English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report the discovery of rising X-ray emission from the binary neutron star(BNS) merger event GW170817. This is the first detection of X-ray emission froma gravitational-wave source. Observations acquired with the Chandra X-rayObservatory (CXO) at t~2.3 days post merger reveal no significant emission,with L_x<=3.2x10^38 erg/s (isotropic-equivalent). Continued monitoring revealedthe presence of an X-ray source that brightened with time, reaching L_x\sim9x10^39 erg/s at ~15.1 days post merger. We interpret these findings in thecontext of isotropic and collimated relativistic outflows (both on- andoff-axis). We find that the broad-band X-ray to radio observations areconsistent with emission from a relativistic jet with kinetic energyE_k~10^49-10^50 erg, viewed off-axis with theta_obs~ 20-40 deg. Our modelsfavor a circumbinary density n~ 0.0001-0.01 cm-3, depending on the value of themicrophysical parameter epsilon_B=10^{-4}-10^{-2}. A central-engine origin ofthe X-ray emission is unlikely. Future X-ray observations at $t\gtrsim 100$days, when the target will be observable again with the CXO, will provideadditional constraints to solve the model degeneracies and test ourpredictions. Our inferences on theta_obs are testable with gravitational waveinformation on GW170817 from Advanced LIGO/Virgo on the binary inclination.

The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. V. Rising X-ray Emission from an Off-Axis Jet