SHOCK WAVES

The central engine of GRB 130831A and the energy breakdown of a relativistic explosion

Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these …

The Detection of a Type IIn Supernova in Optical Follow-up Observations of IceCube Neutrino Events

The IceCube neutrino observatory pursues a follow-up program selecting interesting neutrino events in real-time and issuing alerts for electromagnetic follow-up observations. In 2012 March, the most significant neutrino alert during the first three …

Discovery, Progenitor and Early Evolution of a Stripped Envelope Supernova iPTF13bvn

The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC 5806 (22.5 Mpc). Our spectral sequence in the optical and infrared suggests a Type Ib classification. We identify a blue …

Beaming in Gamma-Ray Bursts: Evidence for a Standard Energy Reservoir

We present a comprehensive sample of all gamma-ray burst (GRB) afterglows with known distances, and we derive their conical opening angles based on observed broadband breaks in their light curves. Within the framework of this conical jet model, we …

The Radio Afterglow and the Host Galaxy of the X-Ray-rich GRB 981226

We report the discovery of a radio transient VLA 232937.2-235553, coincident with the proposed X-ray afterglow for the gamma-ray burst GRB 981226. This gamma-ray burst (GRB) has the highest ratio of X-ray to gamma-ray fluence of all the GRBs detected …

The Radio Afterglow and the Host Galaxy of the X-Ray-rich GRB 981226

We report the discovery of a radio transient VLA 232937.2-235553, coincident with the proposed X-ray afterglow for the gamma-ray burst GRB 981226. This gamma-ray burst (GRB) has the highest ratio of X-ray to gamma-ray fluence of all the GRBs detected …

Optical and Radio Observations of the Afterglow from GRB 990510: Evidence for a Jet

We present multicolor optical and two-frequency radio observations of the bright BeppoSAX event GRB 990510. Neither the well-sampled optical decay nor the radio observations are consistent with simple spherical afterglow models. The achromatic …

Optical and Radio Observations of the Afterglow from GRB 990510: Evidence for a Jet

We present multicolor optical and two-frequency radio observations of the bright BeppoSAX event GRB 990510. Neither the well-sampled optical decay nor the radio observations are consistent with simple spherical afterglow models. The achromatic …

Discovery of a Radio Flare from GRB 990123

We report the discovery of a radio counterpart to GRB 990123. In contrast to previous well-studied radio afterglows that rise to peak flux on a timescale of a week and then decay over several weeks to months, the radio emission from this gamma-ray …

Discovery of a Radio Flare from GRB 990123

We report the discovery of a radio counterpart to GRB 990123. In contrast to previous well-studied radio afterglows that rise to peak flux on a timescale of a week and then decay over several weeks to months, the radio emission from this gamma-ray …