Progenitor Insights of Type IIP SN 2018pq: A Comprehensive Photometric and Spectroscopic Study

TL;DR

This study provides detailed photometric and spectroscopic observations of SN 2018pq, revealing its properties, spectral features, and progenitor characteristics through modeling, confirming it as a typical Type IIP supernova with a red supergiant progenitor.

Contribution

It offers a comprehensive observational dataset and combines radiative transfer and hydrodynamical modeling to constrain the progenitor's properties, advancing understanding of Type IIP supernovae.

Findings

SN 2018pq has a 97-day plateau similar to normal Type IIP supernovae.

Spectral modeling indicates a spectroscopically normal Type IIP supernova.

Progenitor mass estimates range from 11 to 16 solar masses.

Abstract

We present high-cadence photometric and low-resolution (R $\sim$ 400--700) optical spectroscopic observations of Type IIP supernova, SN~2018pq, which exploded on the outskirts of the galaxy IC~3896A. The optically thick phase (``plateau'') lasts approximately 97 d, the plateau duration of normal Type IIP supernovae. SN~2018pq has a {\em V}-band absolute magnitude of $-16.42 \pm 0.01$ mag at 50 d, resembles normal-luminous supernova, and the V-band decline rate of 0.42$\pm$0.06 mag 50 d$^{-1}$ during the plateau phase. A steeper decline rate of 11.87$\pm$1.68 mag 100 d$^{-1}$ was observed compared to that of typical Type IIP supernovae during the transition between plateau to nebular phase. We employ detailed radiative transfer spectra modelling, TARDIS, to reveal the photospheric temperature and velocity at two spectral epochs. The well-fitted model spectra indicate SN~2018pq is a spectroscopically normal Type IIP supernova. Semi-analytical light curve modelling suggests the progenitor as a red supergiant star with an ejecta mass of $\sim$11 $M_\odot$ and an initial radius of 424 $R_\odot$. On the contrary, hydrodynamical modelling suggests a higher mass progenitor between 14--16 $M_\odot$.