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Title: Precious metals in SDSS quasar spectra. II. Tracking the evolution of strong, 0.4 < z < 2.3 Mg II absorbers with thousands of systems

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 {sub 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 {sub r} ≥ 1 Å absorber line density, dN{sub MgII}/dX, grew by roughlymore » 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).« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Department of Physics, MIT, 77 Massachusetts Avenue, 37-664D, Cambridge, MA 02139 (United States)
  2. MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-685, Cambridge, MA 02139 (United States)
  3. Department of Chemistry and Physics, Saint Michael's College, One Winooski Park, Colchester, VT 05439 (United States)
  4. Caltech, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
  5. Department of Astronomy and UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)
Publication Date:
OSTI Identifier:
22348438
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 779; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; APPROXIMATIONS; CATALOGS; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; CROSS SECTIONS; DENSITY; DISTRIBUTION; GALAXIES; METALS; MONTE CARLO METHOD; QUASARS; RED SHIFT; SPECTRA