2016/12/14 by Shubham Srivastav, G. C. Anupama, D. K. Sahu +1 · 1 citation
Physics and Astronomy · #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stw3263
16 pages, 16 figures, MNRAS accepted
arxiv created 2016/12/14 · arxiv updated 2016/12/15
Photometric and spectroscopic observations of type Ia supernova 2015bp are presented, spanning ∼ -6 to ∼ +141 days since B-band maximum. Also presented are unpublished HCT spectra of type Ia iPTF13ebh between -11 to +34 days since B-band maximum. SN 2015bp shows rapidly declining light curves with Δm15(B)=1.72 ± 0.04. The I-band light curve shows a clear secondary maximum and peaks before the B-band maximum, placing SN 2015bp in the transitional category of SNe Ia. The spectral evolution of SN 2015bp resembles other transitional SNe Ia rather than 1991bg-like events. The C~\sc ii λ6580 feature is detected in both SN 2015bp and iPTF13ebh, though it is present till the epoch of B-band maximum in the case of SN 2015bp. The velocity gradients of Si~\sc ii λ6355 place SN 2015bp and iPTF13ebh in the FAINT subclass, whereas pseudo-equivalent widths of Si~\sc ii features place them in the Cool (CL) subclass of SNe Ia. The bolometric light curve of SN 2015bp indicates that ∼ 0.2 M\odot of 56Ni was synthesized in the explosion, with a total ejected mass of ∼ 0.9 M\odot, suggesting a sub-Chandrasekhar mass white dwarf progenitor.