Elizabeth J. Barton and Jeff Cooke 2009 The Astronomical Journal 138 1817 doi:10.1088/0004-6256/138/6/1817
Elizabeth J. Barton and Jeff Cooke1
Show affiliationsWe 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 ~ 0.1), luminous (M 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
0.1 and the presence of an appropriate bright background quasar within a projected 75 h –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 eq(2796) ≥ 0.3 Å) 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 eq(2796) ≥ 1-2 Å) absorption. The absorbers fall at higher impact parameters than many non-absorber sightlines, indicating a covering fraction fc
0.4 for ≥0.3 Å absorbers at z ~ 0.1, even at impact parameters ≤35 h –1 kpc (f c ~ 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.
galaxies: evolution; galaxies: ISM; quasars: absorption lines
Issue 6 (2009 December)
Received 2009 May 7, accepted for publication 2009 September 26
Published 2009 November 3
Elizabeth J. Barton and Jeff Cooke 2009 The Astronomical Journal 138 1817
M. E. Brown et al 2009 ApJ 706 L110
Michał Hanasz et al 2009 ApJ 706 L155
Emilio Romano-Díaz et al. 2009 ApJ 702 1250
M. Böttcher et al. 2009 ApJ 703 1168
Richard A. Carrigan Jr 2009 ApJ 698 2075
N. V. Sujatha et al. 2009 ApJ 692 1333
F. K. Liu et al 2009 ApJ 706 L133
Angela Osterman Meyer et al. 2009 The Astronomical Journal 138 1902
M. Cuntz et al 2009 ApJ 706 L178