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arXiv · 1711.00862

The Highly Luminous Type Ibn Supernova ASASSN-14ms

P. J. Vallely·J. L. Prieto·K. Z. Stanek·C. S. Kochanek·T. Sukhbold·D. Bersier·J. S. Brown·Ping Chen·Subo Dong·E. Falco·P. Berlind·M. Calkins·R. A. Koff·S. Kiyota·J. Brimacombe·B. J. Shappee·T. W. -S. Holoien·T. A. Thompson·M. D. Stritzinger
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Abstract

We present photometric and spectroscopic follow-up observations of the highly luminous Type Ibn supernova ASASSN-14ms, which was discovered on UT 2014-12-26.61 at $m_V \sim 16.5$. With a peak absolute $V$-band magnitude brighter than $-20.5$, a peak bolometric luminosity of $1.7 \times 10^{44}$ ergs s$^{-1}$, and a total radiated energy of $2.1 \times 10^{50}$ ergs, ASASSN-14ms is one of the most luminous Type Ibn supernovae yet discovered. In simple models, the most likely power source for this event is a combination of the radioactive decay of $^{56}$Ni and $^{56}$Co at late times and the interaction of supernova ejecta with the progenitor's circumstellar medium at early times, although we cannot rule out the possibility of a magnetar-powered light curve. The presence of a dense circumstellar medium is indicated by the intermediate-width He I features in the spectra. The faint ($m_g \sim 21.6$) host galaxy SDSS J130408.52+521846.4 has an oxygen abundance below $12+\log(O/H) \lesssim 8.3$, a stellar mass of $M_* \sim 2.6 \times 10^8 M_{\odot}$, and a star formation rate of $\textrm{SFR} \sim 0.02$ $M_{\odot}$ yr$^{-1}$.

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P. J. Vallely, J. L. Prieto, K. Z. Stanek, C. S. Kochanek, T. Sukhbold, D. Bersier, J. S. Brown, Ping Chen, Subo Dong, E. Falco, P. Berlind, M. Calkins, R. A. Koff, S. Kiyota, J. Brimacombe, B. J. Shappee, T. W. -S. Holoien, T. A. Thompson, M. D. Stritzinger. 2020-01-17. The Highly Luminous Type Ibn Supernova ASASSN-14ms. https://doi.org/10.1093/mnras%2Fstx3303

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