V. Vittorini
A5040181186- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Particle Accelerators and Free-Electron Lasers
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Neutrino Physics Research
- Solar and Space Plasma Dynamics
- SAS software applications and methods
- Nuclear Physics and Applications
- Astronomy and Astrophysical Research
- Particle physics theoretical and experimental studies
- Astronomical Observations and Instrumentation
- Ionosphere and magnetosphere dynamics
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Computational Physics and Python Applications
- Earthquake Detection and Analysis
- Lightning and Electromagnetic Phenomena
- Superconducting Materials and Applications
Institute for Space Astrophysics and Planetology
2010-2023
National Institute for Astrophysics
2013-2023
University of Rome Tor Vergata
2000-2023
Gran Sasso Science Institute
2023
Agenzia Spaziale Italiana
2023
Accademia Nazionale dei Lincei
2023
Friedrich-Alexander-Universität Erlangen-Nürnberg
2023
Université Paris Cité
2023
Université Côte d'Azur
2017
Epistem (United Kingdom)
2015
<i>Context. <i/> AGILE is an Italian Space Agency mission dedicated to observing the gamma-ray Universe. The AGILE's very innovative instrumentation for first time combines a imager (sensitive in energy range 30 MeV–50 GeV), hard X-ray 18–60 keV), calorimeter 350 keV–100 MeV), and anticoincidence system. was successfully launched on 2007 April 23 from Indian base of Sriharikota inserted equatorial orbit with low particle background.<i>Aims. <i/>AGILE provides crucial data study active...
The well known Crab Nebula is at the center of SN1054 supernova remnant. It consists a rotationally-powered pulsar interacting with surrounding nebula through relativistic particle wind. emissions originating from and have been considered to be essentially stable. Here we report detection strong gamma-ray (100 MeV-10 GeV) flares observed by AGILE satellite in September, 2010 October, 2007. In both cases, unpulsed flux increased factor 3 compared non-flaring flux. flare luminosity short...
We report the detection by Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite of terrestrial gamma ray flashes (TGFs) obtained with minicalorimeter (MCAL) detector operating in energy range 0.3–100 MeV. select events typically lasting few milliseconds spectral and directional selections consistent TGF characteristics previously reported other space missions. During period 1 June 2008 to 31 March 2009 we detect 34 high‐confidence showing millisecond durations geographical distribution...
We present the AGILE gamma-ray observations in energy range 50 MeV - 10 GeV of supernova remnant (SNR) W44, one most interesting systems for studying cosmic-ray production. W44 is an intermediate-age SNR (20, 000 years) and its ejecta expand a dense medium as shown by prominent radio shell, nearby molecular clouds, bright [SII] emitting regions. extend our analysis to energies substantially lower than previous measurements which could not conclusively establish nature radiation. find that...
Strong electric discharges associated with thunderstorms can produce terrestrial gamma-ray flashes (TGFs), i.e., intense bursts of x rays and $\ensuremath{\gamma}$ lasting a few milliseconds or less. We present in this Letter new TGF timing spectral data based on the observations Italian Space Agency AGILE satellite. determine that emission above 10 MeV has significant power-law component reaching energies up to 100 MeV. These results challenge theoretical models runaway electron...
The Supernova Remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray and gamma-ray energy emissions. In this Letter we study the emission above 100 MeV from as obtained by AGILE satellite. A distinct pattern of diffuse in range MeV-3 GeV detected across SNR with prominent maximum (source "A") localized Northeastern shell a flux F = (47 \pm 10) 10^{-8} photons cm^{-2} s^{-1} MeV. This location site strongest shock interaction between blast wave dense...
We present the first catalog of high-confidence <i>γ<i/>-ray sources detected by AGILE satellite during observations performed from July 9, 2007 to June 30, 2008. Cataloged were merging all available data over entire time period. AGILE, launched in April 2007, is an ASI mission devoted 30 MeV–50 GeV energy range, with simultaneous X-ray imaging capability 18–60 keV band. This based on Gamma-Ray Imaging Detector (GRID) for energies greater than 100 MeV. For catalog, we adopted a conservative...
