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161 results on '"Salotti, L."'

1. Characterization of a tagged [formula omitted] beam line at the [formula omitted] Beam Test Facility

Author

Cattaneo, P.W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A.W., D'Ammando, F., Foggetta, L., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, M., Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., and Salotti, L.

Published
2012
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2. Discovery of Powerful Gamma-Ray Flares from the Crab Nebula

Author

Tavani, M., Bulgarelli, A., Vittorini, V., Pellizzoni, A., Striani, E., Caraveo, P., Weisskopf, M. C., Tennant, A., Pucella, G., Trois, A., Costa, E., Evangelista, Y., Pittori, C., Verrecchia, F., Monte, E. Del, Campana, R., Pilia, M., De Luca, A., Donnarumma, I., Horns, D., Ferrigno, C., Heinke, C. O., Trifoglio, M., Gianotti, F., Vercellone, S., Argan, A., Barbiellini, G., Cattaneo, P. W., Chen, A. W., Contessi, T., D'Ammando, F., DeParis, G., Di Cocco, G., Di Persio, G., Feroci, M., Ferrari, A., Galli, M., Giuliani, A., Giusti, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Fuschino, F., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Vallazza, E., Zambra, A., Zanello, D., Lucarelli, F., Santolamazza, P., Giommi, P., Salotti, L., and Bignami, G. F.

Published
2011
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3. Detection of Gamma-Ray Emission from the Vela Pulsar Wind Nebula with AGILE

Author

Pellizzoni, A., Trois, A., Tavani, M., Pilia, M., Giuliani, A., Pucella, G., Esposito, P., Sabatini, S., Piano, G., Argan, A., Barbiellini, G., Bulgarelli, A., Burgay, M., Caraveo, P., Cattaneo, P. W., Chen, A. W., Cocco, V., Contessi, T., Costa, E., Del Monte, E., D'Ammando, F., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Hotan, A., Labanti, C., Lipari, P., Longo, F., Marisaldi, M., Mastropietro, M., Mereghetti, S., Moretti, E., Morselli, A., Pacciani, L., Palfreyman, J., Perotti, F., Picozza, P., Pittori, C., Possenti, A., Prest, M., Rapisarda, M., Rappoldi, A., Rossi, E., Rubini, A., Santolamazza, P., Scalise, E., Soffitta, P., Striani, E., Trifoglio, M., Vallazza, E., Vercellone, S., Verrecchia, F., Vittorini, V., Zambra, A., Zanello, D., Giommi, P., Colafrancesco, S., Antonelli, A., Salotti, L., D'Amico, N., and Bignami, G. F.

Published
2010
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4. First results about on-ground calibration of the silicon tracker for the AGILE satellite

Author

Cattaneo, P.W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A.W., D’Ammando, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, M., Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., and Salotti, L.

Published
2011
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5. The flaring blazars of the first 1.5 years of the AGILE mission

Author

Pacciani, L., Bulgarelli, A., Chen, A.W., D’Ammando, F., Donnarumma, I., Giuliani, A., Longo, F., Pucella, G., Tavani, M., Vercellone, S., Vittorini, V., Argan, A., Barbiellini, G., Boffelli, F., Caraveo, P., Cattaneo, P.W., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Antonelli, L.A., Colafrancesco, S., Giommi, P., Pittori, C., Verrecchia, F., Santolamazza, P., and Salotti, L.

Published
2011
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6. Galactic sources science with AGILE: The case of the Carina Region

Author

Sabatini, S., Tavani, M., Pian, E., Bulgarelli, A., Caraveo, P., Viotti, R., Corcoran, M.F., Giuliani, A., Pittori, C., Verrecchia, F., Vercellone, S., Mereghetti, S., Argan, A., Barbiellini, G., Boffelli, F., Cattaneo, P.W., Chen, A.W., Cocco, V., D’Ammando, F., Costa, E., Paris, G. De, Monte, E. Del, Cocco, G. Di, Donnarumma, I., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mastropietro, M., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Pucella, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Vittorini, V., Zambra, A., Zanello, D., Santolamazza, P., Giommi, P., Colafrancesco, S., Antonelli, L.A., and Salotti, L.

Published
2011
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7. Preliminary results on TeV sources search with AGILE

Author

Rappoldi, A., Longo, F., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P.W., Chen, A.W., Cocco, V., Colafrancesco, S., Costa, E., D’ Ammando, F., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giommi, P., Giuliani, A., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pittori, C., Porrovecchio, G., Prest, M., Pucella, G., Rapisarda, M., Rubini, A., Sabatini, S., Salotti, L., Santolamazza, P., Soffitta, P., Striani, E., Tavani, M., Trifoglio, M., Trois, A., Vallazza, E., Verrecchia, F., Vercellone, S., Vittorini, V., Zambra, A., and Zanello, D.

Published
2011
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8. The observation of gamma ray bursts and terrestrial gamma-ray flashes with AGILE

Author

Del Monte, E., Barbiellini, G., Fuschino, F., Giuliani, A., Longo, F., Marisaldi, M., Mereghetti, S., Moretti, E., Trifoglio, M., Vianello, G., Costa, E., Donnarumma, I., Evangelista, Y., Feroci, M., Gallil, M., Lapshov, I., Lazzarotto, F., Lipari, P., Pacciani, L., Rapisarda, M., Soffitta, P., Tavani, M., Vercellone, S., Cutini, S., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P.W., Chen, A., Di Cocco, G., Gianotti, F., Labanti, C., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rappoldi, A., Sabatini, S., Striani, E., Trois, A., Vallazza, E., Vittorini, V., Antonelli, L.A., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.

Published
2011
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15. Extreme particle acceleration in the microquasar Cygnus X-3

Author

Tavani, M., Bulgarelli, A., Piano, G., Sabatini, S., Striani, E., Evangelista, Y., Trois, A., Pooley, G., Trushkin, S., Nizhelskij, N. A., McCollough, M., Koljonen, K. I. I., Pucella, G., Giuliani, A., Chen, A. W., Costa, E., Vittorini, V., Trifoglio, M., Gianotti, F., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., DʼAmmando, F., Del Monte, E., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Feroci, M., Ferrari, A., Fuschino, F., Galli, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Mattaini, E., Marisaldi, M., Mastropietro, M., Mauri, A., Mereghetti, S., Morelli, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rossi, E., Rubini, A., Scalise, E., Soffitta, P., Vallazza, E., Vercellone, S., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Giommi, P., Colafrancesco, S., Santolamazza, P., Antonelli, A., and Salotti, L.

