Dust depletion, chemical uniformity and environment of Ca II H&K quasar absorbers (2009)
Zych, Berkeley J., Murphy, Michael T., Hewett, Paul C., Prochaska, Jason X.
Ca ii λλ3934, 3969 absorbers, which are likely to be a subset of damped Lyman α systems (DLAs), are the most dusty quasar absorbers known with an order of magnitude more extinction in E(B - V)...
GRB 080503: implications of a naked short gamma-ray burst dominated by extended emission (2009)
Perley, D. A., Metzger, B. D., Granot, J., Butler, N. R., Sakamoto, T., Ramirez-Ruiz, Enrico, ...
We report on observations of GRB 080503, a short gamma-ray burst (GRB) with very bright extended emission (about 30 times the gamma-ray fluence of the initial spike) in conjunction with a thorough...
Dust depletion, chemical uniformity and environment of Ca II H&K quasar absorbers (2009)
Zych, Berkeley J., Murphy, Michael T., Hewett, Paul C., Prochaska, Jason X.
Ca ii λλ3934, 3969 absorbers, which are likely to be a subset of damped Lyman α systems (DLAs), are the most dusty quasar absorbers known with an order of magnitude more extinction in E(B - V)...
GRB 080503: implications of a naked short gamma-ray burst dominated by extended emission (2009)
Perley, D. A., Metzger, B. D., Granot, J., Butler, N. R., Sakamoto, T., Ramirez-Ruiz, Enrico, ...
We report on observations of GRB 080503, a short gamma-ray burst (GRB) with very bright extended emission (about 30 times the gamma-ray fluence of the initial spike) in conjunction with a thorough...
An 84 microGauss Magnetic Field in a Galaxy at Redshift z=0.692 (2008)
Wolfe, Arthur M., Jorgenson, Regina A., Robishaw, Timothy, Heiles, Carl, Prochaska, Jason X.
The magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of...
Dust depletion, chemical uniformity and environment of CaII H&K quasar absorbers (2008)
Zych, Berkeley J., Murphy, Michael T., Hewett, Paul C., Prochaska, Jason X.
CaII 3934,3969 absorbers, which are likely to be a subset of damped Lyman alpha systems, are the most dusty quasar absorbers known, with an order of magnitude more extinction in E(B-V) than other...
Prochaska, Jason X., Dessauges-Zavadsky, Miroslava, Ramirez-Ruiz, Enrico, Chen, Hsiao-Wen
We survey NV absorption in the afterglow spectra of long-duration gamma-ray bursts (GRBs) with the intent to study highly ionized gas in the galaxies hosting these events. We identify a high...
Baryons: What, When and Where? (2008)
Prochaska, Jason X., Tumlinson, Jason
We review the current state of empirical knowledge of the total budget of baryonic matter in the Universe as observed since the epoch of reionization. Our summary examines on three milestone...
Resolving The ISM Surrounding GRBs with Afterglow Spectroscopy (2008)
Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.
We review current research related to spectroscopy of gamma-ray burst (GRB) afterglows with particular emphasis on the interstellar medium (ISM) of the galaxies hosting these high redshift events....
The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB 070125 (2008)
Updike, Adria C., Haislip, Joshua B., Nysewander, Melissa C., Fruchter, Andrew S., Kann, D. Alexander, Klose, Sylvio, ...
We report on multi-wavelength observations, ranging from the X-ray to radio wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic observations reveal the presence of absorption...
Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4 (2008)
Weiner, Benjamin J., Coil, Alison L., Prochaska, Jason X., Newman, Jeffrey A., Cooper, Michael C., Bundy, Kevin, ...
Galactic winds are a prime suspect for the metal enrichment of the intergalactic medium and may have a strong influence on the chemical evolution of galaxies and the nature of QSO absorption line...
Bimodality in Damped Lyman alpha Systems (2008)
Wolfe, Arthur M., Prochaska, Jason X., Jorgenson, Regina A., Rafelski, Marc
We report evidence for a bimodality in damped Ly systems (DLAs). Using [C II] 158 mu cooling rates, lc, we find a distribution with peaks at lc=10^-27.4 and 10^-26.6 ergs s^-1 H^-1 separated by a...
The Molecular Hydrogen Deficit in Gamma-Ray Burst Afterglows (2008)
Whalen, Daniel, Prochaska, Jason X., Heger, Alexander, Tumlinson, Jason
Recent analysis of five gamma-ray burst (GRB) afterglow spectra reveal the absence of molecular hydrogen absorption lines, a surprising result in light of their large neutral hydrogen column...
Vladilo, Giovanni, Prochaska, Jason X., Wolfe, Arthur M.
We analyzed the spectroscopic and photometric database of the 5th data release of the Sloan Digital Sky Survey (SDSS) to search for evidence of the quasar reddening produced by dust embedded in...
