Pipeline for detection of transient objects in optical surveys

Communications in Computer and Information Science. 2022. Vol. 1620. P. 104–134.

Nicolai Pankov, Alexei Pozanenko, Kouprianov V., Belkin S.

Identification and following study of optical transients (OTs) associated with cosmic gamma-ray bursts (GRBs) and gravitational wave (GWs) events is a relevant research problem of multi-messenger astronomy. Since their first discovery, one of the greatest challenges is the localisation uncertainty. The sources of OTs are initially localised with space gamma and X-ray telescopes or ground-based laser interferometers LIGO, Virgo and KAGRA having the poor positional accuracy on average. A joint localisation area typically covers about 1000 deg$^2$ of the sky based on previous runs of LIGO and Virgo. The last 25 years has seen a rapid development of the robotic optical surveys. Such instruments equipped with wide-field cameras allow to cover the entire localisation area in several scans. As the result, a massive amount of scientific products is generated, including bulky series of astronomical images. After their processing, large object catalogues that may contain up to $10^5$ celestial objects are created. It is necessary to identify the peculiar objects among other in the formed catalogues. Both data processing and identification of OTs must be carried out in real-time due to steep decay of brightness. To response pointed problems, the software pipelines are becoming a relevant solution. This paper provides a complete overview of the units of the actively developed pipeline for OT detection. The accuracy and performance metrics of the pipeline units, estimated for two wide-field telescopes are given. In conclusions, the future plans for the development are briefly discussed.

Keywords: астрономия, optical transients, оптические транзиенты, time-domain astronomy, wide-field surveys, real-time data processing, широкопольные обзоры, обработка данных в режиме реального времени