Published
2009
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17. Detection and period measurements of GX1+4 at hard x ray energies with the SIGMA telescope

Author

Laurent, PH, Salotti, L, Lebrun, F, Paul, J, Denis, M, Barret, D, Jourdain, E, Roques, J. P, Churazov, E, and Gilfanov, M

Subjects
Space Radiation
Abstract

The galactic Low Mass X ray Binary GX1+4 was detected by the coded aperture hard X ray gamma ray SIGMA telescope during the Feb. to April 1991 observations of the galactic center regions. The source, whose emission varied during the survey of a factor greater than 40 pct., reached a maximum luminosity in the 40 to 140 energy range of 1.03 x 10(exp 37) erg/s (D = 8.5 kpc), thus approaching the emission level of the 1970 to 1980 high state. Two minute flux pulsations were detected on Mar. 22 and on Mar. 31 and Apr. 1. Comparison with the last period measurements shows that the current spin-down phase of GX1+4 is ending. Concerning the proposed association of this source with the galactic center 511 keV annihilation emission, upper limits were derived.

Published
1992

18. Characterization of a tagged gamma-ray beam line at the DA Phi NE Beam Test Facility

Author

Cattaneo, P. W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A. W., D'Ammando, F., Foggetta, L., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, Michela, Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., Salotti, L., Cattaneo PW, Argan A, Boffelli F, Bulgarelli A, Buonomo B, Chen AW, DAmmando F, Foggetta L, Froysland T, Fuschino F, Galli M, Gianotti F, Giuliani A, Longo F, Marisaldi M, Mazzitelli G, Pellizzoni A, Prest M, Pucella G, Quintieri L, Rappoldi A, Tavani M, Trifoglio M, Trois A, Valente P, Vallazza E, Vercellone S, Zambra A, Barbiellini G, Caraveo P, Cocco V, Costa E, De Paris G, Del Monte E, Di Cocco G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Mastropietro M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Perotti F, Piano G, Picozza P, Pilia M, Porrovecchio G, Rapisarda M, Rubini A, Sabatini S, Soffitta P, Striani E, Vittorini V, Zanello D, Colafrancesco S, Giommi P, Pittori C, Santolamazza P, Verrecchia F, and Salotti L

Subjects
photon tagged beam, Gamma Ray Imaging Detector, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, AGILE satellite, Electron and positron beam, Photon beam, silicon tracker, Beam Test Facility, bremsstrahlung, Position-sensitive detector
Abstract

At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a gamma-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the gamma rays. A tagged gamma-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating gamma-rays through bremsstrahlung in a position-sensitive target. The gamma-ray energy is deduced by difference with the post-bremsstrahlung electron energy [1,2]. The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-FTS system as tagged photon beam requires understanding the efficiency of gamma-ray tagging, the probability of fake tagging, the energy resolution andthe relation of the PTS hit position versus the gamma-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation. (C) 2012 Elsevier B.V. All rights reserved.

Published
2012

19. Detection of terrestrial gamma ray flashes up to 40 MeV by the AGILE satellite

Author

Marisaldi, M., Fuschino, F., Labanti, C., Galli, M., Longo, Francesco, Monte, E. D., Barbiellini, G., Tavani, M., Giuliani, A., Moretti, E., Vercellone, S., Costa, E., Cutini, S., Donnarumma, I., Evangelista, Y., Feroci, M., Lapshov, I., Lazzarotto, F., Lipari, P., Mereghetti, S., Pacciani, L., Rapisarda, M., Soffitta, P., Trifoglio, M., Argan, A., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A., Cocco, V., D'Ammando, F., Paris, G. D., Cocco, G. D., Persio, G. D., Ferrari, A., Fiorini, M., Froysland, T., Gianotti, F., Morselli, A., Pellizzoni, A., Perotti, F., Picozza, P., Piano, G., Pilia, M., Prest, M., Pucella, G., Rappoldi, A., Rubini, A., Sabatini, S., Striani, E., Trois, A., Vallazza, E., Vittorini, V., Zambra, A., Zanello, D., Antonelli, L. A., Colafrancesco, S., Gasparrini, D., Giommi, P., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Salotti, L., Marisaldi M, Fuschino F, Labanti C, Galli M, Longo F, Del Monte E, Barbiellini G, Tavani M, Giuliani A, Moretti E, Vercellone S, Costa E, Cutini S, Donnarumma I, Evangelista Y, Feroci M, Lapshov I, Lazzarotto F, Lipari P, Mereghetti S, Pacciani L, Rapisarda M, Soffitta P, Trifoglio M, Argan A, Boffelli F, Bulgarelli A, Caraveo P, Cattaneo PW, Chen A, Cocco V, DAmmando F, De Paris G, Di Cocco G, Di Persio G, Ferrari A, Fiorini M, Froysland T, Gianotti F, Morselli A, Pellizzoni A, Perotti F, Picozza P, Piano G, Pilia M, Prest M, Pucella G, Rappoldi A, Rubini A, Sabatini S, Striani E, Trois A, Vallazza E, Vittorini V, Zambra A, Zanello D, Antonelli LA, Colafrancesco S, Gasparrini D, Giommi P, Pittori C, Preger B, Santolamazza P, Verrecchia F, Salotti L, M., Marisaldi, F., Fuschino, C., Labanti, M., Galli, Longo, Francesco, E. D., Monte, G., Barbiellini, M., Tavani, A., Giuliani, E., Moretti, S., Vercellone, E., Costa, S., Cutini, I., Donnarumma, Y., Evangelista, M., Feroci, I., Lapshov, F., Lazzarotto, P., Lipari, S., Mereghetti, L., Pacciani, M., Rapisarda, P., Soffitta, M., Trifoglio, A., Argan, F., Boffelli, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, A., Chen, V., Cocco, F., D'Ammando, G. D., Pari, G. D., Cocco, G. D., Persio, A., Ferrari, M., Fiorini, T., Froysland, F., Gianotti, A., Morselli, A., Pellizzoni, F., Perotti, P., Picozza, G., Piano, M., Pilia, M., Prest, G., Pucella, A., Rappoldi, A., Rubini, S., Sabatini, E., Striani, A., Troi, E., Vallazza, V., Vittorini, A., Zambra, D., Zanello, L. A., Antonelli, S., Colafrancesco, D., Gasparrini, P., Giommi, C., Pittori, B., Preger, P., Santolamazza, F., Verrecchia, and L., Salotti

Subjects
Agile, terrestrial gamma ray flashes, minicalorimeter, High Energy Gamma-ray Astronomy, AGILE satellite, Terrestrial Gamma-ray Flashes, terrestrial gamma ray flashes, AGILE satellite
Abstract

We report the detection by the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite of terrestrial gamma ray flashes (TGFs) obtained with the minicalorimeter (MCAL) detector operating in the energy range 0.3-100 MeV. We select events typically lasting a few milliseconds with spectral and directional selections consistent with the TGF characteristics previously reported by other space missions. During the period 1 June 2008 to 31 March 2009 we detect 34 high-confidence events showing millisecond durations and a geographical distribution peaked over continental Africa and Southeast Asia. For the first time, AGILE-MCAL detects photons associated with TGF events up to 40 MeV. We determine the cumulative spectral properties of the spectrum in the range 0.5-40 MeV, which can be effectively described by a Bremsstrahlung spectrum. We find that both the TGF cumulative spectral properties and their geographical distribution are in good agreement with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) results.

