ASASSN-14ms:the Most Energetic Known Explosion of a Type Ibn Supernova and its Physical Origin Institutional Repository Document uri icon

abstract

  • ASASSN-14ms may represent the most luminous Type Ibn supernova (SN~Ibn) ever detected, with an absolute U-band magnitude brighter than -22.0 mag and a total bolometric luminosity >1.0x10^{44} erg/s near maximum light. The early-time spectra of this SN are characterized by a blue continuum on which are superimposed narrow P~Cygni profile lines of He I, suggesting the presence of slowly moving (~1000 km/s), He-rich circumstellar material (CSM). At 1--2 months after maximum brightness, the He I line profiles become only slightly broader, with blueshifted velocities of 2000--3000 km/s, consistent with the CSM shell being continuously accelerated by the SN light and ejecta. Like most SNe~Ibn, the light curves of ASASSN-14ms show rapid post-peak evolution, dropping by ~7 mag in the V band over three months. Such a rapid post-peak decline and high luminosity can be explained with interaction between SN ejecta and helium-rich CSM of 0.9~M_{odot} at a distance of~10^{15} cm. The CSM around ASASSN-14ms is estimated to originate from a pre-explosion event with a mass-loss rate of 6.7~M_odot /yr (assuming a velocity of ~1000 km/s), which is consistent with abundant He-rich material violently ejected during the late Wolf-Rayet (WN9-11 or Opfe) stage. After examining the light curves for a sample of SNe~Ibn, we find that the more luminous ones tend to have slower post-peak decline rates, reflecting that the observed differences may arise primarily from discrepancies in the CSM distribution around the massive progenitors.

author list (cited authors)

  • Wang, X., Lin, W., Zhang, J., Zhang, T., Cai, Y., Zhang, K., ... Zhai, Q.

citation count

  • 0

complete list of authors

  • Wang, Xiaofeng||Lin, Weili||Zhang, Jujia||Zhang, Tianmeng||Cai, Yongzhi||Zhang, Kaicheng||Filippenko, Alexei V||Graham, Melissa||Maeda, Keiichi||Mo, Jun||Xiang, Danfeng||Xi, Gaobo||Yan, Shengyu||Wang, Lifan||Wang, Lingjun||Kawabata, Koji||Zhai, Qian

Book Title

  • arXiv

publication date

  • June 2021