Broad-line type Ic Supernova SN 2014ad

TL;DR

SN 2014ad is a broad-line type Ic supernova with high ejecta velocity and explosion energy, brighter than normal Ic supernovae but fainter than GRB-associated ones, with detailed photometric and spectroscopic analysis.

Contribution

This study provides detailed optical and ultraviolet observations of SN 2014ad, revealing its high velocity, energetic explosion parameters, and host galaxy metallicity, expanding understanding of broad-line type Ic supernovae.

Findings

Ejecta velocity up to 33500 km/s at maximum brightness.

Explosion energy approximately 10^52 ergs.

Synthesized about 0.24 solar masses of nickel.

Abstract

We present optical and ultraviolet photometry, and low resolution optical spectroscopy of the broad-line type Ic supernova SN 2014ad in the galaxy PGC 37625 (Mrk 1309), covering the evolution of the supernova during $-$5 to +87 d with respect to the date of maximum in $B$-band. A late phase spectrum obtained at +340 d is also presented. With an absolute $V$ band magnitude at peak of $M_{V}$ = $-$18.86 $\pm$ 0.23 mag, SN 2014ad is fainter than Gamma Ray Burst (GRB) associated supernovae, and brighter than most of the normal and broad-line type Ic supernovae without an associated GRB. The spectral evolution indicates the expansion velocity of the ejecta, as measured using the Si\,{\sc ii} line, to be as high as $\sim$ 33500 km\,s$^{-1}$ around maximum, while during the post-maximum phase it settles down at $\sim$ 15000 km\,s$^{-1}$. The expansion velocity of SN 2014ad is higher than all other well observed broad-line type Ic supernovae except the GRB associated SN 2010bh. The explosion parameters, determined by applying the Arnett's analytical light curve model to the observed bolometric light curve, indicate that it was an energetic explosion with a kinetic energy of $\sim$ (1 $\pm$ 0.3)$\times$10$^{52}$ ergs, a total ejected mass of $\sim$ (3.3 $\pm$ 0.8) M$_\odot$, and $\sim$ 0.24 M$_\odot$ of $^{56}$Ni was synthesized in the explosion. The metallicity of the host galaxy near the supernova region is estimated to be $\sim$ 0.5 Z$_\odot$.