Neutral hydrogen optical depth near star-forming galaxies at z~2.4 in the Keck Baryonic Structure Survey

Abstract

[Abridged] We study the interface between galaxies and the intergalactic medium by measuring the absorption by neutral hydrogen in the vicinity of star-forming galaxies at z~2.4. Our sample consists of 679 rest-frame-UV selected galaxies with spectroscopic redshifts that have impact parameters < 2 (proper) Mpc to the line of sight of one of 15 bright, background QSOs. We present the first 2-D maps of the absorption around galaxies, plotting the median Ly-a pixel optical depth as a function of transverse and line of sight, LOS, separation from galaxies. The median optical depth, and hence the median density of atomic hydrogen, drops by more than an order of magnitude around 100 kpc, which is similar to the virial radius of the halos thought to host the galaxies. The median remains enhanced (>3 sigma level) out to at least 2.8 Mpc (i.e. > 9 comoving Mpc). Within 100 (200) kpc, and over \pm 165 km/s, the covering fraction of gas with Ly-a optical depth greater than unity is 100(+0)(-32)% (86(+14)(-18)%). Absorbers with tau(Ly-a)> 0.1 are typically closer to galaxies than random. The mean galaxy overdensity around absorbers increases with the optical depth and also as the length scale over which the galaxy overdensity is evaluated is decreased. Absorbers with tau(Ly-a)~1 reside in regions where the galaxy number density is close to the cosmic mean on scales > 0.25 Mpc. We detect two types of redshift space anisotropies. On scales < 200 km/s, or < 1 Mpc, the absorption is stronger along the LOS than in the transverse direction. This "finger of God" effect may be partly due to redshift errors, but is probably dominated by gas motions within or very close to the halos. On the other hand, on scales of 1.4 - 2.0 Mpc the absorption is compressed along the LOS (>3 sigma significance), which we attribute to large-scale infall (i.e. the Kaiser effect).

Accepted for publication in the ApJ (replaced with revised version incorporating referee's comments)

References in corpus (17)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• The Mass-Metallicity Relation at z~2
• The Stellar, Gas and Dynamical Masses of Star-Forming Galaxies at z~2
• Multi-Wavelength Constraints on the Cosmic Star Formation History from Spectroscopy: the Rest-Frame UV, H-alpha, and Infrared Luminosity Functions at Redshifts 1.9<z<3.4
• H-alpha Observations of a Large Sample of Galaxies at z~2: Implications for Star Formation in High Redshift Galaxies
• The Gaseous Environment of High-z Galaxies: Precision Measurements of Neutral Hydrogen in the Circumgalactic Medium of z ~ 2-3 Galaxies in the Keck Baryonic Structure Survey
• Bimodal gas accretion in the Horizon-MareNostrum galaxy formation simulation
• X-ray coronae in simulations of disc galaxy formation
• A large population of metal-rich, compact, intergalactic C IV absorbers - Evidence for poor small-scale metal mixing
• A Flat Photoionization Rate at 2<z<4.2: Evidence for a Stellar-Dominated UV Background and Against a Decline of Cosmic Star Formation Beyond z~3
• Observing the End of Cold Flow Accretion using Halo Absorption Systems
• EVLA Observations of Galactic Supernova Remnants: Wide-field Continuum and Spectral-index Imaging
• The Varied Fates of z~2 Star-forming Galaxies
• Enriched haloes at redshift $z=2$ with no star-formation: Implications for accretion and wind scenarios
• Cross correlation of Lyman-alpha absorbers with gas-rich galaxies
• The association between gas and galaxies II: The 2-point correlation function

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