The Carnegie Supernova Project II. Observations of SN 2014ab possibly revealing a 2010jl-like SN IIn with pre-existing dust

TL;DR

This paper reports detailed optical, near-infrared, and mid-infrared observations of SN 2014ab, revealing its similarities to SN 2010jl and suggesting pre-existing circumstellar dust with high mass-loss rates from the progenitor.

Contribution

It provides comprehensive multi-wavelength data on SN 2014ab, including late-time infrared spectra, and discusses dust origin and mass-loss characteristics, advancing understanding of Type IIn supernovae.

Findings

SN 2014ab's light curve and spectra resemble SN 2010jl.

Mid-infrared emission likely from pre-existing dust heated by the shock.

Progenitor's mass-loss rate estimated at ~0.1 solar masses per year.

Abstract

We present optical and near-infrared photometry and spectroscopy of the Type IIn supernova (SN) 2014ab, obtained by the Carnegie Supernova Project II (CSP-II) and initiated immediately after its optical discovery. We also present mid-infrared photometry obtained by the Wide-field Infrared Survey Explorer (WISE) satellite extending from 56 days prior to the optical discovery to over 1600 days. The light curve of SN 2014ab evolves slowly, while the spectra exhibit strong emission features produced from the interaction between rapidly expanding ejecta and dense circumstellar matter. The light curve and spectral properties are very similar to those of SN 2010jl. The estimated mass-loss rate of the progenitor of SN 2014ab is of the order of 0.1 Msun/yr under the assumption of spherically symmetric circumstellar matter and steady mass loss. Although the mid-infrared luminosity increases due to emission from dust, which is characterized by a blackbody temperature close to the dust evaporation temperature (~ 2000 K), no clear signatures of in situ dust formation within the cold dense shell located behind the forward shock are observed in SN 2014ab in early phases. Mid-infrared emission of SN 2014ab may originate from pre-existing dust located within dense circumstellar matter that is heated by the SN shock or shock-driven radiation. Finally, for the benefit of the community, we also present in an Appendix five near-infrared spectra of SN 2010jl obtained between 450 to 1300 days post discovery.