Mini-Spirals: Signatures of Galaxy Transformation

Type Conference Paper
Names John S. Gallagher, K. Dellenbusch, A. Parker
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Meeting, AAS Meeting #217, #245.07
Volume 43
Date January 1, 2011
Short Title Mini-Spirals
Library Catalog NASA ADS
Abstract Dissipative processes play a major role in controlling the growth of galaxies, particularly in producing their dense baryon dominated central regions. Observations exploring how baryons lose energy and angular momentum to allow gas to flow into the centers of galaxies therefore provide important windows into galaxy evolution. One such pathway is associated with the presence of small, gas-rich disks. These features can be especially prominent in lower mass starburst galaxies, where they sometimes appear as remarkable miniature spirals. The compact starburst galaxies NGC 3928 (MB = -18.6) and II Zw 168 (MB = -21.4) are examples of this phenomenon, hosting high surface brightness inner disks with diameters of approximately 3 kpc and 5 kpc, respectively. Both disks display well developed spiral structure, and are embedded in larger diffuse stellar envelopes. Using a combination of data from the archives and our observations, we present basic physical characteristics of these two systems, which include spiral arms with widths of only 100 pc, and utilize this information to investigate their unusual evolutionary states. This research has been supported in part by grant NSF AST-0708967 and made use of the WIYN Observatory 0.9-m and 3.5-m telescopes.
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