High state of Mkn 421 in the hard X-rays
ATel #840; G. G. Lichti (MPE), A. Neronov, N. Mowlavi (ISDC), M. Ajello, V. Beckmann, C. Boisson, J. Buckley, P. Charlot, W. Collmar, B. Degrange, A. Djannati-Atai, A. Falcone, J. Finley, G. Fossati, G. Henri, K. Katarzynski, D. Kieda, A. Lahteemaki, K. Mannheim, A. Marcowith, M. Punch, A. Saggione, L. Sauge, V. Schoenfelder, A. Sillanpaa, D. Smith, H. Sol, F. Tavecchio, L. Takalo, M. Tornikoski, A. von Kienlin, T. Weekes (Co-Is of the INTEGRAL observation)
on 16 Jun 2006; 20:12 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Nami Mowlavi (Nami.Mowlavi@obs.unige.ch)
Subjects: X-ray, Gamma Ray, AGN
RXTE/ASM data revealed an increased activity in the 3-10 keV energy of the
TeV gamma-ray loud blazar Mkn 421. Its intensity began to rise in the middle
of April 2006, reached a maximum around mid May and decreased since then.
Its intensity began to increase again around 10th of June, 2006.
This second increase led to the triggering of a target-of-opportunity
observation with INTEGRAL.
The observation of this blazar by INTEGRAL started on June 14, 2006.
The source is detected by both the IBIS/ISGRI imager and the JEM-X
The flux level during the first two days of observation was ~25 mCrab
in both 3-10 keV and 20-40 keV energy bands.
From 2006-06-16T07:16 UTC, the fluxes increased to ~50 mCrab within 3 hours
in both energy bands, and the source became detected in the 40-80 keV
band with a flux of ~25 mCrab.
The blazar will be monitored continually by INTEGRAL until July 25.
Simultaneous observations with other telescopes and instruments are planned
with the Metsahovi Radio Observatory at 37 GHz,
with the KVA telescope in La Palma, with the VLBA at NRAO, and with SWIFT.
MAGIC will also try to observe this source.
Further follow-up observations of this source at all wavelengths are strongly encouraged.