AAS 195th Meeting, January 2000
Session 8. Dwarf, Irregular and Starburst Galaxies
Display, Wednesday, January 12, 2000, 9:20am-6:30pm, Grand Hall

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[8.08] HST WFPC2 Images and CFHT Fabry-Perot Optical Spectra of the Starburst Disk and Energetic Superbubble in NGC 3079

G. Cecil (U. of N. Carolina at Chapel Hill/SOAR Project, NOAO), S. Veilleux (U. of Maryland), A.V. Filippenko (U. of California at Berkeley), J. Bland-Hawthorn (Anglo-Australian Observatory)

The nearly edge-on spiral LINER/Seyfert galaxy NGC 3079 (17 Mpc) has a ``boxy" bulge, stellar bar, and contains the most energetic known example of a windblown superbubble (ionized mass 107/ne Msun & KE 2x1056/ne erg) that extends 12" (1 kpc) above the disk. We have mapped emission-line profiles across the galaxy disk and superbubble with an imaging Fabry-Perot spectrophotometer. We have also obtained dithered WFPC2 658N H\alpha+[N II]\lambda6583 and 814W continuum images of the inner 13-kpc diameter. We find that gas within 9-kpc diameter is lofted into narrow filaments that project up to 2 kpc above the disk, and which are usually unresolved in their narrow dimensions at 0\farcs1 resolution.

The superbubble is the most striking of these structures. The brightest filaments are organized into 4 distinct streams in azimuth that all fragment \approx0.7 kpc above the disk. The top of the superbubble is composed of numerous resolved droplets, each comprising \approx104/ne Msun of ionized gas, that resemble the ``cometary" blobs of stredded, dense clumps of disk material generated in the dense-disk+tenuous-halo hydro model of Suchkov et al (1994 ApJ, 430, 511). This morphology supports the presence of a free-streaming, blowout superwind, whose origin (AGN or starburst driven) and energetics we will discuss.

The starburst disk is composed of diffuse filaments, along with numerous H II regions that are often ruptured on their top sides. A striking spray of linear filaments that trail for \ga0.6 kpc behind unresolved ``bullets" is found outside the main starburst region. They emerge from a bright star-forming complex at \ga7 kpc radius that lies well beyond the ends of the stellar bar, and which has X-ray luminosity \approx7\times1038 erg/s in the ROSAT bands.

This program is supported by NASA HST grant GO-6674

The author(s) of this abstract have provided an email address for comments about the abstract: gcecil@noao.edu

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