一颗具有长极大前“平台”和强CII特征的近距超亮超新星
高能天体物理现象
2018-12-05 v2
摘要
超亮超新星(SLSNe)是一类罕见事件,其定义为显著亮于正常恒星末期爆炸。实现此类光度所需的额外能量来源仍不清楚。在本地宇宙(即 )中的发现十分稀少,但可进行密集的多波段观测。因此,额外的低红移天体极具价值。我们展示了I型SLSN ASASSN-18km/SN~2018bsz的早期观测。利用这些数据表征该事件并与文献中的SLSNe及光谱模型进行比较。同时还分析了宿主星系性质。我们对光学与近红外测光和光谱进行了分析。利用ATLAS早期测光约束上升光变曲线。我们在光学波段光谱中辨认出若干谱线特征并追踪其时间演化。最后,我们利用存档的宿主星系测光与HII区光谱约束宿主环境。ASASSN-18km/SN~2018bsz被确认为位于红移0.0267(111 Mpc)星系中的I型SLSN,使其成为迄今发现的最低红移事件。光谱中识别出强CII谱线。由Wolf-Rayet前身星爆炸并注入磁星能源所产生的光谱模型,在定性上与ASASSN-18km/SN~2018bsz相似,这与多数显示弱/不存在CII谱线的SLSNe-I相反。ASASSN-18km/SN~2018bsz在更陡、更快的上升达到极大之前,呈现出持续 26 天的漫长、缓慢上升的红色“平台”。宿主星系绝对星等为 --19.8 mag (),质量为 M = 1.5 10 M,恒星形成率为 = 0.50 M yr。附近一个HII区的氧丰度(O3N2)为 8.310.01 dex。
引用
@article{arxiv.1806.10609,
title = {A nearby superluminous supernova with a long pre-maximum 'plateau' and strong CII features},
author = {J. P. Anderson and P. J. Pessi and L. Dessart and C. Inserra and D. Hiramatsu and K. Taggart and S. J. Smartt and G. Leloudas and T. -W. Chen and A. Möller and R. Roy and S. Schulze and D. Perley and J. Selsing and S. J. Prentice and A. Gal-Yam and C. R. Angus and I. Arcavi and C. Ashall and M. Bulla and C. Bray and J. Burke and E. Callis and R. Cartier and S. -W. Chang and K. Chambers and P. Clark and L. Denneau and M. Dennefeld and H. Flewelling and M. Fraser and L. Galbany and M. Gromadzki and C. P. Gutiérrez and A. Heinze and G. Hosseinzadeh and D. A. Howell and E. Y. Hsiao and E. Kankare and Z. Kostrzewa-Rutkowska and E. Magnier and K. Maguire and P. Mazzali and O. McBrien and C. McCully and N. Morrell and T. B. Lowe and C. A. Onken and F. Onori and M. M. Phillips and A. Rest and R. Ridden-Harper and A. J. Ruiter and D. J. Sand and K. W. Smith and M. Smith and B. Stalder and M. D. Stritzinger and M. Sullivan and J. L. Tonry and B. E. Tucker and S. Valenti and R. Wainscoat and C. Z. Waters and C. Wolf and D. Young},
journal= {arXiv preprint arXiv:1806.10609},
year = {2018}
}
备注
Accepted for publication in A&A after minor corrections to first arXiv version