On the Nature of Velocity Fields in High z Galaxies

Abstract

We analyze the gas kinematics of damped Lya systems (DLAs) hosting high z gamma-ray bursts (GRBs) and those toward quasars (QSO-DLAs) focusing on threestatistics: (1) dv, the velocity interval encompassing 90% of the totaloptical depth, (2,3) Wsi and Wciv, the rest equivalent widths of the SiII1526 and CIV1548 transitions. The dv distributions of the GRB-DLAs and QSO-DLAs are similar, each has median dv~80km/s and a significant tail to several hundred km/s. This suggests comparable galaxy masses for the parent populations of GRB-DLAs and QSO-DLAs and we infer the average dark matter halo mass of GRB galaxies is <~10^{12} Msol. The unique configuration of GRB-DLA sightlines and the presence (and absence) of fine-structure absorption together give special insight into the nature of high z, protogalactic velocity fields. The data support a scenario where the dv statistic reflects dynamics in the interstellar medium (ISM) and Wsi traces motions outside the ISM (e.g. halo gas, galactic-scale winds). The Wsi statistic and gas metallicity [M/H] are tightly correlated, especially for the QSO-DLAs: [M/H]=a + b log(Wsi/1A) with a=-0.92+/-0.05 and b=-1.41+/-0.10. We argue that the Wsi statistic primarily tracks dynamical motions in the halos of high z galaxies and interpret this correlation as a mass-metallicity relation with very similar slope to the trend observed in local, low-metallicity galaxies. Finally, the GRB-DLAs exhibit systematically larger Wsi values (>0.5A) than the QSO-DLAs (<Wsi>~ 0.5A) which may suggest galactic-scale outflows contribute to the largest observed velocity fields.

14 pages, 9 figures. Submitted to ApJ

References in corpus (10)

• The Mass-Metallicity Relation at z~2
• Long gamma-ray bursts and core-collapse supernovae have different environments
• UV star-formation rates of GRB host galaxies
• Velocity-Metallicity Correlation for high-z DLA Galaxies: Evidence for a Mass-Metallicity Relation?
• New perspectives on strong z=0.5 MgII absorbers: are halo-mass and equivalent width anti-correlated?
• Where is the Molecular Hydrogen in Damped Lyman-Alpha Absorbers?
• The Metal-Strong Damped Lyman-alpha Systems
• The Interstellar Medium of GRB Host Galaxies I. Echelle Spectra of Swift GRB Afterglows
• Missing Molecular Hydrogen and the Physical Conditions of GRB Host Galaxies
• The connection between metallicity and metal-line kinematics in (sub-)damped Lyman-alpha systems

Cited by in corpus (50)

