Thursday, September 30, 2010

Fermi LAT weekly report N. 119



Covered period: 2010.September.20 - 2010.September.26

LAT Mission week: 120.57 - 121.57




  • After the gamma-ray flux increase from the direction of the Crab Nebula reported by the AGILE and LAT Collaborations ( ATel #2855, ATel #2861) a dedicated pointed observation of the Crab Nebula from 2010-09-23 15:50 UT to 2010-09-27 19:49 UT was performed by Fermi.

  • The Fermi LAT monitoring of this source showed a flux enhancement during the interval 18-22 September. Measurements taken starting on 23 September are consistent with the typical flux of the Crab. The average total flux from this location (which includes the nebula and pulsed emission) above 100 MeV measured between 2010-09-23 00:00:00 and 2010-09-26 18:43:01 UTC was (280 +/- 20) x 10^-8 ph/cm2/sec. The systematic error on the flux is generally estimated to be ~10% at 100 MeV.
    A preliminary phase-resolved analysis of the flaring source shows that the excess flux due to the flare is the same in the on and off pulse selections for the pulsar and thus it does not appear that the enhanced emission is pulsed. This suggests that origin of the flare is related to the nebula rather than the pulsar emission ( ATel #2879).




  • PKS 0727-11 detected in flare on Sept. 21, with daily flux of (1.4+/-0.4)E-6 (see ATel #2860) and continued to be active during the entire week, at daily flux between 0.5E-6 (Sept. 24) and 0.8E-6 (Sept. 25).

  • NGC 1275 (Perseus A) detected on Sept. 23 and 26, with daily flux of (0.5+/-0.2)E-6 and (0.3+/-0.1)E-6.

  • PKS 1329-49 detected in flaring state on four consecutive days this week (Sept. 20-23), with daily flux between 2.5E-6 and 4.5E-6.

  • B2 1846+32A detected on Sept. 20 and 22, at daily flux of about 0.6E-6 and 0.8E-6, respectively.

  • 3C 279 detected on three consecutive days this week (Sept. 20-22), with daily flux between 0.6E-6 and 1.0E-6.

  • PKS 1313+333 detected on two consecutive days this week (Sept. 22 and 23), with daily flux between 0.6E-6 and 0.9E-6.

  • B2 1520+31 detected in high activity state on Sept. 22, with daily flux of about 1.1E-6.

  • PKS 2326-502 detected in high activity state on Sept. 20, with daily flux of about 1.2E-6.

  • B2 0619+33 detected on Sept. 24 and 26, at daily flux of about 0.5E-6 and 0.9E-6, respectively.

  • 3C 454.3 bright for all the week with daily flux between 3.0E-6 (Sept. 26) and 6.5E-6 (Sept. 22).


  • Sporadic daily detections of blazars B2 0200+30 (Sept. 20), S5 0716+714(Sept. 21), Mrk 421 (Sept. 21), 4C +21.35 (Sept. 22), PKS 0736+01 (Sept. 24) and PKS 0524-485 (Sept. 25).



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



Note. All the fluxes reported above are from 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. D'Ammando (dammando[at]ifc.inaf.it) for generic information related to this week

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




Thursday, September 16, 2010

Fermi LAT weekly report N. 118



Covered period: 2010.Sep.06 - 2010.Sept.12 (UT)

LAT Mission week: 118.57 - 119.57





  • PKS 1329-049 (ATel #2837) on September 6, 2010, was in a high state with a gamma-ray flux (E>100MeV) of (3.0 +/-0.5) x10^-6 photons cm^-2 s^-1, making it the brightest source in the extragalactic gamma-ray sky on that day. On September 7, the source was still bright with a flux of (2.3 +/-0.7) x10^-6 photons cm^-2 s^-1, it was also detected with lower flux on September 8 and 11. Previously, the source was detected by Fermi on the 1-day timescale on September 22, 2009, and July 7, 2010, at a flux level of about 1.0 x10^-6 photons cm^-2 s^-1 (ATel #2728). The Fermi LAT contact person for this source is D. Donato (donato[at]milkyway.gsfc.nasa.gov).

  • S5 0716+714> was detected on September 10 with a flux of (0.6 +/-0.2) x10^-6 photons cm^-2 s^-1.

