Gamma-ray Bursts

My main research topic is the prompt emission of gamma-ray bursts (GRBs). I have mainly focused on physical modeling of the emitted spectra. Currently, I am interested in the methods and models that can be used to finally understand what processes are occurring in these relativistic outflows.

Prompt Emission

One of the most pressing debates in GRBs is the emission process responsible for the observed prompt gamma-rays. The primary theories are either photospheric emission occurring below or very near the photosperic radius of the GRB, or non-thermal (possibly synchrotron) emission high above the photosphere. Diving further into the unknown, we come across the problem of how the internal energy of the jet is converted into radiation: either shocks or some form of magnetic dissipation.

Image credit: NASA

One way we can explore these scenarios is the examination of prompt emission spectra via direct physical modeling. By this, I mean using numerical and/or analytic expressions for the hypothesized emission processes to directly fit the observed spectral data. This is in contrast to the historical approach of fitting empirical models to the data and using distributions of these empirical model parameters to infer physics. This is currently my main interest in the study of GRBs and what my recent papers have focused on.


A new topic I have been exploring is the afterglow emission of GRBs. In particular, I am interested in the modeling of the intrinsic host galaxy gas as well and how its observation can be affected by the use of physical models. With the development of our new tool, 3ML, I am performing multi-wavelength studies using physical spectral models.