TY  - JOUR
AU  - Ruiter, Iris de
AU  - Meyers, Zachary Samuel
AU  - Rowlinson, Antonia
AU  - Shimwell, Timothy W.
AU  - Wijers, Ralph A. M. J.
TI  - Transient study using LoTSS - framework development and preliminaryresults
JO  - Monthly notices of the Royal Astronomical Society
VL  - 531
IS  - 4
SN  - 0035-8711
CY  - Oxford
PB  - Oxford Univ. Press
M1  - PUBDB-2023-01522
SP  - 4805-4822
PY  - 2024
AB  - We present a search for transient radio sources on time-scales of seconds to hours at 144 MHz using the LOFAR Two-metre Sky Survey (LoTSS). This search is conducted by examining short time-scale images derived from the LoTSS data. To allow imaging of LoTSS on short time-scales, a modern imaging procedure and fast filtering strategy are introduced. This includes sky model source subtraction, no cleaning or primary beam correction, a simple source finder, fast filtering schemes, and source catalogue matching. This new strategy is first tested by injecting simulated transients, with a range of flux densities and durations, into the data. We find the limiting sensitivity to be 113 and 6 mJy for 8 s and 1 h transients, respectively. The new imaging and filtering strategies are applied to 58 fields of the LoTSS survey, corresponding to LoTSS-DR1 (2 per cent of the survey). One transient source is identified in the 8 s and 2 min snapshot images. The source shows 1 min duration flare in the 8 h observation. Our method puts the most sensitive constraints on/estimates of the transient surface density at low frequencies at time-scales of seconds to hours; <4.0 × 10<sup>−4</sup> deg<sup>−2</sup> at 1 h at a sensitivity of 6.3 mJy; 5.7 × 10<sup>−7</sup> deg<sup>−2</sup> at 2 min at a sensitivity of 30 mJy; and 3.6 × 10<sup>−8</sup> deg<sup>−2</sup> at 8 s at a sensitivity of 113 mJy. In the future, we plan to apply the strategies presented in this paper to all LoTSS data. 
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001253064300001
DO  - DOI:10.1093/mnras/stae1458
UR  - https://bib-pubdb1.desy.de/record/581023
ER  -