VizieR Online Data Catalog: Swift XRT follow-up of LIGO/Virgo GW triggers (Klingler+, 2019)

The observing strategy employed in this campaign is the same as that which has been described in detail by Evans+ (2016MNRAS.462.1591E and 2016MNRAS.455.1522E).

The overall observing strategy was to carry out three phases of observations. First (phase 1), a series of short (60s) exposures were taken covering as much of the galaxy-map-convolved gravitational-wave (GW) error region as possible. This phase was designed with the intention of detecting an on-axis sGRB afterglow, if present, and continued for ~2 days. Next (phase 2), 2-3 days after the trigger, the GW error region was reobserved for 500s per tile. These observations, which continued for up to 4 days, were optimized to search for the rising X-ray afterglow from an sGRB observed off-axis. Collectively, phases 1 and 2 are referred to as the "wide-area search" phase. Finally (phase 3), if no confirmed counterpart was found, any potentially interesting (i.e., unidentified) X-ray source was reobserved with exposures >1ks. Any such source found to be fading was reobserved repeatedly over the following days until it could be confirmed to be the counterpart, or ruled out as such. See Section 2 for further details.

(2 data files).