Thursday, August 11, 2011

Fermi LAT weekly report N. 165

Covered period: 2011.Aug.01-2011.Aug.07

LAT Mission week: 165.57 - 166.57

The transition to Pass7 data happened on August 1st at 10am. As a consequence the daily run on this day was difficult to analyze. But from August 2nd on, the pipeline ran through normally.

Extragalactic sky:

  • B2 1144+40 reaching (0.4 ± 0.1) e-6 on Aug. 2 and 5, and also detected on Aug. 3.
  • 4C +21.35 detected on the daily run on Aug. 4 but also on a 6 hours run on Aug. 6 reaching (1.1 ± 0.5) e-6.
  • PKS 1510–08 detected on Aug. 5 and 7 reaching a daily flux of (1.3 ± 0.3) e-6 peaking at (2.98e-6 ± 0.85) e-6 in a 6-hours run.
  • 3C 279 detected on Aug. 4 and 7 reaching (0.7 ± 0.2) e-6 that day.
  • CRATES J1239+0443 detected on Aug. 5 and 7 reaching (0.7 ± 0.2) e-6 that day.
  • After a very active period in July, BL Lac was detected on August 2nd with a modest daily flux of (1.0 ± 0.3) e-6.
  • Sporadic detections on on day of the week: B2 1308+32 (Aug. 2), PKS 0537–441 (Aug. 2), B2 0716+33 (Aug. 3), Mkn 421 (Aug. 7).

Solar Activity:

  • The Sun was very active during this week, with several M-class Xray flares. This caused the response of the LAT to be compromised on small time intervals. [All the fluxes indicated in this week's report should be taken with even more caution that usual.]
  • On August 4, following a M9.3 class flare, a gamma-ray source coincident with the Sun was detected, reaching a integrated daily flux of (5.8 ± 0.6) e-6 with a test statistic of 384.

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

Note. All the fluxes reported above 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:

- Alice Allafort ( for generic information related to this week.

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

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