A real-time transient detector and the Living Swift-XRT Point Source catalogue

TL;DR

This paper introduces the Living Swift-XRT Point Source catalogue and a real-time transient detector, enabling rapid detection and follow-up of faint X-ray transients with near real-time updates, a significant advancement for time-domain astrophysics.

Contribution

It presents the first low-latency, real-time X-ray transient detection system and an up-to-date, continuously updated X-ray point source catalogue from Swift-XRT data.

Findings

First real-time detection of faint X-ray transients

Near real-time updates of the X-ray point source catalogue

Community-accessible tools for rapid follow-up and analysis

Abstract

We present the Living Swift-XRT Point Source catalogue (LSXPS) and real-time transient detector. This system allows us for the first time to carry out low-latency searches for new transient X-ray events fainter than those available to the current generation of wide-field imagers, and report their detection in near real-time. Previously, such events could only be found in delayed searches, e.g. of archival data; our low-latency analysis now enables rapid and ongoing follow up of these events, enabling the probing of timescales previously inaccessible. The LSXPS is, uniquely among X-ray catalogues, updated in near real-time, making this the first up-to-date record of the point sources detected by a sensitive X-ray telescope: the Swift-X-ray Telescope (XRT). The associated upper limit calculator likewise makes use of all available data allowing contemporary upper limits to be rapidly produced on-demand. These facilities, which enable the low-latency transient system are also fully available to the community, providing a powerful resource for time-domain and multi-messenger astrophysics.