High Spatial Resolution Imaging of Arp 220 from 3 to 25 Microns
Abstract
Images of Arp 220 from 3.45 to 24.5 μm with 0farcs5 resolution are presented that clearly separate the nucleus into at least two components. The western component is about 3 times more luminous than the eastern component, but the silicate absorption in the fainter, eastern component is roughly 50% greater than the absorption in the western component. Each component is marginally resolved. The two components seen at 24.5 μm are identified with the two radio components. The western source most likely coincides with the high-extinction disk previously suggested to exist in Arp 220, while the eastern nucleus is identified with a faint, highly reddened source seen in HST 2.2 μm NICMOS images. The two nuclei together account for essentially all of the measured 24.5 μm flux density. Two models are presented, both of which fit the observations. In one the majority of the total luminosity is produced in an extended star formation region, and in the other most of the luminosity is produced in the compact but extincted regions associated with the two nuclei seen at 24.5 μm. In both pictures, substantial luminosity at 100 μm emerges from a component having a diameter of 2"-3" (~1 kpc).
Additional Information
© 1999. The American Astronomical Society. Received 1998 July 27. Accepted 1998 October 6. B. T. S., G. N., and K. M. are supported by grants from NASA and NSF. We thank J. Aycock, R. Goodrich, R. Moskitis, and the entire Keck staff for their help establishing the visitor port and obtaining these observations, and R. Chary, A. Evans, D. Koerner, K. Sakamoto, D. Sanders, and N. Scoville for helpful discussions about Arp 220 and these observations. The W. M. Keck Observatory is operated as a scientific partnership between the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. It was made possible by the generous financial support of the W. M. Keck Foundation. This research has made use of the NASA/IPAC Extragalactic Database, which is operated by the Jet Propulsion Laboratory, Caltech, under contract with NASA.Attached Files
Published - Soifer_1999_ApJ_513_207.pdf
Submitted - 9810120.pdf
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Additional details
- Eprint ID
- 74321
- Resolver ID
- CaltechAUTHORS:20170215-110545810
- NSF
- W. M. Keck Foundation
- NASA/JPL/Caltech
- Created
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2017-02-15Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)