Search

Your search keyword '"L. Salotti"' showing total 89 results
Start Over Author "L. Salotti"
89 results on '"L. Salotti"'

51. X/γ-ray observation of the crab pulsar with the sigma telescope

Author

A. V. Kuznetsov, A. Diachkov, D. Stepanov, Lorenzo Natalucci, Andrea Goldwurm, L. Salotti, S. Iounin, R. A. Sunyaev, B. Novikov, M. Denis, Sandro Mereghetti, I. Tchoulkov, Laurent Bouchet, N. G. Khavenson, Ph. Laurent, and Francois Lebrun

Subjects
Physics, Atmospheric Science, X-ray astronomy, Crab Pulsar, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Aerospace Engineering, Astronomy, Astronomy and Astrophysics, Astrophysics, Gamma-ray astronomy, Light curve, law.invention, Telescope, Geophysics, Crab Nebula, Pulsar, Space and Planetary Science, Sky, law, General Earth and Planetary Sciences, media_common
Abstract

The region of the sky containing the Crab Nebula and its pulsar was observed by SIGMA several times during February and March, 1990. Data in the energy range 30–1300 keV were recorded in different functioning modes. One observation of ∼ 2 hours in timing mode allowed us to study the pulsed emission from PSR 0531+21. The pulsed signal has been detected up to ∼ 500 keV. We report here the results of the timing and spectral analysis of the data recorded in this observation.

Published
1991

52. First observations with the sigma telescope

Author

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

Subjects
Physics, Atmospheric Science, X-ray astronomy, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Aerospace Engineering, Astronomy, Sigma, Astronomy and Astrophysics, X-ray telescope, Astrophysics, Gamma-ray astronomy, law.invention, Telescope, Geophysics, Space and Planetary Science, law, General Earth and Planetary Sciences
Abstract

The SIGMA telescope has been launched on December 1st 1989. After a calibration period, January and February 1990, the scientific observations started. In this paper, we review the first measurements obtained with SIGMA, and we give the preliminary highlights results obtained in the field of hard X-Ray/Gamma-Ray astronomy.

Published
1991

53. One year of in-orbit operation of the AGILE Payload

Author

C. Pittori, A. Pellizzoni, M. Mastropietro, V. Vittorini, Sandro Mereghetti, A. Giuliani, Marco Feroci, E. Mattaini, G. Di Cocco, Luigi Pacciani, F. Fornari, C. Pontoni, F. Longo, G. Di Persio, F. Viola, A. Zambra, Ennio Morelli, Paolo Soffitta, M. Rapisarda, F. Mauri, Marco Tavani, P. Santolamazza, A. Mauri, A. Rappoldi, F. Boffelli, E. Vallazza, Sergio Colafrancesco, E. Rossi, M. Fiorini, M. Prest, G. Barbiellini, F. Perotti, Alessandro Traci, Martino Marisaldi, Alda Rubini, L. Salotti, P. W. Cattaneo, S. Vercellone, Geiland Porrovecchio, G. Guarrera, G. Piano, E. Del Monte, G. Pucella, Francesco Lazzarotto, V. Cocco, F. Liello, Claudio Labanti, Massimo Frutti, A. Antonelli, I. Donnarumma, Y. Evangelista, P. Giommi, D. Zanello, M. Trifoglio, P. Lipari, I. Lapshov, G. De Paris, B. Preger, P. Picozza, Fulvio Gianotti, A. W. Chen, Alessio Trois, A. Argan, Andrea Bulgarelli, F. Fuschino, P. A. Caraveo, Enrico Costa, T. Froysland, F. D Ammando, A. Morselli, M. Galli, and F. Verrecchia

Subjects
Physics, Physics::Instrumentation and Detectors, business.industry, Payload, Astrophysics::High Energy Astrophysical Phenomena, Detector, Gamma ray, Field of view, Space exploration, Optics, Angular resolution, business, Gamma-ray burst, Image resolution, Remote sensing
Abstract

AGILE, an Italian Space Agency (ASI) mission dedicated to the exploration of the gamma-ray Universe, was successfully launched on April 23, 2007 from the Indian base of Sriharikota in an low-particle background equatorial orbit at 550 km height. AGILE gamma ray range cover the 30 MeV – 50 GeV band with its detectors combined together in the Gamma-Ray Imaging Detector (GRID). An X-ray imager (SuperAGILE) operates in the 18 – 60 keV band. Some of the payload instruments are also operated to detect transient X and gamma events with the main target being the Gamma Ray Burst in the SuperAGILE band and above 300 keV. The GRID instrument consists of a Silicon-Tungsten Tracker, a Caesium Iodide Mini-Calorimeter (MCAL), and a plastic-scintillator Anticoincidence system (ACS). The GRID achieves an angular resolution of about 15’ for bright sources with an unprecedented large field-of-view about 2.5 sr with a time resolution of few microsec and a very reduced dead-time (less than 200 microsec for a gamma detection). The hard X-ray imager (SuperAGILE) combines a tungsten coded mask with Si detector with a technology identical to the Si-Tracker. It is on top of the gamma-ray detector and has an optimal angular resolution (about 6 arcmin) with good sensitivity over about 1 sr field of view (10–15 mCrab on axis for a 1-day integration). The burst monitoring combines the data from SuperAGILE and from MCAL which operates independently with a specific operative mode from 300 keV up to several tens of MeV. All the detector operations are mastered by the Payload Data Handling Unit (PDHU) that includes several operation for data selection and background rejection. AGILE has very innovative scientific payload for what concern both its detectors and its operative mode. After more than one year of in orbit operation the in-flight performances of the instruments as well as the operation of the background reducing algorithm are presented and the main scientific results achieved are discussed.

Published
2008

55. AGILE and the Gamma-Ray Bursts

Author

M. Tavani, A. Argan, G. Barbiellini, A. Bulgarelli, P. Cattaneo, P. Caraveo, A. Chen, E. Costa, G. De Paris, E. Del Monte, G. Di Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, F. Fuschino, M. Galli, F. Gianotti, A. Giuliani, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, A. Morselli, A. Pellizzoni, F. Perotti, P. Picozza, M. Prest, G. Pucella, M. Rapisarda, P. Soffitta, M. Trifoglio, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, A. Zambra, P. Giommi, C. Pittori, B. Preger, F. Verrecchia, L. A. Antonelli, L. Salotti, M. Galassi, David Palmer, and Ed Fenimore

Subjects
Physics, Calorimeter (particle physics), Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astronomy, Field of view, Gamma-ray astronomy, Astrophysics, Universe, Orbit (dynamics), Angular resolution, Satellite, Gamma-ray burst, media_common
Abstract

AGILE is an ASI high‐energy astrophysics mission dedicated to the observation of the Universe. The satellite was successfully launched on April 23, 2007 to a quasi equatorial low‐background orbit. The AGILE instrument is very compact and light (∼100 kg): a gamma‐ray imager (sensitive in the energy band 30 MeV–50 GeV) is the central part of the instrument that includes also a light hard X‐ray imager (18–60 keV) positioned on top of the instrument, and an omnidirectional Calorimeter (350 keV–100 MeV). AGILE is aimed at the study of the most energetic phenomena of our Universe including AGNs, GRBs, Galactic sources and transients. For the first time in gamma‐ray astrophysics, AGILE reaches a field of view of about 3 sr with excellent angular resolution and good sensitivity. The unique combination of a hard X‐ray imager and a gamma‐ray imager is ideal for GRB and transient studies that constitute a crucial part of the AGILE scientific program. We summarize here the main characteristics of the GRB broad‐band d...

