[vsnet-grb-info 26509] IceCube-201007A: No candidate counterparts from the Zwicky Transient Facility

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28609
SUBJECT: IceCube-201007A: No candidate counterparts from the Zwicky Transient Facility
DATE:    20/10/13 14:05:53 GMT
FROM:    Simeon Reusch at DESY  <simeon.reusch at desy.de>

Simeon Reusch (DESY), Sven Weimann (Ruhr University Bochum), Robert Stein (DESY) and Anna Franckowiak (DESY/Ruhr University Bochum) report,

On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations:

We serendipitously observed the localization region of the neutrino event IC-201007A (Santander et al. GCN 28575) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019), followed by dedicated Target-of-Opportunity observations. We observed in the g- and r-band beginning at 2020-10-08 02:52:02 UTC, approximately 4.8 hours after event time.  We covered 0.5 sq deg at least twice, corresponding to 87.5% of the reported localization region. This estimate accounts for chip gaps. Each serendipitous exposure was 30s with a typical depth of 20.5 mag, while ToO exposures were 300s with a typical depth of 21.0.

The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019; Stein et al. 2020) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019). We looked for high-significance transient candidates with our pipeline, lying within the 90.0% localization of the skymap.

No counterpart candidates were detected.

ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia.
ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341.
GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.
Alert distribution service provided by DIRAC at UW (Patterson et al. 2019).
Alert database searches are done by AMPEL (Nordin et al. 2019).
Alert filtering is performed with the AMPEL Follow-up Pipeline (Stein et al. 2020).