Neutral carbon and highly excited CO in a massive star-forming main sequence galaxy at z = 2.2

Brisbin, Drew; Aravena, Manuel; Daddi, Emanuele; Dannerbauer, Helmut; Decarli, Roberto; González-López, Jorge; Riechers, Dominik; Wagg, Jeff
Bibliographical reference

Astronomy and Astrophysics, Volume 628, id.A104, 8 pp.

Advertised on:
8
2019
Number of authors
8
IAC number of authors
1
Citations
16
Refereed citations
16
Description
We used the Plateau De Bure Interferometer to observe multiple CO and neutral carbon transitions in a z = 2.2 main sequence disk galaxy, BX610. Our observation of CO(7-6), CO(4-3), and both far-infrared (FIR) [CI] lines complements previous observations of Hα and low-J CO, and reveals a galaxy that is vigorously forming stars with UV fields (Log(GG0-1) ≲ 3.25); although less vigorously than local ultra-luminous infrared galaxies or most starbursting submillimeter galaxies in the early universe. Our observations allow new independent estimates of the cold gas mass which indicate Mgas ˜ 2 × 1011 M⊙, and suggest a modestly larger αCO value of ˜8.2. The corresponding gas depletion timescale is ˜1.5 Gyr. In addition to gas of modest density (Log(n cm3) ≲ 3) heated by star formation, BX610 shows evidence for a significant second gas component responsible for the strong high-J CO emission. This second component might either be a high-density molecular gas component heated by star formation in a typical photodissociation region, or could be molecular gas excited by low-velocity C shocks. The CO(7-6)-to-FIR luminosity ratio we observe is significantly higher than typical star-forming galaxies and suggests that CO(7-6) is not a reliable star-formation tracer in this galaxy. The reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/628/A104
Related projects
Galaxy proto-cluster
Molecular Gas and Dust in Galaxies Across Cosmic Time
Two of the most fundamental questions in astrophysics are the conversion of molecular gas into stars and how this physical process is a function of environments on all scales, ranging from planetary systems, stellar clusters, galaxies to galaxy clusters. The main goal of this internal project is to get insight into the formation and evolution of
Helmut
Dannerbauer