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The AGILE Mission will explore the gamma-ray Universe with a very innovative instrument combining for the first time a gamma-ray imager and a hard X-ray imager. AGILE will be operational at the beginning of 2007 and it will provide crucial data for the study of Active Galactic Nuclei, Gamma-Ray Bursts, unidentified gamma-ray sources, Galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. The AGILE instrument is designed to simultaneously detect and image photons in the 30 MeV – 50 GeV and 15 – 45 keV energy bands with excellent imaging and timing capabilities, and a large field of view covering ∼ 1/5 of the entire sky at energies above 30 MeV. A CsI calorimeter is capable of GRB triggering in the energy band 0.3–50 MeV. The broadband detection of GRBs and the study of implications for particle acceleration and high energy emission are primary goals of the mission. AGILE can image GRBs with 2–3 arcminute error boxes in the hard X-ray range, and provide broadband photon-by photon detection in the 15–45 keV, 03–50 MeV, and 30 MeV–30 GeV energy ranges. Microsecond on-board photon tagging and a ∼ 100 microsecond gamma-ray detection deadtime will be crucial for fast GRB timing. On-board calculated GRB coordinates and energy fluxes will be quickly transmitted to the ground by an ORBCOMM transceiver. AGILE is now (January 2007) undergoing final satellite integration and testing. The PLS V launch is planned in spring 2007. AGILE is then foreseen to be fully operational during the summer of 2007. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

AGILE is a Scientific Mission dedicated to high-energy astrophysics supported by ASI with scientific participation of INAF and INFN. The AGILE instrument is designed to simultaneously detect and image photons in the 30 MeV – 50 GeV and 15 – 45 keV energy bands with excellent imaging and timing capabilities, and a large field of view covering ∼ 1/5 of the entire sky at energies above 30 MeV. A CsI calorimeter is capable of GRB triggering in the energy band 0.3–50 MeV. The broadband detection of GRBs and the study of implications for particle acceleration and high energy emission are primary goals of th emission. AGILE can image GRBs with 2–3 arcminutes error boxes in the hard X-ray range, and provide broadband photon-by photon detection in the 15–45 keV, 03–50 MeV, and 30 MeV–30 GeV energy ranges. Microsecond on-board photon tagging and a ∼ 100 microsecond gamma-ray detection deadtime will be crucial for fast GRB timing. On-board calculated GRB coordinates and energy fluxes will be quickly transmitted to the ground by an ORBCOMM transceiver. AGILE have recently (December 2005) completed its gamma-ray calibration. It is now (January 2006) undergoing satellite integration and testing. The PLSV launch is planned in early 2006. AGILE is then foreseen to be fully operational during the summer of 2006. It will be the only mission entirely dedicated to high-energy astrophysics above 30 MeV during the period mid-2006/mid-2007. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We report the results of the temporal and spectral analysis of the longest BeppoSAX pointing (about 770 ks) of the microquasar GRS 1915+105, performed in October 2000. The source was mainly observed in the variability class ρ characterized by series of sharp pulses with a typical recurrence time of about 50 s. This behaviour was generally stable but, occasionally, it changed to a more irregular state. A spectral analysis of the 1–100 keV emission showed a small but significant change of the disk temperature between the regular and irregular ρ-mode. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

SuperAGILE is the hard X-ray (10–40 keV) imager for the gamma-ray mission AGILE, currently scheduled for launch in mid-2005. It is based on 4 Si-microstrip detectors, with a total geometric area of 1444 cm2 (max effective about 300 cm2), equipped with one-dimensional coded masks. The 4 detectors are perpendicularly oriented, in order to provide pairs of orthogonal one-dimensional images of the X-ray sky. The field of view of each 1-D detector is 107 °×68°, at zero response, with an overlap in the central 68°×68° area. The angular resolution on axis is 6 arcmin (pixel size). We present here the current status of the hardware development and the scientific potential for GRBs, for which an onboard trigger and imaging system will allow distributing locations through a fast communication telemetry link from AGILE to the ground. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The 3rd Interplanetary Network (IPN) has been operating since April 2001 with two distant spacecraft, Ulysses and Mars Odyssey, and numerous near-Earth spacecraft, such as BeppoSAX, Wind, and HETE-II. Mars Odyssey is presently in orbit about Mars, and the network has detected approximately 30 cosmic, SGR, and solar bursts. We discuss the results obtained to date and use them to predict the future performance of the network. [ABSTRACT FROM AUTHOR]

