ABSENCE OF FAST-MOVING IRON IN AN INTERMEDIATE TYPE Ia SUPERNOVA BETWEEN NORMAL AND SUPER-CHANDRASEKHARShow others and affiliations
Number of Authors: 17
2016 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 823, no 2, article id 147Article in journal (Refereed) Published
Abstract [en]
In this paper, we report observations of a peculiar SN Ia iPTF13asv (a.k.a., SN2013cv) from the onset of the explosion to months after its peak. The early-phase spectra of iPTF13asv show an absence of iron absorption, indicating that synthesized iron elements are confined to low-velocity regions of the ejecta, which, in turn, implies a stratified ejecta structure along the line of sight. Our analysis of iPTF13asv's light curves and spectra shows that it is an intermediate case between normal and super-Chandrasekhar events. On the one hand, its light curve shape (B-band Delta m(15)=1.03 +/- 0.01) and overall spectral features resemble those of normal SNe Ia. On the other hand, its large peak optical and UV luminosity (M-B = -19.84 mag, M-uvm2 = -15.5 mag) and its low but almost constant Si II velocities of about 10,000 km s (1) are similar to those in super-Chandrasekhar events, and its persistent carbon signatures in the spectra are weaker than those seen commonly in super-Chandrasekhar events. We estimate a Ni-56 mass of 0.81(-0.18)(+0.10) M-circle dot and a total ejecta mass of 1.59(-0.12)(+0.45) M-circle dot. The large ejecta mass of iPTF13asv and its stratified ejecta structure together seemingly favor a double-degenerate origin.
Place, publisher, year, edition, pages
2016. Vol. 823, no 2, article id 147
Keyword [en]
supernovae: general, supernovae: individual (iPTF13asv), ultraviolet: general
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:su:diva-131925DOI: 10.3847/0004-637X/823/2/147ISI: 000377410000078OAI: oai:DiVA.org:su-131925DiVA, id: diva2:946551
2016-07-052016-07-042017-11-28Bibliographically approved