Thursday, May 26, 2011



Covered period: 2011.May.15 - 2011.May.22

LAT Mission week: 154.57 - 155.57





  • BL Lac is detected in a high state all week reaching a flux of 1.4e-6 on 20th May; see ATel #3368 and the follow up Atels in which optical/X-ray brightening has been reported (#3371, #3375 and #3377).

  • 4C +38.41 is very active all week reaching a flux of (1.5 ± 0.3) e-6.

  • 4C 49.22 is in high state all week, with a flux of (1.3± 0.3)e-6 on 17th May.

  • CTA 102 detected on 18th and 19th May.

  • 4C +21.35, PKS 0521-36, PKS 0537-441, PMN J2345-1555 and 3C279, 3C66A are detected during the week.

  • Referring to the AGILE ATel (#3357) on AGL 2302-3251, we do not confirm the detection in the soft energy band (100MeV-400MeV).





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:

- S. Cutini (sara.cutini[at]asdc.asi.it) for generic information related to this week

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




Fermi LAT weekly report N. 153



Covered period: 2011 May 9-15

LAT Mission week: 153.57-154.57





Highlights of this week:

Detection of gamma ray activity from blazar PKS 0208-512 with a flux of (1.1 +/- 0.3)E-6. This was reported in ATel #3338

CTA 102 brightened on May 11, up to a flux of (1.6 ± 0.4) E-6, which is above the level reported in a recent telegram from May 3 (ATel #3320)

Blazar SBS 1150+497 (also known as as 4C 49.22, OM 484) became active this week after a one month hiatus following a short flare on April 15 (ATEL #3313). Back then there were two possible AGN counterparts to the gamma-ray source, but follow-up observations have revealed a contemporaneous increase in flux at GeV, X-ray and NIR (ATEL#3317) wavelengths, which confirms the identification of the Fermi source with SBS 1150+497. A peak flux of (3.4 +/- 0.6)E-6 was observed by Fermi LAT during a 12hr interval on May 15, but since then the source has been detected at a more moderate flux of aprox. 1 E-6.

4C +38.41 remains bright this week, with daily fluxes consistently around 1.3 E-6 for most days and as high as ( 2.5 +/- 0.4) E-6 on May 15

Other daily detections of blazars this week: PKS 1244-255, 3C 279, 4C +28.07, PKS 0537-441, Mkn 421, PKS 2155-304, CRATES J1239+0443, 3C 454.3, BL Lac, PMN J2345-1555

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]slac.stanford.edu) and L. Reyes (lcreyes [at] uchicago.edu) for generic information related to this week

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

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]slac.stanford.edu) and L. Reyes (lcreyes [at] uchicago.edu) for generic information related to this week

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

Monday, May 9, 2011

Fermi LAT weekly report N. 151





Covered period: 2011 Apr.25-May.1

LAT Mission week: 151.57 - 152.57








  • Flare of CTA 102 (daily flux (1.4+/-0.3)E-6 on April 29, 2011. This is
    the first firm daily detection too since the beginning of the mission. See ATel#3320


  • Flare of PKS 0521-36 on April 25 (daily flux (1.6 ± 0.4) E-6).


  • PKS 1510-08 active during the week around 1E-6.


  • NGC 1275 detected on April 30, 2011.


  • Other daily detection of blazars during the week: PKS 1244-255, PKS 1510-08, 3C 279, B2 1520+31, PMN J2345-1555, 3C 454.3, PKS 0537–441, 4C 38.41, B2 0321+33B, PKS 1502+106, B2 1633+38, PKS 0906+01, PKS 1424-41, 4C 28.07 (B2 0234+28), GB6 J0742+5444, PMN J0531-4827



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



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:

- S. Ciprini (stefano.ciprini[at]pg.infn.it) for generic information related to this week

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




Sunday, May 8, 2011

Fermi LAT weekly report N. 150




Covered period: 2011 Apr.18-Apr.24

LAT Mission week: 150.57 - 151.57





  • Crab Nebula fading since peak on Apr. 14, but still above average for the pulsar + nebula until Apr. 19. The TOO observation continued from the previous week until Apr. 19. This reduced daily exposure on some portions of the sky during that time.


  • Detection of a flare from a new LAT source near S4 1150+49 (4C 49.22) with GB6 J1152+4939 (BZQ J1152+4939) just outside the error circle. See ATel 3313.


  • Flare associated with PKS 1622–253 to (1.6 +/- 0.4) E-6 on April 18, 2011. Previously active in October 2009 (ATel 2231).


  • PKS 0521–36 active this week reaching a flux of (1.8 ± 0.4) e-6 on Apr. 23.


  • B2 1520+31 flared to (1.4 +/- 0.4) e-6 on Apr. 22.


  • Some activity throughout the week from 3C 279 reaching 1.1 ± 0.3 E-6 on Apr. 21.


  • Other daily detection of blazars during the week:  PKS 1510–089, 3C 454.3.



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


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:

- E. Hays (elizabeth.a.hays[at]nasa.gov) for generic information related to this week

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