CO(1-0) line imaging of massive star-forming disc galaxies at z=1.5-2.2
- Author(s)
- M Aravena, J. A. Hodge, J Wagg, Helmut Dannerbauer
- Abstract
We present detections of the CO(J = 1-0) emission line in a sample of four massive starforming galaxies at z~1.5-2.2 obtained with theKarlG. JanskyVery LargeArray. Combining these observations with previous CO(2-1) and CO(3-2) detections of these galaxies, we study the excitation properties of the molecular gas in our sample sources. We find an average line brightness temperature ratios of R
21 = 0.70 ± 0.16 and R
31 = 0.50 ± 0.29, based on measurements for three and two galaxies, respectively. These results provide additional support to previous indications of sub-thermal gas excitation for the CO(3-2) line with a typically assumed line ratio R
31 ~ 0.5. For one of our targets, BzK-21000, we present spatially resolved CO line maps. At the resolution of 0.18 arcsec (1.5 kpc), most of the emission is resolved out except for some clumpy structure. From this, we attempt to identify molecular gas clumps in the data cube, finding four possible candidates. We estimate that <40 per cent of the molecular gas is confined to giant clumps (~1.5 kpc in size), and thus most of the gas could be distributed in small fainter clouds or in fairly diffuse extended regions of lower brightness temperatures than our sensitivity limit.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Universidad Diego Portales, European Southern Observatory (Chile), National Radio Astronomy Observatory, Charlottesville, Square Kilometre Array
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 442
- Pages
- 558 - 564
- No. of pages
- 7
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stu838
- Publication date
- 07-2014
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/co10-line-imaging-of-massive-starforming-disc-galaxies-at-z1522(a1060583-099c-4082-9916-50df8e30442e).html