GCN Circular 24411

LIGO/Virgo S190426c: Update on Source Classification

The LIGO Scientific Collaboration and Virgo Collaboration report:

Based on posterior support from preliminary parameter estimation
[1,2], under the assumption that the candidate S190426c is
astrophysical in origin, the relative probabilities amongst
the signal categories NSBH : MassGap : BNS : BBH are revised
to be approximately 12 : 5 : 3 : 0.

Under the same assumption of astrophysical origin, we find
strong evidence that the lighter compact object has a
mass < 3 solar masses (HasNS: >99%) and a 72% probability
of having disrupted material outside the final compact object
(HasRemnant: 72%).

The probability of non-astrophysical origin and the false
alarm rate are not being updated at this time; both measures
of significance should be expected to change with offline analyses
and continued observations.

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)