Published
2010

20. MULTIWAVELENGTH OBSERVATIONS OF A TeV-FLARE FROM W COMAE

Author

Veritas, Collaboration, Acciari, V. A., Aliu, E., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Buckley, J. H., Bradbury, S. M., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., Lebohec, S., Maier, G., Mcarthur, S., Mccann, A., Mccutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Sembroski, G. H., Smith, A. W., Steele, D., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Agile, The Team, Pian, E., Vercellone, S., Donnarumma, I., D Ammando, F., Bulgarelli, A., Chen, A. W., Giuliani, A., Longo, F., Pacciani, L., Pucella, G., Vittorini, V., Tavani, M., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Froysland, T., Frutti, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, S. Sabatini P., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., Colafrancesco, S., Salotti, L., Massimo Villata, Raiteri, C. M., Aller, H. D., Aller, M. F., Arkharov, A. A., Efimova, N. V., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Pasanen, M., Kurtanidze, O. M., Tetradze, S. D., Lahteenmaki, A., Kotiranta, M., Cucchiara, A., Romano, P., Nesci, R., Pursimo, T., Heidt, J., Benitez, E., Hiriart, D., Nilsson, K., Berdyugin, A., Mujica, R., Dultzin, D., Lopez, J. M., Mommert, M., Sorcia, M., La Calle Perez, I., V. A., Acciari, E., Aliu, T., Aune, M., Beilicke, W., Benbow, M., Bottcher, D., Boltuch, J. H., Buckley, S. M., Bradbury, V., Bugaev, K., Byrum, A., Cannon, A., Cesarini, L., Ciupik, P., Cogan, W., Cui, R., Dickherber, C., Duke, A., Falcone, J. P., Finley, P., Fortin, L., Fortson, A., Furni, N., Galante, D., Gall, K., Gibb, G. H., Gillander, J., Grube, R., Guenette, G., Gyuk, D., Hanna, J., Holder, C. M., Hui, T. B., Humensky, P., Kaaret, N., Karlsson, M., Kertzman, D., Kieda, A., Konopelko, H., Krawczynski, F., Krennrich, M. J., Lang, S., Lebohec, G., Maier, S., Mcarthur, A., Mccann, M., Mccutcheon, J., Milli, P., Moriarty, R. A., Ong, A. N., Otte, D., Pandel, J. S., Perkin, A., Pichel, M., Pohl, J., Quinn, K., Ragan, L. C., Reye, P. T., Reynold, E., Roache, H. J., Rose, G. H., Sembroski, A. W., Smith, D., Steele, M., Theiling, S., Thibadeau, A., Varlotta, V. V., Vassiliev, S., Vincent, S. P., Wakely, J. E., Ward, T. C., Weeke, A., Weinstein, T., Weisgarber, D. A., William, S., Wissel, M., Wood, E., Pian, S., Vercellone, I., Donnarumma, F., D'Ammando, A., Bulgarelli, A. W., Chen, A., Giuliani, Longo, Francesco, L., Pacciani, G., Pucella, V., Vittorini, M., Tavani, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, V., Cocco, E., Costa, E. D., Monte, G. D., Pari, G. D., Cocco, Y., Evangelista, M., Feroci, M., Fiorini, T., Froysland, M., Frutti, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Morelli, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, G., Porrovecchio, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, F., Verrecchia, P., Giommi, S., Colafrancesco, L., Salotti, M., Villata, C. M., Raiteri, H. D., Aller, M. F., Aller, A. A., Arkharov, N. V., Efimova, V. M., Larionov, P., Leto, R., Ligustri, E., Lindfor, M., Pasanen, O. M., Kurtanidze, S. D., Tetradze, A., Lahteenmaki, M., Kotiranta, A., Cucchiara, P., Romano, R., Nesci, T., Pursimo, J., Heidt, E., Benitez, D., Hiriart, K., Nilsson, A., Berdyugin, R., Mujica, D., Dultzin, J. M., Lopez, M., Mommert, M., Sorcia, I. D., Perez, Acciari VA, Aliu E, Aune T, Beilicke M, Benbow W, Bottcher M, Boltuch D, Buckley JH, Bradbury SM, Bugaev V, Byrum K, Cannon A, Cesarini A, Ciupik L, Cogan P, Cui W, Dickherber R, Duke C, Falcone A, Finley JP, Fortin P, Fortson L, Furniss A, Galante N, Gall D, Gibbs K, Gillanders GH, Grube J, Guenette R, Gyuk G, Hanna D, Holder J, Hui CM, Humensky TB, Kaaret P, Karlsson N, Kertzman M, Kieda D, Konopelko A, Krawczynski H, Krennrich F, Lang MJ, LeBohec S, Maier G, McArthur S, McCann A, McCutcheon M, Millis J, Moriarty P, Ong RA, Otte AN, Pandel D, Perkins JS, Pichel A, Pohl M, Quinn J, Ragan K, Reyes LC, Reynolds PT, Roache E, Rose HJ, Sembroski GH, Smith AW, Steele D, Theiling M, Thibadeau S, Varlotta A, Vassiliev VV, Vincent S, Wakely SP, Ward JE, Weekes TC, Weinstein A, Weisgarber T, Williams DA, Wissel S, Wood M, Pian E, Vercellone S, Donnarumma I, DAmmando F, Bulgarelli A, Chen AW, Giuliani A, Longo F, Pacciani L, Pucella G, Vittorini V, Tavani M, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Cocco V, Costa E, Del Monte E, De Paris G, Di Cocco G, Evangelista Y, Feroci M, Fiorini M, Froysland T, Frutti M, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Marisaldi M, Mastropietro M, Mereghetti S, Morelli E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Porrovecchio G, Prest M, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Soffitta P, Trifoglio M, Trois A, Vallazza E, Zambra A, Zanello D, Pittori C, Santolamazza P, Verrecchia F, Giommi P, Colafrancesco S, Salotti L, Villata M, Raiteri CM, Aller HD, Aller MF, Arkharov AA, Efimova NV, Larionov VM, Leto P, Ligustri R, Lindfors E, Pasanen M, Kurtanidze OM, Tetradze SD, Lahteenmaki A, Kotiranta M, Cucchiara A, Romano P, Nesci R, Pursimo T, Heidt J, Benitez E, Hiriart D, Nilsson K, Berdyugin A, Mujica R, Dultzin D, Lopez JM, Mommert M, Sorcia M, and Perez ID