Published
2008

58. Technological spin-offs of the PMST program of the Italian. Space agency (ASI)

Author

R. Stalio, Simona Zoffoli, L. Salotti, C. Bonifazi, Giovanni F. Bignami, F. Svelto, C. Musso, E. D'Aversa, and S. Di Pippo

Subjects
Engineering, Earth observation, Space technology, business.industry, Observatory, Agency (sociology), Electrical engineering, Space (commercial competition), business, Telecommunications, Aerospace, Phase (combat), Agile software development
Abstract

ASI Small ("Piccole") Missions for Science and Technology (PMST) have been running full speed ahead for four years already. The program is one of Italy's responses to the general call, by the Space Agencies, for challenging science missions that are also a good opportunity for new advancements in space technology and in the related technology transfer. Both research institutes and industries are asked to cooperate in the program. Another goal of the program is to demonstrate ASI's capability of launching a scientific/technological satellite every two years with the objective of doubling launching frequency by 2005. Currently ASI has two PMST already approved and in advanced development phases: AGILE and DAVID. The former is a /spl gamma/-ray observatory, which uses innovative photon detectors developed in Italian centers; the latter a dedicated TLC program operating at very high frequencies: 80-100 GHz. A third PMST, for Earth observation science, will be selected by the end of the year, out of five preselected proposals which have been funded for Phase A study.

Published
2003

59. AGILE detection of GeV $\sf$γ-ray emission from the SNR W28

Author

A. Giuliani, M. Tavani, A. Bulgarelli, E. Striani, S. Sabatini, M. Cardillo, Y. Fukui, A. Kawamura, A. Ohama, N. Furukawa, K. Torii, H. Sano, F. A. Aharonian, F. Verrecchia, A. Argan, G. Barbiellini, P. A. Caraveo, P. W. Cattaneo, A. W. Chen, V. Cocco, E. Costa, F. D'Ammando, E. Del Monte, G. De Paris, G. Di Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, M. Fiorini, T. Froysland, F. Fuschino, M. Galli, F. Gianotti, C. Labanti, Y. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, A. Morselli, E. Moretti, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, M. Pilia, M. Prest, G. Pucella, M. Rapisarda, A. Rappoldi, P. Soffitta, M. Trifoglio, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, A. Zambra, D. Zanello, C. Pittori, P. Santolamazza, P. Giommi, S. Colafrancesco, L. Salotti, A., Giuliani, M., Tavani, A., Bulgarelli, E., Striani, S., Sabatini, M., Cardillo, Y., Fukui, A., Kawamura, A., Ohama, N., Furukawa, K., Torii, H., Sano, F. A., Aharonian, F., Verrecchia, A., Argan, G., Barbiellini, P. A., Caraveo, P. W., Cattaneo, A. W., Chen, V., Cocco, E., Costa, F., D'Ammando, E. D., Monte, G. D., Pari, G. D., Cocco, I., Donnarumma, Y., Evangelista, M., Feroci, M., Fiorini, T., Froysland, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, Y., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, A., Morselli, E., Moretti, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, P., Giommi, S., Colafrancesco, L., Salotti, Giuliani A, Tavani M, Bulgarelli A, Striani E, Sabatini S, Cardillo M, Fukui Y, Kawamura A, Ohama A, Furukawa N, Torii K, Sano H, Aharonian FA, Verrecchia F, Argan A, Barbiellini G, Caraveo PA, Cattaneo PW, Chen AW, Cocco V, Costa E, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Donnarumma I, Evangelista Y, Feroci M, Fiorini M, Froysland T, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov Y, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mereghetti S, Morselli A, Moretti E, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Soffitta P, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Pittori C, Santolamazza P, Giommi P, Colafrancesco S, and Salotti L

Subjects
Supernova Remnants, Supernova, Astrophysics::High Energy Astrophysical Phenomena, Hadron, acceleration of particles – diffusion – ISM: supernova remnants – gamma rays: ISM, FOS: Physical sciences, Flux, Cosmic ray, Astrophysics, AGILE, galactic cosmic rays, High Energy Gamma-ray Astronomy, Spectral line, law.invention, Telescope, law, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Molecular cloud, AGILE satellite, Gamma ray, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Supernova remnants (SNRs) are believed to be the main sources of Galactic cosmic rays. Molecular clouds associated with SNRs can produce gamma-ray emission through the interaction of accelerated particles with the concentrated gas. The middle aged SNR W28, for its associated system of dense molecular clouds, provides an excellent opportunity to test this hypothesis. We present the AGILE/GRID observations of SNR W28, and compare them with observations at other wavelengths (TeV and 12CO J=1-->0 molecular line emission). The gamma-ray flux detected by AGILE from the dominant source associated with W28 is (14 +- 5) 10^-8 ph cm^-2 s^-1 for E > 400 MeV. This source is positionally well correlated with the TeV emission observed by the HESS telescope. The local variations of the GeV to TeV flux ratio suggest a difference between the CR spectra of the north-west and south molecular cloud complexes. A model based on a hadronic-induced interaction and diffusion with two molecular clouds at different distances from the W28 shell can explain both the morphological and spectral features observed by AGILE in the MeV-GeV energy range and by the HESS telescope in the TeV energy range. The combined set of AGILE and H.E.S.S. data strongly support a hadronic model for the gamma-ray production in W28., Accepted for publication in Astronomy & Astrophysics Letters

Published
2010

61. SIGMA observation of the sky region containing the COS-B source 2CG135+01

Author

Jacques Paul, N. G. Khavenson, M. Niel, E. Churazov, L. Bouchet, B. Novikov, A. Diachkov, I. Chulkov, R. Sunyaev, L. Natalucci, M. Gilfanov, J. Ballet, L. Salotti, Y. Gaigé, Francois Lebrun, and A. Kuznetsov

Subjects
Physics, High energy, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astronomy, Sigma, Quasar, Gamma ray spectra, Astrophysics, Sky, Angular resolution, Emission spectrum, Gamma-ray burst, media_common
Abstract

The region of the sky containing the high energy gamma‐ray source 2CG 135+01 was observed by SIGMA on 1990, July 28–30th. The images obtained were searched for positive emission from the known candidate counterparts. No significant excess was detected. Upper limits in the hard X‐ray range are presented and discussed in the light of the present observational status.