Damped Lyman Alpha Systems at High Redshift and Models of Protogalactic Disks (2007)
Karsten Jedamzik, Jason X. Prochaska
this paper we compare observationally inferred velocity widths of a sample of damped Ly-ff systems at mean redshift z ß 3 to theoretically predicted velocity widths for a variety of disk models. In...
Can gravitational infall energy lead to the observed velocity dispersion in DLAs? (2007)
Razoumov, Alexei O., Norman, Michael L., Prochaska, Jason X., Sommer-Larsen, Jesper, Wolfe, Arthur M., Yang, Yi-Jung
The median observed velocity width v_90 of low-ionization species in damped Ly-alpha systems is close to 90 km/s, with approximately 10% of all systems showing v_90 > 210 km/s at z=3. We show that a...
Henry, R. B. C., Prochaska, Jason X.
Abundances of N, Si, S, and Fe for 45 damped Lyman alpha systems (DLAs) have been compiled and detailed one-zone chemical evolution models have been constructed for 30 of them. Assuming continuous...
Chen, Hsiao-Wen, Prochaska, Jason X., Gnedin, Nickolay Y.
We describe a new method to measure the escape fraction fesc of ionizing radiation from distant star-forming galaxies using the afterglow spectra of long-duration gamma-ray bursts (GRBs). Optical...
The Galactic Deuterium Abundance and Dust Depletion: Insights From an Expanded Ti/H Sample (2007)
Ellison, Sara L., Prochaska, Jason X., Lopez, Sebastian
The primordial abundance of deuterium (D/H) yields a measure of the density of baryons in the universe and is an important complement to determinations from cosmic microwave background (CMB)...
Characterizing the Low-Redshift Intergalactic Medium towards PKS1302-102 (2007)
Cooksey, Kathy L., Prochaska, Jason X., Chen, Hsiao-Wen, Mulchaey, John S., Weiner, Benjamin J.
We present a detailed analysis of the intergalactic metal-line absorption systems in the archival HST/STIS and FUSE ultraviolet spectra of the low-redshift quasar PKS1302-102 (z_QSO = 0.2784). We...
On the Incidence of C IV Absorbers Along the Sightlines to Gamma-Ray Bursts (2007)
Tejos, Nicolas, Lopez, Sebastian, Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava
We report on the statistics of strong (W_r > 0.15 A) C IV absorbers at z=1.5-3.5 toward high-redshift gamma-ray bursts (GRBs). In contrast with a recent survey for strong Mg II absorption systems at...
On the Nature of Velocity Fields in High z Galaxies (2007)
Prochaska, Jason X., Chen, Hsiao-Wen, Wolfe, Arthur M., Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.
We analyze the gas kinematics of damped Lya systems (DLAs) hosting high z gamma-ray bursts (GRBs) and those toward quasars (QSO-DLAs) focusing on threestatistics: (1) dv, the velocity interval...
Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.
We study the chemical abundances of the interstellar medium surrounding high z gamma-ray bursts (GRBs) through analysis of the damped Lya systems (DLAs) identified in afterglow spectra. These...
Missing Molecular Hydrogen and the Physical Conditions of GRB Host Galaxies (2007)
Tumlinson, Jason, Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.
We examine the abundance of molecular hydrogen (H2) in the spectra of gamma ray burst afterglows (GRBs). In nearby galaxies H2 traces the cold neutral medium (CNM) and dense molecular star-forming...
The SDSS-DR5 Survey for Proximate Damped Lya Systems (2007)
Prochaska, Jason X., Hennawi, Joseph F., Herbert-Fort, Stephane
Using the Sloan Digital Sky Survey, Data Release 5, we survey proximate damped Lya systems (PDLAs): absorption line systems with HI column density N(HI)> 2x10^20 cm^{-2} at velocity separation dv <...
The Ucsd/Keck Damped Lya Abundance Database: A Decade of High Resolution Spectroscopy (2007)
Prochaska, Jason X., Wolfe, Arthur M., Howk, J. Christopher, Gawiser, Eric, Burles, Scott M., Cooke, Jeff
We publish the Keck/HIRES and Keck/ESI spectra that we have obtained during the first 10 years of Keck observatory operations. Our full sample includes 42 HIRES spectra and 39 ESI spectra along 65...
Chen, Hsiao-Wen, Prochaska, Jason X., Ramirez-Ruiz, Enrico, Bloom, Joshua S., Dessauges-Zavadsky, Miroslava, Foley, Ryan J.
We investigate available constraints on the circumstellar medium (CSM) around long-duration gamma-ray burst (GRB) progenitors from afterglow spectra. We first establish a statistical sample of five...
O'Meara, John M, Prochaska, Jason X., Burles, Scott, Prochter, Gabriel, Bernstein, Rebecca A., Burgess, Kristin M.