Subjects
Agile, High energy, agile space mission, Astrophysics::High Energy Astrophysical Phenomena, bl-lacertae objects, FOS: Physical sciences, Flux, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, telescope, 01 natural sciences, High Energy Gamma-ray Astronomy, blazar, law.invention, multiwavelength, BL Lacertae, law, 0103 physical sciences, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Very High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, Gamma ray, background-radiation, Astronomy and Astrophysics, gamma-ray emission, lac objects, spectral energy-distributions, veritas observations, Space and Planetary Science, source list, Spectral energy distribution, BL Lacertae objects: individual (W Com), Astrophysics - High Energy Astrophysical Phenomena, gamma rays: observations, Flare, BL Lac object
Abstract

We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z=0.102) during a strong outburst of very high energy gamma-ray emission in June 2008. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) = (5.7+-0.6)x10^-11 cm-2s-1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high energy gamma-rays (AGILE, E>100 MeV), and X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution (SED) of the source from contemporaneous data taken throughout the flare., 26 pages, 5 figures; Accepted for publication by The Astrophysical Journal

Published
2009

24. AGILE detection of Cygnus X-3 γ-ray active states during the period mid-2009/mid-201bulgarelli@iasfbo.inaf.it

Author

Bulgarelli, A., Tavani, M., Chen, A. W., Evangelista, Y., Trifoglio, M., Gianotti, F., Piano, G., Sabatini, S., Striani, E., Pooley, G., Trushkin, S., Nizhelskij, N. A., Mccollough, M., Koljonen, K. I. I., Hannikainen, D., Lahteenmaki, A., Tammi, J., Lavonen, N., Steeghs, D., Aboudan, A., Argan, A., Barbiellini, G., Campana, R., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., Costa, E., D'Ammando, F., Del Monte, E., De Paris, G., Di Cocco, G., Donnarumma, I., Feroci, M., Fiorini, M., Fuschino, F., Galli, M., Giuliani, A., Giusti, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, P., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Giommi, P., Pittori, C., Verrecchia, F., Santolamazza, P., Lucarelli, F., Colafrancesco, S., and Salotti, L.

Subjects
gamma-rays: stars, stars: individual: Cygnus x-3
Published
2012

25. The characterization of the distant blazar GB6 J1239+0443 from flaring and low activity periods

Author

Pacciani, L., Donnarumma, I., Denney, K. D., Assef, R. J., Ikejiri, Y., Yamanaka, M., Uemura, M., Domingo, A., Giommi, P., Tarchi, A., Verrecchia, F., Longo, F., Rainó, S., Giusti, M., Vercellone, S., Chen, A. W., Striani, E., Vittorini, V., Tavani, M., Bulgarelli, A., Giuliani, A., Pucella, G., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Colafrancesco, S., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zanello, D., Pittori, C., Santolamazza, P., Lucarelli, F., Salotti, L., Valentini, G., L., Pacciani, I., Donnarumma, K. D., Denney, R. J., Assef, Y., Ikejiri, M., Yamanaka, M., Uemura, A., Domingo, P., Giommi, A., Tarchi, F., Verrecchia, Longo, Francesco, S., Raino, M., Giusti, S., Vercellone, A. W., Chen, E., Striani, V., Vittorini, M., Tavani, A., Bulgarelli, A., Giuliani, G., Pucella, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, S., Colafrancesco, E., Costa, Paris, G., E. D., Monte, G. D., Cocco, Y., Evangelista, A., Ferrari, M., Feroci, M., Fiorini, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, D., Zanello, C., Pittori, P., Santolamazza, F., Lucarelli, L., Salotti, and G., Valentini

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Cosmology and Nongalactic Astrophysics (astro-ph.CO), gamma-ray flaring, general [quasars], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, individual: GB6 J1239+0443 [galaxies], Astrophysics::Cosmology and Extragalactic Astrophysics, AGILE satellite, radiation mechanisms, black hole, blazar, radiation mechanisms: non-thermal, non-thermal [radiation mechanisms], galaxies: individual: GB6 J1239+0443, quasars: general, active [galaxies], astro-ph.CO, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

In 2008 AGILE and Fermi detected gamma-ray flaring activity from the unidentified EGRET source 3EG J1236+0457, recently associated with a flat spectrum radio quasar GB6 J1239+0443 at z=1.762. The optical counterpart of the gamma-ray source underwent a flux enhancement of a factor 15-30 in 6 years, and of ~10 in six months. We interpret this flare-up in terms of a transition from an accretion-disk dominated emission to a synchrotron-jet dominated one. We analysed a Sloan Digital Sky Survey (SDSS) archival optical spectrum taken during a period of low radio and optical activity of the source. We estimated the mass of the central black hole using the width of the CIV emission line. In our work, we have also investigated SDSS archival optical photometric data and UV GALEX observations to estimate the thermal-disk emission contribution of GB6 J1239+0443. Our analysis of the gamma-ray data taken during the flaring episodes indicates a flat gamma-ray spectrum, with an extension of up to 15 GeV, with no statistically-relevant sign of absorption from the broad line region, suggesting that the blazar-zone is located beyond the broad line region. This result is confirmed by the modeling of the broad-band spectral energy distribution (well constrained by the available multiwavelength data) of the flaring activity periods and by the accretion disk luminosity and black hole mass estimated by us using archival data., Comment: 30 pages, 7 figures, 4 tables MNRAS Accepted on 2012 June 18

Published
2012

26. Characterization of a tagged $\gamma$-ray beam line at the DAFNE Beam Test Facility

Author

Cattaneo, P W, Argan, A, Boffelli, F, Bulgarelli, A, Buonomo, B, Chen, A W, D’Ammando, F, FoggettA, L, Froysland, T, Fuschino, F, Galli, M, Gianotti, F, Giuliani, A, Longo, F, Marisaldi, M, Mazzitelli, G, Pellizzoni, A, Prest, M, Pucella, G, Quintieri, L, Rappoldi, A, Tavani, M, Trifoglio, M, Trois, A, Valente, P, Vallazza, E, Vercellone, S, Zambra, A, Barbiellini, G, Caraveo, P, Cocco, V, Costa, E, De Paris, G, Del Monte, E, Di Cocco, G, Donnarumma, I, Evangelista, Y, Feroci, M, Ferrari, A, Fiorini, M, Labanti, C, Lapshov, I, Lazzarotto, F, Lipari, P, Mastropietro, M, Mereghetti, S, Morelli, E, Moretti, E, Morselli, A, Pacciani, L, Perotti, F, Piano, G, Picozza, P, Pilia, M, Porrovecchio, G, Rapisarda, M, Rubini, A, Sabatini, S, Soffitta, P, Striani, E, Vittorini, V, Zanello, D, Colafrancesco, S, Giommi, P, Pittori, C, Santolamazza, P, Verrecchia, F, and Salotti, L

Subjects
Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Test beams infrastructure at CERN and Frascati [8.2], Improvement and equipment of irradiation and test beam lines [8], Detectors and Experimental Techniques
Abstract

At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a γ-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the γ rays. A tagged γ-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating γ-rays through bremsstrahlung in a position-sensitive target. The γ-ray energy is deduced by difference with the post-bremsstrahlung electron energy [1] and [2]. The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-PTS system as tagged photon beam requires understanding the efficiency of γ-ray tagging, the probability of fake tagging, the energy resolution and the relation of the PTS hit position versus the γ-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation.

