arXiv subjects

Melina C. Bersten

Publications and source records attributed to Melina C. Bersten.

21 records · Page 2Linked to original sources

arXiv2012

The Type IIb Supernova 2011dh from a Supergiant Progenitor

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 of SN 2011dh. This is consistent with the suggestion that the yellow super-giant star detected at the location of the SN in deep pre-explosion images is the progenitor star. From the main peak of the bolometric light curve and expansion velocities we constrain the mass of the ejecta to be ~2 Msun, 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 to 4 Msun and a thin hydrogen-rich envelope of ~0.1 M_sun 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 M_ZAMS > 25 Msun. This suggests that a single star evolutionary scenario for SN 2011dh is unlikely.

astro-ph.HE↗

arXiv2011

Hydrodynamical models of Type II-Plateau Supernovae

We present bolometric light curves of Type II-plateau supernovae (SNe II-P) obtained using a newly developed, one-dimensional Lagrangian hydrodynamic code with flux-limited radiation diffusion. Using our code we calculate the bolometric light curve and photospheric velocities of SN1999em obtaining a remarkably good agreement with observations despite the simplifications used in our calculation. The physical parameters used in our calculation are E=1.25 foe, M= 19 M_\odot, R= 800 R_\odot and M_{Ni}=0.056 M_\odot. We find that an extensive mixing of 56Ni is needed in order to reproduce a plateau as flat as that shown by the observations. We also study the possibility to fit the observations with lower values of the initial mass consistently with upper limits that have been inferred from pre-supernova imaging of SN1999em in connection with stellar evolution models. We cannot find a set of physical parameters that reproduce well the observations for models with pre-supernova mass of \leq 12 M_\odot, although models with 14 M_\odot cannot be fully discarded.

astro-ph.SR↗

arXiv2009

Bolometric Light Curves for 33 Type II-Plateau Supernovae

Using data of three well-observed type-II plateau supernovae (SNe II-P), SNe 1987A, 1999em and 2003hn; and two atmosphere models by Eastman et al. (1996) and Dessart & Hillier (2005b) we derive calibrations for bolometric corrections and effective temperature from BVI photometry. The typical scatter of the bolometric correction is 0.11 mag. With these results we obtain bolometric light curves and effective temperature evolution for a sample of 33 SNe II-P. The SN sample shows a range of 1 dex in plateau luminosity and plateau durations from 75 to 120 days. Comparing the shape of the transition between the plateau and the radioactive tail, we find that the size of the drop is in the range of 0.8 to 1.12 dex.

astro-ph.SR↗