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

Journal Article · Fri Oct 20 00:00:00 EDT 2017 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8213/AA905D· OSTI ID:22872524

Alexander, K. D.; Berger, E.; Williams, P. K. G.; Blanchard, P. K.; Cowperthwaite, P. S.; Eftekhari, T.; Nicholl, M. ^[1]; Fong, W.; Margutti, R. ^[2]; Guidorzi, C. ^[3]; Metzger, B. D. ^[4]; Annis, J.; Frieman, J. ^[5]; Brout, D. ^[6]; Brown, D. A. ^[7]; Chen, H. -Y.; Holz, D. E. ^[8]; Chornock, R. ^[9]; Drout, M. ^[10]; Rest, A. ^[11] ; others, and

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
2. Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)
3. Department of Physics and Earth Science, University of Ferrara, via Saragat 1, I-44122, Ferrara (Italy)
4. Department of Physics and Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
5. Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
6. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States)
7. Department of Physics, Syracuse University, Syracuse NY 13224 (United States)
8. Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States)
9. Astrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Lab, Ohio University, Athens, OH 45701 (United States)
10. Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
11. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

We present Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA) radio observations of GW170817, 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 hr 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 days. 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 ≳10{sup 48} erg. For fiducial SGRB parameters, our limits require an observer viewer angle of ≳20°. The radio and X-ray data can be jointly explained as the afterglow emission from an SGRB with a jet energy of ∼10{sup 49}--10{sup 50} erg that exploded in a uniform density environment with n∼10{sup −4}--10{sup −2} cm{sup −3}, viewed at an angle of ∼20°–40° 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 ∼5–10 years that will remain detectable for decades with next-generation radio facilities, making GW170817 a compelling target for long-term radio monitoring.

• OSTI ID: 22872524
• Journal Information: Astrophysical Journal Letters, Vol. 848, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AFTERGLOW
COSMIC GAMMA BURSTS
EMISSION
GHZ RANGE
GRAVITATIONAL WAVE DETECTORS
INTERFEROMETERS
JETS
LASERS
LIMITING VALUES
MONITORING
NEUTRON STARS
RELATIVISTIC RANGE
SIMULATION