Open AccessMultiwavelength Observations of a Dramatic High‐Energy Flare in the Blazar 3C 279
Author(s) -
A. E. Wehrle,
E. Pian,
C. M. Urry,
L. Maraschi,
I. M. McHardy,
A. J. Lawson,
G. Ghisellini,
R. C. Hartman,
G. M. Madejski,
F. Makino,
Alan P. Marscher,
S. J. Wagner,
J. R. Webb,
G. Aldering,
M. F. Aller,
H. D. Aller,
D. E. Backman,
T. J. Balonek,
P. Boltwood,
J. T. Bonnell,
J. Caplinger,
A. Celotti,
W. Collmar,
J. B. Dalton,
A. Drucker,
R. Falomo,
C. E. Fichtel,
W. Freudling,
W. K. Gear,
N. Gonzales,
Patrick B. Hall,
H. Inoue,
W. N. Johnson,
Demosthenes Kazanas,
M. Kidger,
T. Kii,
R. I. Kollgaard,
Y. Kondo,
J. D. Kurfess,
Y. C. Lin,
B. McCollum,
K. McNaronBrown,
F. Nagase,
A. D. Nair,
Steven V. Penton,
Joseph E. Pesce,
M. Pohl,
C. M. Raiteri,
M. Renda,
E. I. Robson,
R. M. Sambruna,
A. F. Schirmer,
C. R. Shrader,
M. Sikora,
A. Sillanpää,
Paul S. Smith,
J. A. Stevens,
John T. Stocke,
L. O. Takalo,
H. Teräsranta,
D. J. Thompson,
R. Thompson,
M. Tornikoski,
G. Tosti,
A. Treves,
P. Turcotte,
S. C. Unwin,
E. Valtaoja,
M. Villata,
W. Xu,
Ayumu Yamashita,
A. C. Zook
Publication year - 1998
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/305461
Subject(s) - blazar , flare , physics , astrophysics , light curve , rosat , astronomy , flux (metallurgy) , observatory , amplitude , gamma ray , bl lac object , sky , optics , galaxy , metallurgy , materials science
The blazar 3C 279, one of the brightest identified extragalactic objects inthe gamma-ray sky, underwent a flare of a factor 10 amplitude in gamma-raystowards the end of a 3-week pointing by CGRO, in 1996 January-February. Theflare peak represents the highest gamma-ray intensity ever recorded for thisobject. During the high state, extremely rapid gamma-ray variability was seen.Coordinated multifrequency observations were carried out with RXTE, ASCA, ROSATand IUE and from many ground-based observatories, covering most accessiblewavelengths. The well-sampled, simultaneous RXTE light curve shows an outburstof lower amplitude (factor of ~3) well correlated with the gamma-ray flarewithout any apparent lag. The optical-UV light curves, which are not wellsampled during the high energy flare, exhibit more modest variations (factor of~2) and a lower degree of correlation. The flux at millimetric wavelengths wasnear an historical maximum during the gamma-ray flare peak, with suggestion ofa correlated decay. We present simultaneous spectral energy distributions of 3C279 prior to and near to the flare peak. The gamma-rays vary by more than thesquare of the observed IR-optical flux change, which poses some problems forspecific blazar emission models. The synchrotron-self Compton model wouldrequire that the largest synchrotron variability occurred in the mostlyunobserved sub-mm/far-infrared region. Alternatively, a large variation in theexternal photon field could occur over a time scale of few days. This occursnaturally in the ``mirror'' model, wherein the flaring region in the jetphotoionizes nearby broad-emission-line clouds, which in turn provide softphotons that are Comptonized to gamma-ray energies.Comment: 18 pages, Latex, 2 tables, 3 postscript figures, to appear in The Astrophysical Journa
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