SN 2012ec: mass of the progenitor from PESSTO follow-up of the photospheric phase

TL;DR

This study combines photometric, spectroscopic, and hydrodynamical modeling to estimate the progenitor mass and explosion parameters of SN 2012ec, confirming consistency with pre-explosion imaging and validating Type II-P supernovae as distance indicators.

Contribution

It provides a detailed analysis of SN 2012ec's progenitor and explosion parameters, integrating observational data with hydrodynamical models and comparing results with other supernovae.

Findings

Progenitor mass estimated at 12.6 Msun from models and 14-22 Msun from pre-explosion images.

SN 2012ec's light curve shows a shorter plateau (~90 days) than typical Type II-P supernovae.

SN 2012ec's properties follow the standard SCM relations for distance measurement.

Abstract

We present the results of a photometric and spectroscopic monitoring campaign of SN 2012ec, which exploded in the spiral galaxy NGC 1084, during the photospheric phase. The photometric light curve exhibits a plateau with luminosity L= 0.9 x 10^{42} erg/s and duration ~90 days, which is somewhat shorter than standard Type II-P supernovae. We estimate the nickel mass as 0.040 +/- 0.015 Msun from the luminosity at the beginning of the radioactive tail of the light curve. The explosion parameters of SN 2012ec were estimated from the comparison of the bolometric light curve and the observed temperature and velocity evolution of the ejecta with predictions from hydrodynamical models. We derived an envelope mass of 12.6 Msun, an initial progenitor radius of 1.6 x 10^{13} cm and an explosion energy of 1.2 foe. These estimates agree with an independent study of the progenitor star identified in pre-explosion images, for which an initial mass of M=14-22 Msun was determined. We have applied the same analysis to two other type II-P supernovae (SNe 2012aw and 2012A), and carried out a comparison with the properties of SN 2012ec derived in this paper. We find a reasonable agreement between the masses of the progenitors obtained from pre-explosion images and masses derived from hydrodynamical models. We estimate the distance to SN 2012ec with the Standardized Candle Method (SCM) and compare it with other estimates based on other primary and secondary indicators. SNe 2012A, 2012aw and 2012ec all follow the standard relations for the SCM for the use of Type II-P SNe as distance indicators.