Published
1991

62. SIGMA results on the fast variability of Cyg X-1 in the hard x-ray/gamma-ray energy band

Author

S. Bonazzola, R. Sunyaev, Alyn Lambert, A. Kuznetzov, I. Chulkov, L. Salotti, M. Gilfanov, E. Churazov, N. Khavenson, A. Goldwurm, J. P. Roques, B. Novikov, A. V. Dyachkov, S. Mereghetti, B. Cordier, and P. Mandrou

Subjects
Physics, Millisecond, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Sigma, Astronomy, X-ray telescope, Astrophysics, law.invention, Telescope, Pulsar, law, Binary star, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum
Abstract

The black‐hole candidate Cyg X‐1 has been one of the first targets of the SIGMA γ‐ray telescope on board the Soviet GRANAT spacecraft. SIGMA, an imaging telescope based on the coded mask principle, operates in the 35 keV‐1.3 MeV energy range and, when used in ‘‘fast variability’’ mode, has a time resolution of one millisecond. We present here the preliminary results of a ‘‘fast variability’’ observation of Cyg X‐1 performed in March 1990.

Published
1991

63. GRANAT images of the Galactic Center region in 4–1300 keV band: Localization of the possible candidate for 511 keV source

Author

A. Kuznetsov, I. Dekhanov, L. Salotti, M. Pavlinsky, S. Grebenev, P. Mandrou, E. Churazov, R. Sunyaev, J. Paul, N. Yamburenko, M. Niel, J. Ballet, M. Gilfanov, Ph. Laurent, J. P. Roques, and L. Natalucci

Subjects
Physics, Black hole, Neutron star, Annihilation, Astrophysics::High Energy Astrophysical Phenomena, Galactic Center, Astronomy, Astrophysics, Emission spectrum, Gamma-ray astronomy, Astrophysics::Galaxy Astrophysics, Spectral line, Astronomical spectroscopy
Abstract

The most important results of the Galactic Center observations by GRANAT during 1990 are: discovery of new very hard X‐ray source GRS1758–258 in 40 arcmin from GX5‐1, strong variability of Sgr A* in 4–30 keV energy range, unambiguous detection of 1E1740.7–2942 as the brightest hard X‐ray source in the vicinity of the Galactic Center and discovery of the variable hard component in its spectrum. The shape of the latter allows one to suppose the relation of this component with electron‐positron annihilation. The hardness of the spectra of both 1E1740.7–2942 and GRS1758–258 gives strong arguments to include them to the list of black hole candidates.

Published
1991

64. Discovery of a low-frequency broad quasi-periodic oscillation peak in the power density spectrum of Cygnus X-1 with Granat/SIGMA

Author

J. Ballet, K. Sukhanov, J. P. Roques, Arnaud Claret, P. Mandrou, E. M. Churazov, N. G. Khavenson, J. F. Olive, Alexey Vikhlinin, R.S. Kremnev, A. V. Dyachkov, M. Denis, R. A. Sunyaev, P. Laurent, Marat Gilfanov, and L. Salotti

Subjects
Physics, X-ray astronomy, Quasi-periodic oscillation, Space and Planetary Science, Spectrum (functional analysis), Granat, Sigma, Astronomy and Astrophysics, Astrophysics, Low frequency, Power density
Published
1994

65. Sigma hard X-ray observations of GX 339-4 during the hard state and a transition to the soft state

Author

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

Subjects
Physics, X-ray astronomy, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, Astronomy, Astronomy and Astrophysics, Astrophysics, Astronomical spectroscopy, law.invention, Telescope, Space and Planetary Science, Observatory, law, Binary star, Emission spectrum, Main sequence
Abstract

The X-ray system GX 339-4 has been observed (more than 135 hr), between 1990 March and 1991 September, with the SIGMA hard X-ray/soft γ-ray (35 keV-1.3 MeV) imaging telescope on board the GRANAT observatory. In particular, the 1991 outburst has been well covered by SIGMA. The source stayed in a hard state during more than 3 weeks with an intensity greater than 380 mCrab up to 350 keV. Then, the last two observations performed on 1991 September 28 and October 5 revealed that the source had begun a transition from the hard to the soft state, as the intensity in the 35-230 keV band decreased below 100 mCrab. In the hard state, the spectra we observe are usually compatible with a power law of index ∼2.2. During the transition phase, this index rises to ∼3

Published
1993

66. Discovery with the Sigma telescope of hard X-rays from the globular cluster Terzan 2

Author

A. V. Dyachkov, I. Chulkov, L. Salotti, R. A. Sunyaev, Ph. Laurent, A. Kuznetzov, Sandro Mereghetti, E. M. Churazov, N. G. Khavenson, Francois Lebrun, J. P. Roques, Didier Barret, M. Gifanov, J. Ballet, P. Mandrou, and B. Novikov

Subjects
Physics, Range (particle radiation), Astrophysics::High Energy Astrophysical Phenomena, Galactic Center, X-ray binary, Sigma, Astronomy, Astronomy and Astrophysics, Astrophysics, law.invention, Telescope, Neutron star, Space and Planetary Science, law, Globular cluster, Emission spectrum, Astrophysics::Galaxy Astrophysics
Abstract

During the survey of the Galactic center performed with the Sigma hard X-ray/soft gamma-ray telescope, a new source has been discovered in the 35−200 keV energy range. The location of the source is consistent with the position of the globular cluster Terzan 2. Although we also discuss other possibilities, it is likely that the hard X-rays emission originates in X1724−308 (4U 1724−30), a source of X-ray bursts located in the globular cluster. Under this assumption, it would be the first detection of a low-mass X-ray binary in this energy range

Published
1991

67. Sigma observation of the pulsar OAO 1657 - 415: Precise localization at hard X-ray energy and discovery of spin-down

Author

N. Khavenson, P. Mandrou, A. V. Kuznetsov, R. A. Sunyaev, Marat Gilfanov, Lorenzo Natalucci, L. Salotti, Alyn Lambert, J. Ballet, G. Babalyan, J. A. Paul, S. Yunin, E. M. Churazov, J. P. Roques, Sandro Mereghetti, and D. Stepanov

Subjects
Physics, Accretion (meteorology), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, X-ray binary, Astronomy, Astronomy and Astrophysics, Astrophysics, law.invention, Luminosity, Telescope, Stars, Neutron star, Pulsar, Space and Planetary Science, law, Binary star
Abstract

The region of sky containing the 38 s X-ray pulsar OAO 1657 - 415 has been observed on March 1990 with Sigma, an imaging gamma-ray telescope exploiting the coded mask technique. This observation has yielded an accurate (about arcminute-scale) localization for OAO 1657 - 415 at hard X-ray energy, confirming its association with a previously suggested soft X-ray candidate. A timing analysis of the 40-120 keV data has revealed for the first time a spin-down episode in OAO 1657 - 415, implying that an important change in the accretion torque experienced by this X-ray pulsar must have recently occurred. 18 refs.

Published
1991

68. Evidence for an increasing 59 s period in the X-ray emission from Geminga

Author

L. Salotti, Giovanni F. Bignami, and P. A. Caraveo

Subjects
Physics, X-ray astronomy, Period (periodic table), Einstein Telescope, X-ray, Astronomy, Astrophysics, Gamma-ray astronomy, Light curve
Abstract

Einstein Observatory and EXOSAT X-ray data from 1E0630+178 reveal a ∼50% periodic emission at ≳59s. This confirms the early SAS-II and COS-B findings on 2CG 195+04 atE>50 MeV and provides the temporal signature for the identification of Geminga. The observations, spanning over a decade (1973–1983), also suggest a very high positive $$\dot P$$ which has become still higher in 1979–1983.

