Far-infrared Fine-structure Line Diagnostics of Ultraluminous Infrared Galaxies
Creators
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Virginia Tech
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Cornell University
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CEA Saclay
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The Open University
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Rutherford Appleton Laboratory
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University of Oxford
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Harvard-Smithsonian Center for Astrophysics
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University of Alcalá
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Imperial College London
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European University Cyprus
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Heidelberg University
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University of Lisbon
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University of Sussex
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Infrared Processing and Analysis Center
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University of California, Berkeley
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Sapienza University of Rome
Abstract
We present Herschel observations of 6 fine-structure lines in 25 ultraluminous infrared galaxies at z < 0.27. The lines, [O III]52 μm, [N III]57 μm, [O I]63 μm, [N II]122 μm, [O I]145 μm, and [C II]158 μm, are mostly single Gaussians with widths <600 km s^(–1) and luminosities of 10^7-10^9 L_☉. There are deficits in the [O I]63/L_(IR), [N II]/L_(IR), [O I]145/L_(IR), and [C II]/L_(IR) ratios compared to lower luminosity systems. The majority of the line deficits are consistent with dustier H II regions, but part of the [C II] deficit may arise from an additional mechanism, plausibly charged dust grains. This is consistent with some of the [C II] originating from photodissociation regions or the interstellar medium (ISM). We derive relations between far-IR line luminosities and both the IR luminosity and star formation rate. We find that [N II] and both [O I] lines are good tracers of the IR luminosity and star formation rate. In contrast, [C II] is a poor tracer of the IR luminosity and star formation rate, and does not improve as a tracer of either quantity if the [C II] deficit is accounted for. The continuum luminosity densities also correlate with the IR luminosity and star formation rate. We derive ranges for the gas density and ultraviolet radiation intensity of 10^1 < n < 10^(2.5) and 10^(2.2) < G_0 < 10^(3.6), respectively. These ranges depend on optical type, the importance of star formation, and merger stage. We do not find relationships between far-IR line properties and several other parameters: active galactic nucleus (AGN) activity, merger stage, mid-IR excitation, and SMBH mass. We conclude that these far-IR lines arise from gas heated by starlight, and that they are not strongly influenced by AGN activity.
Additional Information
© 2013 American Astronomical Society. Received 2013 May 8; accepted 2013 August 6; published 2013 September 24. We thank the staff of the Herschel helpdesk for many valuable discussions, and the referee for a very helpful report. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. This work is based on observations made with the Spitzer Space Telescope. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This research has made extensive use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA, and of NASA's Astrophysics Data System. This research has also made use of Ned Wright's online cosmology calculator (Wright 2006). V.L. is supported by a CEA/Marie Curie Eurotalents fellowship. 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. E.G.-A. is a Research Associate at the Harvard-Smithsonian Center for Astrophysics and thanks the support by the Spanish Ministerio de Economía y Competitividad under projects AYA2010-21697-C05-0 and FIS2012-39162-C06-01. Facilities: Herschel, SpitzerAttached Files
Published - 0004-637X_776_1_38.pdf
Submitted - 1308.4165v1.pdf
Files
0004-637X_776_1_38.pdf
Additional details
Identifiers
- Eprint ID
- 42209
- Resolver ID
- CaltechAUTHORS:20131104-084058008
Related works
- Describes
- http://arxiv.org/abs/1308.4165 (URL)
Funding
- NASA/JPL/Caltech
- Marie Curie Fellowship
- 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)
- AYA2010-21697-C05-0
- Ministerio de Economía y Competitividad (MINECO)
- FIS2012-39162-C06-01
- Commissariat à l'Energie Atomique (CEA)
Dates
- Created
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2013-11-04Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field