Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 21786

LIGO/Virgo G298048: Continued X-ray monitoring and X-ray detection of GW170817 [erratum]]
2017-09-02T16:57:54Z (7 years ago)
Raffaella Margutti at Northwestern U <>
W. Fong, R. Margutti (Northwestern), D. Haggard (McGill) report on behalf
of a larger collaboration:

We analyzed observations of the field of the EM counterpart to LVC trigger
G298048 with the Chandra X-ray Observatory (CXO; ObsID 20728, PI Troja)
starting on 2017 Sep 1.640 UT (15.1 days after the LVC trigger time). In 50
ksec of observations, we clearly detect X-ray emission at the location of
the optical transient (Coulter et al., LVC GCN 21529; Allam et al., LVC GCN
21530; Sheng Yang et al., LVC GCN 21531; Chambers et al., LVC GCN 21553),
suggesting continued X-ray emission from the transient (Troja et al., LVC
GCN 21765). Extended emission from the host galaxy (Margutti et al., LVC
GCN 21648; Evans et al., LVC GCN 21612) is still detected. We also note the
presence of a third X-ray source in the Swift/XRT error circle (Evans et
al., LVC GCN 21612; RA,Dec = 13:09:48.014,-23:23:04.93), that has not been
previously reported.

We thank Belinda Wilkes and the entire Chandra team for their great support
with these observations.

[GCN OPS NOTE(03sep17): This circular (21786) completely replaces 21784
(whose text was the result of a copy-paste mistake).]
Looking for U.S. government information and services? Visit