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Precious Metals in SDSS Quasar Spectra. II. Tracking the Evolution of Strong, 0.4 < z < 2.3 Mg II Absorbers with Thousands of Systems

Seyffert, Eduardo N. and Cooksey, Kathy L. and Simcoe, Robert A. and O'Meara, John M. and Kao, Melodie M. and Prochaska, J. Xavier (2013) Precious Metals in SDSS Quasar Spectra. II. Tracking the Evolution of Strong, 0.4 < z < 2.3 Mg II Absorbers with Thousands of Systems. Astrophysical Journal, 779 (2). Art. No. 161. ISSN 0004-637X.

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We have performed an analysis of over 34,000 Mg II doublets at 0.36 < z < 2.29 in Sloan Digital Sky Survey (SDSS) Data Release 7 quasar spectra; the catalog, advanced data products, and tools for analysis are publicly available. The catalog was divided into 14 small redshift bins with roughly 2500 doublets in each and from Monte Carlo simulations, we estimate 50% completeness at rest equivalent width W_r ≈ 0.8 Å. The equivalent width frequency distribution is described well by an exponential model at all redshifts, and the distribution becomes flatter with increasing redshift, i.e., there are more strong systems relative to weak ones. Direct comparison with previous SDSS Mg II surveys reveals that we recover at least 70% of the doublets in these other catalogs, in addition to detecting thousands of new systems. We discuss how these surveys came by their different results, which qualitatively agree but because of the very small uncertainties, differ by a statistically significant amount. The estimated physical cross section of Mg II-absorbing galaxy halos increased approximately threefold from z = 0.4 to z = 2.3, while the W_r ≥ 1 Å absorber line density, dN_(Mg II)/dX, grew by roughly 45%. Finally, we explore the different evolution of various absorber populations—damped Lyα absorbers, Lyman limit systems, strong C IV absorbers, and strong and weaker Mg II systems—across cosmic time (0 < z < 6).

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Simcoe, Robert A.0000-0003-3769-9559
O'Meara, John M.0000-0002-7893-1054
Kao, Melodie M.0000-0001-5125-1414
Prochaska, J. Xavier0000-0002-7738-6875
Additional Information:© 2013 American Astronomical Society. Received 2013 August 23; accepted 2013 October 22; published 2013 December 3. The current study was funded largely by the National Science Foundation Astronomy and Astrophysics Postdoctoral Fellowship (AST 1003139) and in part by MIT Undergraduate Research Opportunity Program (UROP) Direct Funding, from the Office of Undergraduate Advising and Academic Programming and the John Reed UROP Fund. R.A.S. acknowledges support from NSF grants AST 0908920 and AST 1109915, and J.X.P. acknowledges support from grants AST 0709235 and AST 1010004. We appreciate J.-R. Gauthier and H.-W. Chen’s help in making our catalog better. We thank M. Sinha for his programming help and P. Jonsson for productive discussions regarding statistics and programming. We gratefully acknowledge the vital role and last huzzah (for us) of the Adam J. Burgasser Endowed Chair. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS Website is The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. The Participating Institutions are the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, University of Cambridge, Case Western Reserve University, University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max Planck Institute for Astronomy (MPIA), the Max Planck Institute for Astrophysics (MPA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the US Naval Observatory, and the University of Washington. Facility: Sloan
Funding AgencyGrant Number
NSF Astronomy and Astrophysics FellowshipAST-1003139
Massachusetts Institute of Technology (MIT)UNSPECIFIED
Subject Keywords: galaxies: halos; intergalactic medium; quasars: absorption lines; techniques: spectroscopic
Issue or Number:2
Record Number:CaltechAUTHORS:20140121-134616002
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Official Citation:Precious Metals in SDSS Quasar Spectra. II. Tracking the Evolution of Strong, 0.4 < z < 2.3 Mg II Absorbers with Thousands of Systems Eduardo N. Seyffert et al. 2013 ApJ 779 161
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:43455
Deposited By: Ruth Sustaita
Deposited On:22 Jan 2014 17:48
Last Modified:09 Mar 2020 13:19

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