Thursday, October 29, 2009

Fermi LAT weekly report N.72



Covered period: 2009.Oct.12 - 2009.Oct.18




  • 4C 14.23 (z=1.038) was detected on Oct. 13. The flux was (1.5+/-0.4)x10^-6. See Atel #2243. The source was in high state during this week with an average flux of 1x10^-6.

  • 3C 454.3 was detected every day in this week. The average flux was 2x10^-6.



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



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:

- Yasuyuki Tanaka (tanaka[at]astro.isas.jaxa.jp) for generic information related to this week

- source contact persons on this page for individual objects cited above.




Fermi LAT weekly report N.71



Covered period: 2009.Oct.5 - 2009.Oct.11




  • 3C 454.3 was detected every day in this week with an average flux of 4x10^-6.

  • 3C 273 and 4C 21 were bright in this week. The average fluxes were 2x10^-6 and 1x10^-6, respectively.

  • PKS 1118-05 was detected on Oct. 11. The flux was (0.9+/-0.4)x10^-6, which increased by ~12 compared to the average one during the period August 2008 to July 2009. This source showed an increased gamma-ray activity on Feb. 17, 2009. See ATel#1932.



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



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:

- Yasuyuki Tanaka (tanaka[at]astro.isas.jaxa.jp) for generic information related to this week

- source contact persons on this page for individual objects cited above.




Wednesday, October 14, 2009

Fermi LAT Weekly report No. 69



Covered period: 2009.Sep.21 - 2009.Sep.27




  • 3C 273 continued to be active. The fluxes were highest at the beginning of the week, with an average flux value of (8.7 +- 0.8) X 10^-6 on the first two days (21 and 22 of September) and values ~3 X 10^-6 for the rest of the week.


  • 3C 454.3 continued to be active, with an average flux of ~3 X 10^-6 during the week.


  • The FSRQ B3 1343+451 flared the entire week, whith a flux of ~1 X 10^-6. This corresponds to an increase of a factor ~15 in flux with respect to the first year of Fermi observations. Given the high redshift (z=2.534, Shaw, M.S. et al., in preparation) of the source such high fluxes are very rare and
    Atel #2217 was sent out.


  • PKS 1222+21 was detected with a flux of (1.4 +- 0.5) X 10^-6 on 25 of September.

  • GRB 090926181 was detected on 26 of September.



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



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:

- R. Buehler (buehler[at]slac.stanford.edu) for generic information related to this week

- source contact persons on this page for individual objects cited above.




Tuesday, October 13, 2009

Fermi LAT Weekly report No. 70



Covered period: 2009.Sept.28 - 2009.Oct.04




This was a busy week for the Fermi extragalactic sky:

  • Three gamma-ray blazars consistently reached very high fluxes of 4 x 10-6 ph cm-2. These were 3C 454.3, 3C 273 and 4C 21 (PKS 1222+21). The high fluxes of the former two are in line with their recent trends. In the case of 4C 21, the flare is quite remarkable since this is not a usually bright blazar. Unfortunately, the source is too close to the Sun and few observations at other wavelengths are possible.

  • A gamma-ray flare was detected on Sept 29-30 that was positionally consistent with the location of Fermi Bright source 0FGL J1641.4+3939 (Abdo, A. et al. 2009 ApJ, 700, 597). This is an interesting region for Fermi because there are at least 3 possible counterparts: 3C345, NRAO 512 and CLASS J1641+3935. Well-known blazar 3C 345 is the leading counterpart candidate given the localization of the Fermi flare (as described in ATel#2226) and the increased activity observed at other wavelengths (see ATel#2222). Hopefully, the identity of this Fermi source will be revealed based on the MW data obtained during this week.

  • There was a short but significant flare by PKS 1621-253 (see ATel#2231). Its flux on October 4th (1.9 +/- 0.2 x 10-6 ph cm-2 s-1) was about ~17 times higher than the average flux during the first year of Fermi observations. This blazar was detected by EGRET as 3EG J1626-2519 (Hartman, R.C. et al. 1999, ApJS, 123, 79).

  • The following publicly monitored sources were active during the week: S5 0716+714, PKS 0537-441, PKS 0454-234 and Mrk 421 (one or two significant detections during the week with fluxes <~ 10-6 ph cm-2 s-1).



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:

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

- source contact persons on this page for individual objects cited above.