SPIRALS, BRIDGES, AND TAILS: A GALAXY EVOLUTION EXPLORER ULTRAVIOLET ATLAS OF INTERACTING GALAXIES
- Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States)
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)
We have used the Galaxy Evolution Explorer (GALEX) ultraviolet telescope to study stellar populations and star formation morphology in a well-defined sample of 42 nearby optically selected pre-merger interacting galaxy pairs. Galaxy interactions were likely far more common in the early universe than in the present; thus our study provides a nearby well-resolved comparison sample for high-redshift studies. We have combined the GALEX near-ultraviolet (NUV) and far-ultraviolet images with broadband optical maps from the Sloan Digitized Sky Survey to investigate the ages and extinctions of the tidal features and the disks. The distributions of the UV/optical colors of the tidal features and the main disks of the galaxies are similar; however, the tidal features are bluer on average in NUV - g when compared with their own parent disks; thus tails and bridges are often more prominent relative to the disks in UV images compared to optical maps. This effect is likely due to enhanced star formation in the tidal features compared to the disks rather than reduced extinction; however, lower metallicities may also play a role. We have identified a few new candidate tidal dwarf galaxies in this sample. Other interesting morphologies such as accretion tails and 'beads on a string' are also seen in these images. We also identify a possible 'Taffy' galaxy in our sample, which may have been produced by a head-on collision between two galaxies. In only a few cases are strong tidal features seen in H I maps but not in GALEX.
- OSTI ID:
- 21301239
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 3 Vol. 139; ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
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