SN 2016iog: A fast-declining Type II-L supernova with an ultra-faint tail persistently interacting with circumstellar material
/ Authors
Z.-H. Peng, S. Benetti, Y.-Z. Cai, A. Pastorello, G. Valerin, A. Reguitti, A. Fiore, Q. Fang, Z.-Y. Wang, M. Berton
and 19 more authors
L. Borsato, E. Cappellaro, E. Congiu, N. Elias-Rosa, V. Granata, J. Isern, G. Mura, P. Ochner, R. Raddi, G. Terreran, L. Tomasella, M. Turatto, S. Yan, S.-P. Pei, C.-Y. Wu, S. Zha, X. Wang, B. Wang, Y. Pan
/ Abstract
-1 post-peak. Such a high decline rate makes SN 2016iog one of the fastest-declining Type IIL SNe observed to date. The rapid rise in the light curve, combined with the nearly featureless continuum observed in the spectrum at +9.3 days, suggests the presence of interaction. In the recombination phase, we observed broad Hα lines that persist at all epochs. In addition, the prominent double-peaked Hα feature observed in the late-time spectrum (+190.8 days) is likely attributable either to significant dust formation within a cool dense shell or to asymmetric circumstellar material. These features suggest the presence of a sustained interaction around SN 2016iog. We propose that the observed characteristics of SN 2016iog can be qualitatively explained by assuming a low-mass H-rich envelope surrounding a red supergiant progenitor star with low-density circumstellar material.
Journal: Astronomy & Astrophysics