Bibcode
DOI
Pesce, J. E.; Pohl, M.; Raiteri, C. M.; Nagase, F.; Nair, A. D.; Penton, S.; Lin, Y. C.; McCollum, B.; McNaron-Brown, K.; Kollgaard, R. I.; Kondo, Y.; Kurfess, J.; Kii, T.; Johnson, W. N.; Kazanas, D.; Kidger, M. R.; Hall, P.; Inoue, H.; Fichtel, C. E.; Freudling, W.; Gear, W. K.; Gonzalez-Perez, N.; Drucker, A.; Falomo, R.; Collmar, W.; Dalton, J.; Celotti, A.; Zook, A.; Yamashita, A.; Xu, W.; Villata, M.; Valtaoja, E.; Unwin, S. C.; Turcotte, P.; Treves, A.; Tosti, G.; Tornikoski, M.; Thompson, R.; Thompson, D. J.; Teraesranta, H.; Takalo, L. O.; Smith, P. S.; Stevens, J. A.; Stocke, J.; Sikora, M.; Sillanpaeae, A.; Schirmer, A. F.; Shrader, C.; Renda, M.; Robson, E. I.; Sambruna, R. M.; Boltwood, P.; Bonnell, J.; Caplinger, J.; Aller, H. D.; Backman, D. E.; Balonek, T. J.; Webb, J. R.; Aldering, G. S.; Aller, M. F.; Makino, F.; Marscher, A. P.; Wagner, S. J.; Ghisellini, G.; Hartman, R. C.; Madejski, G. M.; Maraschi, L.; McHardy, I. M.; Lawson, A. J.; Pian, E.; Urry, C. M.; Wehrle, A. E.
Bibliographical reference
Astrophysical Journal v.497, p.178
Advertised on:
4
1998
Citations
232
Refereed citations
178
Description
The blazar 3C 279, one of the brightest identified extragalactic objects
in the gamma -ray sky, underwent a large (factor of ~10 in amplitude)
flare in gamma -rays toward the end of a 3 week pointing by Compton
Gamma Ray Observatory (CGRO), in 1996 January-February. The flare peak
represents the highest gamma -ray intensity ever recorded for this
object. During the high state, extremely rapid gamma -ray variability
was seen, including an increase of a factor of 2.6 in ~8 hr, which
strengthens the case for relativistic beaming. Coordinated
multifrequency observations were carried out with Rossi X-Ray Timing
Explorer (RXTE), Advanced Satellite for Cosmology and Astrophysics
(ASCA; or, Astro-D), Roentgen Satellite (ROSAT), and International
Ultraviolet Explorer (IUE) and from many ground-based observatories,
covering most accessible wavelengths. The well-sampled, simultaneous
RXTE light curve shows an outburst of lower amplitude (factor of ~=3)
well correlated with the gamma -ray flare without any lag larger than
the temporal resolution of ~1 day. The optical-UV light curves, which
are not well sampled during the high-energy flare, exhibit more modest
variations (factor of ~2) and a lower degree of correlation. The flux at
millimetric wavelengths was near a historical maximum during the gamma
-ray flare peak, and there is a suggestion of a correlated decay. We
present simultaneous spectral energy distributions of 3C 279 prior to
and near to the flare peak. The gamma -rays vary by more than the square
of the observed IR-optical flux change, which poses some problems for
specific blazar emission models. The synchrotron self-Compton (SSC)
model would require that the largest synchrotron variability occurred in
the mostly unobserved submillimeter/far-infrared region. Alternatively,
a large variation in the external photon field could occur over a
timescale of a few days. This occurs naturally in the "mirror" model,
wherein the flaring region in the jet photoionizes nearby broad emission
line clouds, which, in turn, provide soft external photons that are
Comptonized to gamma -ray energies.