The co-alignment of two detectors of the BeppoSAX Gamma-Ray Burst Monitor (40-700 keV) with the Wide Field Cameras (2-26 keV) on-board the same satellite has permitted simultaneous detection of several GRBs in X and gamma rays and their localization with high precision. These measurements allow us also to extend the study of GRB spectra down to 2 keV and with good accuracy thanks to the knowledge of source direction. We show and discuss preliminary results of the analysis of X to gamma-rays average spectra based on a sample of 12 BeppoSAX events. [ABSTRACT FROM AUTHOR]

The gamma-ray observatory AGILE, the first ASI Small Mission, is planned to operate in 2002-2005. We present here Super-AGILE, an X-ray detector added on top of the gamma-ray tracker. Super-AGILE will have a large field of view, providing hard X-ray imaging and moderate spectroscopy together with the gamma-ray detector. Super-AGILE is composed by Si-microstrip detectors, equipped with a low-noise electronics allowing a sensitive range of 10-40 keV, and coupled with a set of mutually orthogonal one-dimensional coded masks. A bidimensional source location capability is obtained by dividing the total 1444 cm² geometric area of the detectors in two orthogonal directions. [ABSTRACT FROM AUTHOR]

The Galactic Microquasar GRS 1915+105 was observed by the Narrow Field Instruments onboard BeppoSAX in two pointings during year 2000. We present the preliminary results of wideband study of the observed variability, carried out also with the wavelet analysis. [ABSTRACT FROM AUTHOR]

AGILE is an ASI gamma-ray astrophysics space Mission which will operate in the 30 MeV - 30 GeV with imaging capabilities also in the 10-40 keV range. Primary scientific goals include the study of AGNs, gamma-ray bursts, Galactic sources, unidentified gamma-ray sources, diffuse Galactic and extragalactic gamma-ray emission, high-precision timing studies, and Quantum Gravity testing. AGILE will be the only Mission entirely dedicated to source detection above 30 MeV during the period 2003-2006. [ABSTRACT FROM AUTHOR]

We present the source imaging performance of the AGILE Satellite in the hard X-ray (10-40 keV) and gamma-ray (30 MeV-50 GeV) energy bands. The AGILE instrument will combine state-of-the-art Silicon detection technology for gamma-ray imaging (Gamma-Ray Imaging Detector - GRID) with a coded-mask imager sensitive in the hard X-ray band (Super-AGILE). AGILE is designed to reduce the uncertainty in gamma-ray source localization to the level of a few arcminutes, depending on the source intensity, spectrum and background properties. The AGILE Event Simulator (AEV) is a tool to generate gamma-ray images taking into account the proper instrument characteristics. We present preliminary results obtained with AEV for several astrophysical sources. [ABSTRACT FROM AUTHOR]

The AGILE scientific instrument is based on an innovative design based on three detecting systems: (1) a Silicon Tracker, (2) a Mini-Calorimeter, and (3) an ultralight coded mask system with Si-detectors (Super-AGILE). AGILE is designed to provide: (1) excellent imaging in the energy bands 30 MeV-50 GeV (5-10 arcmin for intense sources) and 10-40 kev (1-3 arcmin);, (2) optimal timing capabilities, with independent readout systems and minimal deadtimes for the Silicon tracker, Super-AGILE and Mini-Calorimeter; (3) large fields of view for the gamma-ray imaging detector (∼3 sr) and Super-AGILE (∼1 sr). [ABSTRACT FROM AUTHOR]

