Author Archives: AGILE Team

Updated online version of the 3rd AGILE TGF Catalog, including events up to October 31, 2020

We announce that the SSDC online version of the 3rd AGILE Terrestrial Gamma-ray Flashes (TGF) Catalog, initially including events detected by the Minicalorimeter (MCAL) during the period March 2015 – September 2018 (A. Lindanger et al. 2020 and C. Maiorana et al. 2020), has been recently updated to include 517 new events associated with lightning sferics detected from October 1, 2018 to October 31, 2020. The total number of AGILE TGF events associated with lightning sferics from March 2015 to October 2020 is more than a thousand (1116).
The complete SSDC AGILE TGF web table is available here, and it also gives access to the available TGF light curves and counts details, providing supplementary material to the published papers. The current version, published online on September 2, 2021 also includes minor bug fixes affecting the previous plotting of some of the TGF lightcurves during the so-called DRIFT period (see references for more details).

14th AGILE Science Workshop

We are pleased to invite you to the 14th AGILE Science Workshop entitled

“AGILE ON THE WAVE”

to be held in Rome, ASI Headquarters Sala “Cassini” – via del Politecnico snc, Roma 20-21 June, 2016

The workshop is aimed at providing an update and discussion of the most recent developments  in high-energy astrophysics and terrestrial physics
connected with AGILE mission.

A series of talks will cover the following topics:

* State of the AGILE Mission
* Prospects for Gravitational Wave Research
* Galactic High-Energy Astrophysics
* Extragalactic High-Energy Astrophysics
* Terrestrial Gamma-Ray Flashes and Meteorology
* Particle Properties in the Inner Magnetosphere
* Future Gamma-Ray Missions and Experiments

The scientific program and logistics information will be available shortly at the workshop website: http://www.asdc.asi.it/14thagilemeeting
and it will be communicated through a Second Announcement.

AGILE restarts the scientific observations!

AGILE restart after a no-telemetry hiatus (Jan. 1 – March 25, 2014). Sequence of sky maps showing the one-by-one gamma-ray photon detection as accumulated during the first day of operations (March 26-27, 2014). The AGILE satellite is in ‘spinning mode’ making a complete rotation in about 7 minutes. The empty sky regions corresponds to sky areas now inaccessible by the AGILE sky scanning. The last frame shows the summed-up photon intensity map. Sequence made by F. Verrecchia (ASDC) for the AGILE Team. Thanks to who has signed the petition.

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End of the show? Sign the petition for AGILE

Starting on January 1, 2014, the AGILE satellite interrupted normal scientific operations due to lack of funds. It is currently in a dormant state waiting for future decisions on its fate. We are kindly asking you to signing the petition, and to pass it on to other individuals you deem interested at signing as well (click on the link in this App). Thanks for your help.

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AGILE-GRID view of GRB131108A

GRBs (Gamma-Rays Bursts) are flashes of gamma rays of high intensity but lasting only a few seconds. It is believed that they are related to the end of massive stars, although the mechanisms that produce these phenomena are still largely shrouded in mystery. On the night of November 8, AGILE has revealed GRB 131108A, that, for some tens of seconds, showed a brightness exceptionally high even for events of this kind.
This discovery is even more interesting considering the distance from which the gamma photons of this GRB are coming. The place of origin was in fact identified in a galaxy at redshift 2.4, which corresponds to about 10 billion light years. The brightness and the distance of this event imply that the energy released in a few seconds by this GRB is 1000 times greater than that produced by the Sun during its entire life.

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11th AGILE Science Workshop – May 16-17, 2013

First Announcement. Dear Sirs, we are pleased to invite you to the 11th AGILE Science Workshop entitled: “GAMMA-RAYS AND GALACTIC COSMIC RAYS” that will be held at the new ASI Headquarters in Rome, Tor Vergata (Via del Politecnico snc), on May 16-17, 2013. The scientific program and logistics information will be soon available and will be communicated with a Second Announcement. Please let us have your confirmation within May 9th 2013 to the following e-mail address: info.comunicazioni@asi.it. Regards, ASI External Relations Office

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Discovery of variable gamma-ray emission from the Crab Nebula

AGILE discovery that the archetypical source of gamma-ray astrophysics is not constant. Very rapid and intense gamma-ray flares from the inner Nebula driven by plasma instabilities. Theoretical particle acceleration models challenged and to be drastically revised. Consequences and broad applications in plasma physics experiments and theoretical studies of particle acceleration.

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Bruno Rossi prize to Marco Tavani and the AGILE Team

The 2012 Rossi Prize has been awarded to astrophysicist Marco Tavani and the AGILE team for the discovery of variable gamma-ray emission from the Crab Nebula. Believed to be a steady source of energy – from optical to gamma rays – this finding has changed our understanding of cosmic accelerators. “The production of these incredible gamma-ray flares from the Crab Nebula is a feat that will lead us to a deeper understanding of the fundamental processes of particle acceleration in cosmic sources,” said Dr. Tavani. “AGILE unveiled this phenomenon in part because of its rapid data acquisition and processing – a large success for a ‘Small Mission’.” The AAS High Energy Astrophysics Division (HEAD) awards the Rossi Prize in recognition of significant contributions as well as recent and original work in high-energy astrophysics. The prize is in honor of Professor Bruno Rossi, an authority on cosmic-ray physics and a pioneer in the field of X-ray astronomy. Dr. Tavani will give a lecture at the 221st AAS meeting in Long Beach, California, in January 2013.

