Metal-line absorption around $z\approx$2.4 star-forming galaxies in the Keck Baryonic Structure Survey

Understand

(Abridged) We study metal absorption around 854 $z\approx$2.4 star-forming galaxies taken from the Keck Baryonic Structure Survey (KBSS).

• The galaxies examined in this work lie in the fields of 15 hyper-luminous background QSOs, with galaxy impact parameters ranging from 35 proper kpc (pkpc) to 2 proper Mpc (pMpc).
• Using the pixel optical depth technique, we present the first galaxy-centred 2-D maps of the median absorption by OVI, NV, CIV, CIII, and SIV, as well as updated results for HI.
• At small galactocentric radii we detect a strong enhancement of the absorption relative to randomly located regions that extend out to at least 180 pkpc in the transverse direction, and $\pm$240 km/s along the line-of-sight (LOS, ~1 pMpc in the case of pure Hubble flow) for all ions except NV.