Saturday, December 5, 2009

Fermi LAT weekly report N.77

Covered period: 2009.Nov.23 - 2009.Nov.29

LAT Mission week: 77.57 - 78.57

Another good week for gamma-ray blazars with the detection of a spectrally hard flare from the FSRQ, GB6 B1310+4844, and record breaking activity in the LAT from 3C 454.3. Several of last week's active sources have faded (B2 1520+31, PKS 1622-253, PKS 1510-089).

  • GB6 B1310+4844 (GB1 1310+487, LAT ATels #2306, #2316) continued the previous week's flare and peaked on Nov. 27 with daily flux=(2.5 ± 0.4) x 10-6. The spectrum exhibited significant hardening during the flare with a daily photon index for Nov. 26 of 1.8 ± 0.1. This is harder than any of the average photon indices found for FSRQs in the LAT bright AGN sample (Abdo et al., 2009, ApJ, 700, 597).

  • 3C 454.3 became more active and surpassed previous gamma-ray flux levels on Nov. 28 at daily flux=(8.7 ± 0.9) x 10-6. It ended the week on Nov. 30 with daily flux=(9.2 ± 0.8) x 10-6. (The weekly average flux is also high at (6.6 ± 0.3) x 10-6).

  • 4C +14.23 (PKS 0722+145, LAT ATel #2243) was active at a similar level to last week reaching daily flux=(1.8 ± 0.6) x 10-6 on Nov. 27. The source has since faded below threshold.

  • PKS 1222+216 (LAT ATel #2021) appeared on Nov. 24 with daily flux=(0.9 ± 0.3) x 10-6 and continued at this level through Nov. 28.

  • 4C +38.41 matched previous days on Nov. 23 with flux=(0.7 ± 0.2) x 10-6. This is a mild rebrightening of a recently reported high redshift blazar (ATel #2136)

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

Note. All the fluxes reported above are from 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:

- Elizabeth Hays (elizabeth.a.hays[at] for generic information related to this week

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

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