TITLE:   GCN CIRCULAR
NUMBER:  24196
SUBJECT: LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
DATE:    19/04/25 21:21:41 GMT
FROM:    Marin M Anderson at Caltech  <mmanders@astro.caltech.edu>

M. M. Anderson (Caltech), T. A. Callister (Caltech), G. Hallinan (Caltech) on behalf of the OVRO-LWA collaboration.

We report contemporaneous observations of the localization region of the BNS gravitational wave event S190425z (GCN 24168) with the OVRO-LWA. The observations span from -1 hour to +3 hour relative to the merger time (2019-04-25 08:18:05.17 UT), with continuous coverage of approximately 57% of the probability region. This includes the locations of the 2 candidates identified in ZTF (GCN 24191). The OVRO-LWA is a low-frequency radio telescope operating from 28 MHz to 86 MHz, with an approximately 20,000 sq. deg. instantaneous field-of-view.

Data reduction and analysis have commenced investigating the possible presence of a low frequency prompt counterpart to the event (see Anderson et al. 2018, Callister et al. 2019).