Measuring the halo mass of Mg n absorbers from their cross-correlation with Luminous Red Galaxies

摘要

We study the cross-correlation between 716 Mgll quasar absorption systems and ~ 100,000 Luminous Red Galaxies (LRGs) selected from the Sloan Digital Sky Survey Data Release 3 in the redshift range 0 4 < z < 0.8 The Mgll systems were selected to have AA2796 & 2803 rest-frame equivalent widths ^ 1.0A and identifications confirmed by the Fell A2600 or Mgl A2852 lines. Over co-rnoving scales 0 2-13/J^1 Mpc, the Mgll-LRG cross-correlation has an amplitude 0.69 ± 0 09 times that of the LRG-LRG auto-correlation Since LRGs have halo-masses of 1O13M0, this strong cross-correlation signal implies that the absorber host-galaxies have halo-masses 1-2 x 1012 M.