GRB 070724B: the first Gamma Ray Burst localized by SuperAGILE and its Swift X-ray Afterglow

TL;DR

This paper reports the first localization of a Gamma Ray Burst by SuperAGILE, its X-ray afterglow detection by Swift, and the absence of gamma-ray, optical, and radio afterglows, providing new constraints on high-energy emissions.

Contribution

It presents the first GRB localization by SuperAGILE and details multi-wavelength follow-up observations, establishing upper limits in high-energy gamma rays.

Findings

X-ray afterglow detected by Swift XRT

No significant gamma-ray emission in MeV-GeV range

No optical or radio afterglow detected

Abstract

GRB 070724B is the first Gamma Ray Burst localized by SuperAGILE, the hard X-ray monitor aboard the AGILE satellite. The coordinates of the event were published $\sim 19$ hours after the trigger. The Swift X-Ray Telescope pointed at the SuperAGILE location and detected the X-ray afterglow inside the SuperAGILE error circle. The AGILE gamma-ray Tracker and Minicalorimeter did not detect any significant gamma ray emission associated with GRB 070724B in the MeV and GeV range, neither prompt nor delayed. Searches of the optical afterglow were performed by the Swift UVOT and the Palomar automated 60-inch telescopes without any significant detection. Similarly the Very Large Array did not detect a radio afterglow. This is the first GRB event with a firm upper limit in the 100 MeV -- 30 GeV energy range, associated with an X-ray afterglow.