THE CHANDRA ACIS SURVEY OF M33: X-RAY, OPTICAL, AND RADIO PROPERTIES OF THE SUPERNOVA REMNANTS
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
- The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States)
- Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)
- Department of Physics, University of California, 1 Shields Avenue, Davis, CA 95616 (United States)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- Columbia Astrophysics Laboratory, 550 W. 120th Street, New York, NY 10027 (United States)
- Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States)
- Department of Earth and Space Sciences, Space Science Center, 235 Martindale Drive, Morehead State University, Morehead, KY 40351 (United States)
- Astronomy Department, University of Washington, Seattle, WA 98195 (United States)
M33 contains a large number of emission nebulae identified as supernova remnants (SNRs) based on the high [S II]:H{alpha} ratios characteristic of shocked gas. Using Chandra data from the ChASeM33 survey with a 0.35-2 keV sensitivity of {approx}2 x 10{sup 34} erg s{sup -1}, we have detected 82 of 137 SNR candidates, yielding confirmation of (or at least strongly support for) their SNR identifications. This provides the largest sample of remnants detected at optical and X-ray wavelengths in any galaxy, including the Milky Way. A spectral analysis of the seven X-ray brightest SNRs reveals that two, G98-31 and G98-35, have spectra that appear to indicate enrichment by ejecta from core-collapse supernova explosions. In general, the X-ray-detected SNRs have soft X-ray spectra compared to the vast majority of sources detected along the line of sight to M33. It is unlikely that there are any other undiscovered thermally dominated X-ray SNRs with luminosities in excess of {approx}4 x 10{sup 35} erg s{sup -1} in the portions of M33 covered by the ChASeM33 survey. We have used a combination of new and archival optical and radio observations to attempt to better understand why some objects are detected as X-ray sources and others are not. We have also developed a morphological classification scheme for the optically identified SNRs and discussed the efficacy of this scheme as a predictor of X-ray detectability. Finally, we have compared the SNRs found in M33 to those that have been observed in the Galaxy and the Magellanic Clouds. There are no close analogs of Cas A, Kepler's SNR, Tycho's SNR, or the Crab Nebula in the regions of M33 surveyed, but we have found an X-ray source with a power-law spectrum coincident with a small-diameter radio source that may be the first pulsar-wind nebula recognized in M33.
- OSTI ID:
- 21301163
- Journal Information:
- Astrophysical Journal, Supplement Series, Vol. 187, Issue 2; Other Information: DOI: 10.1088/0067-0049/187/2/495; Country of input: International Atomic Energy Agency (IAEA); ISSN 0067-0049
- Country of Publication:
- United States
- Language:
- English
Similar Records
CHANDRA ACIS SURVEY OF M33 (ChASeM33): THE ENIGMATIC X-RAY EMISSION FROM IC131
XMM-NEWTON OBSERVATIONS OF TWO CANDIDATE SUPERNOVA REMNANTS