Monday, February 22, 2010

Extra Note - Feb. 22, 2010



Mrk 421 on Feb. 22th, 2010




Markarian 421 (EUVE J1104+38.1, QSO B1101+384, RX J1104.4+3812,1FGL J1104.4+3812 ), a gamma-ray blazar with redshift z=0.03 (Healey, S. et al. 2008ApJS..175...97) currently exhibits a high energy flare, specially at X-ray (ATel #2444) and TeV energies (ATel #2443). This source showed a preliminary daily flux above 100 MeV of (0.4 +/- 0.1)E-6 photons/cm2/s with a photon index of 1.6 +/- 0.2 on Feb. 16th and a daily flux of (0.3 +/- 0.1)E-6 photons/cm2/s on Feb. 17th with a photon index 1.4 +/- 0.2 (errors statistical only).


For questions and comments please contact the Flare Advocates on shift (L. Escande (escande@cenbg.in2p3) and D. Bastieri (denis.bastieri@pd.infn.it)).





Friday, February 19, 2010

Fermi LAT weekly report N.87



Covered period: 2010.Feb.01 - 2010.Feb.07

LAT Mission week: 87.57 - 88.57



  • The flat-spectrum radio quasar 3C 454.3 was still the brightest source on the sky with a flux of (2.7 +/- 0.2)e-6.

  • The flat-spectrum radio quasar PKS 0402-362 flared to a flux of (1.0 +/- 0.3)e-6 on February 1, 2010, roughly one order of magnitude higher than the eleven-month average flux of 1FGL J0403.9-3603 (the associated LAT 1-year point source catalog object). Details are reported in ATel #2413.

  • A new, flaring GeV source was detected by the Fermi LAT on February 1, 2010. The source is located ~1 deg from the Galactic plane. The flux during the one-day period of February 1 was (0.8 +/- 0.3)e-6. Details are reported in ATel #2414. The Fermi LAT report triggered multi-wavelength observations which have been reported in the following ATel's: 2416, 2420, 2421, 2428, 2429, 2433.

  • The flat-spectrum radio quasar 3C 273 has been bright, with a flux of (1.2 +/- 0.1)e-6 on the one-week timescale.
  • The flat-spectrum radio quasar 3C 279 has been detected with a flux of (0.5 +/- 0.1)e-6 during the one-week timescale.

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

Note: All the fluxes 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:

- J. Vandenbroucke (justinv[at]stanford.edu) for generic information related to this week

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


Tuesday, February 16, 2010

Fermi lat weekly report N.85



Covered period: 2010.Jan.18 - 2010.Jan.24

LAT Mission week: 85.57 - 86.57





  • 3C 454.3 still dominates extragalactic gamma-ray sky with the flux of (5.7 +/-0.3)*10^-6.

  • OX 169 flared on January 18, 2010, peaking at flux (1.4 +/-0.4)*10^-6, reported in ATel #2393.

  • PKS 0420-01 showed a gradual increase of gamma-ray flux in the last ~40 days. On January 21, 2010, is showed a flare with a peak flux of (0.8 +/-0.2)*10^-6. On the same day, BL Lacertae showed a short gamma-ray flare with the peak flux of (1.1 +/-0.5)*10^-6 in the six-hour interval centered on 2010 January 21.375 (UT). These events were reported in ATel #2402.

  • 3C 66A was detection on weekly timescale with a high significance level and flux of (0.27 +/-0.06)*10^-6. However, no exceptional activity of this source was observed.

  • ATel #2403 reported detection of a new unidentified gamma-ray source in the Galactic plane by AGILE satellite. Preliminary analysis revealed no Fermi/LAT sources near the reported position both on daily and weekly timescales...

  • Other bright (flux>0.5) extragalactic sources detected on weekly timescale:
    PKS 1510-08, CGRaBS J2345-1555, PKS 0402-362, 4C 21.35, 4C 38.41



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:

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

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




Thursday, February 11, 2010

LAT Limit on M87 during TeV Flare

Following the announcement by the MAGIC team of a TeV flare from M87, http://www.astronomerstelegram.org/?read=2431, we have checked the LAT data for the same time period. The 95% confidence upper limit for E>100 MeV for one day of observation is 1.3 e-7 ph/cm2/s assuming a photon index Gamma=2.26 which was the average for the first 10 months of the mission.

Sunday, February 7, 2010

Fermi LAT weekly report N. 86



Covered period: 2010, Jan. 25  -  2010,
Jan. 31 (UT)


LAT Mission week: 86.57 - 87.57





  • Brightest blazars of the week are 3C 454.3, PKS 1501-08, PKS 0537-441, PKS 0402-362 (LAT ATEL #2402, above 1.3 on Jan.25), PKS 0426-380 (LAT ATel#2366). 

  • Non-confirmation of source in AGILE's ATEL #2403 in the same time interval and weekly interval.

  • Special appearance of PKS 0244-470 on Jan.26.

  • PMN J2345-1555 (1FGL J2344.6-1554, z= 0.621, FSRQ) flared at the 1E-6 threshold on Jan. 27. ATel#2408 submitted.

  • PKS 0521-36 (1H 0515-363, 3EG J0530-3626, possible BL Lac object even if classified also as FSRQ/Sey1/FRII in literature, z=0.055) popped up only on Jan. 29 at daily flux about 0.7E-6, photon index around 2. Low redshift source of possible interest for TeV telescopes. 

  • S5 0716+71 and Mkn 421 detected a couple of times during the week with daily flux below 0.4E-6.



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.