  • 4C +21.35 was detected on September 6, 8 and 11 flux of about 1.0 x10^-6 ph cm^-2 s^-1.

  • 3C 454.3 was detected throughout the week at a flux of about 2.0 x10^-6 ph cm^-2 s^-1.

  • Active sources appearing for short periods of time during this week were:
    PKS 0332-403 (Sep. 10), S4 1030+61 (Sep. 7, 8), TON 599 (4C +29.45, Sep. 6), B2 1520+31 (Sep. 6, 11), PKS 2155-304 (Sep. 7, 9, 10), PKS 2326-502 (Sep. 7, 11, 12).



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



Note. All the fluxes reported above are from 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:

- K. Sokolovsky (ksokolov[at]mpifr-bonn.mpg.de) for generic information related to this week

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




Fermi LAT weekly report N.117



2010.Aug.30 - 2010.Sept.5 (UT)

117.57 - 118.57





  • B2 0619+33 first detected on September 1st, showed a GeV flare on
    September 3, reaching a peak flux level on daily scale of 1.0
    +/-0.2*10^-6 ph cm^-2 s^-1 (ATel #2829).

  • 4C +21.35 was detected throughout the week at flux levels between 0.5
    and around 2.0*10^-6 ph cm^-2 s^-1.

  • 3C 454.3 was detected throughout the week at a flux of above
    2.0*10^-6 ph cm^-2 s^-1.

  • Active sources appearing for short periods of time during this week
    were: PKS 0537-441 (Aug. 30), PKS 2326-502 (Aug. 30,31,Sept. 2, and 5), B2 1520+31 (Sept. 3 and 5).



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



Note. All the fluxes reported above are from 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]mpifr-bonn.mpg.de) for generic information related to this week

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




Thursday, September 9, 2010

Fermi LAT weekly report N.116



Covered period: 2010.Aug.23 - 2010.Aug.29

LAT Mission week: 116.57 - 117.57





  • PKS 0537-441 is detected through the week with stable daily flux (0.5 X 10-6).

  • TON 599 continues to be detected through the week (flux between 0.9 and 1.5 X 10-6).

  • 4C 21.35 detected only on Aug. 29 with flux 1.5 X 10-6.

  • 3C 454.3 is still bright during all week, with daily flux below 4.2 X 10-6.

  • PKS 2326-502 is detected through the entire week (flux between 0.6 and 1.8 X 10-6).

  • The radio source B2 0619+33/VCS J0622+3326 is detected on Aug. 24, 25, 27 and 28 with flux between 0.6 and 1.2 X 10-6 (peak observed on Aug. 27).

  • Sporadic activity observed from B2 2234+28A (Aug. 23), PKS 0727-11, PKS 1510-08, 4C +47.44 (Aug. 24), PKS 0458-02 (Aug. 25), and 3C 273 (Aug. 26). All fluxes below 1.0 X 10-6.



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



Note. All the fluxes reported above are from 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:

- D. Donato (donato[at]milkyway.gsfc.nasa.gov) for generic information related to this week

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




Fermi LAT weekly report N.115



Covered period: 2010.Aug.16 - 2010.Aug.22

LAT Mission week: 115.57 - 116.57





  • PKS 0537-441 is detected between Aug. 20 and 22 (daily flux 0.5 X 10-6).

  • TON 599 continues to be detected through the entire week (flux between 0.5 and 1.3 X 10-6).

  • 4C 21.35 and 3C 454.3 were relatively bright during all week, with daily flux below 1.2 and 2.4 X 10-6, respectively.

  • PKS 2326-502 is detected through the entire week (flux between 0.7 and 1.4 X 10-6).

  • The radio source B2 0619+33/VCS J0622+3326 is detected on Aug. 16 and 17 with flux at (0.8 +/- 0.3) and (0.6 +/- 0.2) X 10-6.

  • Sporadic activity observed from CGRaBS J0850-1213 (Aug. 17), S5 0716+71, PKS 0805-07 (Aug. 18), PKS 0332-403 (Aug. 19), 3C 66A (Aug. 21), and B2 2234+28A (Aug. 22). All fluxes below 1.0 X 10-6.



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



Note. All the fluxes reported above are from 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:

- D. Donato (donato[at]milkyway.gsfc.nasa.gov) for generic information related to this week

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