异常类型Ia超新星1999ac的光谱观测与分析
天体物理学
2012-08-27 v1
摘要
我们报告了异常类型Ia超新星（SN Ia）1999ac的光谱。数据覆盖相对于B波段最大值的-15至+42天，揭示了一个在几个方面都异常的事件。在B波段最大之前，光谱类似于SN 1999aa（缓慢衰减事件），但具有更强的SiII和CaII特征（更类似于光谱上正常的SN）。在B波段最大之后，光谱显得更正常。从铁线推导出的膨胀速度低于平均值；相比之下，从钙线H和K推导出的膨胀速度高于平均值。从SiII推导出的膨胀速度是迄今为止最慢的之一，尽管SN 1999ac并不暗淡。对参数v_10、R(SiII)、dv(SiII)/dt和d_m15的分析进一步凸显了SN 1999ac的独特特征。我们发现有力地证据显示CII 6580在第-15天光谱中存在，喷出速度v > 16000 km/s，但该特征在第-9天消失。这一在早期时段的快速演化凸显了极其早期光谱的重要性。
引用
@article{arxiv.astro-ph/0507288,
title = {Spectroscopic Observations and Analysis of the Unusual Type Ia SN 1999ac},
author = {The Supernova Cosmology Project and : and G. Garavini and G. Aldering and A. Amadon and R. Amanullah and P. Astier and C. Balland and G. Blanc and A. Conley and T. Dahlen and S. E. Deustua and R. Ellis S. Fabbro and V. Fadeyev and X. Fan and G. Folatelli and B. Frye and E. L. Gates and R. Gibbons and G. Goldhaber and B. Goldman and A. Goobar and D. E. Groom and J. Haissinski and D. Hardin and I. Hook and D. A. Howell and S. Kent and A. G. Kim and R. A. Knop and M. Kowalski and N. Kuznetsova and B. C. Lee C. Lidman and J. Mendez and G. J. Miller and M. Moniez and M. Mouchet and A. Mourao and H. Newberg and S. Nobili and P. E. Nugent and R. Pain and O. Perdereau and S. Perlmutter and R. Quimby and N. Regnault and J. Rich and G. T. Richards and P. Ruiz-Lapuente and B. E. Schaefer and K. Schahmaneche and E. Smith and A. L. Spadafora and V. Stanishev and R. C. Thomas and N. A. Walton and L. Wang and W. M. Wood-Vasey},
journal= {arXiv preprint arXiv:astro-ph/0507288},
year = {2012}
}
备注
40 pages, 24 figures, accepted for publication in The Astronomical Journal