Mg II ABSORPTION CHARACTERISTICS OF A VOLUME-LIMITED SAMPLE OF GALAXIES AT z {approx} 0.1

Journal Article · Tue Dec 15 04:00:00 EST 2009 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/138/6/1817; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301503

Barton, Elizabeth J ^[1]; Cooke, Jeff

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1. Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575 (United States)

We present an initial survey of Mg II absorption characteristics in the halos of a carefully constructed, volume-limited subsample of galaxies embedded in the spectroscopic part of the Sloan Digital Sky Survey (SDSS). We observed quasars near sightlines to 20 low-redshift (z {approx} 0.1), luminous (M {sub r} + 5log h {<=}-20.5) galaxies in SDSS DR4 and DR6 with the LRIS-B spectrograph on the Keck I telescope. The primary systematic criteria for the targeted galaxies are a redshift z {approx}> 0.1 and the presence of an appropriate bright background quasar within a projected 75 h {sup -1} kpc of its center, although we preferentially sample galaxies with lower impact parameters and slightly more star formation within this range. Of the observed systems, six exhibit strong (W {sub eq}(2796) {>=} 0.3 A) Mg II absorption at the galaxy's redshift, six systems have upper limits which preclude strong Mg II absorption, while the remaining observations rule out very strong (W {sub eq}(2796) {>=} 1-2 A) absorption. The absorbers fall at higher impact parameters than many non-absorber sightlines, indicating a covering fraction f{sub c} {approx}< 0.4 for {>=}0.3 A absorbers at z {approx} 0.1, even at impact parameters {<=}35 h {sup -1} kpc (f {sub c} {approx} 0.25). The data are consistent with a possible dependence of covering fraction and/or absorption halo size on the environment or star-forming properties of the central galaxy.

• OSTI ID: 21301503
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 6 Vol. 138; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
ABSORPTION
GALACTIC EVOLUTION
GALAXIES
IMPACT PARAMETER
QUASARS
RED SHIFT
STARS
TELESCOPES