The VLT LBG Redshift Survey - IV. Gas and galaxies at z ~ 3 in observations and simulations

Abstract

We use observations and simulation to study the relationship between star-forming galaxies and the intergalactic medium at z~3. The observed galaxy sample is based on spectroscopic redshift data from a combination of the VLT LBG Redshift Survey and Keck observations in fields centred on bright z>3 QSOs, whilst the simulation data is taken from GIMIC. In the simulation, we find that the dominant peculiar velocities are in the form of large-scale coherent motions of gas and galaxies. Gravitational infall of galaxies towards one another is also seen. At smaller scales, the peculiar velocities in the simulation over-predict the difference between the simulated real- and z-space galaxy correlation functions. Peculiar velocity pairs separated by <1Mpc/h have a smaller dispersion and explain the z-space correlation function better. The Lyα auto- and cross-correlation functions in the GIMIC simulation show infall smaller than implied by previous work. This reduced infall may be due to the galaxy wide outflows implemented in the simulation. The main challenge in comparing these simulated results with the observed correlation functions comes from the presence of velocity errors for the observed LBGs which dominate at ~1Mpc/h scales. When these are taken into account, the observed LBG correlation function is well matched by a simulated $M_{\ast }>10^9{M}_{\odot }$ galaxy sample. The simulated cross-correlation shows similar neutral gas densities around galaxies as are seen in the observations. The simulated and observed Lyα z-space autocorrelation functions agree well with each other. Our overall conclusion is that gas and galaxy peculiar velocities are towards the low end of expectation. Finally, little direct evidence is seen in either simulation or observations for high transmission near galaxies due to feedback. (Abridged)

24 pages, 22 figures, Published in MNRAS

References in corpus (12)

• Planck 2013 results. XVI. Cosmological parameters
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Chemical enrichment in cosmological, smoothed particle hydrodynamics simulations
• Cosmological Simulations of Intergalactic Medium Enrichment from Galactic Outflows
• Mass, Metal, and Energy Feedback in Cosmological Simulations
• A Direct Precision Measurement of the Intergalactic Lyman-alpha Opacity at 2<z<4.2
• Metal-line absorption around $z\approx$2.4 star-forming galaxies in the Keck Baryonic Structure Survey
• Through Thick and Thin - HI Absorption in Cosmological Simulations
• The effect of metal enrichment and galactic winds on galaxy formation in cosmological zoom simulations
• The VLT LBG Redshift Survey - III. The clustering and dynamics of Lyman-break galaxies at z ~ 3
• Rotation rates, sizes, and star formation efficiencies of a representative population of simulated disc galaxies
• A measurement of galaxy halo mass from the surrounding HI Lyα absorption

Cited by in corpus (19)

• EIGER I. a large sample of [OIII]-emitting galaxies at $5.3<z<6.9$ and direct evidence for local reionization by galaxies
• A comparison of observed and simulated absorption from HI, CIV, and SiIV around $z\approx 2$ star-forming galaxies suggests redshift-space distortions are due to inflows
• The Role of Galaxies and AGN in Reionising the IGM - I: Keck Spectroscopy of 5 < z < 7 Galaxies in the QSO Field J1148+5251
• The Keck Baryonic Structure Survey: Using foreground/background galaxy pairs to trace the structure and kinematics of circumgalactic neutral hydrogen at $z\sim 2$
• The MUSE Ultra Deep Field (MUDF). II. Survey design and the gaseous properties of galaxy groups at 0.5 < z < 1.5
• MUSE Analysis of Gas around Galaxies (MAGG) -- I: Survey design and the environment of a near pristine gas cloud at z~3.5
• Probing the intra-group medium of a z = 0.28 galaxy group
• MUSE Analysis of Gas around Galaxies (MAGG) -- IV: The gaseous environment of $z\sim$ 3-4 Lyman-alpha emitting galaxies
• The VLT LBG Redshift Survey - V. Characterising the z = 3.1 Lyman Alpha Emitter Population
• Discovery of a dual AGN at z~3.3 with 20kpc separation
• Quasar Sightline and Galaxy Evolution (QSAGE) Survey - I. The Galaxy Environment of OVI Absorbers up to z=1.4 around PKS 0232-04
• Environmental Dependence of Galactic Properties Traced by Ly$\alpha$ Forest Absorption: Diversity among Galaxy Populations
• The VLT LBG Redshift Survey - VI. Mapping HI in the proximity of $z\sim 3$ LBGs with X-Shooter
• Cosmic Galaxy-IGM HI Relation at $z\sim 2-3$ Probed in the COSMOS/UltraVISTA $1.6$ deg${}^2$ Field
• A new model framework for circumgalactic Ly$\alpha$ radiative transfer constrained by galaxy-Ly$\alpha$ forest clustering
• Gas around galaxy haloes - II: hydrogen absorption signatures from the environments of galaxies at redshifts 2 < z < 3
• Connection Between Galaxies and HI in the Circumgalactic and Intergalactic Media: Variation According to Galaxy Stellar Mass and Star-formation Activity
• A meeting at z~3: Young massive galaxies and an AGN within 30kpc of the luminous QSO LBQS0302-0019
• Cosmological-Scale Lyman-alpha Forest Absorption Around Galaxies and AGN Probed with the HETDEX and SDSS Spectroscopic Data