Published
1984

69. The EXOSAT and Einstein observations of 1E0630+178 («Geminga») as complementary data sets

Author

Sandro Mereghetti, P. A. Caraveo, L. Salotti, and Giovanni F. Bignami

Subjects
Physics, X-ray astronomy, symbols.namesake, symbols, High resolution, Astronomy, Cosmic ray, Scale (descriptive set theory), Astrophysics, Einstein
Abstract

Data for the soft X-ray source 1E0630+178 are now available from four independent measurements of the Einstein and EXOSAT missions. These are presented and compared in the light of the different characteristics and energy response of the different X-ray imaging detectors used (IPC, LE 1, LE 2). The time variability on medium (∼ hours) time scale is also investigated.

Published
1984

70. X-ray and optical variability at the hour timescale for 1E 0630+178 (GEMINGA) and its proposed optical couterpart

Author

Giovanni F. Bignami, L. Salotti, P. Delache, Jacques Paul, L. Vigroux, and P. A. Caraveo

Subjects
Physics, 3D optical data storage, X-ray, Astronomy, Astronomy and Astrophysics, Gamma ray spectra, Astrophysics, law.invention, Telescope, Space and Planetary Science, law, Spectral energy distribution, Spectrum analysis, X ray spectra
Abstract

Einstein and EXOSAT data on the soft X-ray source 1E 0630+178, the proposed counterpart of the γ-ray source GEMINGA, are analyzed for variability on the time scale of one to three hours. The EXOSAT September 1983 data, with an uninterrupted strech of over 10 hours offer the most interesting case. In parallel, a similar analysis is presented for the first time, for the optical data of the mV-21 proposed counterpart. About 30 CCD exposures, of 15 min. each, taken over two consecutive nights at the 3.6 m CFH telescope, yield evidence of variability, when compared to the data of similar nearby objects in the field.

Published
1985

71. An updated list of AGILE bright gamma-ray sources and their variability in pointing mode

Author

L. Salotti, A. Trois, E. Mattaini, G. Di Cocco, Francesco Lucarelli, F. Gianotti, G. Barbiellini, R. Primavera, A. Rubini, F. Mauri, M. Prest, Alessandro Traci, F. Perotti, P. A. Caraveo, I. Donnarumma, Y. Evangelista, E. Moretti, Massimo Frutti, G. Valentini, Claudio Labanti, F. Liello, F. Fornari, L. A. Antonelli, G. De Paris, C. Pittori, M. Tavani, D. Zanello, F. Lazzarotto, G. Di Persio, L. Pacciani, A. Rappoldi, T. Froysland, G. Fanari, Martino Marisaldi, F. Fuschino, Geiland Porrovecchio, A. Argan, A. Morselli, P. Giommi, M. Pilia, P. Lipari, Andrea Bulgarelli, V. Cocco, S. Stellato, C. Pontoni, E. Morelli, M. Trifoglio, F. Longo, P. Picozza, E. Striani, S. Vercellone, T. Contessi, G. Piano, A. W. Chen, I. Lapshov, E. Del Monte, G. Pucella, S. Sabatini, A. Mauri, Sandro Mereghetti, A. Pellizzoni, E. Costa, M. Feroci, A. Giuliani, M. Fiorini, Elena M. Rossi, S. Colafrancesco, M. Mastropietro, V. Vittorini, M. Cardillo, Arnaud Ferrari, P. Santolamazza, P. W. Cattaneo, M. Rapisarda, P. Soffitta, E. Vallazza, M. Galli, F. Tamburelli, F. Verrecchia, F., Verrecchia, C., Pittori, A. W., Chen, A., Bulgarelli, M., Tavani, F., Lucarelli, P., Giommi, S., Vercellone, A., Pellizzoni, A., Giuliani, Longo, Francesco, BARBIELLINI AMIDEI, Guido, M., Trifoglio, F., Gianotti, A., Argan, L. A., Antonelli, P., Caraveo, M., Cardillo, P. W., Cattaneo, V., Cocco, S., Colafrancesco, T., Contessi, E., Costa, E., Del Monte, G., De Pari, G., Di Cocco, G., Di Persio, I., Donnarumma, Y., Evangelista, G., Fanari, M., Feroci, A., Ferrari, M., Fiorini, F., Fornari, F., Fuschino, T., Froysland, M., Frutti, M., Galli, C., Labanti, I., Lapshov, F., Lazzarotto, F., Liello, P., Lipari, E., Mattaini, M., Marisaldi, M., Mastropietro, A., Mauri, F., Mauri, S., Mereghetti, E., Morelli, Moretti, Elena, A., Morselli, L., Pacciani, F., Perotti, G., Piano, P., Picozza, M., Pilia, C., Pontoni, G., Porrovecchio, M., Prest, R., Primavera, G., Pucella, M., Rapisarda, A., Rappoldi, E., Rossi, A., Rubini, S., Sabatini, P., Santolamazza, P., Soffitta, S., Stellato, E., Striani, F., Tamburelli, A., Traci, A., Troi, E., Vallazza, V., Vittorini, D., Zanello, L., Salotti, and G., Valentini

Subjects
catalog, Brightness, FOS: Physical sciences, Field of view, Astrophysics, gamma-ray source, gamma rays: galaxies, galaxie [gamma rays], Blazar, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Nebula, Crab Pulsar, Mode (statistics), Gamma ray, Astronomy and Astrophysics, gamma rays: general, Galactic plane, silicon tracker, AGILE satellite, Space and Planetary Science, catalogs, Astrophysics - High Energy Astrophysical Phenomena, general [gamma rays]
Abstract

We present a variability study of a sample of bright gamma-ray (30 MeV -- 50 GeV) sources. This sample is an extension of the first AGILE catalogue of gamma-ray sources (1AGL), obtained using the complete set of AGILE observations in pointing mode performed during a 2.3 year period from July 9, 2007 until October 30, 2009. The dataset of AGILE pointed observations covers a long time interval and its gamma-ray data archive is useful for monitoring studies of medium-to-high brightness gamma-ray sources. In the analysis reported here, we used data obtained with an improved event filter that covers a wider field of view, on a much larger (about 27.5 months) dataset, integrating data on observation block time scales, which mostly range from a few days to thirty days. The data processing resulted in a better characterized source list than 1AGL was, and includes 54 sources, 7 of which are new high galactic latitude (|BII| >= 5) sources, 8 are new sources on the galactic plane, and 20 sources from the previous catalogue with revised positions. Eight 1AGL sources (2 high-latitude and 6 on the galactic plane) were not detected in the final processing either because of low OB exposure and/or due to their position in complex galactic regions. We report the results in a catalogue of all the detections obtained in each single OB, including the variability results for each of these sources. In particular, we found that 12 sources out of 42 or 11 out of 53 are variable, depending on the variability index used, where 42 and 53 are the number of sources for which these indices could be calculated. Seven of the 11 variable sources are blazars, the others are Crab pulsar+nebula, LS I +61{\deg}303, Cyg X-3, and 1AGLR J2021+4030., Comment: 30 pages, 12 figures