We present the results of a survey for super Lyman limit systems (SLLS; defined to be absorbers with 19.0
On the incidence of strong MgII absorbers along gamma-ray burst sight lines (2006)
Prochter, Gabriel E., Prochaska, Jason X., Chen, Hsiao-Wen, Bloom, Joshua S., Dessauges-Zavadsky, Miroslava, Foley, Ryan J., ...
We report on a survey for strong ( rest equivalent width W-r >= 1 angstrom) intervening Mg II systems along the sight lines to long-duration gamma-ray bursts (GRBs). The GRB spectra that comprise the...
The Metal-Strong Damped Lyman-alpha Systems (2006)
Herbert-Fort, Stéphane, Prochaska, Jason X., Dessauges-Zavadsky, Miroslava, Ellison, Sara L., Howk, J. Chris, Wolfe, Arthur M., ...
We have identified a metal-strong (logN(Zn+) > 13.15 or logN(Si+) > 15.95) DLA (MSDLA) population from an automated quasar (QSO) absorber search in the Sloan Digital Sky Survey Data Release 3...
Cooke, Jeff, Wolfe, Arthur M., Gawiser, Eric, Prochaska, Jason X.
We use 211 galaxy spectra from our survey for Lyman break galaxies (LBGs) associated with 11 damped Lyman alpha systems (DLAs) to measure the three-dimensional LBG auto-correlation and DLA-LBG...
Super-Solar Super Lyman Limit Systems (2006)
Prochaska, Jason X., O'Meara, John M., Herbert-Fort, Stephane, Burles, Scott, Prochter, Gabriel E., Bernstein, Rebecca A.
We present abundance measurements for two super Lyman Limit systems (SLLS; quasar absorption line systems with 10^19 cm^-2 < N_HI < 10^20.3 cm^-2) selected from a set of metal-strong absorbers in the...
Temporal Variation in Excited Fe^+ Near a GRB Afterglow (2006)
Dessauges-Zavadsky, Miroslava, Chen, Hsiao-Wen, Prochaska, Jason X., Bloom, Joshua S., Barth, Aaron J.
Excited Si^+ and Fe^+ species are routinely observed in the host environment of gamma-ray burst (GRB) afterglows, but are not commonly seen in other extragalactic locations. Their presence signals...
We examine the practice of deriving interstellar medium (ISM) abundances from low-resolution spectroscopy of GRB afterglows. We argue that the multi-ion single-component curve-of-growth analysis...
Hennawi, Joseph F., Prochaska, Jason X.
With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We used a sample of 17 Lyman limit systems with...
The N/O Plateau of Blue Compact Galaxies: Monte Carlo Simulations of the Observed Scatter (2006)
Henry, R. B. C., Nava, A., Prochaska, Jason X.
Chemical evolution models and Monte Carlo simulation techniques have been combined for the first time to study the distribution of blue compact galaxies on the N/O plateau. Each simulation comprises...
The UCSD Radio-Selected Quasar Survey for Damped Lyman alpha System (2006)
Jorgenson, Regina A., Wolfe, Arthur M., Prochaska, Jason X., Lu, Limin, Howk, J. Christopher, Cooke, Jeff, ...
As large optical quasar surveys for damped Lya become a reality and the study of star forming gas in the early Universe achieves statistical robustness, it is now vital to identify and quantify the...
Quasars Probing Quasars I: Optically Thick Absorbers Near Luminous Quasars (2006)
Hennawi, Joseph F., Prochaska, Jason X., Burles, Scott, Strauss, Michael A., Richards, Gordon T., Schlegel, David J., ...
With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We search 149 moderate resolution background...
Prochaska, Jason X., Weiner, Benjamin J., Chen, Hsiao-Wen, Mulchaey, John S.
We present a galaxy survey of the field surrounding PKS0405-123 performed with the WFCCD spectrometer at Las Campanas Observatory. The survey is comprised of two datasets: (1) a greater than 95%...
GRB Afterglows as a New Probe of the ISM and IGM at High Redshift (2006)
Chen, Hsiao-Wen, Prochaska, Jason X., Bloom, Josh S.
We summarize results from a study of the metallicity, relative abundances, gas density, and kinematics of dense media in the host environment of two Swift bursts, GRB050730 at z=3.968 and GRB051111...
Dissecting the Circumstellar Environment of Gamma-Ray Burst Progenitors (2006)
Prochaska, Jason X., Chen, Hsiao-Wen, Bloom, Joshua S.
We investigate properties of the interstellar medium (ISM) in galaxies hosting long-duration gamma-ray bursts (GRBs) from an analysis of atomic species (MgI, FeI) and excited fine-structure levels of...
Germanium in damped Lyman-alpha systems and copper connection (2006)
Gallino, Roberto, Pignatari, M., Bisterzo, S., Prochaska, Jason X., Fenner, Y., Heger, Alexander, ...