Published
2012

27. Characterization of a tagged $\gamma$-ray beam line at the DA$\Phi$NE Beam Test Facility

Author

Cattaneo, P. W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A. W., D'Ammando, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, M., Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., and Salotti, L.

Subjects
Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a $\gamma$-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the $\gamma$ rays. A tagged $\gamma$-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating $\gamma$ rays through bremsstrahlung in a position-sensitive target. The $\gamma$-ray energy is deduced by difference with the post-bremsstrahlung electron energy \cite{prest}-\cite{hasan}. The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-PTS system as tagged photon beam requires understanding the efficiency of $\gamma$-ray tagging, the probability of fake tagging, the energy resolution and the relation of the PTS hit position versus the $\gamma$-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation., Comment: 23 pages; 17 figures. Second and final version accepted by Nucl. Instr. & Meth. A

Published
2011

28. Variable and transient galactic gamma-ray sources with AGILE

Author

Longo, Francesco, Bulgarelli, A., Chen, A., Gianotti, F., Giuliani, A., Lucarelli, F., Piano, G., Pittori, C., Sabatini, S., Striani, E., Tavani, M., Trifoglio, M., Verrecchia, F., Argan, A., BARBIELLINI AMIDEI, Guido, Costa, E., Caraveo, P., Cattaneo, P. W., D'Ammando, F., De Paris, G., Del Monte, E., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mereghetti, S., Moretti, Elena, Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, P., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Antonelli, L. A., Colafrancesco, S., Cutini, S., Giommi, P., Santolamazza, P., Salotti, L., Longo, Francesco, A., Bulgarelli, A., Chen, F., Gianotti, A., Giuliani, F., Lucarelli, G., Piano, C., Pittori, S., Sabatini, E., Striani, M., Tavani, M., Trifoglio, F., Verrecchia, A., Argan, BARBIELLINI AMIDEI, Guido, E., Costa, P., Caraveo, P. W., Cattaneo, F., D'Ammando, G., De Pari, E., Del Monte, G., Di Cocco, G., Di Persio, I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, T., Froysland, F., Fuschino, M., Galli, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, S., Mereghetti, Moretti, Elena, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, A., Rubini, P., Soffitta, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, L. A., Antonelli, S., Colafrancesco, S., Cutini, P., Giommi, P., Santolamazza, and L., Salotti

Subjects
Microquasar, Microquasars, High Energy Gamma-ray Astronomy, Galactic sources
Abstract

AGILE has been providing continous monitoring of the Galactic plane in its three years of operation. Thanks to its sensitivity at energies near 100 MeV, AGILE has observed variability and transient behaviour in a number of sources. Simultaneous hard-X ray coverage, rapid alerts to the astronomical community, and multiwavelength campaigns have provided identifications for some of these sources and placed constraints on others. We provide an overview of these observations and their possible counterparts, including microquasars and colliding wind binaries.

Published
2011

29. Discovery of extreme particle acceleration in the microquasar Cygnus X-3

Author

Tavani, M., Bulgarelli, A., Piano, G., Sabatini, S., Striani, E., Evangelista, Y., Trois, A., Pooley, G., Trushkin, S., Nizhelskij, N. A., McCollough, M., Koljonen, K. I. I., Pucella, G., Giuliani, A., Chen, A. W., Costa, E., Vittorini, V., Trifoglio, M., Gianotti, F., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., D'Ammando, F., Del Monte, E., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Feroci, M., Ferrari, A., Fuschino, F., Galli, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Mattaini, E., Marisaldi, M., Mastropietro, M., Mauri, A., Mereghetti, S., Morelli, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rossi, E., Rubini, A., Scalise, E., Soffitta, P., Vallazza, E., Vercellone, S., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Giommi, P., Colafrancesco, S., Santolamazza, P., Antonelli, A., and Salotti, L.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The study of relativistic particle acceleration is a major topic of high-energy astrophysics. It is well known that massive black holes in active galaxies can release a substantial fraction of their accretion power into energetic particles, producing gamma-rays and relativistic jets. Galactic microquasars (hosting a compact star of 1-10 solar masses which accretes matter from a binary companion) also produce relativistic jets. However, no direct evidence of particle acceleration above GeV energies has ever been obtained in microquasar ejections, leaving open the issue of the occurrence and timing of extreme matter energization during jet formation. Here we report the detection of transient gamma-ray emission above 100 MeV from the microquasar Cygnus X-3, an exceptional X-ray binary which sporadically produces powerful radio jets. Four gamma-ray flares (each lasting 1-2 days) were detected by the AGILE satellite simultaneously with special spectral states of Cygnus X-3 during the period mid-2007/mid-2009. Our observations show that very efficient particle acceleration and gamma-ray propagation out of the inner disk of a microquasar usually occur a few days before major relativistic jet ejections. Flaring particle energies can be thousands of times larger than previously detected maximum values (with Lorentz factors of 105 and 102 for electrons and protons, respectively). We show that the transitional nature of gamma-ray flares and particle acceleration above GeV energies in Cygnus X-3 is clearly linked to special radio/X-ray states preceding strong radio flares. Thus gamma-rays provide unique insight into the nature of physical processes in microquasars., 29 pages (including Supplementary Information), 8 figures, 2 tables version submitted to Nature on August 7, 2009 (accepted version available at http://www.nature.com/nature/journal/vaop/ncurrent/pdf/nature08578.pdf)

Published
2009

34. Terrestrial gamma-ray flashes as powerful particle accelerators.

Author

Tavani M, Marisaldi M, Labanti C, Fuschino F, Argan A, Trois A, Giommi P, Colafrancesco S, Pittori C, Palma F, Trifoglio M, Gianotti F, Bulgarelli A, Vittorini V, Verrecchia F, Salotti L, Barbiellini G, Caraveo P, Cattaneo PW, Chen A, Contessi T, Costa E, D'Ammando F, Del Monte E, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Galli M, Giuliani A, Giusti M, Lapshov I, Lazzarotto F, Lipari P, Longo F, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Pucella G, Prest M, Rapisarda M, Rappoldi A, Rossi E, Rubini A, Sabatini S, Scalise E, Soffitta P, Striani E, Vallazza E, Vercellone S, Zambra A, and Zanello D

