13/09/04 Bright Source Catalogue for INTEGRAL

Based on IBIS and SPI analysis of released data, BSC features only two sources of our sample 3C 273 and NGC 4151, the latter however without ISGRI lightcurves.

3/05/04 Intensive Mrk 421 Observations On May 9 and May 10, 2004

From Henryk Krawczynski: Mrk 421 was very active during the April viewing period. April observations showed very high average TeV gamma-ray flux levels of about 3 times the steady flux from the Crab Nebula. The source seemed to be in a very interesting state showing rather slow flux variability compared to earlier observations. Although the RXTE ASM X-ray activity (2-12 keV) has declined from a historical maximum of 110 mCrab in mid April to between 20 and 40 mCrab during the last days, the latter flux level is still very high.
To elucidate the flux variability on time scales of between ~2 hours and one day (those covered by TeV observations and diurnal RXTE observations), the RXTE Science Operations Facility kindly scheduled 1 1/2 days of very intensive RXTE observations.
The RXTE campaign culminates on May 9 and 10 with very dense observational coverage around the clock. Please observe the source on May 9 - May 11 as intensively as possible with a special emphasis on May 10. Deirdre Horan who organizes the Whipple 10m observations will post the updated Whipple and RXTE schedules at the Whipple/VERITAS web-site.

26/03/04 S5 0716+714 Target of Opportinity triggered!

According to the WEBT results presented here the source has reached its historical maximum in the optical band on March 24, was followed by two RXTE TOO observations on March 27 and 28/29. From our local optical monitoring, you can look at the half-year lightcurve from BART, however, for most of the time this source is at the detection limit of its Wide Field Camera.

16/02/04

Aimo Sillanpaa has informed that 3c66a is undergoing a big optical flare, a picture is at this page. The criteria for triggering our INTEGRAL proposal are formally not yet met, but the object is clearly brightening very much.

5/11/03

The proposal of Elena Pian for observation of blazars in outburst with INTEGRAL was granted 500 ks as a target of opportunity in AO-2 programme.

3/11/03

The multiwavelength campaign of INTEGRAL observations on blazar S5 0716+714 supported by optical and radio observatories was extended from 10. till 18. November 2003.

For general news from INTEGRAL, check here (Integral section of ESA pages), here (Integral science home page) or here (ISDC).