1208.0307 (Zach Cano)

The Nature of Gamma Ray Burst Supernovae    [PDF]

Zach Cano

Gamma Ray Bursts (GRBs) and Supernovae (SNe) are among the brightest and most energetic physical processes in the universe. It is known that core-collapse SNe arise from the gravitational collapse and subsequent explosion of massive stars (the progen- itors of nearby core-collapse SNe have been imaged and unambiguously identified). It is also believed that the progenitors of long-duration GRBs (L-GRBs) are massive stars, mainly due to the occurrence and detection of very energetic core-collapse su- pernovae that happen both temporally and spatially coincident with most L-GRBs. However many outstanding questions regarding the nature of these events exist: How massive are the progenitors? What evolutionary stage are they at when they explode? Do they exist as single stars or in binary systems (or both, and to what fractions)? The work presented in this thesis attempts to further our understanding at the types of progenitors that give rise to long-duration GRB supernovae (GRB-SNe). This work is based on optical photometry obtained for three GRB-SNe events: GRB 060729, GRB 090618 and XRF 100316D (an X-Ray Flash is similar to a L-GRB, but has a lower peak energy). For GRB 060729 and GRB 090618 we model the optical light curves and account for light coming from three sources: the host galaxy, the afterglow and the supernova. When we remove the host flux, and model the afterglow, the re- maining flux resembles that of a SN, both in the shape of the light curve and the shape of the spectral energy distribution. Our investigation of XRF 100316D and its spectroscopically-confirmed Ic-BL SN 2010bh is more detailed as we were able to obtain optical and infrared data in many filters, which we utilize to created a quasi-bolometric light curve that we model to determine physical parameters of the SN...

View original: http://arxiv.org/abs/1208.0307