{
  "createdOn": 1579622118000,
  "subject": "LIGO/VIRGO S200115j: No obvious candidates from Pan-STARRS2 observations",
  "eventId": "LIGO/Virgo S200115j",
  "version": 2,
  "editedBy": "courey.elliott@gmail.com",
  "email": "S.Srivastav@qub.ac.uk",
  "body": "S. Srivastav, S. J Smartt (QUB), M. Huber (IfA, Univ. of Hawaii), K. W. Smith (QUB), K. Chambers,\nA. Schulz (IfA), D. R. Young, O. McBrien, J. Gillanders, D. O'Neil, P. Clark, S. Sim (QUB),\nT. de Boer, J. Bulger, J. Fairlamb, M. Huber, C.-C. Lin, T. Lowe, E. Magnier, R. J. Wainscoat,\nM. Willman (IfA, Univ.  of Hawaii), T.-W, Chen (Stockholm), A. Rest (STScI),\nC. Stubbs (Harvard)\n\nWe report observations of the skymap of the mass gap event S200115j (LVC, GCN 26759).\nWe targeted one of the eastern lobes in the Lal Inference probability region (RA ~ 3 hr)\nwith the Pan-STARRS2 telescope. The images were obtained in the w-band\n(Tonry et al. 2012, ApJ 750, 99). A sequence of quads (4 x 45 sec) was taken at\neach pointing position during the nights of 2020-01-18 and 2020-01-19.\n\nThe images were processed with the IPP (Magnier et al. 2016,arXiv:1612.05240)\nand difference images were produced using the Pan-STARRS1 Science Consortium 3Pi\nimages as reference frames. Transient candidates were run through our standard filtering\nprocedures, combined with a machine learning algorithm\n(Wright et al. 2015, MNRAS, 449, 451) and all candidates were spatially\ncross-matched with known minor planets, and major star, galaxy, AGN and multi-wavelength\ncatalogues (as described in Smartt et al. 2016, MNRAS, 462 4094).\n\nWe report the following transients within the 90% contour of the skymap.\nAll the candidates are offset from a clear galaxy. PS20ev and PS20fr have spectroscopic\nhost redshifts (from NED), while the rest have photometric redshifts from GLADE or SDSS.\nThe GW event was reported by LVC on MJD 58863.18.\n\nName     TNS Name    RA (J2000)     Dec (J2000)  Disc. MJD  Disc. Mag  redshift\nPS20ev   AT2020ait    02:36:56.51    -02:12:03.5    58866.30     20.23     0.0701 (s)\nPS20fs   AT2020ajy    02:53:21.00    +03:23:17.4    58866.32     21.46     0.301 (p)\nPS20fo   AT2020ajw    02:25:53.75    -03:13:04.6    58866.30     19.90     0.138 (p)\nPS20fr   AT2020ajx    02:25:23.51    -07:50:15.5    58866.30     20.42     0.0538 (s)\nPS20fu   AT2020ajz    02:49:02.17    +04:59:11.6    58866.30     21.16       -\nPS20fv   AT2020aka    02:37:24.50    -01:09:20.1    58867.26     19.91     0.142 (p)\nPS20fw   AT2020akb    03:10:05.41    +05:59:16.4    58867.32     21.05     0.098 (p)\nPS20fx   AT2020akc    02:52:35.05    +07:15:11.9    58866.30     20.89       -\n\nOnly PS20fs (AT2020ajy) shows a ~0.5 mag rise, the other transients show a flat\nw-band light curve. There are no obvious candidates that show rapid fading.\nThe LVC distance of 332 +/- 78 Mpc corresponds to 0.06 < z < 0.09 (for Ho = 70).\n\nWe also recover the following transients discovered by the ATLAS and ZTF surveys\nafter the GW event. Our photometry does not indicate any unusual rise or fade.\n\nSource    TNS Name    RA (J2000)     Dec (J2000)    MJD         PS2 Mag   redshift\nATLAS     AT2020afo    02:27:31.13    -01:06:41.6   58867.26    18.61     0.0857 (s)\nZTF       AT2020agw    02:34:02.13    -04:26:44.3   58866.30    20.62       -\nZTF       AT2020aeo    02:59:39.07    +06:41:11.2   58867.25    20.89       -",
  "circularId": 26839,
  "submitter": "Shubham Srivastav at QUB  <S.Srivastav@qub.ac.uk>",
  "bibcode": "2020GCN.26839....1S",
  "editedOn": 1757443009657
}