Thursday, June 10, 2010

Fermi LAT weekly report N. 104

Covered period: 2010.May.31 - 2010.Jun.06

LAT Mission week: 104.57 - 105.57

  • PKS 1915-458 (June 4; ATel #2666). Fermi/LAT has detected a new gamma-ray source positionally consistent with PKS 1915-458, a flat spectrum radio quasar at z=2.47 (Jackson et al. 2002, A&A, 386, 97). The redshift is unusually high for a flaring LAT blazar, however not unprecedented (ATEL #2217). On June 4, 2010 the gamma-ray flux (E>100MeV) of (0.36 +/-0.15) x10^-6 was observed corresponding to a detection significance of slightly greater than 5 sigma. Swift ToO observations have been requested to confirm identification of the flaring gamma-ray source with PKS 1915-458.

  • GB6 B1310+4844 (GB1 1310+487) is showing increasing gamma-ray flux during the last few weeks. The source was occasionally detected on daily timescale during this week with the moderate flux of ~0.4x10^-6.
    Multiwavelength observations of the source are desirable to compare its current elevated gamma-ray state with the previous major gamma-ray flare in November 2009 (ATel #2306, #2310, #2311, #2316, #2320).

  • BL Lac was detected on June 4 and 5 with a flux of ~(0.8 +/-0.2)x10^-6.

  • 4C +21.35 was detected during the first half of the week.

  • 3C 454.3 was detected throughout the week.

  • Other sources detected on daily timescale during the week:
    PKS 0426-380 (May 31, June 6), PKS 0537-441 (June 2, 5, 6), S5 0716+714 (May 31, June 5), S4 1030+61 (June 2, 4), PKS 1329-049 (June 1), PKS 1326-697 (June 2), PKS 1424-41 (June 1, 2, 6), PKS 1510-08 (June 3), 1FGL J1642.5+3947 (=3C 345?, June 2), PKS 2233-148 (June 3).

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] and Frank Schinzel (schinzel[at] for generic information related to this week.

- Contact persons on this page for individual sources.

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