Other
Scientific paper
Nov 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997mnras.291..517w&link_type=abstract
Monthly Notices of the Royal Astronomical Society, vol. 291, p. 517
Other
47
Starburst Galaxies, Supernova Remnants, Radio Galaxies, Absorption Spectra, Ionized Gases, Low Frequencies, Continuous Radiation, Infrared Spectra
Scientific paper
We have used MERLIN at 408 MHz to image the central starburst region of M82 with a resolution of 0.5 arcsec. We detect about 20 SNR at this frequency, which is a much smaller number than we detect at higher frequencies. We attribute this difference to free-free absorption by ionized gas. We find that seven remnants show low-frequency turnovers in their spectra consistent with free-free absorption. These spectra are similar to the spectrum previously obtained for the brightest, youngest SNR, 41.95-t-57.5. We find a mean optically thin spectral index of -0.6 and emission measures about 10 exp 5/cm exp -6 pc for the remnants detected at 408 MHz. These emission measures are an order of magnitude smaller than other published values for the central region of M82 and we therefore suggest that the remnants we detect at 408 MHz are embedded within ionized gas towards the near side of the distribution. In addition to the supemova remnants, we detect the extended background in which several regions attributable to free-free absorption by ionized gas can be seen. The most striking is an extended absorption region approximately centered on 41.95+57.5 which may be an H II region photoionized by a cluster of early-type stars. The progenitor of 41.95+57.5 may well have been a member of this cluster. We find one source near the dynamical center of M82, which we speculate could be a possible candidate for an AGN.
Muxlow Thomas W. B.
Pedlar Alan
Wilkinson Peter N.
Wills Karen A.
No associations
LandOfFree
Low-frequency observations of supernova remnants in M82 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Low-frequency observations of supernova remnants in M82, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low-frequency observations of supernova remnants in M82 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-924313