72. GRB 070724B: the first Gamma Ray Burst localized by SuperAGILE

Author

E. Del Monte, E. Costa, I. Donnarumma, Y. Evangelista, M. Feroci, I. Lapshov, F. Lazzarotto, M. Rapisarda, P. Soffitta, A. Argan, G. Barbiellini, M. Basset, A. Bulgarelli, P. Caraveo, A. Chen, G. Di Cocco, L. Foggetta, F. Fuschino, M. Galli, F. Gianotti, A. Giuliani, C. Labanti, P. Lipari, F. Longo, M. Marisaldi, F. Mauri, S. Mereghetti, A. Morselli, A. Pellizzoni, F. Perotti, P. Picozza, M. Prest, G. Pucella, M. Tavani, M. Trifoglio, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, A. Zambra, P. Romano, D. N. Burrows, G. Chincarini, N. Gehrels, V. La Parola, P. T. O'Brien, J. P. Osborne, B. Preger, C. Pittori, L. A. Antonelli, F. Verrecchia, P. Giommi, L. Salotti, M. Galassi, David Palmer, and Ed Fenimore

Subjects
Physics, Swift Gamma-Ray Burst Mission, Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Gamma ray spectra, Astrophysics, Gamma-ray burst, Gamma detection
Abstract

GRB070724B is the first Gamma Ray Burst localized by the SuperAGILE instrument aboard the AGILE space mission. The SuperAGILE localization has been confirmed after the after‐glow observation by the XRT aboard the Swift satellite. No significant gamma ray emission above 50 MeV has been detected for this GRB. In this paper we describe the SuperAGILE capabilities in detecting Gamma Ray Burst and the AGILE observation of GRB 070724B.

73. Gamma-ray localization of terrestrial gamma-ray flashes

Author

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

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, Agile, Photon, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Attenuation, Gamma ray, FOS: Physical sciences, General Physics and Astronomy, minicalorimeter, terrestrial gamma-ray flashes, Astrophysics, Electromagnetic radiation, Particle detector, Semiconductor detector, Physics - Atmospheric and Oceanic Physics, Atmosphere of Earth, Optics, Terrestrial Gamma-Ray Flashes, Atmospheric and Oceanic Physics (physics.ao-ph), Satellite, business, Astrophysics - Earth and Planetary Astrophysics
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 degrees at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the sub-satellite 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., Comment: 5 pages, 4 figures, 1 table, available at http://prl.aps.org/abstract/PRL/v105/i12/e128501

74. The status of the AGILE GRB observations and the noticeable case of GRB 080514B

Author

E. Del Monte, E. Costa, I. Donnarumma, Y. Evangelista, F. Fornari, F. Fuschino, M. Galli, A. Giuliani, I. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, E. Moretti, L. Pacciani, M. Rapisarda, P. Soffitta, S. Vercellone, A. Argan, G. Barbiellini, A. Bulgarelli, P. Caraveo, P. W. Cattaneo, A. Chen, G. Di Cocco, M. Feroci, F. Gianotti, C. Labanti, A. Morselli, A. Pellizzoni, F. Perotti, G. Piano, P. Picozza, M. Prest, G. Pucella, A. Rappoldi, S. Sabatini, M. Tavani, M. Trifoglio, A. Trois, E. Vallazza, V. Vittorini, B. Preger, C. Pittori, L. Salotti, Charles Meegan, Chryssa Kouveliotou, and Neil Gehrels

Subjects
Physics, Scintillation, Astrophysics::High Energy Astrophysical Phenomena, Scintillation counter, Detector, Gamma ray, Astronomy, Field of view, Context (language use), Astrophysics, Gamma-ray burst, Afterglow
Abstract

Since Summer 2007, the AGILE mission is successfully detecting and localizing Gamma Ray Bursts by using its wide‐field hard X‐ray monitor SuperAGILE (17–60 keV) and its CsI Minicalorimeter (0.3–20 MeV). Moreover, all the events with a known localization in the field of view of the Gamma Ray Imaging Detector are searched for in the 30 MeV–50 GeV energy range. Among the several bursts occurred in the field of view of the Gamma Ray Imaging Detector during more than one year of operations, at the time of writing the remarkable GRB 080514B is detected at high significance and GRB 080721 and GRB 081001 are detected at low significance. GRB 080514B is the first Gamma Ray Burst showing a significant emission above 20 MeV after EGRET, and the first ever associated with an afterglow, measured at X‐rays and in the IR/Optical/UV. Significant upper limits are derived for the other GRBs. In this paper we report about the status and the scientific performances of the AGILE instrumentation in the study of GRBs and we discuss the properties of GRB 080514B in the context of the long Gamma Ray Bursts.

75. Search for Very Short Bursts with the AGILE Mini-Calorimeter

Author

M. Marisaldi, C. Labanti, F. Fuschino, M. Galli, A. Argan, G. Barbiellini, F. Boffelli, A. Bulgarelli, P. Caraveo, P. W. Cattaneo, A. Chen, E. Costa, F. D’Ammando, E. Del Monte, G. Di Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, F. Fornari, F. Gianotti, A. Giuliani, I. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, S. Mereghetti, E. Moretti, A. Morselli, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, M. Prest, G. Pucella, M. Rapisarda, A. Rappoldi, P. Soffitta, M. Tavani, M. Trifoglio, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, C. Pittori, L. A. Antonelli, S. Cutini, D. Gasparrini, P. Giommi, B. Preger, P. Santolamazza, F. Verrecchia, L. Salotti, Charles Meegan, Chryssa Kouveliotou, and Neil Gehrels

Subjects
Physics, business.industry, Time windows, Telemetry, Real-time computing, Astronomy, Geophysical Phenomena, Gamma-ray burst, Gamma detection, business, Calorimeter, Agile software development, Data transmission
Abstract

In this paper the results of the first months of burst search on very short time scales with the Mini‐Calorimeter (MCAL) on‐board the AGILE mission are presented. MCAL is equipped with a flexible on‐board trigger logic for autonomous GRB detection. In addition to standard trigger time windows, MCAL has been equipped with trigger capabilities on 16 ms, 1 ms and sub‐millisecond time windows. Since June 2008 burst search on these short time scales has been enabled, resulting in an average rate of 4 triggers/orbit, compliant with telemetry budget. An on‐ground rejection strategy is applied, allowing more sophisticated selection criteria than those allowed by the on‐board trigger logic. Triggers due to instrumental effects or geophysical phenomena can be spotted due to their photon‐by‐photon pattern; what remains after this cleaning is an almost unexplored territory and could shed light on the origin of very short bursts. The trigger criteria, as well as the on‐ground rejection strategy and the properties of the selected events will be described and discussed.

76. A deep optical study of the field of IE 0630 + 178

Author

J. A. Paul, L. Vigroux, L. Salotti, P. A. Caraveo, and Giovanni F. Bignami

Subjects
Physics, Proper motion, Field (physics), Hertzsprung–Russell diagram, Astronomy, Astronomy and Astrophysics, Astrophysics, Electromagnetic radiation, Spectral line, Astronomical spectroscopy, symbols.namesake, Neutron star, Space and Planetary Science, Position (vector), symbols
Abstract

A further optical/IR investigation of the HRI error-box of the X-ray source 1E 0630 + 178, proposed as the counterpart of Geminga (2CG 195 + 04), is presented. After recognizing that the previously suggested m of about 21 object (also called a G candidate) is probably excluded by the recent data, deep CCD data of the region are presented and the two very faint objects which appear compatible with the X-ray position are discussed. No evidence of proper motion is seen, contrary to previous reports. Possible interpretations of this peculiar L(x)/L(v) greater than 1000 X-ray source are then discussed, in the light of the gamma-ray emission. 22 references.

