July 26, 2010: The Gamma-Ray Imaging Detector (GRID) on board AGILE detected the long bright GRB 100724B (Bhat, GCN 10977; Tanaka et al., GCN 10978;
Golenetskii et al., GCN 10981, Marisaldi et al., GCN 10994) in the energy range 25 - 500 MeV with a statistical significance larger than 9 sigma.
The gamma-ray emission observed by the AGILE-GRID instrument lasted about 100 seconds, and two peaks are evident in the lightcurve consistent with the behaviour reported by Fermi LAT
July 26, 2010: A plot showing the distance between the position of GRB 100724B and the AGILE boresight as a function of time.
GRB 100724B turns out to be the brightest GRB detected by AGILE above 100 MeV during its operations in space.
The AGILE satellite detects
"super-energetic TGFs"
The AGILE satellite detects "super-energetic TGFs" that could affect air travel
"Terrestrial Gamma-Ray Flashes" (TGF) are phenomena of terrestrial
(atmospheric) origin only lasting a few milliseconds that are likely associated to very intense tropical thunderstorms. The AGILE satellites detected several of these events since its first months of operations.
The AGILE equatorial orbit, together with its advanced payload capabilities, allowed the discovery of TGFs with gamma-ray energy reaching up to 50 MeV.
Such highly energetic radiation must be produced in atmospheric conditions requiring potential differences of 100 Mega Volts or more, hundreds of times larger than that required to produce the usual terrestrial lightning.
As announced in a joint press release that can be found on the ASI and INAF websites, the AGILE Team and ASI are collaborating with ENAC (Ente Nazionale per l'Aviazione Civile) to understand the possible hazards to air traffic that these very energetic atmospheric events might cause.
THE AGILE paper "Detection of Terrestrial Gamma-Ray Flashes up to 40 MeV by the AGILE satellite" by M. Marisaldi et al. (2009), previously announced on this website on October 29th 2009, is now being published in the Journal of Geophysical research and it is accessible on-line at:
http://www.asdc.asi.it/news/Marisaldi2009_AGILE-TGF.pdf
AGILE DETECTS A GIANT GAMMA-RAY
FLARE FROM THE BLACK HOLE
GALAXY 3C 454.3
("Crazy Diamond")
(December 2-8, 2009)
The strongest ever gamma-ray source in the sky !
AGILE first detection of gamma-rays above 100 MeV
from the microquasar Cygnus X-3
The paper "Extreme particle acceleration in the microquasar Cygnus X-3",
Tavani et al., Nature, vol. 462, 620-623 (3 December 2009)
Click here
(see also arXiv:0910.5344), reports the AGILE detection of gamma-ray flaring
emission from the microquasar Cygnus X-3, which tends to occur before the onset
of powerful relativistic radio jets.
Press Release
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English Version
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On November 4, 2009 at 12:25:54 the AGILE scientific operations were reconfigured. The satellite will be operating in a "spinning mode", i.e., with the instrument axis sweeping the accessible sky with an angular speed of 1 degree/sec. The instrument and all detectors are operating nominally.
The figure above (in Galactic coordinates) shows a typical 100-orbit gamma-ray intensity map above 100 MeV in the AGILE spinning configuration.
