. -A. Faucher-Giguere , A. Lidz , L. Hernquist , M. Zaldarriaga

Foreground emission and scattered light from interplanetary dust (IPD) particles and emission from Galactic stellar sources are the greatest obstacles for determining the cosmic infrared background (CIB) from diffuse sky measurements in the…

Astrophysics · Physics 2007-05-23 E. Dwek , R. G. Arendt

Using archival Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope (HST) data, we have assembled a survey of eight sightlines through high-velocity cloud Complex C. Abundances of the observed ion species vary…

Astrophysics · Physics 2009-11-07 J. A. Collins , J. M. Shull , M. L. Giroux

Using our photoionization code CIRRUS, we show that the study of proximity effect on metal elements provides a possibility of placing constraints on the spectral shape of the metagalactic UV background (MUVB). From theoretical point of…

Astrophysics · Physics 2007-05-23 J. M. Liu