What GRBs Do in the Shadows: A Radio Bright, Dust Obscured Population of Long GRBs

Long gamma-ray bursts (GRBs) are among the most energetic explosions in the universe, and are commonly accepted to come from the core collapse of massive stars. These explosive events produce broadband (X-ray to radio) synchrotron emission, known as the “afterglow”, which can be modeled to determine burst properties such as burst energy, circumburst density, and jet opening angle. However, a subset of these long GRBs encounter significant amounts of dust obscuration along the line of sight, leading to a suppressed optical afterglow that is often faint or undetected (“dark” GRB). Radio detections of these dark GRBs can break modeling degeneracies caused by the lack of optical emission, constraining the low frequency end of the synchrotron spectrum while the X-ray afterglow as observed by satellites such as Swift constrain the high frequency end. I will present a sample of dark GRBs, revealed by bright radio detections, whose afterglows and host galaxies I modeled in order to determine burst, environmental, and global properties. I compare the dark GRB population to the unobscured long GRB population to determine what, if anything, sets dark GRBs apart from the unobscured long GRB population, as well as determine the location of the dust along the line of sight of the GRB. I conclude with placing constraints on obscured star formation within the host galaxies of long GRBs, and make predictions for the radio detectability of long GRB hosts with future radio observatories.