A SINFONI Integral Field Spectroscopy Survey for Galaxy Counterparts to Damped Lyman-alpha Systems - VI. Metallicity and Geometry as Gas Flow Probes

TL;DR

This study uses integral field spectroscopy to investigate the metallicity and geometry of gas flows in galaxies associated with damped Lyman-alpha systems, revealing complex relationships between gas inflow and outflow indicators.

Contribution

It provides new observational data on galaxy gas flows at z=0.7-1, combining metallicity and geometric analyses to challenge simple models of gas accretion and outflow.

Findings

Detected H-alpha emission in a sub-DLA at z=0.94 with SFR=3.6 solar masses/year.

Measured a dynamical mass of 10^9.9 solar masses and halo mass of 10^11.9 solar masses.

Found no clear correlation between metallicity differences and galaxy orientation, indicating complex gas flow behaviors.

Abstract

The use of background quasars provides a powerful tool to probe the cool gas in the circum-galactic medium of foreground galaxies. Here, we present new observations with SINFONI and X-Shooter of absorbing-galaxy candidates at z=0.7-1. We report the detection with both instruments of the H-alpha emission line of one sub-DLA at z_abs=0.94187 with log N(HI)=19.38^+0.10_-0.15 towards SDSS J002133.27+004300.9. We estimate the star formation rate: SFR=3.6+/-2.2 solar masses per year in that system. A detailed kinematic study indicates a dynamical mass M_dyn=10^9.9+/-0.4 solar masses and a halo mass M_halo=10^11.9+/-0.5 solar masses. In addition, we report the OII detection with X-Shooter of another DLA at z_abs=0.7402 with log N(HI)=20.4+/-0.1 toward Q0052+0041 and an estimated SFR of 5.3+/-0.7 solar masses per year. Three other objects are detected in the continuum with X-Shooter but the nature and redshift of two of these objects are unconstrained due to the absence of emission lines, while the third object might be at the redshift of the quasar. We use the objects detected in our whole N(HI)-selected SINFONI survey to compute the metallicity difference between the galaxy and the absorbing gas, delta_HI(X), where a positive (negative) value indicates infall (outflow). We compare this quantity with the quasar line of sight alignment with the galaxy's major (minor) axis, another tracer of infall (outflow). We find that these quantities do not correlate as expected from simple assumptions. Additional observations are necessary to relate these two independent probes of gas flows around galaxies.