GCN Circular 24329
Subject
LIGO/Virgo S190426c: Continued infrared wide-field search with Palomar Gattini-IR
Date
2019-04-28T15:04:06Z (6 years ago)
From
Matthew Hankins at Caltech <mhankins@caltech.edu>
M. Hankins (Caltech), K. De (Caltech), M. Coughlin (Caltech), M. M.
Kasliwal (Caltech), S. M. Adams (Caltech), I. Andreoni (Caltech), S.
Anand (Caltech), L. Singer (NASA GSFC), T. Ahumada (UMD), A. Moore
(ANU), J. Soon (ANU), M. Ashley (UNSW), T. Travouillon (ANU), R. Lau (ISAS JAXA)
report on behalf of the Palomar Gattini-IR team and the larger GROWTH
(Global Relay of Observatories Watching Transients Happen)
collaboration
We report continuing wide-field near-infrared follow-up observations (GCN #24284)
of the localization region of the gravitational wave event S190426c (GCN
#24237) by the Palomar Gattini-IR survey (Moore and Kasliwal 2019).
Gattini-IR is a newly commissioned near-IR camera with a field of view
of 25 square degrees mounted on a robotic 30 cm telescope at Palomar
observatory.
We started customized Target of Opportunity observations at UT
2019-04-28 03:28. The tiling was optimally determined and triggered
using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a,
Kasliwal et al. 2019b). We imaged a total of 1900 square degrees,
covering 94% of the probability region of the event for 1 to 5 epochs
until UT 2019-04-28 12:33. Each field visit consisted of a sequence of
8 dithers of 8 second exposures each on the field, which were
processed and stacked with the Palomar Gattini-IR data reduction
pipeline (De et al., in prep.). The typical limiting magnitude of each
stacked epoch (64 second exposure time) was between 14.5 and 15.5 AB mag
in J-band, and shallower than usual due to poor weather conditions.
No viable counterparts without previous history of variability were identified.