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]nasa.gov) for generic information related to this week

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



Posted by Flare Advocate at 2:21 PM 0 comments
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Thursday, December 3, 2009

Fermi LAT weekly report N.76


Covered period: 2009.Nov.16 - 2009.Nov.22 (UT)

LAT Mission week: 61.57 - 62.57



The gamma-ray sky showed some exciting activity this week, with five blazars exceeding the 1⋅10^-6 flux above 100 MeV that defines flaring and a surprise detection of the quasar GB6 B1310+4844.




  • On Nov. 18, GB6 B1310+4844 (LAT ATels #2306, #2316) attracted attention by the detection of a GeV flare consistent with the position of this source (daily flux: (1.0±0.2)⋅10^-6). It remained bright ending the week with an even higher daily flux of (2.2±0.2)⋅10^-6 on Nov. 22.
    (LAT contact: K. Sokolovsky, ksokolov[at]mpifr-bonn.mpg.de)

  • 4C +14.23 (PKS 0722+145, LAT ATel #2243) stays bright above 1⋅10^-6. It faded intermittently during the middle of the week and re-brightened to a daily flux level of (1.8±0.4)⋅10^-6 (average weekly flux: (1.5±0.1)⋅10^-6).

  • Rapid brightening of 3C 454.3 toward the second half of the week, peaking at a daily flux level of (5.7±0.7)⋅10^-6 on Nov 20 (weekly average flux: (3.7±0.2)⋅10^-6).

  • On Nov. 17, B2 1520+31 (LAT ATel #2026) showed a weak flare (daily flux: (0.9±0.3)⋅10^-6), faded and re-appeared even stronger (Nov. 19 - Nov. 21), peaking on Nov. 21 (daily flux: (1.5±0.3)⋅10^-6).

  • On Nov. 17, PKS 1622-253 (LAT ATel #2231) flared. (daily flux: (1.9±0.7)⋅10^-6, weekly flux: (0.5±0.2)⋅10^-6).

  • On Nov. 17, PKS 1510-089 (LAT ATel #2033) flared as well. (daily flux: (1.2±0.4)⋅10^-6, weekly flux: (0.8±0.2)⋅10^-6).

  • 4C +38.41 (LAT ATel #2136) was brightening during Nov. 21 (daily flux: (0.7±0.2)⋅10^-6) and was detected at the same level during Nov. 22.



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

- 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.



Posted by Flare Advocate at 10:27 AM 0 comments

Monday, November 30, 2009

Fermi LAT weekly report N.75



Covered period: 2009.Nov.08 - 2009.Nov.15 (UT)



  • 3C273 detected in a flaring state reaching his maximum in the daily time scale on 9th November with a flux of (3.9+/-0.5)10^-6 (statistical only).
  • 3C454.3 detected most of the week
  • PKS0722+145 show an increasing trend during the week
  • MRK 421 was not detected during the BAT hard-X ray flare in November 10th.
  • PKS 0537-441 detected November 11th, 12th and 15th.

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

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

Posted by Flare Advocate at 9:45 AM 0 comments

Friday, November 27, 2009

Update on GeV activity and spectral hardness of GB6 B1310+4844

The LAT source positionally consistent with the flat spectrum radio quasar GB6 B1310+4844 (commonly known as GB1 1310+487 or TXS 1310+487) continues to show strong and variable activity (ATEL 2306, also see ATEL 2310, ATEL 2311). In the daily run for November 26, the flux(E>100MeV) = 1.2 ± 0.2 10-6 photons cm-2 s-1 and photon index=1.8 ± 0.1 (errors are statistical only; results are preliminary from the automated analysis processing). We note that the spectrum is very hard for this type of source in the GeV band. We strongly encourage multiwavelength observations, in particular optical monitoring, of this object given the ongoing activity and GeV spectrum. The LAT contact person is Kirill Sokolovsky (ksokolov[at]mpifr-bonn.mpg.de).

Note. All the flux values 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.

For questions and comments please contact:

- Liz Hays (elizabeth.a.hays[at]nasa.gov) or Lise Escande (escande[at]cenbg.in2p3.fr) for generic information related to this week
Posted by Flare Advocate at 9:19 AM 0 comments

Wednesday, November 25, 2009

Fermi LAT weekly report N.74 


Covered period: 2009.Nov.02 - 2009.Nov.08 (UT)

LAT Mission week: 59.57 - 60.57



  • OJ 287 (LAT+MW ATel #2256) bright and detected with daily flux (0.5+/-0.1)E-6 on Nov.04 and a bit lower on Nov.05. The weekly averaged flux of OJ 287 is showing an increasing trend in the last month (October).

  • 4C 14.23 (PKS 0722+145, LAT ATel #2243) is bright (daily flux above 1E-6 in the first part of the week).

  • 3C 273 is flaring from Nov.06 to Nov.08 (daily flux above 3E-6, reaching the daily peak of (4.6+/-0.4)E-6 ).

  • 3C 279 was detected around 0.7E-6.

  • 3C 454.3 bright (daily flux reached 2E-6 during some days of the week).

  • Mkn 501 and Mkn 421 detected in two days (daily flux about 0.2E-6 on Nov.04 and 0.5E-6 on Nov.07 respectively).

  • B2 1520+31 detected on Nov.06 (daily flux around 0.8E-6).

  • Sun detected a couple of times this week.


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.


Posted by Flare Advocate at 3:12 AM 0 comments

Monday, November 9, 2009

Fermi LAT weekly report N.73


Covered period: 2009.Oct.26 - 2009.Nov.01


  • 3C 454.3 (z=0.859) is still bright with peak flux 3.33 +/-0.63 x 10^-6 on October 29, weekly average flux 2.80 +/-0.19 x 10^-6. However, it is fading rapidly (see daily lightcurve).

  • 3C 273 (z=0.158) weekly flux 1.08 +/-0.18 x 10^-6.

  • 4C 14.23 (z=1.038) was not detected this week, however it reappeared in the first days of the following week: detected on Nov 02, 03, 04.


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



Note. All the flux values 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:


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

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



Posted by Flare Advocate at 8:55 AM 0 comments

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.



Posted by Flare Advocate at 7:51 PM 0 comments
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