Published
1987

77. Calibration of AGILE-GRID with in-flight data and Monte Carlo simulations

Author

F. Perotti, Ennio Morelli, Massimiliano Fiorini, Sandro Mereghetti, G. Valentini, P. W. Cattaneo, E. Moretti, C. Pittori, A. Rappoldi, V. Vittorini, P. Santolamazza, T. Contessi, G. De Paris, E. Vallazza, Francesco Longo, Fulvio Gianotti, I. Donnarumma, M. Trifoglio, A. Pellizzoni, M. Galli, Piergiorgio Picozza, M. Giusti, Alda Rubini, G. Piano, Paolo Giommi, A. Morselli, Y. Evangelista, F. Verrecchia, G. Di Cocco, Francesco Lazzarotto, E. Striani, Attilio Ferrari, Valentina Fioretti, Marco Tavani, S. Sabatini, Paolo Lipari, A. Argan, Maura Pilia, I. Lapshov, F. Lucarelli, Sergio Colafrancesco, Guido Barbiellini, E. Del Monte, Martino Marisaldi, G. Pucella, Massimo Rapisarda, Alessio Trois, F. Fuschino, Andrea Bulgarelli, M. Prest, D. Zanello, Enrico Costa, C. Labanti, A. Giuliani, P. A. Caraveo, A. W. Chen, S. Vercellone, Marco Feroci, Luigi Pacciani, Paolo Soffitta, Rapisarda, M., Pucella, G., Tadayuki Takahashi, Stephen S. Murray, Jan-Willem A. den Herder, A. W., Chen, A., Argan, A., Bulgarelli, P. W., Cattaneo, A., Giuliani, C., Pittori, G., Pucella, M., Tavani, A., Troi, G., Barbiellini, P., Caraveo, S., Colafrancesco, E., Costa, Paris, G., Monte, E., Cocco, G., I., Donnarumma, Y., Evangelista, A., Ferrari, M., Feroci, M., Fiorini, F., Fuschino, M., Galli, F., Gianotti, P., Giommi, M., Giusti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, F., Lucarelli, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Santolamazza, P., Soffitta, E., Striani, M., Trifoglio, L., Salotti, E., Vallazza, S., Vercellone, F., Verrecchia, V., Vittorini, D., Zanello, T., Contessi, BARBIELLINI AMIDEI, Guido, G., De Pari, E., Del Monte, G., Di Cocco, V., Fioretti, Moretti, Elena, and G., Valentini

Subjects
Photon, Monte Carlo method, X-ray telescope, techniques: image processing, Astrophysics, telescope, Orbital mechanics, Vela, High Energy Gamma-ray Astronomy, law.invention, law, imaging detector, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Instrumentation: detector, image processing [techniques], detector [instrumentation], Detector, agile, Astrophysics::Instrumentation and Methods for Astrophysics, Calibrations, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Interpolation, Point spread function, gamma ray source, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Telescope, Optics, data analysis [methods], Calibration, instrumentation: detectors, gamma rays: general, telescopes, methods: data analysis, Instrumentation and Methods for Astrophysics (astro-ph.IM), business.industry, Astronomy and Astrophysics, Kalman filter, calibration, silicon tracker, Computational physics, Space and Planetary Science, Gamma rays: general, Instrumentation: detectors, Methods: data analysis, Techniques: image processing, Telescopes, Orbit (dynamics), AGILE satellite, business, general [gamma rays], Methods: data analysi
Abstract

Context: AGILE is a gamma-ray astrophysics mission which has been in orbit since 23 April 2007 and continues to operate reliably. The gamma-ray detector, AGILE-GRID, has observed Galactic and extragalactic sources, many of which were collected in the first AGILE Catalog. Aims: We present the calibration of the AGILE-GRID using in-flight data and Monte Carlo simulations, producing Instrument Response Functions (IRFs) for the effective area A_eff), Energy Dispersion Probability (EDP), and Point Spread Function (PSF), each as a function of incident direction in instrument coordinates and energy. Methods: We performed Monte Carlo simulations at different gamma-ray energies and incident angles, including background rejection filters and Kalman filter-based gamma-ray reconstruction. Long integrations of in-flight observations of the Vela, Crab and Geminga sources in broad and narrow energy bands were used to validate and improve the accuracy of the instrument response functions. Results: The weighted average PSFs as a function of spectra correspond well to the data for all sources and energy bands. Conclusions: Changes in the interpolation of the PSF from Monte Carlo data and in the procedure for construction of the energy-weighted effective areas have improved the correspondence between predicted and observed fluxes and spectra of celestial calibration sources, reducing false positives and obviating the need for post-hoc energy-dependent scaling factors. The new IRFs have been publicly available from the Agile Science Data Centre since November 25, 2011, while the changes in the analysis software will be distributed in an upcoming release.

Published
2013

78. 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

79. 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

80. High spatial resolution correlation of AGILE TGFs and global lightning activity above the equatorial belt

Author

Fuschino F, Marisaldi M, Labanti C, Barbiellini G, Del Monte E, Bulgarelli A, Trifoglio M, Gianotti F, Galli M, Argan A, Trois A, Tavani M, Moretti E, Giuliani A, Longo F, Costa E, Caraveo P, Cattaneo PW, Chen A, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, 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, Salotti L., D'AMMANDO, FILIPPO, F., Fuschino, M., Marisaldi, C., Labanti, G., Barbiellini, Monte, E., A., Bulgarelli, M., Trifoglio, F., Gianotti, M., Galli, A., Argan, A., Troi, M., Tavani, E., Moretti, A., Giuliani, Longo, Francesco, E., Costa, P., Caraveo, P. W., Cattaneo, A., Chen, F., D'Ammando, Paris, G., Cocco, G., Persio, G., I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, I., Lapshov, F., Lazzarotto, P., Lipari, S., Mereghetti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, G., Piano, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, E., Striani, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, L. A., Antonelli, S., Colafrancesco, S., Cutini, P., Giommi, F., Lucarelli, C., Pittori, P., Santolamazza, F., Verrecchia, L., Salotti, Fuschino F, Marisaldi M, Labanti C, Barbiellini G, Del Monte E, Bulgarelli A, Trifoglio M, Gianotti F, Galli M, Argan A, Trois A, Tavani M, Moretti E, Giuliani A, Longo F, Costa E, Caraveo P, Cattaneo PW, Chen A, DAmmando F, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, 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

Subjects
AGILE satellite, terrestrial gamma ray flashes, CsI calorimeter, satellite optical observations, global lightning, Atmospheric Processes: Lightning, Lightning [Atmospheric Processes], Atmospheric Processes: Atmospheric electricity, AGILE, TGF, global lightning activity, Atmospheric electricity [Atmospheric Processes]
Abstract

