{
  "subject": "LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61",
  "createdOn": 1713895881380,
  "bibcode": "2024GCN.36259....1H",
  "circularId": 36259,
  "eventId": "LIGO/Virgo/KAGRA S240422ed",
  "submittedHow": "web",
  "body": "Lei Hu (CMU), Tomás Cabrera (CMU), Brendan O'Connor (CMU), Keerthi Kunnumkai (CMU), Igor Andreoni (UMD), Antonella Palmese (CMU) report on behalf of the GW-MMADS team:\n\n\nDuring GW-MMADS DECam follow-up (Palmese et al., GCN 36245) of the LIGO/Virgo/KAGRA event S240422ed (GCN 36236, GCN 36240), we serendipitously observed the location of the Swift/XRT source 61 (here labelled S240422ed_X61) at coordinates RA, Dec = 120.3245d, -28.1765d (J2000; [1]).\n\nIn our difference imaging relative to archival DECam images, obtained using SFFT (Hu et al., 2021), we do not detect any optical transient or variable emission within a 20 arcsec radius. Upper limits are reported below.\n\nfilter | observation time UT | limiting magnitude (AB, 5 sigma)\nDECam-r | 2024-04-22T23:59:29 | 22.46\nDECam-z | 2024-04-23T02:55:26 | 21.33\n\n\n[1] https://gcn.gsfc.nasa.gov/other/S240422ed.counterpart",
  "submitter": "Igor Andreoni at JSI/UMD/NASA <igor.andreoni@gmail.com>"
}