From the analysis of recent high-resolution spectroscopy data of Cu in unevolved galactic stars at various metallicities, as compared with nucleosynthesis predictions in massive stars exploding as...
Germanium in damped Lyman-alpha systems and copper connection (2006)
Gallino, Roberto, Pignatari, M., Bisterzo, S., Prochaska, Jason X., Fenner, Y., Heger, Alexander, ...
From the analysis of recent high-resolution spectroscopy data of Cu in unevolved galactic stars at various metallicities, as compared with nucleosynthesis predictions in massive stars exploding as...
Razoumov, Alexei O., Norman, Michael L., Prochaska, Jason X., Wolfe, Arthur M.
We use high resolution Eulerian hydrodynamics simulations to study kinematic properties of the low ionization species in damped Ly-alpha systems at redshift z=3. Our adaptive mesh refinement...
Damped Lyman alpha Systems (2005)
Wolfe, Arthur M., Gawiser, Eric, Prochaska, Jason X.
Observations of damped Lyman alpha systems offer a unique window on the neutral-gas reservoirs that gave rise to galaxies at high redshifts. This review focuses on critical properties such as the H I...
The SDSS Damped Lya Survey: Data Release 3 (2005)
Prochaska, Jason X., Herbert-Fort, Stephane, Wolfe, Arthur M.
We present the results from a damped Lya survey of the Sloan Digital Sky Survey, Data Release 3 based on over 500 new damped Lya systems at z>2.2. We measure the HI column density distribution f(N)...
Chen, Hsiao-Wen, Prochaska, Jason X., Bloom, Joshua S., Thompson, Ian B.
We present an echelle spectrum of the Swift GRB 050730, obtained four hours after the burst using the MIKE spectrograph on the Magellan Clay Telescope when the afterglow was at R=17.7. The spectrum...
Chen, Hsiao-Wen, Prochaska, Jason X., Weiner, Benjamin J., Mulchaey, John S., Williger, Gerard M.
We present a pilot study of the clustering properties of Lya absorbers with respect to known galaxies based on 112 Lya absorbers and 482 galaxies identified at z= 14 shows a comparable strength to...
Evidence for Correlated Titanium and Deuterium Depletion in the Galactic ISM (2005)
Prochaska, Jason X., Tripp, Todd M., Howk, J. Christopher
Current measurements indicate that the deuterium abundance in diffuse interstellar gas varies spatially by a factor of ~4 among sightlines extending beyond the Local Bubble. One plausible explanation...
On the Incidence and Kinematics of Strong Mg II Absorbers (2004)
Prochter, Gabriel E., Prochaska, Jason X., Burles, Scott
We present the results of two investigations into the nature of strong (rest equivalent width > 1.0 Ang) Mg II absorption systems at high redshift. The first line of questioning examines the complete...
Elemental Abundances in Two High Column Density Damped Lyman Alpha Systems at z < 1.5 (2004)
Rao, Sandhya M., Prochaska, Jason X., Howk, J. Christopher, Wolfe, Arthur M.
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...
Prochaska, Jason X., Chen, Hsiao-Wen, Howk, J. Christopher, Weiner, Benjamin J., Mulchaey, John
We present results from an analysis of FUSE and HST/STIS spectroscopy of the z_em=0.57 quasar PKS0405-123. We focus on the intervening metal-line systems identified along the sightline and...
On the Nature of the Heat Source for Damped Lya Systems (2004)
Wolfe, Arthur M., Howk, J. Chris, Gawiser, Eric, Prochaska, Jason X., Lopez, Sebastian
We investigate the heat source of the neutral gas comprising DLAs. Unlike the Lya forest, where the extragalactic background radiation field ionizes and heats the gas, we find that grain...
Tripp, Todd M., Jenkins, Edward B., Bowen, David V., Prochaska, Jason X., Aracil, Bastien, Ganguly, Rajib
We present a new UV echelle spectrum of PG1216+069, obtained with HST+STIS, which reveals damped Lya (DLA) absorption as well as O I, C II, Si II, and Fe II absorption lines at z(abs) = 0.00632 near...
Cold Neutral Gas in a z=4.2 Damped Lyman-alpha System: The Fuel for Star Formation (2004)
Howk, J. Christopher, Wolfe, Arthur M., Prochaska, Jason X.
We discuss interstellar temperature determinations using the excitation equilibrium of the ^2P levels of Si II and C II. We show how observations of the ^2P_3/2 fine structure levels of Si II and C...
The SDSS Damped Lya Survey: Data Release 1 (2004)
Prochaska, Jason X., Herbert-Fort, Stephane
We present the results from an automated search for damped Lya (DLA) systems in the quasar spectra of Data Release 1 from the Sloan Digital Sky Survey (SDSS-DR1). At z~2.5, this homogeneous dataset...
Prochaska, Jason X., Bloom, Joshua S., Chen, Hsiao-Wen, Hurley, Kevin C., Melbourne, Jason, Dressler, Alan, ...
