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Observation of H_2O in a strongly lensed Herschel-ATLAS source at z = 2.3

Omont, A. and Murphy, E. J. and Riechers, D. and Vieira, J. D. and Bock, J. and Bradford, C. M. and Zmuidzinas, J. (2011) Observation of H_2O in a strongly lensed Herschel-ATLAS source at z = 2.3. Astronomy and Astrophysics, 530 . Art. No. L3. ISSN 0004-6361.

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The Herschel survey, H-ATLAS, with its large areal coverage, has recently discovered a number of bright, strongly lensed high-z submillimeter galaxies. The strong magnification makes it possible to study molecular species other than CO, which are otherwise difficult to observe in high-z galaxies. Among the lensed galaxies already identified by H-ATLAS, the source J090302.9-014127B (SDP.17b) at z = 2.305 is remarkable because of its excitation conditions and a tentative detection of the H_2O 2_(02)-1_(11) emission line (Lupu et al. 2010, ApJ, submitted). We report observations of this line in SDP.17b using the IRAM interferometer equipped with its new 277–371 GHz receivers. The H_2O line is detected at a redshift of z = 2.3049 ± 0.0006, with a flux of 7.8 ± 0.5 Jy km s^(-1) and a FWHM of 250 ± 60   km   s^(-1). The new flux is 2.4 times weaker than the previous tentative detection, although both remain marginally consistent within 1.6σ. The intrinsic line luminosity and ratio of H_2O(2_(02) − 1_(11))/CO(8 − 7) are comparable with those of the nearby starburst/enshrouded-AGN Mrk 231, and the ratio I(H_2O)/L_(FIR) is even higher, suggesting that SDP.17b could also host a luminous AGN. The detection of a strong H_2O 2_(02) − 1_(11) line in SDP.17b implies an efficient excitation mechanism of the water levels that must occur in very dense and warm interstellar gas probably similar to Mrk 231.

Item Type:Article
Related URLs:
URLURL TypeDescription
Omont, A.0000-0002-4721-3922
Murphy, E. J.0000-0001-7089-7325
Riechers, D.0000-0001-9585-1462
Bock, J.0000-0002-5710-5212
Bradford, C. M.0000-0001-5261-7094
Additional Information:© 2011 ESO. Received 18 March 2011. Accepted 11 April 2011. Published online 28 April 2011. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. Based on observations carried out with the IRAM Plateau de Bure interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). The authors are grateful to the IRAM staff for their support. US participants in H-ATLAS acknowledge support from NASA through a contract from JPL. Italian participants in H-ATLAS acknowledge a financial contribution from the agreement ASI-INAF I/009/10/0. The SPIRE development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK); and NASA (USA).We also thank the anonymous referee for very helpful suggestions.
Funding AgencyGrant Number
Institut national des sciences de l'Univers (INSU)UNSPECIFIED
Max Planck GesellschaftUNSPECIFIED
Instituto Geográfico Nacional (IGN)UNSPECIFIED
Agenzia Spaziale Italiana (ASI)I/009/10/0
Canadian Space Agency (CSA)UNSPECIFIED
National Astronomical Observatories, Chinese Academy of Sciences (NAOC)UNSPECIFIED
Commissariat à l’Energie Atomique (CEA)UNSPECIFIED
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Istituto Nazionale di Astrofisica (INAF)UNSPECIFIED
Ministerio de Ciencia e Innovación (MCINN)UNSPECIFIED
Swedish National Space Board (SNSB)UNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Subject Keywords:galaxies: high-redshift; galaxies: starburst; galaxies: active; infrared: galaxies; submillimeter: galaxies; radio lines: galaxies
Record Number:CaltechAUTHORS:20110613-083728464
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Official Citation:Observation of H2O in a strongly lensed Herschel-ATLAS source at z = 2.3 L3 A. Omont et al. Published online: 28 April 2011 DOI: 10.1051/0004-6361/201116921
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:23980
Deposited By: Ruth Sustaita
Deposited On:13 Jun 2011 16:11
Last Modified:09 Mar 2020 13:19

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