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Confirmation of the proton acceleration in Supernova Remnants

AGILE has discovered a pattern of gamma-ray emission from the Supernova Remnant W44 that can be unambiguosly attributed to accelerate protons smashing against surrounding gas. For many decades, a direct identification of sites in our galaxy where proton acceleration takes place has been elusive. The AGILE data resolves the problem of clearly identifying a source of energetic cosmic rays in our galaxy. The AGILE team reported these findings in the paper by Giuliani et al., ApJL, 742, L30, 2011.

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AGILE 9th and 10th Science Workshop

We are pleased to invite you to the Scientific Workshops that will be held at the ESA-ESRIN Headquarters in Frascati where ASDC (ASI Science Data Center) is based: April 16-17, “Astrophysics with AGILE: Five Years of Surprises”, April 18, “Lightning, Terrestrial Gamma-Ray Flashes, and Meteorology”. Scientific topics to be addressed are inspired by the AGILE Mission and will cover a wide range of astrophysics and atmospheric physics of general interest.

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SuperAGILE detects a Gamma-Ray Burst associated to a Supernova

On December 11, 2011 at 22:17:33 UT the SuperAGILE hard X-ray monitor aboard the Italian AGILE satellite localized a Gamma-Ray Burst, GRB 111211A ( see GCN #12666 F. Lazzarotto et al.). The GRB 111211A is the first event detected by SuperAGILE associated with a Supernova. While an average number of about 200 – 300 GRBs are localised each year in the X-ray band, less than twenty firm associations with Supernovae are established up to now. The SuperAGILE GRB 111211A is a rare occurrence of a burst which appears to be accompanied by a Supernova explosion, and gives the opportunity to further investigate the GRB-Supernova connection.

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AGILE resolves the mystery of the origin of cosmic rays

AGILE has discovered a pattern of gamma-ray emission from the Supernova Remnant W44 that can be unambiguosly attributed to accelerate protons smashing against surrounding gas. For many decades, a direct identification of sites in our galaxy where proton acceleration takes place has been elusive. The AGILE data resolves the problem of clearly identifying a source of energetic cosmic rays in our galaxy. The AGILE team reported these findings in the paper by Giuliani et al., ApJL, 742, L30, 2011.

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AGILE extraordinary detection from the blazar 3C 454.3

Starting on Nov. 17, 2010 (see ATel # 3034) the AGILE satellite detected another extraordinary gamma-ray flare from the blazar 3C 454.3 that we are calling “Crazy Diamond” for the unpredictable variability of its emission. This gamma-ray flare is the most intense and prolonged one (see ATel # 3043) ever detected, and transformed 3C 454.3 into the brightest gamma-ray source in the sky.

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AGILE discovery that the Crab Nebula is variable

The Crab Nebula is certainly one of the most famous astronomical objects. It is at the center of a bright supernova that exploded in 1054 and was recorded by Chinese astronomers. It encloses now at its very center one of the most powerful pulsars. The Crab has been considered for decades as one of the strongest persistent X-ray and gamma-ray source in the sky and was then used as a standard calibration source in astrophysics. Therefore, when between Sept. 19 and Sept.21, 2010 the AGILE team detected a strongly enhanced gamma-ray emission from the Crab Nebula region (see ATel # 2855) it provoked a sort of shock in the community. Following the AGILE discovery and the confirmation by Fermi/LAT on the following day (see Atel #2861), many telescopes (Swift, INTEGRAL, Hubble, Chandra) have then pointed and are still pointing at the Crab, gathering precious information for precisely identifying the phenomenon. The AGILE team reported the surprising gamma-ray flares of the Crab Nebula in the paper by Tavani et al., Science, 331, 736, 2011.

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The fastest gamma-ray alert monitoring system of the world

The overall gamma-ray alert monitoring system of AGILE is compound by two independent pipelines that process the data with different data quality results. The INAF/IASF Bologna pipeline processes the data in the fastest possible way, loosing the tail of the data acquired during an AGILE orbit but it generates alert within 1.5-2 hours from the time of the last GRID event acquired in orbit. The ASDC pipeline is more accurate because all events are considered during the analysis but the alerts are generated 3-3.5 hours after. Due also to this ground segment architecture the 2012 Bruno Rossi Prize of the American Astronomical Society has been awarded to Marco Tavani, AGILE Principal Investigator, and his team for the discovery of gamma-ray flares from the Crab Nebula.

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AGILE discovery of TGF gamma-ray emission up to 100 MeV

A detection that shows how the atmosphere can very efficiently accelerate particles during lightning associated with powerful thunderstorms. The AGILE discovery challenges current models of TGF acceleration based on relativistic electron production and cascading, and leads to substantial revisions of extreme particle acceleration models in lightning. This investigations have very important impacts on the study of the atmospheric environment and implications for global climate change studies. AGILE obtained the first gamma-ray imaging of TGFs from space using a special technique of on-board data selection. The AGILE Team reported the surprising discovery of gamma-ray radiation up to 100 MeV in the paper by Tavani et al., PRL, 106, 018501, 2011.

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AGILE detection of GRB 100724B

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. See AGILE GCN number 10996.

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AGILE first detection of gamma-rays above 100 MeV.

Discovery of extreme particle acceleration preceding relativistic jet plasmoid ejections from the black hole candidate Cyg X-3. Repeatedly detected by AGILE since 2008. First comprehensive survey of all Galactic microquasars by SuperAGILE and AGILE-GRID. The AGILE Team reported the discovery in the paper by Tavani et al., Nature, 462, 620, 2009.

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AGILE in spinning mode

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.

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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 satellite 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 Team reported the detection of TGFs up to 40 MeV in the paper by Marisaldi et al., JGR, 115, A00E13, 2010.

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