We present Keck/NIRSPEC near-IR images and Magellan/IMACS optical spectroscopy of the host galaxy of GRB 031203. The host is an actively star-forming galaxy at z=0.1055 +/- 0.0001. This is the lowest...
Fenner, Yeshe, Prochaska, Jason X., Gibson, Brad K.
We have investigated chemical evolution in the young universe by analysing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements...
Constraints on early nucleosynthesis from the abundance of a damped Ly- system at z =2.626 (2004)
Fenner, Yeshe, Prochaska, Jason X., Gibson, Brad K.
We have investigated chemical evolution in the young universe by analyzing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements...
Constraints on early nucleosynthesis from the abundance of a damped Ly- system at z =2.626 (2004)
Fenner, Yeshe, Prochaska, Jason X., Gibson, Brad K.
We have investigated chemical evolution in the young universe by analyzing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements...
Constraints on early nucleosynthesis from the abundance of a damped Ly- system at z =2.626 (2004)
Fenner, Yeshe, Prochaska, Jason X., Gibson, Brad K.
We have investigated chemical evolution in the young universe by analyzing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements...
Constraints on early nucleosynthesis from the abundance of a damped Ly- system at z =2.626 (2004)
Fenner, Yeshe, Prochaska, Jason X., Gibson, Brad K.
We have investigated chemical evolution in the young universe by analyzing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements...
Murphy, Michael T., Flambaum, Victor V., Webb, J. K., Dzuba, Vladimir V., Prochaska, Jason X., Wolfe, Arthur M.
We present evidence for variations in the fine-structure constant from Keck/HIRES spectra of 143 quasar absorption systems over the redshift range 0.2 < zabs < 4.2. This includes 15 new systems,...
Constraints on early nucleosynthesis from the abundance of a damped Ly- system at z =2.626 (2004)
Fenner, Yeshe, Prochaska, Jason X., Gibson, Brad K.
We have investigated chemical evolution in the young universe by analyzing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements...
Murphy, Michael T., Flambaum, Victor V., Webb, J. K., Dzuba, Vladimir V., Prochaska, Jason X., Wolfe, Arthur M.
We present evidence for variations in the fine-structure constant from Keck/HIRES spectra of 143 quasar absorption systems over the redshift range 0.2 < zabs < 4.2. This includes 15 new systems,...
Comparing Chemical Abundances of the Damped Lya Systems and Metal-Poor Stars (2003)
I briefly draw comparisons between the fields of damped Lya and metal-poor stellar abundances. In particular, I examine their complementary age-metallicity relations and comparisons between the...
Chemical Abundances in the Damped Lya Systems (2003)
I introduce and review the data and analysis techniques used to measure abundances in the damped Lya systems, quasar absorption-line systems associated with galaxies in the early Universe. The...
The C IV Mass Density of the Universe at Redshift 5 (2003)
Pettini, Max, Madau, Piero, Bolte, Michael, Prochaska, Jason X., Ellison, Sara L., Fan, Xiaohui
In order to search for metals in the Lyman alpha forest at redshifts z > 4, we have obtained spectra of high S/N and resolution of three QSOs at z > 5.4 discovered by the Sloan Digital Sky Survey....
The ESI/KeckII Damped Lya Abundance Database (2003)
Prochaska, Jason X., Gawiser, Eric, Wolfe, Arthur M., Cooke, Jeff, Gelino, Dawn
This paper presents chemical abundance measurements for 37 damped Lya systems at z>2.5 observed with the Echellette Spectrograph and Imager on the KeckII telescope. We measure the HI column densities...
New Damped Lya Metallicities from ESI Spectroscopy of Five Palomar Sky Survey Quasars (2003)
Prochaska, Jason X., Castro, Sandra, Djorgovski, S. G.
This paper presents chemical abundance measurements for 12 new z>3 damped Lya systems discovered toward five quasars from the Palomar Sky Survey. We determine HI column densities from profile fits to...
The Age-Metallicity Relation of the Universe in Neutral Gas: The First 100 Damped Lya Systems (2003)
Prochaska, Jason X., Gawiser, Eric, Wolfe, Arthur M., Castro, Sandro, Djorgovski, S. G.
We present accurate metallicity measurements for 121 damped Lya systems at 0.5
The elemental abundance pattern in a galaxy at z=2.626 (2003)
Prochaska, Jason X., Howk, J. Chris, Wolfe, Arthur M.
The discovery of metal-poor stars (where metal is any element more massive than helium) has enabled astronomers to probe the chemical enrichment history of the Milky Way. More recently, element...
CII* Absorption in Damped Lyman Alpha Systems: (I) Star Formation Rates in a Two-Phase Medium (2003)
Wolfe, Arthur M., Prochaska, Jason X., Gawiser, Eric
We describe a technique that for the first time measures star formation rates (SFRs) in damped Lyman alpha systems(DLAs) directly. We assume that massive stars form in DLAs, and that the FUV...