Abstract

Strong electric discharges associated with thunderstorms can produce terrestrial gamma-ray flashes (TGFs), i.e., intense bursts of x rays and γ rays lasting a few milliseconds or less. We present in this Letter new TGF timing and spectral data based on the observations of the Italian Space Agency AGILE satellite. We determine that the TGF emission above 10 MeV has a significant power-law spectral component reaching energies up to 100 MeV. These results challenge TGF theoretical models based on runaway electron acceleration. The TGF discharge electric field accelerates particles over the large distances for which maximal voltages of hundreds of megavolts can be established. The combination of huge potentials and large electric fields in TGFs can efficiently accelerate particles in large numbers, and we reconsider here the photon spectrum and the neutron production by photonuclear reactions in the atmosphere.

Published
2011
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35. Gamma-ray localization of terrestrial gamma-ray flashes.

Author

Marisaldi M, Argan A, Trois A, Giuliani A, Tavani M, Labanti C, Fuschino F, Bulgarelli A, Longo F, Barbiellini G, Del Monte E, Moretti E, Trifoglio M, Costa E, Caraveo P, Cattaneo PW, Chen A, D'Ammando F, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Froysland T, Galli M, Gianotti F, Lapshov I, Lazzarotto F, Lipari P, Mereghetti S, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Piano G, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Soffitta P, Striani E, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Antonelli LA, Colafrancesco S, Cutini S, Giommi P, Lucarelli F, Pittori C, Santolamazza P, Verrecchia F, and Salotti L

Abstract

Terrestrial gamma-ray flashes (TGFs) are very short bursts of high-energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of ∼5-10° at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the subsatellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space.

Published
2010
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36. An orbit determination software suite for Space Surveillance and Tracking applications.

Author

Montaruli, Marco Felice, Purpura, Giovanni, Cipollone, Riccardo, Vittori, Andrea De, Facchini, Luca, Di Lizia, Pierluigi, Massari, Mauro, Peroni, Moreno, Panico, Alessandro, Cecchini, Andrea, and Rigamonti, Marco

Abstract

The growth of both operational satellites and orbital debris is creating the requirement for more robust Space Surveillance and Tracking (SST)-related applications. These systems necessarily must leverage ground-based sensors (optical and radar) to realise higher performance solutions. In this context, the European Union Space Surveillance and Tracking (EUSST) consortium groups European national agencies and institutions, and is in charge of carrying out the following services: conjunction analysis, fragmentation analysis and re-entry prediction, and the Italian Air Force is in charge of the latter two. In this framework, the Italian SST Operational Centre (ISOC) has recently upgraded its system to the ISOC Suite, an integrated platform providing multiple functions and services in the SST domain. This paper presents the orbit determination functions provided by the novel ISOC Suite. First, a statistical index is computed to assess the measurements correlation to a catalogued object. If it is successful, the object predicted orbit is refined through measurements according either to batch or sequential filters; otherwise these are used to refine a first estimate of the target orbital state computed according to dedicated methodologies. After the presentation of the prototypal software architecture, the ISOC Suite performance are assessed and discussed both in terms of synthetic and real data. [ABSTRACT FROM AUTHOR]

Published
2024
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37. Operational Angular Track Reconstruction in Space Surveillance Radars through an Adaptive Beamforming Approach.

Author

Montaruli, Marco Felice, De Luca, Maria Alessandra, Massari, Mauro, Bianchi, Germano, and Magro, Alessio

Subjects
SURVEILLANCE radar, BEAMFORMING, DOPPLER effect, SPACE surveillance, ANGULAR measurements, SIGNAL-to-noise ratio, ELECTRONIC data processing
Abstract

In the last few years, many space surveillance initiatives have started to consider the problem represented by resident space object overpopulation. In particular, the European Space Surveillance and Tracking (EUSST) consortium is in charge of providing services like collision avoidance, fragmentation analysis, and re-entry, which rely on measurements obtained through ground-based sensors. BIRALES is an Italian survey radar belonging to the EUSST framework and is capable of providing measurements including Doppler shift, slant range, and angular profile. In recent years, the Music Approach for Track Estimate and Refinement (MATER) algorithm has been developed to retrieve angular tracks through an adaptive beamforming technique, guaranteeing the generation of more accurate and robust measurements with respect to the previous static beamforming approach. This work presents the design of a new data processing chain to be used by BIRALES to compute the angular track. The signal acquired by the BIRALES receiver array is down-converted and the receiver bandwidth is split into multiple channels, in order to maximize the signal-to-noise ratio of the measurements. Then, the signal passes through a detection block, where an isolation procedure creates, for each epoch, signal correlation matrices (CMs) related to the channels involved in the detection and then processes them to isolate the data stream related to a single detected source. Consequently, for each epoch and for each detected source, just the CM featuring the largest signal contribution is kept, allowing deriving the Doppler shift measurement from the channel illumination sequence. The MATER algorithm is applied to each CM stream, first estimating the signal directions of arrival, then grouping them in the observation time window, and eventually returning the target angular track. Ambiguous estimates may be present due to the configuration of the receiver array, which cause spatial aliasing phenomena. This problem can be addressed by either exploiting transit prediction (in the case of cataloged objects), or by applying tailored criteria (for uncatalogued objects). The performance of the new architecture was assessed in real operational scenarios, demonstrating the enhancement represented by the implementation of the channelization strategy, as well as the angular measurement accuracy returned by MATER, in both nominal and off-nominal scenarios. [ABSTRACT FROM AUTHOR]

Published
2024
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38. Conjunction Analysis Software Suite for Space Surveillance and Tracking.

Author

Bonaccorsi, Sergio, Montaruli, Marco Felice, Di Lizia, Pierluigi, Peroni, Moreno, Panico, Alessandro, Rigamonti, Marco, and Del Prete, Francesco

Subjects
SPACE surveillance, GEOMETRIC series, ORBITS (Astronomy), SPACE debris, SITUATIONAL awareness
Abstract

The increasing number of objects in Earth orbit has encouraged the development of space surveillance and tracking (SST) applications. A critical aspect of SST is the identification and characterization of close encounters between pairs of space objects. The present work introduces a tool for the analysis of conjunctions, consisting of several modules. The first module, which has been shown to greatly speed up the process, employs a series of geometric and temporal filters to shorten the list of potential colliding pairs. The remaining objects are then propagated to compute important parameters such as time of closest approach (TCA), miss distance (MD), and probability of collision (PoC), the latter using three different methods. When a conjunction assessment returns an MD or a PoC that exceeds predefined alert thresholds, the algorithm enables the planning of an impulsive collision avoidance maneuver (CAM) at specific maneuver epochs. CAM candidates are determined using an analytical Keplerian approach, with the goal of achieving the desired PoC or MD. The user can then verify the performance of a specific candidate through perturbed propagation, and the MD and PoC are recalculated after the maneuver to ensure that they meet the desired thresholds. In conclusion, this paper evaluates the performance of the tool using synthetic and real data, providing valuable insights into its effectiveness. [ABSTRACT FROM AUTHOR]

Published
2024
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39. Recent observations and research progresses of terrestrial gamma-ray flashes during thunderstorms.

