A Caltech Library Service

Diagnostics of AGN-Driven Molecular Outflows in ULIRGs from Herschel-PACS Observations of OH at 119 μm

Spoon, H. W. W. and Farrah, D. and Lebouteiller, V. and González-Alfonso, E. and Bernard-Salas, J. and Urrutia, T. and Rigopoulou, D. and Westmoquette, M. S. and Smith, H. A. and Afonso, J. and Pearson, C. and Cormier, D. and Efstathiou, A. and Borys, C. and Verma, A. and Etxaluze, M. and Clements, D. L. (2013) Diagnostics of AGN-Driven Molecular Outflows in ULIRGs from Herschel-PACS Observations of OH at 119 μm. Astrophysical Journal, 775 (2). Art. No. 127. ISSN 0004-637X. doi:10.1088/0004-637X/775/2/127.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We report on our observations of the 79 and 119 μm doublet transitions of OH for 24 local (z < 0.262) ULIRGs observed with Herschel-PACS as part of the Herschel ULIRG Survey (HERUS). Some OH 119 μm profiles display a clear P-Cygni shape and therefore imply outflowing OH gas, while other profiles are predominantly in absorption or are completely in emission. We find that the relative strength of the OH emission component decreases as the silicate absorption increases. This result locates the OH outflows inside the obscured nuclei. The maximum outflow velocities for our sources range from less than 100 to ~2000 km s^(–1), with 15/24 (10/24) sources showing OH absorption at velocities exceeding 700 km s^(–1) (1000 km s^(–1)). Three sources show maximum OH outflow velocities exceeding that of Mrk231. Since outflow velocities above 500-700 km s^(–1) are thought to require an active galactic nucleus (AGN) to drive them, about two-thirds of our ULIRG sample may host AGN-driven molecular outflows. This finding is supported by the correlation we find between the maximum OH outflow velocity and the IR-derived bolometric AGN luminosity. No such correlation is found with the IR-derived star formation rate. The highest outflow velocities are found among sources that are still deeply embedded. We speculate that the molecular outflows in these sources may be in an early phase of disrupting the nuclear dust veil before these sources evolve into less-obscured AGNs. Four of our sources show high-velocity wings in their [C II] fine-structure line profiles, implying neutral gas outflow masses of at least (2-4.5) × 10^8 M_☉.

Item Type:Article
Related URLs:
URLURL TypeDescription
Spoon, H. W. W.0000-0002-8712-369X
Farrah, D.0000-0003-1748-2010
Bernard-Salas, J.0000-0002-8452-8675
Urrutia, T.0000-0001-6746-9936
Rigopoulou, D.0000-0001-6854-7545
Afonso, J.0000-0002-9149-2973
Pearson, C.0000-0001-6139-649X
Efstathiou, A.0000-0002-2612-4840
Clements, D. L.0000-0002-9548-5033
Additional Information:© 2013 American Astronomical Society. Received 2013 April 15; accepted 2013 July 22; published 2013 September 16. The authors thank the anonymous referee for constructive comments that led to an improvement of this paper. We are grateful to the SHINING team for their collegiality and for providing us with the OH119 line profile of Mrk 231. We further thank Jackie Fischer, Henny Lamers, Thomas Nikola, and Gordon Stacey for discussions, and Dan Weedman and Sylvain Veilleux for sharing OH line scans prior to their publication. V.L. is supported by a CEA/Marie Curie Eurotalents fellowship. E.G.-A. is a Research Associate at the Harvard-Smithsonian Center for Astrophysics, and thanks the Spanish Ministerio de Economía y Competitividad for support under projects AYA2010-21697-C05-0 and FIS2012-39162-C06-01. J.A. acknowledges support from the Science and Technology Foundation (FCT, Portugal) through the research grants PTDC/CTE-AST/105287/2008, PEst-OE/FIS/UI2751/2011 and PTDC/FIS-AST/2194/2012. M.E. thanks ASTROMADRID for support through grant S2009ESP-1496, from Spanish MINECO:AYA2009-07304 and from ASTROMOL: CSD2009-00038. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. Facility: Herschel (PACS)
Funding AgencyGrant Number
Marie Curie FellowshipUNSPECIFIED
Ministerio de Economía y Competitividad (MINECO)AYA2010-21697-C05-0
Ministerio de Economía y Competitividad (MINECO)FIS2012-39162-C06-01
Fundação para a Ciência e a Tecnologia (FCT)PTDC/CTE-AST/105287/2008
Fundação para a Ciência e a Tecnologia (FCT)PEst-OE/FIS/UI2751/2011
Fundação para a Ciência e a Tecnologia (FCT)PTDC/FIS-AST/2194/2012
Ministerio de Economía y Competitividad (MINECO)AYA2009-07304
Commissariat à l’Energie Atomique (CEA)UNSPECIFIED
Subject Keywords:infrared: galaxies; ISM: jets and outflows; galaxies: evolution; galaxies: ISM; quasars: absorption lines
Issue or Number:2
Record Number:CaltechAUTHORS:20131025-102131897
Persistent URL:
Official Citation: Diagnostics of AGN-Driven Molecular Outflows in ULIRGs from Herschel-PACS Observations of OH at 119 μm H. W. W. Spoon et al. 2013 ApJ 775 127
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:42064
Deposited By: Ruth Sustaita
Deposited On:25 Oct 2013 17:46
Last Modified:10 Nov 2021 04:37

Repository Staff Only: item control page