Wolfe, Arthur M., Gawiser, Eric, Prochaska, Jason X.
Starting from the SFR per unit physical area, determined for DLAs using the C II* method, we obtain the SFR per unit comoving volume at $z$ $\approx$ 3, and find that it agrees with that for the...
On the Origin of Nitrogen in Damped Ly-alpha Systems (2002)
Henry, R. B. C., Prochaska, Jason X.
Recent measurements of nitrogen and alpha elements in over 20 damped Ly-alpha systems (DLA) are compared with similar measurements for numerous emission line objects and stars. It is found that the...
Maller, Ariyeh H., Prochaska, Jason X., Somerville, Rachel S., Primack, Joel R.
We investigate a model for the high-ionization state gas associated with observed damped Lyman-alpha systems, based on a semi-analytic model of galaxy formation set within the paradigm of...
The Chemical Uniformity of High z DLA Protogalaxies (2002)
We investigate chemical abundance variations along the sightlines through 13 damped Lya systems (DLA). We introduce a technique designed to identify abundance variations in multiple velocity bins...
The Physics of Extragalactic Gas: One Argument for a Next Generation Space Telescope (2002)
Observations of the Galactic ISM have had tremendous impact on our understanding of the physics of galactic gas and the processes of galaxy formation. Similar observations at z>2 reveal the neutral...
Prochaska, Jason X., Ryan-Weber, Emma, Staveley-Smith, Lister
We examine the gas kinematics of the LMC revealed by the high spatial and velocity resolution HI data cube of the combined ATCA and Parkes telescope surveys. We adopt an approach designed to...
Prochaska, Jason X., Henry, Richard B. C., O'Meara, John M., Tytler, David, Wolfe, Arthur M., Kirkman, David, ...
We present 14 N^0 measurements from our HIRES/Keck database of damped Lya abundances. These data are combined with measurements from the recent and past literature to build an homogeneous, uniform...
Metallicity Evolution of Damped Lyman Alpha Systems In Lambda CDM Cosmology (2002)
Cen, Renyue, Ostriker, Jeremiah P., Prochaska, Jason X., Wolfe, Arthur M.
Utilizing a new, high mass resolution hydrodynamic simulation we compute the metallicity evolution of damped Lyman alpha systems (DLAs) and find a reasonable agreement with observations. In...
Prochaska, Jason X., Howk, J. Christopher, O'Meara, John M., Tytler, David, Wolfe, Arthur M., Kirkman, David, ...
We investigate the ionization state of the damped Lya system at z=2.62 toward GB1759+7539 through an analysis of ionic ratios sensitive to photoionization: ArI/SII, FeIII/FeII, NII/NI, AlIII/AlII....
Lopez, Sebastian, Reimers, Dieter, D'Odorico, Sandro, Prochaska, Jason X.
We have obtained a high resolution, high S/N UVES spectrum of the bright QSO HE2243-6031 to analyze the damped Ly-alpha system (DLA) observed at z=2.33. The metallicity of this system is 1/12 solar...
Galaxies Associated with z~4 Damped Lya Systems: I. Imaging and Photometric Selection (2002)
Prochaska, Jason X., Gawiser, Eric, Wolfe, Arthur M., Quirrenbach, Andreas, Lanzetta, Kenneth M., Chen, Hsiao-Wen, ...
This paper describes the acquisition and analysis of imaging data for the identification of galaxies associated with z~4 damped Lya systems. We present deep BRI images of three fields known to...
Prochaska, Jason X., Ryan-Weber, Emma, Staveley-Smith, Lister
We examine the gas kinematics of the Large Magellenic Cloud (LMC) revealed by the high spatial and velocity resolution H i data cube of the combined Australia Telescope Compact Array and Parkes...
Prochaska, Jason X., Ryan-Weber, Emma, Staveley-Smith, Lister
We examine the gas kinematics of the Large Magellenic Cloud (LMC) revealed by the high spatial and velocity resolution H i data cube of the combined Australia Telescope Compact Array and Parkes...
The UCSD HIRES/KeckI Damped Lya Abundance Database: I. The Data (2001)
Prochaska, Jason X., Wolfe, Arthur M., Tytler, David, Burles, Scott, Cooke, Jeff, Gawiser, Eric, ...
We present new chemical abundance measurements of 16 damped Lya systems at z>1.5 and update our previous abundance analyses. The entire database presented here was derived from HIRES observations on...
The UCSD HIRES/KeckI Damped Lya Abundance Database: II. The Implications (2001)
Prochaska, Jason X., Wolfe, Arthur M.
We present a comprehensive analysis of the damped Lya abundance database presented in the first paper of this series. This database provides a homogeneous set of abundance measurements for many...
