Gamma ray burst afterglow studies in turkey

Abstract

Gamma-Ray Bursts (GRBs) accidentally discovered by American Vela military satellites some forty years ago are transient celestial events, lasting milli-seconds to 10's of minutes. They are considered as the most powerful explosions in the whole Universe. About once per day, at some random location in the sky, a shower of gamma-ray photons with energies from about 1keV to 100MeV appears and we can not guess where they will occur next in the sky. Hence their observing and studying have been very difficult. To overcome these difficulties, astronomers designed special purpose detectors such as Robotic Optical Transient Search Experiment (ROTSE). To understand these events, astronomers want to study their afterglows in x-rays, optical and radio waves when a GRB occur. The ROTSE Project is conceived by Univ. of Michigan scientists (Akerlof et al., 1991) and financed by NASA. It aims to achieve the detection of optical emission from GRBs simultaneous or just after the event. The ROTSE system can move quickly on the coordinates of the burst which is usually announced through Internet. Presently, the international ROTSE collaboration includes, besides the main coordinating group at Michigan Univ. (running a station at Los Alomos), 3 other ROTSE stations located in Turkey, Namibia and Australia. Each of these telescopes are fully automated forming a world-wide network. One of them, namely, ROTSE-IIId is located at Antalya, within the Turkish National Observatory (TUG) site and is functional since May 2004. In this work, after some historical notes and afterglow detection statistics, the properties, goals, functions and the technology behind the Global ROTSE system installed around the world will be summarized, with emphasis on Antalya station results.