Type II supernova 1979c in M100 and the distance to the Virgo cluster
Type II supernova 1979c in M100 and the distance to the Virgo cluster
复制标题
M100 中的 II 型超新星 1979c 以及到室女座星团的距离
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
B. Wills
中科院分区：
文献类型：
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作者：
D. Branch;S. W. Falk;M. McCall;P. Rybski;A. Uomoto;B. Wills
本文给出并详细讨论了1979年4月22日至1979年11月24日期间获得的M100超新星1979 c的光谱。研究了来自银河系和M100的星际谱线。合成光谱计算使用黑体光球和纯散射膨胀大气成功地模拟连续和天鹅座P型超新星光谱5月28日。H..阿尔法帽。谱线不能用纯共振散射来解释，但碰撞激发可能是这条线中净发射以及IUE光谱中看到的Mg II γ 2798发射的原因。从光谱中得到的速度和温度与光度数据相结合，通过Baade方法确定超新星的距离。我们发现这个距离为23 +- 3（rms）Mpc，对应于哈勃参数约为60 km s/sup-1/ Mpc/sup-1/。前体星星似乎有一个扩展的星周包层，前体的质量估计至少为9 M/太阳。本文从H Ⅱ区观测和合成光谱两方面讨论了超新星大气的化学组成。
Optical spectra of supernova 1979c in M100 obtained between 1979 April 22 and 1979 November 24 are presented and discussed in detail. Interstellar lines originating from both our Galaxy and M100 are examined. Synthetic spectra computed using a blackbody photosphere and a pure scattering expanding atmosphere successfully model the continua and P Cygni profiles of the supernova spectra up to May 28. The H..cap alpha.. profile is not explained by pure resonance scattering, but collisional excitation may be responsible for the net emission in this line as well as the Mg II lambda2798 emission seen in IUE spectra. Velocities and temperatures derived from the spectra are combined with photometric data to determine the distance to the supernova by the Baade method. We find the distance to be 23 +- 3 (rms) Mpc, corresponding to a Hubble parameter of about 60 km s/sup -1/ Mpc/sup -1/. The precursor star seems to have had an extended circumstellar envelope, and the mass of the precursor is estimated to have been at least 9 M/sub sun/. The chemical composition of the supernova atmosphere is discussed both from the standpoint of H II region observations and the synthetic spectra.