Are Simulations of CDM Consistent with Galactic-Scale Observations at High Redshift? (2001)
Prochaska, Jason X., Wolfe, Arthur M.
We compare new observations on the kinematic characteristics of the damped Lya systems against results from numerical SPH simulations to test the predictions of hierarchical galaxy formation. This...
Chen, Hsiao-Wen, Prochaska, Jason X., Lanzetta, Kenneth M.
We present a detailed analysis of the chemical abundances, ionization state, and origin of a partial Lyman limit system (N(HI) ~ 10^{16} cm^{-2}) at low redshift (z=0.167 towards PKS0405-1219). We...
The First Detection of Co in a Damped Lyman Alpha System (2001)
Ellison, Sara L., Ryan, Sean G., Prochaska, Jason X.
The study of elemental abundances in Damped Lyman Alpha systems (DLAs) at high redshift represents one of our best opportunities to probe galaxy formation and chemical evolution at early times. By...
The First Detection of Cobalt in a Damped Lyman Alpha System (2001)
Ellison, Sara L., Ryan, Sean G., Prochaska, Jason X.
We present the first ever detection of Cobalt in a Damped Lyman Alpha system (DLA) at z = 1.92. In addition to providing important clues to the star formation history of these high redshift galaxies,...
First Investigation of the Clustering Environment of Damped Lyman Alpha Absorbers at z=4 (2001)
Gawiser, Eric, Wolfe, Arthur M., Prochaska, Jason X., Lanzetta, Kenneth M., Yahata, Noriaki, Quirrenbach, Andreas
We report the first observations of the clustering environment of damped Lyman alpha absorption systems at z=4. Color selection and photometric redshifts were used to select 44 candidate Lyman-break...
Prochaska, Jason X., Gawiser, Eric, Wolfe, Arthur M.
We present the first results from an ongoing survey to discover and measure the metallicity of z>3 damped Lya systems with the Echellette Spectrograph and Imager (ESI) on the Keck II telescope. Our...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Dzuba, V. A., Churchill, Christopher W., Prochaska, Jason X., ...
An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar (QSO) absorption-line spectra with...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Churchill, Christopher W., Prochaska, Jason X.
Comparison of quasar (QSO) absorption spectra with laboratory spectra allows us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we...
Further evidence for cosmological evolution of the fine structure constant (2001)
Webb, J. K., Murphy, M. T., Flambaum, Victor V., Dzuba, V. A., Barrow, John D., Churchill, Christopher W., ...
We describe the results of a search for time variability of the fine structure constant α using absorption systems in the spectra of distant quasars. Three large optical data sets and two 21 cm...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Prochaska, Jason X., Wolfe, Arthur M.
Comparison of quasar (QSO) absorption-line spectra with laboratory spectra provides a precise probe for variability of the fine-structure constant, α, over cosmological time-scales. We...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Dzuba, V. A., Churchill, Christopher W., Prochaska, Jason X., ...
An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar (QSO) absorption-line spectra with...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Churchill, Christopher W., Prochaska, Jason X.
Comparison of quasar (QSO) absorption spectra with laboratory spectra allows us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we...
Further evidence for cosmological evolution of the fine structure constant (2001)
Webb, J. K., Murphy, M. T., Flambaum, Victor V., Dzuba, V. A., Barrow, John D., Churchill, Christopher W., ...
We describe the results of a search for time variability of the fine structure constant α using absorption systems in the spectra of distant quasars. Three large optical data sets and two 21 cm...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Prochaska, Jason X., Wolfe, Arthur M.
Comparison of quasar (QSO) absorption-line spectra with laboratory spectra provides a precise probe for variability of the fine-structure constant, α, over cosmological time-scales. We...
The Deuterium to Hydrogen Abundance Ratio Towards a Fourth QSO: HS0105+1619 (2000)
O'Meara, John M., Tytler, David, Kirkman, David, Suzuki, Nao, Prochaska, Jason X., Lubin, Dan, ...
We report the measurement of the primordial D/H abundance ratio towards QSO \object. The column density of the hydrogen in the $z \simeq 2.536$ Lyman limit system is high, \lnhi $= 19.422 \pm 0.009$...
Wolfe, Arthur M., Prochaska, Jason X.
We investigate the kinematics of ionized and neutral gas in a sample of 35 damped Lyman alpha protogalaxies (DLAs) with HIRES on the Keck I 10 m telescope. Velocity profiles with resolution of ~ 8...
Wolfe, Arthur M., Prochaska, Jason X.
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...
The Origin of a Chemically Enriched lya Absorption System at z=0.167 (2000)
Chen, Hsiao-Wen, Prochaska, Jason X.
We present the first detailed analysis of the chemical abundances, ionization state, and origin of a partial Lyman limit system (N(\hI) ~ 10^{16} \cmjj) at low redshift (z=0.167 towards...
