Multifrequency Observations of the Virgo Blazars 3C 273 and 3C 279
in CGRO Cycle 8
W.Collmar
J.E.Grove
W.A.Heindl
A.Kraus
F.Krennrich
O.Reimer
J.Siebert
H.Teräsranta
M.Villata
K.Bennett
H.Bloemen
W.N.Johnson
T.Krichbaum
C.M.Raiteri
J.Ryan
G.Sobrito
V.Schönfelder
O.R.Williams
Abstract
During January and February 1999 high-energy campaigns on the Virgo
blazars 3C 273 and 3C 279 have been carried out by simultaneous RXTE
and CGRO (OSSE, COMPTEL, and partly EGRET) observations. Supplementary
simultaneous ground-based observations have been carried out as well,
resulting in simultaneous multifrequency data for both sources
in (at least) radio, optical, X-ray and Gamma-ray bands.
Currently the different data are analysed and their combination to
broad-band spectra is in progress. At radio and optical bands both blazars
are significantly detected and light curves around the times of the
high-energy observations have been measured.
While, at high energies, 3C 273 is significantly detected by all instruments
from 2 keV (RXTE/PCA) up to MeV energies (COMPTEL), the detection
significance of 3C 279 becomes marginal above 20 keV.
The results of the campaigns on both sources will be presented with
emphasis on the simultaneously measured multifrequency spectra. They will
be compared to earlier broad-band spectra of these sources and discussed
with respect to current blazar emission models.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:19.