TITLE:   GCN CIRCULAR
NUMBER:  25333
SUBJECT: LIGO/Virgo S190814bv: Update on Sky-Localization and Source-Classification
DATE:    19/08/15 10:41:01 GMT
FROM:    Geoffrey Mo at LIGO  <geoffrey.mo@ligo.org>

The LIGO Scientific Collaboration and Virgo Collaboration report:

We have conducted further analysis of the LIGO and Virgo data around
the time of the compact binary coalescence (CBC) candidate S190814bv
(GCN 25324). Parameter estimation has been performed using
LALInference [1] and a new sky map, LALInference.v1.fits.gz,
distributed via GCN Notice, is available for retrieval from the
GraceDB event page:

https://gracedb.ligo.org/superevents/S190814bv/

LALInference.v1.fits.gz is the preferred sky map at this time.
The 90% credible region is 23 deg2. Marginalized over the whole sky,
the a posteriori luminosity distance estimate is 267 +/- 52 Mpc
(a posteriori mean +/- standard deviation).

Based on posterior support from parameter estimation [1, 2], under the
assumption that the candidate S190814bv is astrophysical in origin,
there is strong evidence that the lighter compact object has a
mass < 3 solar masses (HasNS > 99%) and a
negligible probability of having disrupted material outside the final
compact object (HasRemnant < 1%). The parameter estimation based
classification of the GW signal, in order of descending probability,
is NSBH (>99%), MassGap (<1%), BBH (<1%), or BNS (<1%).

The above mentioned probabilities are the preferred classification
results that supersede the ones stated in GCN 25324. The probability
of non-astrophysical origin and the false alarm rate are not being
updated at this time.

For further information about analysis methodology and the contents
of this alert, refer to the LIGO/Virgo Public Alerts User Guide
<https://emfollow.docs.ligo.org/userguide/>.

[1] Veitch, et al. PRD 91, 042003 (2015)
[2] Abbott, et al. PRL 116, 241102 (2016)