TY - JOUR
T1 - Unusual emission-line regions in the tidal arm of NGC 7318B in Stephan's Quintet
AU - Ohyama, Youichi
AU - Nishiura, Shingo
AU - Murayama, Takashi
AU - Taniguchi, Yoshiaki
N1 - Funding Information:
We are grateful to the staff of OAO and Kiso Observatory for their kind help with the observations. We would like to thank Roberto Terlevich and Itziar Aletxaga for helpful discussions. This research has made use of data obtained from the Canada-France-Hawaii Telescope, which is operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Okayama Astrophysical Observatory is operated by the National Astronomical Observatory of Japan, the Ministry of Education, Science, Culture, and Sports. Y. O. and T. M. are Japan Society for the Promotion of Science fellows. This work was partly supported by the Ministry of Education, Science, Culture, and Sports (07044054).
PY - 1998
Y1 - 1998
N2 - We report the optical spectroscopic discovery of two unusual emission-line regions in the tidal arm of a galaxy, NGC 7318B, that belongs to Stephan's Quintet. They are associated spatially with the unusual radio continuum emission discovered between the two galaxies NGC 7318B and NGC 7319. Taking account of both the large velocity widths of the emission lines, ∼900 km s-1, and the strong [S II] XX6717, 6731 emission with respect to Hα emission, we identify them as optical emission-line filaments of supernova remnants (SNRs) traced by the radio continuum and soft X-ray emission. Our narrowband Ha imaging shows that the unusual emission-line regions are indeed parts of the ionized bubble associated with one radio continuum peak. The required number of SNRs is estimated to be ∼105-106 on the basis of the Ha, radio, and soft X-ray luminosities. Since there is no optical counterpart like a star cluster, it is suggested that ∼105-105 supernova events occurred nearly simultaneously in this region several times 106 yr ago.
AB - We report the optical spectroscopic discovery of two unusual emission-line regions in the tidal arm of a galaxy, NGC 7318B, that belongs to Stephan's Quintet. They are associated spatially with the unusual radio continuum emission discovered between the two galaxies NGC 7318B and NGC 7319. Taking account of both the large velocity widths of the emission lines, ∼900 km s-1, and the strong [S II] XX6717, 6731 emission with respect to Hα emission, we identify them as optical emission-line filaments of supernova remnants (SNRs) traced by the radio continuum and soft X-ray emission. Our narrowband Ha imaging shows that the unusual emission-line regions are indeed parts of the ionized bubble associated with one radio continuum peak. The required number of SNRs is estimated to be ∼105-106 on the basis of the Ha, radio, and soft X-ray luminosities. Since there is no optical counterpart like a star cluster, it is suggested that ∼105-105 supernova events occurred nearly simultaneously in this region several times 106 yr ago.
KW - Galaxies: individual (NGC 7318B)
KW - Galaxies: interactions
KW - Radio continuum: ISM
KW - Supernova remnants
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U2 - 10.1086/311086
DO - 10.1086/311086
M3 - Article
AN - SCOPUS:21944456246
VL - 492
SP - L25-L28
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1 PART II
ER -