Author

Lyu, Fanchao, Zhang, Yijun, Lu, Gaopeng, Zhu, Baoyou, Zhang, Hongbo, Xu, Wei, Xiong, Shaolin, and Lyu, Weitao

Subjects
THUNDERSTORMS, ATMOSPHERIC electricity, PHOTON detectors, LIGHTNING, SPATIAL resolution, ATMOSPHERE
Abstract

Terrestrial gamma-ray flashes (TGFs) are high-energy emissions in thunderstorms that were discovered first by satellite-based and then by ground-based gamma-ray detectors with photon energy up to tens of MeV. TGFs are a natural high-energy phenomenon associated with lightning discharges that frequently occur during thunderstorms. However, their production mechanisms and associated processes are still unclear. TGF studies have already been a research spotlight in the atmospheric electricity and high-energy atmosphere research areas. In this paper, we review recent research progresses on TGF studies in the past decade, including TGF detection, the relationship between TGFs and lightning processes, and thunderstorm activities. Several unsolved important scientific questions are discussed. Results suggest that upward TGFs observed by satellite-based detectors are closely connected with the development of in-cloud upward negative leaders. They are usually generated in milliseconds of the initiation of upward negative leaders and may produce a kind of distinct radio emissions because of the generation and propagation of huge amounts of high-energy electrons. By contrast, its counterpart, i.e., downward TGFs observed by ground-based gamma-ray detectors, is associated with different types of lightning processes, such as downward negative or upward positive leaders, the initial continuing current stage of rocket-triggered lightning flashes return stroke processes. Because of limited observations, how these downward TGFs are generated is still unclear. Benefiting from the development of state-of-the-art instruments with high temporal and spatial resolutions, new insights into the processes and mechanisms of TGFs will be achieved with coordinated observations from satellite-based and ground-based measurements. [ABSTRACT FROM AUTHOR]

Published
2023
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40. Study of the characteristics of rocket-triggered lightning energetic radiation and its relationships with the discharge parameters.

Author

Zhang, Xiong, Li, Xiaoqiang, Zhang, Yang, Cao, Baofeng, Zheng, Yi, Jiang, Rubin, Li, Peng, Zhang, Hongbo, and Lyu, Weitao

Subjects
LIGHTNING, X-ray bursts, RADIATION, FIELD research
Abstract

Through the use of the independently developed Thunderstorm Energetic Radiation Observation System (TEROS), observation experiments of rocket-triggered lightning energetic radiation (RLER) were conducted for the first time at the Field Experiment Base on Lightning Sciences, China Meteorological Administration from May 2021 to July 2021. A total of 17 X-ray bursts were detected during all of the 22 leader/return strokes. In this study, the energy, time, and direction characteristics of X-ray burst and its relationships with the corresponding discharge parameters, such as the return stroke peak current, half-peak width, rise time, and interstroke time interval, as well as the associated physical processes, are analyzed and discussed. Results showed that energetic radiation is ubiquitous in triggered lightning and is closely related to the last downward leader phase before the return stroke. The photon energies were concentrated in tens to hundreds of keV, and the average duration of RLER was approximately 27 µs. Moreover, RLER exhibited directional property inconsistent with a vertical downward beam, which may be related to the development orientation of the lightning leader. The intensity of RLER was positively correlated with the return stroke peak current, indicating that it directly depends on the lightning intensity, but it would be modulated by the lightning channel conditions. The 17 RLER events showed 3 different time distribution patterns, namely, discrete, continuous, and discrete/continuous pulses, of which the discharge parameters were also different. The discrete pulse event had the longest duration, a small half-peak width, and a long interstroke time interval. Furthermore, all of these events occurred during the last several leader/return strokes. The continuous pulse event had a short duration and a small peak current. The discrete/continuous pulse event had a moderate duration and a large half-peak width and peak current. These three distinct time distribution patterns may be determined by different development types of lightning leaders. Our observations support the leader high-field runaway mechanism. [ABSTRACT FROM AUTHOR]

Published
2023
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42. SIGMA hard X-ray observations of GX339-4

Author

Bouchet, L., Jourdain, E., Mandrou, P., Roques, J.P., Laurent, Ph., Lebrun, F., Paul, J., Salotti, L., Sunyaev, R., Churazov, E., Gilvanov, M., Khavenson, N., Diachkov, A., Chulkov, I., Novikov, B., and Kuznetsov, A.

Published
1993
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44. Imaging of the Galactic Center field by KVANT and GRANAT

Author

Sunyaev, R.A., Churazov, E.M., Gilfanov, M.R., Pavlinsky, M., Grebenev, S., Dekhanov, I., Kuznetsov, A.V., Yamburenko, N.S., Skinner, G.K., Patterson, T.G., Willmore, A.P., Emam, O., Pan, H., Nottingham, M.R., Brinkman, A.C., Heise, J., in't Zand, J.J.M., Jager, R., Ballet, J., Laurent, P., Paul, J., Salotti, L., Natalucci, L., Niel, M., Roques, J.P., and Mandrou, P.

Published
1991
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46. First observations with the sigma telescope

Author

Roques, J.P., Mandrou, P., Vedrenne, G., Bouchet, L., Ballet, J., Lambert, A., Paul, J., Salotti, L., Gilfanov, M.R., Sunyaev, R.A., Churazov, E.M., Diachkov, A., Khavenson, N., Kuznetsov, A.V., Stepanov, D., and Yunin, S.

Published
1991
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48. Bending Sensors Based on Thin Films of Semitransparent Bithiophene‐Fulleropyrrolidine Bisadducts.