AGILE is an ASI Small Scientific Mission dedicated to high-energy astrophysics. The AGILE instrument is designed to detect and image photons in the 30 MeV-50 GeV and 10-40 keV energy bands, with excellent spatial resolution and timing capability, and an unprecedently large field of view covering ∼ 1/4 of the entire sky at energies above 30 MeV. Primary scientific goals include the study of AGNs,gamma-ray bursts, Galactic sources, unidentified gamma-ray sources, diffuse Galactic and extragalactic gamma-ray emission, high-precision timing studies, and Quantum Gravity testing. The AGILE Science Program will be open to the international scientific community. AGILE is planned to be operational during the year 2002, and will be the only mission entirely dedicated to high-energy astrophysics above 30 MeV to support multiwave-length studies during the period 2002-2005. [ABSTRACT FROM AUTHOR]

The BeppoSAX Gamma Ray Burst Monitor (GRBM) is triggered any time a statistically significant counting excess is simultaneously revealed by at least two of its four independent detectors. Several spurious effects, including highly ionizing particles crossing two detectors, are recorded as onboard triggers. In fact, a large number of false triggers is detected, on the order of 10/day. A software code, based on an heuristic algorithm, was written to discriminate between real and false triggers. We present the results of the analysis on an homogeneous sample of GRBM triggers, thus providing an estimate of the efficiency of the GRB detection system consisting of the GRBM and the software. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The extraordinary giant flare of 1998 August 27 from SGR 1900+14 was the most intense event ever detected from this or any other cosmic source (even more intense than the famous 1979 March 5th event). It was longer than any previous burst from SGR1900+14 by more than one order of magnitude, and it displayed the same 5.16-s periodicity in hard X-rays that was detected in the low-energy X-ray flux of its quiescent counterpart. The event was detected by several gamma-ray experiments in space, among them the Ulysses gamma-ray burst detector and the BeppoSAX Gamma Ray Burst Monitor. These instruments operate in different energy ranges, and a comparison of their data shows that the event emitted a strongly energy-dependent flux, and displayed strong spectral evolution during the outburst, itself. Here we present a joint analysis of the BeppoSAX and Ulysses data, in order to identify the energy-dependent features of this event and understand some of the physical conditions in the environment of the neutron star which generated this flare. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We present some statistical considerations on the BeppoSAX hunt for subsecond GRBs at the Scientific Operation Center. Archival analysis of a BATSE/SAX sub-sample of bursts indicates that the GRB Monitor is sensitive to short (<=2 sec) events, that are in fact approx. 22% of the total. The non-detection of corresponding prompt X-ray counterparts to short bursts in the Wide Field Cameras, in about 3 years of operations, is discussed: with present data no implications on the X-to-γ-ray spectra of short vs. long GRBs may be inferred. Finally, the status of searching procedures at the SOC is reviewed. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Preliminary results on a systematic analysis of the data from the Gamma-Ray Burst Monitor on-board BeppoSAX are presented. The purpose of this analysis is the identification of true celestial gamma-ray bursts. The study considers events that are recognized or not by the on-board trigger system logic. As the on-board logic triggers also spurious events which mimic GRBs (e.g., events due to high energy particles, atmospheric events, etc), it becomes necessary to impose additional constraints in order to recognize true GRBs. These further conditions will be the subject of this contribution. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Afterglows are a powerful source of information on GRBs. In this paper we present a systematic study of 11 afterglows observed with the Narrow Field Instruments on board on BeppoSAX. The intent of this analysis is to: i) disclose the nature of GRB progenitors by the temporal and spectral features imprinted by the nearby environment; ii) disentangle the jet versus spherical expansion of the fireball; iii) test and constrain the fireball model relations. We find no strong evidence of iron lines, except for the cases of GRB970508 (BeppoSAX) and GRB970828 (ASCA). From the average spectral and temporal properties we estimate a lower limit on the opening angle of the jet: θ>12°. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A method to evaluate the capability to localize Gamma-Ray Burst (GRB) sources with the Gamma-Ray Burst Monitor (GRBM) onboard BeppoSAX is presented. The instrument is composed of four differently oriented detectors, so that their relative counting rates can be used to reconstruct the incoming direction of the GRB photons. The method involves the minimization of an energy- and direction-dependent χ[sup 2]-like variable related to the difference between the intensities observed by the four GRBM detectors and their expected values, as derived from the instrument’s response functions. The method is applied to a sample of GRBs simultaneously detected and localized by other experiments, in order to compare the achieved results with locations determined independently. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Preliminary results of a study aimed to the determination of the response function, in direction and energy, of the Gamma-Ray Burst Monitor (GRBM) onboard the BeppoSAX satellite are presented. The study has been carried out by means of Monte Carlo techniques, taking into account on-ground calibration before launch, and the Crab spectrum measured during the flight. The derived response matrix will be used to evaluate properties (e.g., direction, spectrum, fluence) of all Gamma-Ray Bursts detected with the GRBM. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We describe the AGILE gamma-ray astronomy satellite which has recently been selected as the first Small Scientific Mission of the Italian Space Agency. With a launch in 2002, AGILE will provide a unique tool for high-energy astrophysics in the 30 MeV–50 GeV range before GLAST. Despite the much smaller weight and dimensions, the scientific performances of AGILE are comparable to those of EGRET. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Our BeppoSAX observations of IC 443 were primarily directed toward isolating and studying its previously known hard component, thereby to test the hypothesis that this is direct evidence for very energetic (=100 TeV) cosmic rays. Although our analysis is at an early stage, it was immediately obvious that we have, with the BeppoSAX/PDS, detected a very hard (from 14 to >30 keV) component which is almost certainly the counterpart of the EGRET γ-ray source 2 EGJ0618+2234. This object is offset from the prominent soft thermal emission in IC 443. In the same field we found with the BeppoSAX/MECS two hard (5–10 keV) hot spots. Both the hot spots and the 2EG source appear to be evidence for energetic cosmic rays produced where the SNR shock is interacting with a dense molecular cloud. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

