{
  "bibcode": "2023GCN.33900....1K",
  "circularId": 33900,
  "createdOn": 1685503960135,
  "subject": "LIGO/Virgo/KAGRA S230529ay: Zwicky Transient Facility observations",
  "body": "Viraj Karambelkar (CIT), Tomas Ahumada (CIT),  Robert Stein (CIT), Akash\nAnumarlapudi (UWM), Gaurav Waratkar (IITB), Harsh Kumar (IITB), Anirudh\nSalgundi (IITB), Vishwajeet Swain (IITB), Theophile du Laz (CIT), Igor\nAndreoni (UMD), Michael Coughlin (UMN), Mansi Kasliwal (CIT), Varun\nBhalerao (IITB), Simeon Reusch (DESY), Jannis Necker (DESY), Shreya Anand\n(CIT), Eric Bellm (UW), Brian Healy (UMN), S. B. Cenko (UMD), D. Kaplan\n(UWM), D. Perley (LJMU) report on behalf of the ZTF and GROWTH\ncollaborations:\n\n\nWe observed the localization region of the LVC trigger S230529ay as part of\nroutine Zwicky Transient Facility (ZTF; Graham et al., 2019; Bellm et al.,\n2019) survey operations. We obtained images in the r, i, and g bands\nbeginning at 2023-05-30T04:13:34.003 UT (10 hours after the LVC trigger\ntime), covering ~7% of the probability enclosed in the localization region.\n\n\nWe queried the ZTF alert stream using Kowalski (Duev et al. 2019) through\nFritz (Coughlin et al. 2023) and emgwcave (Karambelkar et al. in prep),\nAMPEL (Nordin et al. 2019), and ZTFReST (Andreoni & Coughlin et al., 2021).\nWe required at least 2 detections separated by at least 15 minutes to\nselect against moving objects. Furthermore, we cross-match our candidates\nwith the Minor Planet Center to flag known asteroids, reject stellar\nsources (Tachibana and Miller 2018), and apply machine learning algorithms\n(Mahabal et al. 2019). We require that no spatially coincident ZTF alerts\nwere issued before the detection time of the LVC trigger. We also run\nforced photometry on ZTF images (Masci et al. 2019) and ATLAS images (Tonry\net al. 2018, Smith et al. 2020) and require no detections before the LVC\ntrigger.\n\n\nOne source passed our criteria and is inside the 95% error region:\n\n|-----------------------------------------------------------------------------------------------------\n| id           | alias                |       ra |     dec |        mjd  |\nmag±err (ab)   | filter   |\n|-----------------------------------------------------------------------------------------------------\n| ZTF23aamnpce | AT2023jtt            | 235.9839 | 15.2248 | 60094.23830 |\n20.49±0.23     |  r       |\n|-----------------------------------------------------------------------------------------------------\n\n\nAT2023jtt is 0.5\" from a galaxy that has a photometric redshift of\nphotoz=0.22±0.06 from the Legacy Survey DR8 (Duncan, 2022), suggesting that\nit is probably not associated with the LVC trigger.\n\nFurther follow-up of this localization region will continue as part of\nregular survey operations.\n\n\nZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC,\nUSA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY,\nGermany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan;\nIITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia.\nZTF acknowledges the generous support of the NSF under AST MSIP Grant No\n1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant\nNo 1545949. Alert distribution service provided by DIRAC@UW (Patterson et\nal. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019)\nand Kowalski (Duev et al. 2019). GROWTH India telescope is located at the\nIndian Astronomical Observatory (Hanle), operated by the Indian Institute\nof Astrophysics (IIA). GROWTH-India project is supported by SERB and\nadministered by IUSSTF, under grant number IUSSTF/PIRE\nProgram/GROWTH/2015-16 and IUCAA.\n",
  "eventId": "LIGO/Virgo/KAGRA S230529ay",
  "submitter": "Viraj Karambelkar at Indian Inst of Tech,Bombay <karambelkarvraj21197@gmail.com>"
}