High-energy Gamma-Ray Activity from V404 Cygni Detected by AGILE during the 2015 June Outburst
Abstract
The AGILE satellite detected transient high-energy γ-ray emission from the X-ray binary V404 Cygni, during the 2015 June outburst observed in radio, optical, X-ray, and soft γ-ray frequencies. The activity was observed by AGILE in the 50-400 MeV energy band, between 2015 June 24 UT 06:00:00 and 2015 June 26 UT 06:00:00 (MJD 57197.25-57199.25), with a detection significance of ∼4.3σ. The γ-ray detection, consistent with a contemporaneous observation by Fermi-LAT, is correlated with a bright flare observed at radio and hard X-ray frequencies, and with a strong enhancement of the 511 keV line emission, possibly indicating plasmoid ejections in a lepton-dominated transient jet. The AGILE observations of this binary system are compatible with a microquasar scenario in which transient jets are responsible for the high-energy γ-ray emission.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2017
- DOI:
- 10.3847/1538-4357/aa6796
- arXiv:
- arXiv:1703.10085
- Bibcode:
- 2017ApJ...839...84P
- Keywords:
-
- gamma rays: stars;
- stars: black holes;
- stars: jets;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in ApJ on March 9, 2017