Continuum and spectral line observations of the OH Megamaser galaxy Arp 220
Abstract
We present MERLIN observations of the continuum (both 1.6 and 5 GHz) and OH maser emission towards Arp 220. The correct spatial configuration of the various components of the galaxy is revealed. In the eastern component the masers are shown to be generally coincident with the larger-scale continuum emission; in the west, the masers and continuum do not generally arise from the same location. A velocity gradient [(0.32 ± 0.03) km s^(−1) pc^(−1)] is found in the eastern nuclear region on MERLIN scales; this gradient is three times smaller than that seen in H I and implies that the OH gas lies inside the H I. A re-analysis of previously presented global very long baseline interferometry data reveals a very high velocity gradient [(18.67 ± 0.12) km s^(−1) pc^(−1)] in one component, possibly the site of a heavily obscured active galactic nucleus.
Additional Information
© 2003 RAS. Accepted 2003 February 20. Received 2003 February 20; in original form 2002 November 27. MERLIN is a national facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of PPARC. ER would like to thank the Greek State Scholarships Foundation, without its financial support this work would not have been possible. We thank Al Stirling and Rob Beswick for useful discussions.Attached Files
Published - 373.full.pdf
Accepted Version - 0302416
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Additional details
- Eprint ID
- 76409
- Resolver ID
- CaltechAUTHORS:20170408-214035386
- Particle Physics and Astronomy Research Council (PPARC)
- Greek State Scholarships Foundation
- Created
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2018-04-02Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)