A real-time transient detector and the living Swift-XRT point source catalogue

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.
Comment: Replaced with post-refereeing accepted version of the paper. To appear in MNRAS. 12 pages, plus 18 of appendices. For the sake of rainforests, printing the appendices is not advised. For the sake of sanity, nor is reading them