Sharon, CE, Baker, AJ, Harris, AI, Tacconi, LJ, Lutz, D and Longmore, SN (2015) EXCITATION CONDITIONS IN THE MULTI-COMPONENT SUBMILLIMETER GALAXY SMM J00266+1708. ASTROPHYSICAL JOURNAL, 798 (2). ISSN 0004-637X

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Abstract

We present multiline CO observations of the complex submillimeter galaxy SMMJ00266+1708. Using the Zpectrometer on the Green Bank Telescope, we provide the first precise spectroscopic measurement of its redshift (z = 2.742). Based on followup CO(1–0), CO(3–2), and CO(5–4) mapping,
SMMJ00266+1708 appears to have two distinct components separated by ∼ 500 kms−1 that are nearly coincident along our line of sight. The two components show hints of different kinematics, with the blue-shifted component dispersion-dominated and the red-shifted component showing a clear velocity gradient. CO line ratios differ slightly between the two components, indicating that the physical
conditions in their molecular gas may not be alike. We tentatively infer that SMMJ00266+1708 is an on going merger with a mass ratio of (7.8±4.0)/ sin2(i), with its overall size and surface brightness closely resembling that of other merging systems. We perform large velocity gradient modeling of the CO emission from both components and find that each component’s properties are consistent with a
single phase of molecular gas (i.e., a single temperatures and density); additional multi-phase modelling of the red-shifted component, although motivated by a CO(1–0) size larger than the CO(3–2) size, is inconclusive. SMMJ00266+1708 provides evidence of early stage mergers within the submillimeter galaxy population. Continuum observations of J00266 at the ∼ 1′′ resolution of our observations could not have distinguished between the two components due to their separation (0.′′73 ± 0.′′06),
illustrating that the additional velocity information provided by spectral line studies is important for
addressing the prevalence of unresolved galaxy pairs in low-resolution submillimeter surveys.

Item Type:	Article
Uncontrolled Keywords:	0201 Astronomical And Space Sciences, 0305 Organic Chemistry, 0306 Physical Chemistry (Incl. Structural)
Subjects:	Q Science > QB Astronomy
Divisions:	Astrophysics Research Institute
Publisher:	IOP PUBLISHING LTD
Related URLs:	http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000350853700068&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=7f77ca1697db64ccb27a8011c7ced90d
Date Deposited:	27 May 2015 13:12
Last Modified:	04 Sep 2021 14:33
DOI or ID number:	10.1088/0004-637X/798/2/133
URI:	https://researchonline.ljmu.ac.uk/id/eprint/804

Available Versions of this Item

• Excitation Conditions in the Multi-component Submillimeter Galaxy SMM J00266+1708. (deposited 17 Dec 2014 14:33)
  • EXCITATION CONDITIONS IN THE MULTI-COMPONENT SUBMILLIMETER GALAXY SMM J00266+1708. (deposited 27 May 2015 13:12) [Currently Displayed]

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