AAS 201st Meeting, January, 2003
Session 127. Interstellar Medium: Hot and Cold
Oral, Thursday, January 9, 2003, 10:00-11:30am, 606-607

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[127.03D] FUV & Optical Kinematics of the Magellanic ISM: A Detailed Study of SMC N66 and SNR\,0057-7226

Charles W. Danforth (JHU)

I investigate the kinematics of the interstellar medium (ISM) in the Magellanic Clouds using a large data set of Far Ultraviolet Spectroscopic Explorer (FUSE) observations and high-resolution optical H\alpha echelle data. In addition to studying the global aspects of the ISM in these galaxies, multiple FUSE sight lines through certain objects allow the study of trends within individual \ion{H}{2} regions, supernova remanants (SNRs), superbubbles, and supergiant shells. Optical emission-line images are used to put the other observations in a broader context.

In this paper, I will discuss results from one such FUV/optical study of SMC N66, the largest and brightest \ion{H}{2} region in the Small Magellanic Cloud. N66 is powered by a dozen or more early-type stars including the dense star cluster NGC\,346 and the luminous blue variable HD\,5980. At least one known SNR, SNR\,0057-7226, lies in projection within N66. Optical emission from the remnant is overwhelmed by the bright photoionized emission from the nebula, but the remnant has been detected by way of both FUV absorption and emission lines. I will present data from FUSE showing strong \ion{O}{6} and \ion{C}{3} emission from a position at the edge of SNR\,0057-7226. In addition, new high-resolution, longslit H\alpha spectra across the nebula showing high- and low-velocity emission corresponding closely to the X-ray boundaries of the SNR. These FUV and optical data are used to determine the physical parameters of the shock and how it is interacting with N66. I find that ionizing radiation from the many massive cluster stars nearby likely affects the ionization balance in the post-shock gas, hindering the recombination of lower-ionization and neutral species that would normally occur behind the SNR shock. Given the prevalence of massive stars in clusters like this, it is likely that many SNRs should be found in or near bright \ion{H}{2} regions. The inherent difficulty of distinguishing photoionized emission from shocked emission suggests that far ultraviolet observations provides a viable means to discover and study such remnants.

If you would like more information about this abstract, please follow the link to http://fuse.pha.jhu.edu/~danforth/research.html. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

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

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