Molecular Emission from a Galaxy Associated with a z~2.2 Damped Lyman-alpha Absorber

Understand

Using the Atacama Large Millimeter/sub-millimeter Array, we have detected CO(3-2) line and far-infrared continuum emission from a galaxy associated with a high-metallicity ([M/H] = -0.27) damped Ly-alpha absorber (DLA) at z =2.19289.

• The galaxy is located 3.5" away from the quasar sightline, corresponding to a large impact parameter of 30 kpc at the DLA redshift.
• We use archival Very Large Telescope-SINFONI data to detect Halpha emission from the associated galaxy, and find that the object is dusty, with a dust-corrected star formation rate of 110 +60 -30 Msun/yr.
• The galaxy's molecular mass is large, Mmol = (1.4 +- 0.2) x 10^11 x (\alpha_CO/4.3) x (0.57/r_31) Msun, supporting the hypothesis that high-metallicity DLAs arise predominantly near massive galaxies.