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arXiv · 1712.07359

Broad-lined type Ic supernova iPTF16asu: A challenge to all popular models

L. J. Wang·X. F. Wang·Z. Cano·S. Q. Wang·L. D. Liu·Z. G. Dai·J. S. Deng·H. Yu·B. Li·L. M. Song·Y. L. Qiu·J. Y. Wei
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Abstract

It is well-known that ordinary supernovae (SNe) are powered by 56Ni cascade decay. Broad-lined type Ic SNe (SNe Ic-BL) are a subclass of SNe that are not all exclusively powered by 56Ni decay. It was suggested that some SNe Ic-BL are powered by magnetar spin-down. iPTF16asu is a peculiar broad-lined type Ic supernova discovered by the intermediate Palomar Transient Factory. With a rest-frame rise time of only 4 days, iPTF16asu challenges the existing popular models, for example, the radioactive heating (56Ni-only) and the magnetar+56Ni models. Here we show that this rapid rise could be attributed to interaction between the SN ejecta and a pre-existing circumstellar medium ejected by the progenitor during its final stages of evolution, while the late-time light curve can be better explained by energy input from a rapidly spinning magnetar. This model is a natural extension to the previous magnetar model. The mass-loss rate of the progenitor and ejecta mass are consistent with a progenitor that experienced a common envelope evolution in a binary. An alternative model for the early rapid rise of the light curve is the cooling of a shock propagating into an extended envelope of the progenitor. It is difficult at this stage to tell which model (interaction+magnetar+56Ni or cooling+magnetar+56Ni) is better for iPTF16asu. However, it is worth noting that the inferred envelope mass in the cooling+magnetar+56Ni is very high.

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L. J. Wang, X. F. Wang, Z. Cano, S. Q. Wang, L. D. Liu, Z. G. Dai, J. S. Deng, H. Yu, B. Li, L. M. Song, Y. L. Qiu, J. Y. Wei. 2019-09-17. Broad-lined type Ic supernova iPTF16asu: A challenge to all popular models. https://doi.org/10.1093/mnras%2Fstz2184

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