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Title: The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. VI. Radio Constraints on a Relativistic Jet and Predictions for Late-time Emission from the Kilonova Ejecta

Here, we present Very Large Array (VLA) and Atacama Large Millimeter/sub-millimeter Array ALMA radio observations of GW\,170817, the first Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo gravitational wave (GW) event from a binary neutron star merger and the first GW event with an electromagnetic (EM) counterpart. Our data include the first observations following the discovery of the optical transient at both the centimeter ($13.7$ hours post merger) and millimeter ($2.41$ days post merger) bands. We detect faint emission at 6 GHz at 19.47 and 39.23 days after the merger, but not in an earlier observation at 2.46 d. We do not detect cm/mm emission at the position of the optical counterpart at frequencies of 10-97.5 GHz at times ranging from 0.6 to 30 days post merger, ruling out an on-axis short gamma-ray burst (SGRB) for energies $$\gtrsim 10^{48}$$ erg. For fiducial SGRB parameters, our limits require an observer viewer angle of $$\gtrsim 20^{\circ}$$. The radio and X-ray data can be jointly explained as the afterglow emission from an SGRB with a jet energy of $$\sim 10^{49}-10^{50}$$ erg that exploded in a uniform density environment with $$n\sim 10^{-4}-10^{-2}$$ cm$$^{-3}$$, viewed at an angle of $$\sim 20^{\circ}-40^{\circ}$$ from the jet axis. Using the results of our light curve and spectral modeling, in conjunction with the inference of the circumbinary density, we predict the emergence of late-time radio emission from the deceleration of the kilonova (KN) ejecta on a timescale of $$\sim 5-10$$ years that will remain detectable for decades with next-generation radio facilities, making GW\,170817 a compelling target for long-term radio monitoring.
ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [1] ;  [3] ; ORCiD logo [2] ;  [4] ;  [5] ;  [1] ;  [6] ;  [7] ;  [8] ;  [9] ;  [1] ;  [10] ;  [1] ;  [11] ;  [12] ;  [1] ;  [13] more »;  [6] ;  [5] ;  [1] « less
  1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  2. Northwestern Univ., Evanston, IL (United States)
  3. Univ. of Ferrara, Ferrara (Italy)
  4. Columbia Univ., New York, NY (United States)
  5. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  6. Univ. of Pennsylvania, Philadelphia, PA (United States)
  7. Syracuse Univ., Syracuse, NY (United States)
  8. Univ. of Chicago, Chicago, IL (United States)
  9. Ohio Univ., Athens, OH (United States)
  10. Carnegie Observatories, Pasadena, CA (United States)
  11. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
  12. Univ. of Chicago, Chicago, IL (United States); Enrico Fermi Institute, Chicago, IL (United States)
  13. Space Telescope Science Institute, Baltimore, MD (United States); The Johns Hopkins Univ., Baltimore, MD (United States)
Publication Date:
Report Number(s):
arXiv:1710.05457; FERMILAB-PUB-17-474-A-AE-CD
Journal ID: ISSN 2041-8213; 1630797
Grant/Contract Number:
Accepted Manuscript
Journal Name:
The Astrophysical Journal. Letters
Additional Journal Information:
Journal Volume: 848; Journal Issue: 2; Journal ID: ISSN 2041-8213
Institute of Physics (IOP)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; gravitational waves; relativistic processes
OSTI Identifier: