GCN Circular 36421
Subject
LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
Date
2024-05-09T20:28:27Z (11 days ago)
From
Brendan O'Connor at Carnegie Mellon University <boconno2@andrew.cmu.edu>
Via
Web form
Brendan O'Connor (CMU), Antonella Palmese (CMU), Lei Hu (CMU), Tomás Cabrera (CMU), Igor Andreoni (UMD), Keerthi Kunnumkai (CMU) report on behalf of the GW-MMADS team:
We report additional candidates from the DECam GW-MMADS survey program (GCN 36245, GCN 36273, GCN 36298, GCN 36317, GCN 36351) follow-up of the LIGO/Virgo/KAGRA event S240422ed (GCN 36236, GCN 36240).
We ran the SFFT difference imaging (Hu et al. 2022) on the available images from four nights of observations. Our observations were taken for three nights between 2023-04-22 23:37 and 2024-04-25 02:50 UTC with a final epoch starting at 2024-05-01 22:59 UTC. We have filtered out likely stars and moving objects, and visually inspected the remaining transients.
The following candidates have detections across each of the four epochs, show declining lightcurves, and have potential host galaxies:
+-------------------------+------------+------------+------------+---------+
| id | tns | ra | dec | comment |
|-------------------------+------------+------------+------------+---------|
| T202404220754081m230446 | AT 2024hbf | 118.533917 | -23.079503 | [1] |
| T202404230801416m292704 | AT 2024hdw | 120.423317 | -29.451108 | [2] |
| T202404220750120m261013 | AT 2024hfj | 117.549917 | -26.170144 | [3] |
| T202404230827131m201259 | AT 2024hek | 126.804604 | -20.216328 | [4] |
| T202404230836123m164432 | AT 2024hel | 129.051254 | -16.742358 | [5] |
+-------------------------+------------+------------+------------+---------+
[1] Multiple uncatalogued galaxies exist within 1' and are visible in DECaPS imaging. The galaxy 2MFGC 06268 is located at 2' offset and has a spectroscopic redshift of z=0.059677 consistent within ~3 sigma with the GW distance.
[2] Two candidate hosts exist to the North within 1': WISEA+J080141.03-292637.1 and WISEA+J080142.38-292621.8
[3] One candidate host within 1': WISEA J075010.62-261059.0
[4] Candidate host at a small offset: WISEA J082713.16-201301.5
[5] Candidate host at a small offset: WISEA J083612.37-164424.5
We note that none of these candidates are fast fading (>0.2 mag per day) nor do they display significant color evolution.
We thank the CTIO and NOIRLab staff for supporting these observations and the data calibrations.