The AGILE satellite detects Terrestrial Gamma-ray Flashes (TGFs) in the 0.35-100 MeV energy range using its Mini-Calorimeter (MCAL) instrument with an average detection rate of 10 TGFs/month. Thanks to its Low Earth Orbit with only 2.5 degree of inclination, AGILE guarantees an unprecedented exposure above the equator, where both lightning activity and TGF detection peak. Here we report the comparison between the AGILE TGFs detected between March 2009 and February 2010 and full climatology lightning worldwide distribution based on satellite optical observations from LIS (Lightning Imaging Sensor) and OTD (Optical Transient Detector) instruments. This approach is complementary to the one-to-one TGF/lightning correlations by ground-based sferics measurements. Based on mono and bi-dimensional Kolmogorov-Smirnov tests, we show that the AGILE TGFs and time-averaged global lightning in the equatorial area are not drawn from the same distribution. However, we find significant regional differences in the degree of correlation as well as in the TGF/lightning ratio. In the case of south east Asia we find a 87% probability for the TGF and lightning being samples of the same distribution. This result supports the idea that the physical conditions at play in TGF generation can have strong geographical and climatological modulation. Based on the assumption that the observed range of TGF/flash ratio holds at all latitudes we can estimate a global rate of (N) over dot similar or equal to 220 divided by 570 TGFs per day. The observed TGF/flash geographical modulation as well as the TGF global rate estimate are in agreement with previous observations. Citation: Fuschino, F., et al. (2011), High spatial resolution correlation of AGILE TGFs and global lightning activity above the equatorial belt, Geophys. Res. Lett., 38, L14806, doi:10.1029/2011GL047817.

Published
2011

81. 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

82. The AGILE Mission

Author

Tavani M, Barbiellini G, Argan A, Boffelli F, Bulgarelli A, Caraveo P, Cattaneo PW, Chen AW, Cocco V, Costa E, Del Monte E, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Fornari F, Fuschino F, Froysland T, Frutti M, Galli M, Gianotti F, Giuliani A, Labanti C, Lapshov I, Lazzarotto F, Liello F, Lipari P, Longo F, Mattaini E, Marisaldi M, Mastropietro M, Mauri A, Mauri F, Mereghetti S, Morelli E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Piano G, Picozza P, Pontoni C, Porrovecchio G, Prest M, Pucella G, Rapisarda M, Rappoldi A, Rossi E, Rubini A, Soffitta P, Traci A, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Pittori C, Preger B, Santolamazza P, Verrecchia F, Giommi P, Colafrancesco S, Antonelli A, Cutini S, Gasparrini D, Stellato S, Fanari G, Primavera R, Tamburelli F, Viola F, Guarrera G, Salotti L, D'Amico F, Marchetti E, Crisconio M, Sabatini P, Annoni G, Alia S, Longoni A, Sanquerin R, Battilana M, Concari P, Dessimone E, Grossi R, Parise A, Monzani F, Artina E, Pavesi R, Marseguerra G, Nicolini L, Scandelli L, Soli L, Vettorello V, Zardetto E, Bonati A, Maltecca L, D'Alba E, Patane M, Babini G, Onorati F, Acquaroli L, Angelucci M, Morelli B, Agostara C, Cerone M, Michetti A, Tempesta P, D'Eramo S, Rocca F, Giannini F, Borghi G, Garavelli B, Conte M, Balasini M, Ferrario I, Vanotti M, Collavo E, Giacomazzo M., D'AMMANDO, FILIPPO, M., Tavani, G., Barbiellini, A., Argan, F., Boffelli, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, A. W., Chen, V., Cocco, E., Costa, F., D'Ammando, E. D., Monte, G. D., Pari, G. D., Cocco, G. D., Persio, I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, F., Fornari, F., Fuschino, T., Froysland, M., Frutti, M., Galli, F., Gianotti, A., Giuliani, C., Labanti, I., Lapshov, F., Lazzarotto, F., Liello, P., Lipari, Longo, Francesco, E., Mattaini, M., Marisaldi, M., Mastropietro, A., Mauri, F., Mauri, S., Mereghetti, E., Morelli, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, C., Pontoni, G., Porrovecchio, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, E., Rossi, A., Rubini, P., Soffitta, A., Traci, M., Trifoglio, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, C., Pittori, B., Preger, P., Santolamazza, F., Verrecchia, P., Giommi, S., Colafrancesco, A., Antonelli, S., Cutini, D., Gasparrini, S., Stellato, G., Fanari, R., Primavera, F., Tamburelli, F., Viola, G., Guarrera, L., Salotti, F., D'Amico, E., Marchetti, M., Crisconio, P., Sabatini, G., Annoni, S., Alia, A., Longoni, R., Sanquerin, M., Battilana, P., Concari, E., Dessimone, R., Grossi, A., Parise, F., Monzani, E., Artina, R., Pavesi, G., Marseguerra, L., Nicolini, L., Scandelli, L., Soli, V., Vettorello, E., Zardetto, A., Bonati, L., Maltecca, E., D'Alba, M., Patane, G., Babini, F., Onorati, L., Acquaroli, M., Angelucci, B., Morelli, C., Agostara, M., Cerone, A., Michetti, P., Tempesta, S., D'Eramo, F., Rocca, F., Giannini, G., Borghi, B., Garavelli, M., Conte, M., Balasini, I., Ferrario, M., Vanotti, E., Collavo, M., Giacomazzo, Tavani M, Barbiellini G, Argan A, Boffelli F, Bulgarelli A, Caraveo P, Cattaneo PW, Chen AW, Cocco V, Costa E, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Fornari F, Fuschino F, Froysland T, Frutti M, Galli M, Gianotti F, Giuliani A, Labanti C, Lapshov I, Lazzarotto F, Liello F, Lipari P, Longo F, Mattaini E, Marisaldi M, Mastropietro M, Mauri A, Mauri F, Mereghetti S, Morelli E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Piano G, Picozza P, Pontoni C, Porrovecchio G, Prest M, Pucella G, Rapisarda M, Rappoldi A, Rossi E, Rubini A, Soffitta P, Traci A, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Pittori C, Preger B, Santolamazza P, Verrecchia F, Giommi P, Colafrancesco S, Antonelli A, Cutini S, Gasparrini D, Stellato S, Fanari G, Primavera R, Tamburelli F, Viola F, Guarrera G, Salotti L, D'Amico F, Marchetti E, Crisconio M, Sabatini P, Annoni G, Alia S, Longoni A, Sanquerin R, Battilana M, Concari P, Dessimone E, Grossi R, Parise A, Monzani F, Artina E, Pavesi R, Marseguerra G, Nicolini L, Scandelli L, Soli L, Vettorello V, Zardetto E, Bonati A, Maltecca L, D'Alba E, Patane M, Babini G, Onorati F, Acquaroli L, Angelucci M, Morelli B, Agostara C, Cerone M, Michetti A, Tempesta P, D'Eramo S, Rocca F, Giannini F, Borghi G, Garavelli B, Conte M, Balasini M, Ferrario I, Vanotti M, Collavo E, and Giacomazzo M

