Discovery and Follow-up Observations of the Young Type Ia Supernova 2016coj
Discovery and Follow-up Observations of the Young Type Ia Supernova 2016coj
The Type~Ia supernova (SN~Ia) 2016coj in NGC 4125 (redshift $z=0.004523$) was discovered by the Lick Observatory Supernova Search 4.9 days after the fitted first-light time (FFLT; 11.1 days before $B$-band maximum). Our first detection (pre-discovery) is merely $0.6\pm0.5$ day after the FFLT, making SN 2016coj one of the earliest known detections of a SN Ia. A spectrum was taken only 3.7 hr after discovery (5.0 days after the FFLT) and classified as a normal SN Ia. We performed high-quality photometry, low- and high-resolution spectroscopy, and spectropolarimetry, finding that SN 2016coj is a spectroscopically normal SN Ia, but with a high velocity of \ion{Si}{2} $\lambda$6355 ($\sim 12,600$\,\kmsaround peak brightness). The \ion{Si}{2} $\lambda$6355 velocity evolution can be well fit by a broken-power-law function for up to a month after the FFLT. SN 2016coj has a normal peak luminosity ($M_B \approx -18.9 \pm 0.2$ mag), and it reaches a $B$-band maximum \about16.0~d after the FFLT. We estimate there to be low host-galaxy extinction based on the absence of Na~I~D absorption lines in our low- and high-resolution spectra. The spectropolarimetric data exhibit weak polarization in the continuum, but the \ion{Si}{2} line polarization is quite strong ($\sim 0.9\% \pm 0.1\%$) at peak brightness.
Peter E. Nugent、Bela Abolfathi、Alexei V. Filippenko、Maren Cosens、Yen-Chen Pan、Aaron J. Barth、Ryan J. Foley、Jeffrey M. Silverman、Patrick L. Kelly、D. Andrew Howell、Benjamin J. Fulton、Curtis McCully、Vardha N. Bennert、Sean P. Fillingham、Goni Halevi、Xiaofeng Wang、Tommaso Treu、Jon Mauerhan、Christina Manzano-King、Liuyi Pei、H. Alexander Vogler、Isaac Shivvers、Liming Rui、Sahana Kumar、Michael C. Cooper、Jonelle L. Walsh、Melissa L. Graham、Ron Arbour、WeiKang Zheng、Heechan Yuk、Iair Arcavi、Griffin Hosseinzadeh、Louis E. Abramson、Tiffany Hsyu、Remington Oliver Sexton、Stefano Valenti、Wenxiong Li、Bryan Scott、Linyi Li、Matthew A. Malkan、Benjamin Stahl、Andrew P. Brandel
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Peter E. Nugent,Bela Abolfathi,Alexei V. Filippenko,Maren Cosens,Yen-Chen Pan,Aaron J. Barth,Ryan J. Foley,Jeffrey M. Silverman,Patrick L. Kelly,D. Andrew Howell,Benjamin J. Fulton,Curtis McCully,Vardha N. Bennert,Sean P. Fillingham,Goni Halevi,Xiaofeng Wang,Tommaso Treu,Jon Mauerhan,Christina Manzano-King,Liuyi Pei,H. Alexander Vogler,Isaac Shivvers,Liming Rui,Sahana Kumar,Michael C. Cooper,Jonelle L. Walsh,Melissa L. Graham,Ron Arbour,WeiKang Zheng,Heechan Yuk,Iair Arcavi,Griffin Hosseinzadeh,Louis E. Abramson,Tiffany Hsyu,Remington Oliver Sexton,Stefano Valenti,Wenxiong Li,Bryan Scott,Linyi Li,Matthew A. Malkan,Benjamin Stahl,Andrew P. Brandel.Discovery and Follow-up Observations of the Young Type Ia Supernova 2016coj[EB/OL].(2016-11-28)[2025-05-25].https://arxiv.org/abs/1611.09438.点此复制
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