Author

Chiappara, Clara, Campisciano, Vincenzo, Arrabito, Giuseppe, Errico, Vito, Saggio, Giovanni, Buscarino, Gianpiero, Scopelliti, Michelangelo, Gruttadauria, Michelangelo, Giacalone, Francesco, and Pignataro, Bruno

Subjects
THIN films, VOLTAMMETRY technique, BENT functions, DETECTORS, CYCLIC voltammetry, FULLERENES
Abstract

A novel bithiophene‐fulleropyrrolidine bisadducts system (bis‐Th2PC60) was synthesized and electropolymerized by chronoamperometry onto flexible ITO/PET substrates. The resulting semitransparent thin film was characterized by XPS, FT‐IR, cyclic voltammetry and optical techniques, confirming the good outcome of the electropolymerization process. AFM investigations permitted to highlight an inherent disordered granular morphology, in which the grain‐to‐grain separation depends upon the application of bending. The electrical resistance of the thin film was characterized as a function of bending (in the range 0°–90°), showing promising responsivity to low bending angles (10°–30°). The ΔR/R0 variations turn out to be 8 %,16 % and 20 % for bending angles equal to 10°, 20° and 30°, respectively. This study represents a first step towards the understanding of piezoresistive properties in electropolymerized fullerenes‐based thin films, opening up applications as bending sensor. [ABSTRACT FROM AUTHOR]

Published
2020
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49. The Emission of Terrestrial Gamma Ray Flashes From Encountering Streamer Coronae Associated to the Breakdown of Lightning Leaders.

Author

Köhn, C., Heumesser, M., Chanrion, O., Nishikawa, K., Reglero, V., and Neubert, T.

Subjects
MONTE Carlo method, GAMMA rays, BREMSSTRAHLUNG, THERMAL electrons, EQUATIONS of motion, LIGHTNING, COSMIC rays, PHOTON emission
Abstract

Terrestrial gamma ray flashes (TGFs) are beams of high‐energy photons associated to lightning. These photons are the bremsstrahlung of energetic electrons whose origin is currently explained by two mechanisms: energizing electrons in weak, but large‐scale thundercloud fields or the acceleration of low‐energy electrons in strong, but localized fields of lightning leaders. Contemporary measurements by the Atmosphere‐Space Interactions Monitor suggest that the production of TGFs is related to the leader step and associated streamer coronae when upward moving intracloud lightning illuminates. Based on these observations, we apply a particle‐in‐cell Monte Carlo code tracing electrons in the superposed electric field of two encountering streamer coronae and modeling the subsequent photon emission. We also perform a parameter study by solving the deterministic equations of motion for one electron. We find that this mechanism can explain the occurrence of TGFs with photons energies of several MeV lasting for tens to hundreds of μs, in agreement with observations. Plain Language Summary: For more than two decades, it has been known that thunderstorms emit high‐energy X‐rays and γ rays, the so‐called terrestrial gamma ray flashes (TGFs) lasting for tens to hundreds of μs, which are the bremsstrahlung ("braking radiation") of energetic electrons and are the most energetic natural phenomena on Earth. Within the last years, two theories have been crystallized out to explain the origin of energetic electrons: the acceleration and multiplication of energetic electrons as remnants of cosmic rays in the large‐scale electric fields of thunderclouds or the acceleration of thermal electrons in high electric fields in the vicinity of the tips of lightning leaders. Contemporary measurements of the Atmosphere‐Space Interactions Monitor (ASIM) show that TGFs are produced at the onset of the main optical lightning pulse, indicating that the electron acceleration is related to the upward pointing lighting leader tip. We have performed computational simulations of the electron acceleration in the superposed electric field of two encountering streamer coronae, a compilation of small plasma channels with high‐field tips, arising in the proximity of the lightning leader tip and the upper charge layer. We find that this scenario can explain the occurrence of TGFs with energies and durations compatible with previous and contemporary measurements. Key Points: Relativistic electrons are produced during the breakdown of ICs during a current surge when two streamer coronae approach each otherThe acceleration of electrons between two streamer coronae leads to TGFs lasting for tens to hundreds of μs with photon energies of O(10 MeV)The maximum photon energy in TGFs is determined by the electric field of the upper cloud charge layer [ABSTRACT FROM AUTHOR]

Published
2020
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50. First Measurements of Low‐Frequency Sferics Associated With Terrestrial Gamma‐Ray Flashes Produced by Equatorial Thunderstorms.

Author

Zhang, Hongbo, Lu, Gaopeng, Lyu, Fanchao, Ahmad, Mohd Riduan, Qie, Xiushu, Cummer, Steven A., Xiong, Shaolin, and Briggs, Michael S.

Subjects
THUNDERSTORMS, ATMOSPHERICS, GAMMA ray bursts, RADIO frequency, LIGHT curves, MAGNETIC sensors
Abstract

The low‐frequency (LF) lightning sferics associated with terrestrial gamma‐ray flashes (TGFs) detected by Fermi Gamma‐ray Burst Monitor over equatorial thunderstorms have been recorded at a station in Melaka, Malaysia, since 2017. We examine the LF sferics of two Fermi TGFs, including one TGF‐associated lightning discharge at only about 28 km range. Both TGFs are related to the strongest pulse during the initial stage of their parent intracloud (IC) lightning, while in both cases, the light curve of gamma‐ray photon lags the major lightning pulse by approximately 100 μs. TGF occurred about 3 ms after the lightning initiation when the initial upward negative leader has ascended for about 2 km to reach the height of 10–11 km. Our analyses on a statistical basis show that TGF‐related lightning is mostly located in the strong convection of equatorial thunderstorms at the mature stage, and nearly half TGFs are not produced in the strongest convection region. Plain Language Summary: As one of the effects caused by tropospheric lightning in the near‐Earth space, terrestrial gamma‐ray flashes (TGFs) have been registered as worldwide phenomenon typically associated with deep convection of thunderstorms. Although the equatorial regions appear to be one of the hot spots for the spaceborne observations of TGFs, the ground‐based measurements of TGF‐associated lightning sferics have not been conducted so far near equator. Since the summer of 2017, a low‐frequency (LF) magnetic field sensor has been installed on the campus of Universiti Teknikal Malaysia Melaka to record the radio frequency lightning signal associated with TGFs detected by Fermi. Due to the apparent proximity to the active region of TGF observations, the TGF‐associated lightning signals have been recorded within 200 km for several cases during 2 year operation, including one recorded at a distance as close as 28 km. For another case with TGF‐associated sferics recorded at 270 km range, the progression of negative upward leader can be tracked by examining the sequence of lightning pulses along with their ionospheric reflection. Through individual analysis and statistical research, the types, stages of TGF‐related thunderstorms, and the positions of lightning source relative to storms are discussed in this paper. Key Points: Radio frequency lightning sferics associated with TGFs are measured at range as close as about 28 km with respect to equatorial thunderstormsParent lightning of TGFs in the equatorial area bears the similar progressing features and height of thundercloud top to those at higher latitudesNearly half TGFs are located in the strong but not the strongest convection region of varied‐scale equatorial thunderstorms at the mature stage [ABSTRACT FROM AUTHOR]

Published
2020
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