A GRB Follow-up System at the Xinglong Observatory and Detection of the High-Redshift GRB 060927

TL;DR

The paper describes the development of an automated GRB follow-up system at Xinglong Observatory, capable of rapid response and early afterglow detection, demonstrated by successful observations including the high-redshift GRB 060927.

Contribution

It introduces a new automated follow-up system utilizing multiple telescopes at Xinglong Observatory, enabling rapid response and early detection of GRB afterglows, including the high-redshift GRB 060927.

Findings

Responded to 15 GRBs in 2006, detecting 7 early afterglows.

Responded to 18 GRBs in 2007, detecting 6 afterglows.

Detected the high-redshift GRB 060927 at z=5.5, starting observations 91 seconds after trigger.

Abstract

A gamma-ray burst (GRB) optical photometric follow-up system at the Xinglong Observatory of National Astronomical Observatories of China (NAOC) has been constructed. It uses the 0.8-m Tsinghua-NAOC Telescope (TNT) and the 1-m EST telescope, and can automatically respond to GRB Coordinates Network (GCN)alerts. Both telescopes slew relatively fast, being able to point to a new target field within about 1 min upon a request. Whenever available, the 2.16-m NAOC telescope is also used. In 2006, the system responded to 15 GRBs and detected seven early afterglows. In 2007, six GRBs have been detected among 18 follow-up observations. TNT observations of the second most distant GRB 060927 (z=5.5) are shown, which started as early as 91s after the GRB trigger. The afterglow was detected in the combined image of first 19x20s unfiltered exposures. This GRB follow-up system has joined the East-Asia GRB Follow-up Observation Network (EAFON).