GRB All-Sky Spectrometer Experiment (GASE)

     The goal of the GRB All-Sky Spectrometer Experiment (GASE) is to hunt for prompt low-frequency radio emission associated with Gamma Ray Bursts (GRBs).  GRBs are the largest explosions in our universe after the big bang with energy releases equivalent to the rest mass of our Sun occurring within tens of seconds! 

     GASE is located about a mile from MIT Haystack Observatory.  It consists of eight low frequency (30-40 MHz) antennas and a digital processing system with an instantaneous bandwidth of 4 MHz.  Upon receipt of a GRB alert notice from SWIFT, HETE, or INTEGRAL, the array is activated.  Electric field vectors within the requested bandwidth are sampled, basebanded, and directly recorded to disk.  We have the capability to record continuously for two hours after a GRB trigger, producing more than 720 GB of data.  After the burst, software combines the data from the individual antennas to calculate visibilities and image the entire sky in several thousand narrow frequency channels.

     We currently have all antennas in the ground and all receiver chains built and out at the site.  We have one of the three computers needed for the signal analysis operational.

Justin C. Kasper

Kavli Institute for Astrophysics and Space Research