Further monitoring of FRB 20201124A with Swift
ATel #14836; B. O'Connor (George Washington University), L. Piro (INAF/IAPS), S. Lotti (INAF/IAPS), R. Ricci (INAF/IRA), G. Bruni (INAF/IAPS) , B. Zhang (University of Nevada), F. Panessa (INAF/IAPS)
on 9 Aug 2021; 12:58 UT
Credential Certification: Brendan O'Connor (oconnorb@gwmail.gwu.edu)
Subjects: Optical, Ultra-Violet, X-ray, Fast Radio Burst
We observed the location of FRB 20201124A with the Neil Gehrels Swift Observatory under the Swift Guest Investigator program (Program: 1619112, PI: Piro) on July 28, 2021 starting at 10:54:00 UT for 8.6 ks and on August 7 starting at 01:49:00 UT and ending at 16:37:01 UT for a total of 6.3 ks. These observations were carried out with the X-ray Telescope (XRT) in Photon Counting (PC) mode. No source was identified at the FRB position (ATel #14603) in either observation. We derive a 3-sigma upper limit of <1.3e-3 cts/s on July 28, which we convert to an unabsorbed flux <1.0e-13 erg/cm^2/s using an absorbed power-law model with Photon index gamma=2 and a Galactic hydrogen column density nH=4.5e21 cm^-2 (Willingale et al. 2013). The 3-sigma upper limit on August 7 is <1.7e-3 cts/s yielding an unabsorbed flux <1.3e-13 erg/cm^2/s by adopting the same power-law model.
We also report on simultaneous observations with the Ultraviolet-Optical Telescope (UVOT) on July 28 in the u filter for a total exposure of 8.4 ks, and on August 7 in the uvw2 filter for 2 ks and in the u filter for 3.8 ks. The upper limit at the FRB position on July 28 is u>22.6 AB mag, and on August 7 is uvw2>22.5 and u>22.3 AB mag.
We thank the Swift team for their assistance in scheduling these observations.
