2018ApJ...856L..12N -
Astrophys. J., 856, L12-L12 (2018/March-3)
Molecular emission from a galaxy associated with a z ∼ 2.2 damped Lyα absorber.
NEELEMAN M., KANEKAR N., PROCHASKA J.X., CHRISTENSEN L., DESSAUGES-ZAVADSKY M., FYNBO J.P.U., MOLLER P. and ZWAAN M.A.
Abstract (from CDS):
Using the Atacama Large Millimeter/submillimeter 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 Lyα absorber (DLA) at zDLA = 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 Hα emission from the associated galaxy, and find that the object is dusty, with a dust-corrected star formation rate of 110–30+60 M☉ yr–1. The galaxy's molecular mass is large, Mmol = (1.4 ± 0.2) x 1011 x (αCO/4.3) x (0.57/r31) M☉, supporting the hypothesis that high-metallicity DLAs arise predominantly near massive galaxies. The excellent agreement in redshift between the CO(3-2) line emission and low-ion metal absorption (∼40 km s–1) disfavors scenarios whereby the gas probed by the DLA shows bulk motion around the galaxy. We use Giant Metrewave Radio Telescope H I 21 cm absorption spectroscopy to find that the H I along the DLA sightline must be warm, with a stringent lower limit on the spin temperature of Ts > 1895 x (f/0.93) K. The detection of C I absorption in the DLA, however, also indicates the presence of cold neutral gas. To reconcile these results requires that the cold components in the DLA contribute little to the H I column density, yet contain roughly 50% of the metals of the absorber, underlining the complex multi-phase nature of the gas surrounding high-z galaxies.
Abstract Copyright:
© 2018. The American Astronomical Society. All rights reserved.
Journal keyword(s):
galaxies: high-redshift - galaxies: ISM - galaxies: kinematics and dynamics - quasars: absorption lines - submillimeter: galaxies
Simbad objects:
4
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2018ApJ...856L..12N and select 'bookmark this link' or equivalent in the popup menu