The type Iax supernova, SN 2015H: a white dwarf deflagration candidate

M.R. Magee (1) , R. Kotak (1) , S.A. Sim (1) , M. Kromer (2) , D. Rabinovitz (3) , S.J. Smartt (1) , C. Baltay (3) , Heather Campbell (4) , Ting-Wen Chen (5) , M. Fink (6) , A. Gal-Yam (7) , Lluis Galbany (8, 9) , W. Hillebrandt (10) , C. Inserra (1) , E. Kankare (1) , Laurent Le Guillou (11, 12) , J.D. Lyman (13) , K. Maguire (1) , R. Pakmor (14) , F. K. Röpke (15, 16) , A.J. Ruiter (15, 16) , I. R. Seitenzahl (15, 16) , M Sullivan (17) , Valenti S (18) , David R Young (1)

1 ARC - Astrophysics Research Centre [Belfast]
2 Stockholm University
3 department of physics, Yale University
4 Institute of Astronomy [Cambridge]
5 MPE - Max-Planck-Institut für Extraterrestrische Physik
6 Institut für Theoretische Physik und Astrophysik [Würzburg]
7 Department of Particle Physics and Astrophysics
8 Departamento de Astronomía
9 Millennium Institute of Astrophysics
10 MPA - Max-Planck-Institut für Astrophysik
11 SU - Sorbonne Université
12 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies
13 University of Warwick [Coventry]
14 H-ITS - Heidelberger Institut für Theoretische Studien
15 RSAA - Research School of Astronomy and Astrophysics [Canberra]
16 CAASTRO - Centre of Excellence for All-Sky Astrophysics
17 School of Physics and Astronomy [Southampton]
18 Department of Physics, University of California

We present results based on observations of SN 2015H which belongs to the small group of objects similar to SN 2002cx, otherwise known as type Iax supernovae. The availability of deep pre-explosion imaging allowed us to place tight constraints on the explosion epoch. Our observational campaign began approximately one day post-explosion, and extended over a period of about 150 days post maximum light, making it one of the best observed objects of this class to date. We find a peak magnitude of Mr = -17.27 ± 0.07, and a (Δm15)r = 0.69 ± 0.04. Comparing our observations to synthetic spectra generated from simulations of deflagrations of Chandrasekhar mass carbon-oxygen white dwarfs, we find reasonable agreement with models of weak deflagrations that result in the ejection of ~0.2 M⊙ of material containing ~0.07 M⊙ of 56Ni. The model light curve however, evolves more rapidly than observations, suggesting that a higher ejecta mass is to be favoured. Nevertheless, empirical modelling of the pseudo-bolometric light curve suggests that ≲0.6 M_sun of material was ejected, implying that the white dwarf is not completely disrupted, and that a bound remnant is a likely outcome

Domaines: Phénomènes cosmiques de haute energie [astro-ph.HE]; Astrophysique stellaire et solaire [astro-ph.SR]

M.R. Magee, R. Kotak, S.A. Sim, M. Kromer, D. Rabinovitz, et al.. The type Iax supernova, SN 2015H: a white dwarf deflagration candidate. Astronomy and Astrophysics - A&A, 2016, 589, pp.A89. ⟨10.1051/0004-6361/201528036⟩. ⟨hal-02004224⟩