GRB follow-up observations in the East-Asian region

TL;DR

This paper reports on the establishment and results of a collaborative East-Asian network for gamma-ray burst follow-up observations, enhancing global coverage and providing valuable data on GRB afterglows.

Contribution

It introduces a new regional collaboration for GRB follow-up in East-Asia, filling a coverage gap and demonstrating successful detection of optical afterglows.

Findings

Detection of two optical afterglows, GRB 040924 and GRB 041006.

Successful multi-site follow-up providing detailed light curves and spectra.

Enhanced global GRB observation network with regional focus.

Abstract

In 2004, we established a Japan-Taiwan-China collaboration for GRB study in the East-Asian region. This serves as a valuable addition to the world-wide optical and infrared follow-up network, because the East-Asia region would otherwise be blank. We have been carrying out imaging and spectroscopic follow-up observations at Lulin (Taiwan), Kiso (Japan), WIDGET (Japan) and Xinglong (China). From Xinglong and Kiso, we can locate candidates and obtain early time spectra for afterglows. While WIDGET provides early time observations before the burst, the high-time resolution for multi-band light curves can be obtained at Lulin. With the data from these sites, we can obtain detailed information about the light curve and redshift of GRBs, which are important to understand the mechanism of the afterglows. Up to March 2005, ten follow-up observations have been provided by this East-Asia cooperation. Two optical afterglows were detected, GRB 040924 and GRB 041006. The results of the two detected afterglows are reported in this article.