Thursday, May 26, 2011

Fermi LAT weekly report N. 152

Covered period: 2011 May 2-8

LAT Mission week: 152.57-153.57

Highlights of this week:

4C +38.41 became active this week, with a flux hovering around 10^-6 at the beginning of the week and then peaking on May 8 at the level of (2.1 +/- 0.3) E-6. The flare was reported in ATel #3333. High state in NIR was also reported in ATel #3335.

A gamma-ray flare from the blazar S5 1803+78 was detected on May 2 and May 3, at a level of (1.1 +/- 0.2)E-6. The flare was short-lived since on May 4 the source was not detected by Fermi LAT. Optical follow-up observations, also on May 4, found the source at an average brightness (ATEL#3323).

Another short flare detected by Fermi LAT this week was attributed to blazar PKS 1424-41, which on May 5 reached a flux of (1.1 +/- 0.3)E-6, representing more than an order of magnitude increase over the average flux reported in the first Fermi-LAT catalog. The observed flux is comparable with a previous flare observed on April 23, 2010 (Atel #2583).

Other daily detections of blazars this week: PKS 1244-255, PKS 0537-441, 4C +28.07, 4C +21.35, 3C 279, B2 1520+31, PMN J2345-1555, CRATES J0742+5444, PKS 0208-512

Fluxes are in the unit of photons/cm2/s above 100 MeV. All errors are statistical only.

Note. All the flux reported above are by the Fermi LAT Automated Science Processing (ASP) analysis and should be considered preliminary and should not be used for publication, however they are indicative of the flux range and the current status of a source. Source association is done on the basis of source location, considering spatial coincidence only, and it is not indicative of an identification. - Please acknowledge the LAT team if you use information from this report.

For questions and comments please contact:

- A. Szostek (aszostek[at] and L. Reyes (lcreyes [at] for generic information related to this week

- Contact persons on this page for individual sources cited above.

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