WIDGET: System Performance and GRB Prompt Optical Observations
Abstract
The WIDeField telescope for Gamma-ray burst Early Timing (WIDGET) is used for a fully automated, ultra-wide-field survey aimed at detecting the prompt optical emission associated with Gamma-ray Bursts (GRBs). WIDGET surveys the HETE-2 and Swift/BAT pointing directions covering a total field of view of 62 degree x 62 degree every 10 secounds using an unfiltered system. This monitoring survey allows exploration of the optical emission before the gamma-ray trigger. The unfiltered magnitude is well converted to the SDSS r' system at a 0.1 mag level. Since 2004, WIDGET has made a total of ten simultaneous and one pre-trigger GRB observations. The efficiency of synchronized observation with HETE-2 is four times better than that of Swift. There has been no bright optical emission similar to that from GRB 080319B. The statistical analysis implies that GRB080319B is a rare event. This paper summarizes the design and operation of the WIDGET system and the simultaneous GRB observations obtained with this instrument.
Keywords
Cite
@article{arxiv.1010.5035,
title = {WIDGET: System Performance and GRB Prompt Optical Observations},
author = {Yuji Urata and Makoto S. Tashiro and Toru Tamagawa and Fumihiko Usui and Makoto Kuwahara and Hungmiao Lin and Shoichi Kageyama and Wataru Iwakiri and Takako Sugasahara and Kazuki Takahara and Natsuki Kodaka and Keiichi Abe and Keisuke Masuno and Kaori Onda},
journal= {arXiv preprint arXiv:1010.5035},
year = {2015}
}
Comments
19 pages, 11 figures, Accepted to appear in PASJ