Subjects
Agile, Active galactic nucleus, gamma and X ray detection, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, satellite, FOS: Physical sciences, Astrophysics, High Energy Gamma-ray Astronomy, Pulsar, astro-ph, Angular resolution, media_common, Physics, Calorimeter (particle physics), Astrophysics (astro-ph), Detector, AGILE satellite, Detectors, Astronomy and Astrophysics, Universe, Supernova, Space and Planetary Science, Orbit (dynamics), instrumentation: detectors – techniques: high angular resolution – techniques: image processing – gamma rays: observations – X-rays: general
Abstract

AGILE is an Italian Space Agency mission dedicated to the observation of the gamma-ray Universe. The AGILE very innovative instrumentation combines for the first time a gamma-ray imager (sensitive in the energy range 30 MeV - 50 GeV), a hard X-ray imager (sensitive in the range 18-60 keV) together with a Calorimeter (sensitive in the range 300 keV - 100 MeV) and an anticoincidence system. AGILE was successfully launched on April 23, 2007 from the Indian base of Sriharikota and was inserted in an equatorial orbit with a very low particle background. AGILE provides crucial data for the study of Active Galactic Nuclei, Gamma-Ray Bursts, pulsars, unidentified gamma-ray sources, Galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. An optimal angular resolution (reaching 0.1-0.2 degrees in gamma-rays, 1-2 arcminutes in hard X-rays) and very large fields of view (2.5 sr and 1 sr, respectively) are obtained by the use of Silicon detectors integrated in a very compact instrument. The paper describes the AGILE Mission and its space and ground segments., 20 pages, 26 figures. submitted to Astron. & Astrophys

Published
2009

83. 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

84. GRB 071104: gamma ray burst localization by SuperAGILE

Author

Donnarumma, I., Evangelista, Y., Feroci, M., Costa, E., Del Monte, E., Lapshov, I., Lazzarotto, F., Pacciani, L., Rapisarda, M., Soffitta, P., Giuliani, A., Vercellone, S., Chen, A., Mereghetti, S., Pellizzoni, A., Perotti, F., Fornari, F., Mauro Fiorini, Caraveo, P., Zambra, A., Bulgarelli, A., Gianotti, F., Trifoglio, M., Di Cocco, G., Labanti, C., Fuschino, F., Marisaldi, M., Galli, M., Tavani, M., Pucella, G., D Ammando, F., Vittorini, V., Argan, A., Trois, A., Barbiellini, G., Longo, F., Picozza, P., Morselli, A., Prest, M., Vallazza, E., Lipari, P., Zanello, D., Mauri, F., Giommi, P., Pittori, C., Antonelli, L. A., Salotti, L., I., Donnarumma, Y., Evangelista, M., Feroci, E., Costa, E. M., Del, I., Lapshov, F., Lazzarotto, L., Pacciani, M., Rapisarda, P., Soffitta, A., Giuliani, S., Vercellone, A., Chen, S., Mereghetti, A., Pellizzoni, F., Perotti, F., Fornari, M., Fiorini, P., Caraveo, A., Zambra, A., Bulgarelli, F., Gianotti, M., Trifoglio, Cocco, G., C., Labanti, F., Fuschino, M., Marisaldi, M., Galli, M., Tavani, G., Pucella, F., D'Ammando, V., Vittorini, A., Argan, A., Troi, G., Barbiellini, Longo, Francesco, P., Picozza, A., Morselli, M., Prest, E., Vallazza, P., Lipari, D., Zanello, F., Mauri, P., Giommi, C., Pittori, L. A., Antonelli, and L., Salotti

Subjects
Gamma-ray Bursts

85. Discovery of powerful gamma-ray flares from the Crab Nebula.

Author

Tavani M, Bulgarelli A, Vittorini V, Pellizzoni A, Striani E, Caraveo P, Weisskopf MC, Tennant A, Pucella G, Trois A, Costa E, Evangelista Y, Pittori C, Verrecchia F, Del Monte E, Campana R, Pilia M, De Luca A, Donnarumma I, Horns D, Ferrigno C, Heinke CO, Trifoglio M, Gianotti F, Vercellone S, Argan A, Barbiellini G, Cattaneo PW, Chen AW, Contessi T, D'Ammando F, DePris 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 GF

Abstract

The well-known Crab Nebula is at the center of the SN1054 supernova remnant. It consists of a rotationally powered pulsar interacting with a surrounding nebula through a relativistic particle wind. The emissions originating from the pulsar and nebula have been considered to be essentially stable. Here, we report the detection of strong gamma-ray (100 mega-electron volts to 10 giga-electron volts) flares observed by the AGILE satellite in September 2010 and October 2007. In both cases, the total gamma-ray flux increased by a factor of three compared with the non-flaring flux. The flare luminosity and short time scale favor an origin near the pulsar, and we discuss Chandra Observatory x-ray and Hubble Space Telescope optical follow-up observations of the nebula. Our observations challenge standard models of nebular emission and require power-law acceleration by shock-driven plasma wave turbulence within an approximately 1-day time scale.

Published
2011
Full Text
View/download PDF

86. 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
Full Text
View/download PDF

87. 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
Full Text
View/download PDF

88. 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 PW, Chen AW, Cocco V, 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, Fiorini M, Fuschino F, Galli M, Gianotti F, Hotan A, Labanti C, Lapshov I, Lazzarotto F, 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 GF

Abstract

Pulsars are known to power winds of relativistic particles that can produce bright nebulae by interacting with the surrounding medium. These pulsar wind nebulae are observed by their radio, optical, and x-ray emissions, and in some cases also at TeV (teraelectron volt) energies, but the lack of information in the gamma-ray band precludes drawing a comprehensive multiwavelength picture of their phenomenology and emission mechanisms. Using data from the AGILE satellite, we detected the Vela pulsar wind nebula in the energy range from 100 MeV to 3 GeV. This result constrains the particle population responsible for the GeV emission and establishes a class of gamma-ray emitters that could account for a fraction of the unidentified galactic gamma-ray sources.

Published
2010
Full Text
View/download PDF

89. 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 NA, McCollough M, Koljonen KI, Pucella G, Giuliani A, Chen AW, Costa E, Vittorini V, Trifoglio M, Gianotti F, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, 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

Abstract

Super-massive black holes in active galaxies can accelerate particles to relativistic energies, producing jets with associated gamma-ray emission. Galactic 'microquasars', which are binary systems consisting of a neutron star or stellar-mass black hole accreting gas from a companion star, also produce relativistic jets, generally together with radio flares. Apart from an isolated event detected in Cygnus X-1, there has hitherto been no systematic evidence for the acceleration of particles to gigaelectronvolt or higher energies in a microquasar, with the consequence that we are as yet unsure about the mechanism of jet energization. Here we report four gamma-ray flares with energies above 100 MeV from the microquasar Cygnus X-3 (an exceptional X-ray binary that sporadically produces radio jets). There is a clear pattern of temporal correlations between the gamma-ray flares and transitional spectral states of the radio-frequency and X-ray emission. Particle acceleration occurred a few days before radio-jet ejections for two of the four flares, meaning that the process of jet formation implies the production of very energetic particles. In Cygnus X-3, particle energies during the flares can be thousands of times higher than during quiescent states.

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results