CAREER: Radio and gravitational-wave emission from the largest explosions since the Big Bang

Texas Tech University, Lubbock TX

Investigators

Abstract

Gamma Ray Bursts (GRBs) are the most energetic phenomena in the universe and are rarely observed in distant galaxies. They are thought to be created when a supernova explosion occurs, or binary neutron stars merge, and a narrow beam of material is ejected at highly relativistic speeds. This award funds a program to address several open questions associated with GRBs: namely their connection to supernovae, their connection to compact binary mergers and the composition of their relativistic ejecta as it shocks the surrounding material. This project will focus on studying the only type of supernovae known to be associated with GRBs, which are called type BL Ic. The PI and her team will combine observations of these objects at the Palomar Transient Factory with follow-up radio emission measurements done at the Jansky Very Large Array (VLA) to search for GRB signatures. Using new capabilities of the VLA brought about by the recent upgrade. They also plan to conduct gravitational wave measurements with Advanced LIGO. This work also includes a large educational component, which will provide radio images of the sky and in-class activities to high school teachers and college students. The PI will also conduct annual seminars to teachers of local high schools in order to help spread scientific literacy and promote excitement about astronomy. Much of this communication will be carried out by high school students in the Texas Tech U Clark Scholars program, who will create flyers for public distribution. The PI will also train and mentor graduate and undergraduate students and a postdoctoral scholar in research. The observations will be carried out at early-time (10-30 days of detection) and late-time (100-1000 days) in order to search for observational signatures of mildly relativistic ejecta and off-axis afterglow from a GRB jet, respectively. The VLA data will be coupled with optical observations from the Palomar 60-inch telescope to provide a broad-band dataset for model testing. The PI will also will use Swift/UVOT and other optical data published in GCNs to test whether radio emission is accompanied by a reverse shock optical flare, or else dominated by the forward shock. The Palomar observations will also be used to search for the optical counterpart of the GRB. The team will also search for the first off-axis GRB, which is predicted by the GRB jet model, but so far not detected. Also, this work will be contribute to our understanding of very massive stars (those with more than 20 times the mass of the Sun), which play a key role in understanding ionization and metallicity studies of the early Universe, when many of these stars may have seeded the early Universe with black holes.