AGILE is an innovative, cost-effective gamma-ray mission selected by the Italian Space Agency for a Program of Small Scientific Missions. The AGILE gamma-ray imaging detector (GRID, made of a Silicon tracker and CsI Mini-Calorimeter) is designed to detect and image photons in the 30 MeV–50 GeV energy band with good sensitivity and very large field of view (FOV ∼3 sr). The X-ray detector, Super-AGILE, sensitive in the 10–40 keV band and integrated on top of the GRID gamma-ray tracker will provide imaging (1–3 arcmin) and moderate spectroscopy. For selected sky areas, AGILE might achieve a flux sensitivity (above 100 MeV) better than 5×10[sup -8] ph cm[sup 2] s[sup -1] at the completion of its scientific program. AGILE will operate as an Observatory open to the international community and is planned to be operational during the year 2002 for a nominal 2-year mission. It will be an ideal ‘bridge’ between EGRET and GLAST, and the only mission entirely dedicated to high-energy astrophysics above 30 MeV during that period. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The scientific instrument of the AGILE mission is innovative in many ways. It is an integrated instrument based on three detecting systems: (1) a Silicon Tracker, (2) a Mini-Calorimeter, and (3) an ultralight coded mask system with Si-detectors (Super-AGILE). For a relatively low mass (∼70 kg) and large ratio of expected performance over cost, AGILE is planned to provide (i) Optimal imaging in the energy bands 30 MeV–50 GeV (5–10 arcmin for intense sources) and 10–40 keV (1–3 arcmin). (ii) Optimal timing capabilities, with independent readout systems and minimal dead-times for the Silicon Tracker, Super-AGILE and Mini-Calorimeter. (iii) A very large field of view for the gamma-ray imaging detector (3 sr) and Super-AGILE (1 sr). © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We present here preliminary results of BeppoSAX measurements of the prompt (2-700 keV) and afterglow (0.1 - 10 keV) emission of the 'dark' GRB 001109. The burst light curves show indication of pulse broadening with the decrease of the energy band and its average spectrum is well described by the standard Band function from X to gamma-rays. The X-ray afterglow emission shows a monotonic power-law decay and its spectrum can be satisfactorily fitted with a photo-electrically absorbed power-law. Both the decay index and the photon index are inside the range of common values found in GRBs afterglows. More detailed data analysis and interpretation is in progress. [ABSTRACT FROM AUTHOR]