A Peculiar Subclass of Type Ia Supernovae a.k.a. Type Iax

Abstract

We present optical photometric (upto  410 days since Bmax) and spectroscopic (upto  235 days since Bmax) observations of a type Iax supernova SN 2014dt located in M61. The broad band light curves follow a linear decline upto  100 days after which a significant flattening is seen in the late-time (beyond 150 days) light curves of SN 2014dt. SN 2014dt best matches the light curve evolution of SN 2005hk and reaches a peak magnitude of MB -18.12±0.04 with m15 1.35±0.06 mag. The earliest spectrum at  23 days is dominated by FeII and CoII lines with the absence of the Si II 6150 Å line. Using the peak bolometric luminosity we estimate a 56Ni mass of 0.14 M in the case of SN 2005hk and the striking similarity between SN 2014dt and SN 2005hk implies that a comparable amount of 56Ni would have been synthesized in the explosion of SN 2014dt. There are several explosion scenarios proposed for these peculiar events. Being one of the brightest and closest SN, SN 2014dt is an ideal candidate for long term monitoring. Late phase observations are very essential to understand the progenitor system and the actual explosion scenario for these events.