TITLE:   GCN CIRCULAR
NUMBER:  22211
SUBJECT: LIGO/Virgo GW170817: X-ray observations confirm prediction made from radio data
DATE:    17/12/08 21:30:16 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley (Oxford, NRAO/Caltech) et al. report

The X-ray flux of GW170817 on December 03-06 (reported by Troja et al. 
2017, GCN 22201; Margutti et al. 2017, GCN 22203, Haggard et al. 2017, 
GCN 22206 based on the Chandra observations) is exactly as predicted 
last week by Mooley et al. 2017 (http://arxiv.org/abs/1711.11573) based 
on radio spectral indices.

This suggests that the radio and X-ray emission both arise from a mildly 
relativistic wide-angle outflow, consistent with the cocoon model (see 
also Gottlieb et al. 2017, Hallinan et al. 2017, Kasliwal et al. 2017). 
A relativistic jet core, if it exists, is either too weak (having a 
sub-dominant contribution to the radio light curve early on) or too 
strong (such that its electromagnetic signatures will be observed in the 
future). See Mooley et al. 2017 for details.