A low-luminosity core-collapse supernova very similar to SN 2005cs

TL;DR

This paper analyzes a low-luminosity Type II-P supernova similar to SN 2005cs, using a new Monte-Carlo modeling approach to estimate physical parameters and compare with other such supernovae.

Contribution

It introduces a robust Monte-Carlo code for fitting supernova light curves to derive key physical parameters of low-luminosity Type II-P supernovae.

Findings

Estimated progenitor radius: 91_{-70}^{+119} x 10^{11} cm

Ejected mass: 9.89_{-1.00}^{+2.10} M_{ ext{sun}}

Nickel mass: 1.55_{-0.70}^{+0.75} x 10^{-3} M_{ ext{sun}}

Abstract

We present observations and analysis of PSN J17292918+7542390, a low-luminosity Type II-P supernova (LL SN IIP). The observed sample of such events is still low, and their nature is still under debate. Such supernovae are similar to SN 2005cs, a well-observed low-luminosity Type II-P event, having low expansion velocities, and small ejected $^{56}$Ni mass. We have developed a robust and relatively fast Monte-Carlo code that fits semi-analytic models to light curves of core collapse supernovae. This allows the estimation of the most important physical parameters, like the radius of the progenitor star, the mass of the ejected envelope, the mass of the radioactive nickel synthesized during the explosion, among others. PSN J17292918+7542390 has $R_0 = 91_{-70}^{+119} \cdot 10^{11} \;\text{cm}$, $M_\text{ej} = 9.89_{-1.00}^{+2.10} \; M_{\odot}$, $E_{\mathrm{kin}} = 0.65_{-0.18}^{+0.19} \;\text{foe}$, $v_{\mathrm{exp}} = 3332_{-347}^{+216}$ km s$^{-1}$, for its progenitor radius, ejecta mass, kinetic energy and expansion velocity, respectively. The initial nickel mass of the PSN J17292918+7542390 turned out to be $1.55_{-0.70}^{+0.75} \cdot 10^{-3} M_{\odot}$. The measured photospheric velocity at the earliest observed phase is 7000 km s$^{-1}$. As far as we can tell based on the small population of observed low-luminosity Type II-P supernovae, the determined values are typical for these events.