A Giant Radio Flare from Cygnus X-3 with Associated Gamma-Ray Emission
- Szostek, A.
- January 17, 2012.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Tudose, V., Kerr, M., Readhead, A. C. S., Trushkin, S., Max-Moerbeck, W., Pooley, G., Miller-Jones, J. C. A., Dubois, R., Richards, J. L., Hill, A. B., Bodaghee, A., Pottschmidt, K., Corbel, S., Wilms, J., Corbet, R. H. D., Tomsick, J. A., Dubus, G., and Parent, D.
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available. and Free-to-read Unrestricted online access
- With frequent flaring activity of its relativistic jets, Cygnus X-3 (Cyg X-3) is one of the most active microquasars and is the only Galactic black hole candidate with confirmed high energy gamma-ray emission, thanks to detections by Fermi/LAT and AGILE. In 2011, Cyg X-3 was observed to transit to a soft X-ray state, which is known to be associated with high-energy gamma-ray emission. We present the results of a multiwavelength campaign covering a quenched state, when radio emission from Cyg X-3 is at its weakest and the X-ray spectrum is very soft. A giant (approx 20 Jy) optically thin radio flare marks the end of the quenched state, accompanied by rising non-thermal hard X-rays. Fermi/LAT observations (E greater than or equal 100 MeV) reveal renewed gamma-ray activity associated with this giant radio flare, suggesting a common origin for all non-thermal components. In addition, current observations unambiguously show that the gamma-ray emission is not exclusively related to the rare giant radio flares. A 3-week period of gamma-ray emission is also detected when Cyg X-3 was weakly flaring in radio, right before transition to the radio quenched state. No gamma rays are observed during the one-month long quenched state, when the radio flux is weakest. Our results suggest transitions into and out of the ultrasoft X-ray (radio quenched) state trigger gamma-ray emission, implying a connection to the accretion process, and also that the gamma-ray activity is related to the level of radio flux (and possibly shock formation), strengthening the connection to the relativistic jets.
- NASA Technical Reports Server (NTRS) Collection.
- Document ID: 20120013290. and GSFC.JA.6320.2012.
- Copyright, Distribution under U.S. Government purpose rights.
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