title: The large, oxygen-rich halos of star-forming galaxies are a major reservoir of galactic metals.
abstract: The circumgalactic medium (CGM) is fed by galaxy outflows and accretion of intergalactic gas, but its mass, heavy element enrichment, and relation to galaxy properties are poorly constrained by observations. In a survey of the outskirts of 42 galaxies with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope, we detected ubiquitous, large (150-kiloparsec) halos of ionized oxygen surrounding star-forming galaxies; we found much less ionized oxygen around galaxies with little or no star formation. This ionized CGM contains a substantial mass of heavy elements and gas, perhaps far exceeding the reservoirs of gas in the galaxies themselves. Our data indicate that it is a basic component of nearly all star-forming galaxies that is removed or transformed during the quenching of star formation and the transition to passive evolution.
authors.affiliation: Space Telescope Science Institute, Baltimore, MD 21218, USA. tumlinson@stsci.edu
authors.forename: J
authors.initials: J
authors.lastname: Tumlinson
authors.forename: C
authors.initials: C
authors.lastname: Thom
authors.forename: J K
authors.initials: JK
authors.lastname: Werk
authors.forename: J X
authors.initials: JX
authors.lastname: Prochaska
authors.forename: T M
authors.initials: TM
authors.lastname: Tripp
authors.forename: D H
authors.initials: DH
authors.lastname: Weinberg
authors.forename: M S
authors.initials: MS
authors.lastname: Peeples
authors.forename: J M
authors.initials: JM
authors.lastname: O'Meara
authors.forename: B D
authors.initials: BD
authors.lastname: Oppenheimer
authors.forename: J D
authors.initials: JD
authors.lastname: Meiring
authors.forename: N S
authors.initials: NS
authors.lastname: Katz
authors.forename: R
authors.initials: R
authors.lastname: Davé
authors.forename: A B
authors.initials: AB
authors.lastname: Ford
authors.forename: K R
authors.initials: KR
authors.lastname: Sembach