• Cosmic dynamics in the era of Extremely Large Telescopes
• Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant Universe
• Damped Lyman Alpha Systems in Galaxy Formation Simulations
• Molecular hydrogen in high-redshift Damped Lyman-alpha systems: The VLT/UVES database
• Deuterium Abundance in the Most Metal-Poor Damped Lyman alpha System: Converging on Omega_baryons
• C, N, O Abundances in the Most Metal-Poor Damped Lyman alpha Systems
• The primordial deuterium abundance of the most metal-poor damped Lyman-alpha system
• Galaxy Counterparts of metal-rich Damped Lyman-alpha Absorbers - I: The case of the z=2.35 DLA towards Q2222-0946
• High-Redshift Starbursting Dwarf Galaxies Revealed by GRB Afterglows
• High-Ion Absorption in Seven GRB Host Galaxies at z=2-4: Evidence for both Circumburst Plasma and Outflowing Interstellar Gas
• Reproducing the Kinematics of Damped Lyman-alpha Systems
• A connection between extremely strong Damped Lyman-alpha Systems and Lyman-alpha Emitting Galaxies at small impact parameters
• A Survey for NV Absorption at z~z_GRB in GRB Afterglow Spectra: Clues to Gas Near the Progenitor Star
• GRB 071003: Broadband Follow-up Observations of a Very Bright Gamma-Ray Burst in a Galactic Halo
• Bimodality in Damped Lyman alpha Systems
• A High Signal-to-Noise Ratio Composite Spectrum of Gamma-ray Burst Afterglows
• Metal abundances at z<1.5: new measurements in sub-Damped Lyman-alpha Absorbers
• Chemical abundances of damped Lyman alpha systems in the XQ-100 survey
• On the mass-metallicity relation, velocity dispersion and gravitational well depth of GRB host galaxies
• The host of GRB 060206: kinematics of a distant galaxy
• Mass and metallicity scaling relations of high redshift star-forming galaxies selected by GRBs
• On the Absence of High Metallicity-High Column Density Damped Lyman Alpha Systems: Molecule Formation in a Two-Phase Interstellar Medium
• The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB 070125
• ALMA + VLT observations of a Damped Lyman-α absorbing galaxy: Massive, wide CO emission, gas-rich but with very low SFR
• A Lyα blob and zabs {\approx} zem damped Lyα absorber in the dark matter halo of the binary quasar Q 0151+048
• Lyman Alpha and MgII as Probes of Galaxies and their Environments
• Proximate Molecular Quasar Absorbers: Excess of damped H2 systems at zabs~zQSO in SDSS DR14
• Can gravitational infall energy lead to the observed velocity dispersion in DLAs?
• The host galaxy of GRB 980425 / SN1998bw: a collisional ring galaxy
• High Molecular Gas Masses in Absorption-selected Galaxies at $z\approx 2$
• Incidence of HI 21-cm absorption in strong FeII systems at $0.5<z<1.5$
• The Astrophysical Consequences of Intervening Galaxy Gas on Fast Radio Bursts
• On the Kinematics of Cold, Metal-enriched Galactic Fountain Flows in Nearby Star-forming Galaxies
• The comoving mass density of MgII from $z\sim 2$ to $5.5$
• Quasar 2175 Å dust absorbers I: metallicity, depletion pattern, and kinematics
• A search for damped Lyman-alpha systems towards radio-loud quasars I: The optical survey
• ALMA [CII] 158um imaging of an HI-Selected Major Merger at z~4
• Evolution of cold gas at 2<z<5: a blind search for HI and OH absorption lines towards mid-infrared color selected radio-loud AGNs
• Quasar 2175 Å dust absorbers II: Correlation analysis and relationship with other absorption line systems
• The Ly$\alpha$ emission from high-$z$ galaxies hosting strong Damped Ly$\alpha$ systems
• Towards Understanding the Mass-Metallicity relation of Quasar Absorbers: Evidence for bimodality and consequences
• A search for H$\alpha$ emission in high-metallicity damped Lyman-$\alpha$ systems at $z\sim 2.4$
• Proximate molecular quasar absorbers: Chemical enrichment and kinematics of the neutral gas
• Probing the assembly of dwarf galaxies through cosmic time with damped Lyman-$\alpha$ absorption spectroscopy
• A Massive, Dusty HI-Absorption-Selected Galaxy at $z\approx 2.46$ Identified in a CO Emission Survey
• A [CII]-158-micron Survey of DLA galaxies at z~4: Observations of Dense and Metal-Enriched Neutral Gas within the Circumgalactic Medium of Star-Forming Galaxies
• On the Metallicities and Kinematics of the Circumgalactic Media of Damped Ly$\alpha$ Systems at $z\sim 2.5$
• Constraints on the gas masses of low-z damped Lyman-$\alpha$ systems
• Discovery of a damped Ly$\alpha$ galaxy at z $\sim$ 3 towards the quasar SDSS J011852+040644
• Detecting PAHs in high-z galaxies in proxy: Modelling physical conditions in an extremely strong damped Lyman-alpha absorber towards QSO SDSS J1143+1420 at z=2.323