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Session 76 - Star Formation in Galaxies.
Display session, Friday, January 09
Exhibit Hall,

[76.05] WFPC2 Observations of the Optical Structures of Three Nearby Luminous Blue Galaxies

J. S. Gallagher, N. Homeier (U. Wisconsin-Madison), R. E. Griffiths (Carnegie Mellon U.), WFPC2 ID Team

High angular resolution images taken with WFPC2 in the F555W and F814W filters are presented for IC 2184 (Mrk 8), III Zw 33 (Mrk 36), and II Zw 168. These observations are analyzed in combination with ground-based images obtained at Kitt Peak with the 2.1-m or WIYN 3.5-m telescopes as part of our program to understand the origins of high surface brightness, luminous blue galaxies. These three galaxies suggest a possible evolutionary sequence of interaction strengths and/or phases for luminous blue galaxies. Mrk 8 appears to be in the initial stage of an interaction between two extreme late-type disk galaxies, III Zw 33 has signatures of a recent merger, and the very compact II Zw 168 galaxy could be the remnant of an old interaction or the result of an internally generated starburst. We discuss these data in terms of types and locations of optically blue regions as markers of recent star formation, properties of HII regions, and the characteristics of ripples or anomalous arms in the outer disks, which might be produced by interactions. This work is part of the WFPC2 Investigation Definition Team GTO program and is supported by NASA Contract NAS7-1260 to JPL. The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories.

Program listing for Friday