Thursday, December 3, 2009

Fermi LAT weekly report N.76

Covered period: 2009.Nov.16 - 2009.Nov.22 (UT)

LAT Mission week: 76.57 - 77.57

The gamma-ray sky showed some exciting activity this week, with five blazars exceeding the 1⋅10^-6 flux above 100 MeV that defines flaring and a surprise detection of the quasar GB6 B1310+4844.

  • On Nov. 18, GB6 B1310+4844 (LAT ATels #2306, #2316) attracted attention by the detection of a GeV flare consistent with the position of this source (daily flux: (1.0±0.2)⋅10^-6). It remained bright ending the week with an even higher daily flux of (2.2±0.2)⋅10^-6 on Nov. 22.
    (LAT contact: K. Sokolovsky, ksokolov[at]

  • 4C +14.23 (PKS 0722+145, LAT ATel #2243) stays bright above 1⋅10^-6. It faded intermittently during the middle of the week and re-brightened to a daily flux level of (1.8±0.4)⋅10^-6 (average weekly flux: (1.5±0.1)⋅10^-6).

  • Rapid brightening of 3C 454.3 toward the second half of the week, peaking at a daily flux level of (5.7±0.7)⋅10^-6 on Nov 20 (weekly average flux: (3.7±0.2)⋅10^-6).

  • On Nov. 17, B2 1520+31 (LAT ATel #2026) showed a weak flare (daily flux: (0.9±0.3)⋅10^-6), faded and re-appeared even stronger (Nov. 19 - Nov. 21), peaking on Nov. 21 (daily flux: (1.5±0.3)⋅10^-6).

  • On Nov. 17, PKS 1622-253 (LAT ATel #2231) flared. (daily flux: (1.9±0.7)⋅10^-6, weekly flux: (0.5±0.2)⋅10^-6).

  • On Nov. 17, PKS 1510-089 (LAT ATel #2033) flared as well. (daily flux: (1.2±0.4)⋅10^-6, weekly flux: (0.8±0.2)⋅10^-6).

  • 4C +38.41 (LAT ATel #2136) was brightening during Nov. 21 (daily flux: (0.7±0.2)⋅10^-6) and was detected at the same level during Nov. 22.

Fluxes are in the unit of photons/cm^2/s above 100 MeV. Errors are statistical

Note. All the flux reported above are by the 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:

- F. Schinzel (schinzel[at] for generic information related to this week

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

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