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GCN Circular 21239

LIGO/Virgo G288732: Updated sky map from gravitational-wave data
2017-06-10T00:50:16Z (7 years ago)
Eve Chase at Northwestern U./LIGO <>
The LIGO Scientific Collaboration and Virgo Collaboration report:

We have re-analyzed LIGO data around the time of the compact binary
coalescence (CBC) event candidate G288732 (GCN 21221) taking into
account our current understanding of calibration uncertainties.

Parameter estimation has been performed using LALInference (Veitch et
al., PRD 91, 042003) and a new sky map, LALInference.fits.gz, is
available for retrieval from the GraceDB event page:

This is the preferred sky map at this time. This map spans one arc in
the Northern hemisphere in nearly the same position as the original
BAYESTAR sky map but the region with the highest probability has
shifted further north.

The 50% and 90% credible regions span about 340 and 1090 square
degrees, respectively, which are somewhat larger than the initial
BAYESTAR sky map due to marginalizing over calibration uncertainties.

We will recalculate the sky map once the full recalibration is
complete and will share it at that time, but that is likely at least a
few weeks away.
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