1111.3359 (G. G. Kacprzak et al.)

The HI Mass Density in Galactic Halos, Winds, and Cold Accretion as Traced by MgII Absorption    [PDF]

G. G. Kacprzak, C. W. Churchill

It is well established that MgII absorption lines detected in background quasar spectra arise from gas structures associated with foreground galaxies. The degree to which galaxy evolution is driven by the gas cycling through halos is highly uncertain because their gas mass density is poorly constrained. Fitting the MgII equivalent width (W) distribution with a Schechter function and applying the N(HI)-W correlation of Menard & Chelouche, we computed Omega(HI)_MgII ~ Omega(HI)_halo =(1.41 +0.75 -0.44)x10^-4 for 0.4View original: http://arxiv.org/abs/1111.3359