The Type IIb Supernova 2011dh from a Supergiant Progenitor

BERSTEN; BENVENUTO; NOMOTO; ERGON; FOLATELLI; SOLLERMAN; BENETTI; BOTTICELLA; FRASER; KOTAK; MAEDA; OCHNER; TOMASELLA

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2012 vol. 757 p. 31 - 41

0004-637X

A set of hydrodynamical models based on stellar evolutionary progenitors is used to study the nature of SN 2011dh. Our modeling suggests that a large progenitor star--with R ~ 200 Rsun--is needed to reproduce the early light curve (LC) of SN 2011dh. This is consistent with thesuggestion that the yellow super-giant star detected  at the location of the supernova (SN) in deep pre-explosion images is the progenitor star. From the main peak of the bolometric LC and expansion velocities, we constrain the mass of the ejecta to be ~ 2Msun, the explosion energy to be E = (6-10)x 10^50 erg and the 56Ni mass to be approximately 0.06 Msun. The progenitor star was composed of a helium  core of 3-4 Msun and a thin hydrogen-rich envelope of ~ 0.1 Msun with a main-sequence mass estimated to be in the range of 12-15 Msun. Our models rule out progenitors with helium-core masses larger than 8 Msun, which correspond to MZAMS >  25 Msun. This suggests that a single star evolutionary scenario for SN 2011dh is unlikely.