Submillimeter H2O and H2O+emission in lensed ultra- and hyper-luminous infrared galaxies atz ~ 2–4

Yang, C.; Omont, Alain; Beelen, A.; Gonz�lez-Alfonso, E.; Neri, R.; Gao, Y.; van der Werf, Paul; Wei�, A.; Gavazzi, R.; Falstad, N.; Baker, A. J.; Bussmann, R. S.; Cooray, A.; Cox, P.; Dannerbauer, H.; Dye, S.; Gu�lin, M.; Ivison, R.J.; Krips, M.; Lehnert, M.; Micha?owski, M. J.; Riechers, D. A.; Spaans, M.; Valiante, E.

Abstract

We report rest-frame submillimeter H2O emission line observations of 11 ultra- or hyper-luminous infrared galaxies (ULIRGs or HyLIRGs) at z ~ 2–4 selected among the brightest lensed galaxies discovered in the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS). Using the IRAM NOrthern Extended Millimeter Array (NOEMA), we have detected 14 new H2O emission lines. These include five 321–312ortho-H2O lines (Eup/k = 305 K) and nine J = 2 para-H2O lines, either 202–111(Eup/k = 101 K) or 211–202(Eup/k = 137 K). The apparent luminosities of the H2O emission lines are μLH2O ~ 6–21 × 108 L⊙  (3 1 (optically thick), indicating that H2O is likely to trace highly obscured warm dense gas. However, further observations of J ≥ 4 H2O lines are needed to better constrain the continuum optical depth and other physical conditions of the molecular gas and dust. We have also detected H2O+ emission in three sources. A tight correlation between LH2O and LH2O+ has been found in galaxies from low to high redshift. The velocity-integrated flux density ratio between H2O+ and H2O suggests that cosmic rays generated by strong star formation are possibly driving the H2O+ formation.

Citation

Yang, C., Omont, A., Beelen, A., González-Alfonso, E., Neri, R., Gao, Y., …Valiante, E. (2016). Submillimeter H2O and H2O+emission in lensed ultra- and hyper-luminous infrared galaxies atz ~ 2–4. Astronomy and Astrophysics, 595, A80. https://doi.org/10.1051/0004-6361/201628160

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2016
• Online Publication Date: Nov 3, 2016
• Publication Date: Nov 3, 2016
• Deposit Date: Apr 27, 2017
• Publicly Available Date: Apr 27, 2017
• Journal: Astronomy & Astrophysics
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 595
• Article Number: A80
• Pages: A80
• DOI: https://doi.org/10.1051/0004-6361/201628160
• Keywords: Galaxies: high-redshift, Galaxies: ISM, Infrared: galaxies, Submillimeter: galaxies, Radio lines: ISM, ISM: molecules
• Public URL: https://nottingham-repository.worktribe.com/output/830288
• Publisher URL: https://doi.org/10.1051/0004-6361/201628160
• Additional Information: © ESO, 2016
• Contract Date: Apr 27, 2017