The Galactic Thick Disk Stellar Abundances (2000)
Prochaska, Jason X., Naumov, Sergei O., Carney, Bruce W., McWilliam, Andrew, Wolfe, Arthur M.
We present first results from a program to measure the chemical abundances of a large (N>30) sample of thick disk stars with the principal goal of investigating the formation history of the Galactic...
On the Perils of Hyperfine Splitting: A reanalysis of Mn and Sc Abundance Trends (2000)
Prochaska, Jason X., McWilliam, Andrew
We investigate the impact of hyperfine splitting on stellar abundance analyses of Mn and Sc, and find that incorrect hfs treatment can lead to spurious abundance trends with metallicity. We estimate...
Metallicity Evolution in the Early Universe (2000)
Prochaska, Jason X., Wolfe, Arthur M.
Observations of the damped Lya systems provide direct measurements on the chemical enrichment history of neutral gas in the early universe. In this Letter, we present new measurements for four damped...
Maller, Ariyeh H., Prochaska, Jason X., Somerville, Rachel S., Primack, Joel R.
We investigate the properties of damped Lyman-alpha systems (DLAS) in semi-analytic models, focusing on whether the models can reproduce the kinematic properties of low-ionization metal lines...
Optical Counterparts to Damped Lyman Alpha Systems (2000)
Maller, Ariyeh H., Prochaska, Jason X., Somerville, Rachel S., Primack, Joel R.
Previously we have shown (Maller et al, 1998) that the kinematics of Damped Lyman Alpha Systems (DLAS) as measured by Prochaska and Wolfe (1998) can be reproduced in a multiple disk model (MDM) if...
Maller, Ariyeh H., Somerville, Rachel S., Prochaska, Jason X., Primack, Joel R.
Previously we have shown that it is possible to account for the kinematic properties of damped Lyman alpha systems (DLAS) in the context of semi-analytic models. In these models, hierarchical...
Making Damped Lyman Alpha Systems in Semi-Analytic Models (1998)
Maller, Ariyeh H., Somerville, Rachel S., Prochaska, Jason X., Primack, Joel R.
The velocity profiles of weak metal absorption lines can be used to observationally probe the kinematic state of gas in damped Lyman-alpha systems. Prochaska and Wolfe have argued that the flat...
Investigating the Metal Line Systems at Z=1.9 toward J2233-606 in the HDF-S (1998)
Prochaska, Jason X., Burles, Scott M.
The combination of STIS and optical spectroscopy with STIS imaging of the field surrounding J2233-606 afford a unique opportunity to study the physical nature of the Quasar Absorption Line systems....
The Physical Nature of the Lyman Limit Systems (1998)
We analyze Keck HIRES observations of a Lyman limit system at z=2.652 toward Q2231-00. These observations afford the most comprehensive study of the physical properties of a LL system to date. By...
Chemical Abundances of the Damped Lya Systems at z>1.5 (1998)
Prochaska, Jason X., Wolfe, Arthur M.
We present chemical abundance measurements for 19 damped lya systems observed with HIRES on the 10m W.M. Keck Telescope. Our principal goal is to investigate the abundance patterns of the damped...
Protogalactic Disk Models of Damped Lya Kinematics (1998)
Prochaska, Jason X., Wolfe, Arthur M.
We present new observational results on the kinematics of the damped lya systems. Our full sample is now comprised of 31 low-ion profiles and exhibits similar characteristics to the sample from Paper...
On the Evolution of Damped Lyman Alpha Systems to Galactic Disks (1997)
Wolfe, Arthur M., Prochaska, Jason X.
The mean metallicity of the thick disk of the Galaxy is 0.5 dex higher than that of the damped Lyman alpha systems. This has been interpreted to argue that stars in the former do not arise out of gas...
Damped Lyman Alpha Systems at High Redshift and Models of Protogalactic Disks (1997)
Jedamzik, Karsten, Prochaska, Jason X.
We employ observationally determined intrinsic velocity widths and column densities of damped Lyman-alpha systems at high redshift to investigate the distribution of baryons in protogalaxies within...
On the Kinematics of the Damped Lyman Alpha Protogalaxies (1997)
Prochaska, Jason X., Wolfe, Arthur M.
We present the first results of an ongoing program to investigate the kinematic characteristics of high redshift damped lya systems. Because damped lya systems are widely believed to be the...
Prochaska, Jason X., Wolfe, Arthur M.
We present high resolution, high SNR spectra of the QSO Q2206-199 obtained with HIRES on the 10m W.M. Keck Telescope. Our analysis focuses on the two previously identified damped \lya systems found...
Prochaska, Jason X., Wolfe, Arthur M.
We present high resolution ($\approx 8$ \kms) spectra of the QSO Q0201+365 obtained with HIRES, the echelle spectrograph on the 10m W.M. Keck Telescope. Although we identify over $80\%$ of the...