We present optical, X-ray, high energy ($\lessapprox 30$ GeV) and very ($\gtrapprox 100$ GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 June 23. A $\gamma$-ray signal was detected by AGILE with \sqrt{TS}=4.5 on 9--15, $F(E>100 \mathrm{MeV})= 42^{+14}_{-12}\times 10^{-8}$ photons cm$^{-2}$ s$^{-1}$. This flaring state is brighter than average flux observed EGRET a factor $\sim$3, but still consistent highest flux. In hard X-rays (20-60 keV)...
We present the results of extensive observations by gamma-ray AGILE satellite Galactic region hosting Carina nebula and remarkable colliding wind binary Eta Carinae (η Car) during period 2007 July–2009 January. detect a source (1AGL J1043−5931) consistent with position η Car. If 1AGL J1043−5931 is associated Car system, our data provide long sought first detection above 100 MeV binary. The average flux integrated over preperiastron July–2008 October Fγ = (37 ± 5) × 10−8 ph cm−2 s−1...
We report on 18 months of multiwavelength observations the blazar 3C 454.3 (Crazy Diamond) carried out in July 2007-January 2009. show results AGILE campaigns which took place May-June 2008, July-August and October 2008-January During May 2009 period, source average flux was highly variable, from an gamma-ray F(E>100MeV) > 200E-8 ph/cm2/s to F(E>100MeV)~80E-8 The spectrum between 100 MeV 1 GeV can be fit by a simple power law (Gamma_GRID ~ 2.0 2.2). Only 3-sigma upper limits derived 20-60...
Since 2005, the blazar 3C 454.3 has shown remarkable flaring activity at all frequencies, and during last four years it exhibited more than one γ-ray flare per year, becoming most active in sky. We present for first time multi-wavelength AGILE, Swift, INTEGRAL, GASP-WEBT data collected order to explain extraordinary of which occurred 2010 November. On November 20 (MJD 55520), reached a peak flux (E >100 MeV) Fpγ = (6.8 ± 1.0) × 10−5 photons cm−2 s−1 on timescale about 12 hr, factor six...
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 signal was detected by VERITAS 2008 7-8 with flux F(>200 GeV) = (5.7+-0.6)x10^-11 cm-2s-1, about three times brighter than discovery March. initial detection this flare at energies above 200 GeV followed observations gamma-rays (AGILE, E>100 MeV), and X-rays (Swift XMM-Newton),...
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 interaction accelerated particles concentrated gas. The middle aged SNR W28, for its system dense molecular clouds, provides an excellent opportunity test this hypothesis. We present AGILE/GRID observations and compare them at other wavelengths (TeV 12CO J=1-->0 line emission). flux detected by AGILE from dominant source W28 is...
We report on the extreme gamma-ray activity from FSRQ PKS 1510-089 observed by AGILE in March 2009. In same period a radio-to-optical monitoring of source was provided GASP-WEBT and REM. Moreover, several Swift ToO observations were triggered, adding important information behaviour optical/UV to hard X-rays. paid particular attention calibration Swift/UVOT data make it suitable blazars spectra. Simultaneous radio gamma rays allowed us study detail correlation among emission variability at...
Gamma-ray emission from the Crab Nebula has been recently shown to be unsteady. In this paper, we study flux and spectral variability of above 100 MeV on different timescales ranging days weeks. addition four main intense day-long flares detected by AGILE Fermi-LAT between 2007 September 2012 September, find evidence for week-long less episodes enhanced gamma-ray that call "waves." Statistically significant "waves" show 1–2 weeks, can occur themselves or in association with shorter flares....
We report on the extremely intense and fast gamma-ray are above 100 MeV detected by AGILE from Crab Nebula in mid-April 2011. This event is fourth of a sequence reported major flares produced period 2007/mid-2011. These events attributed to strong radiative plasma instabilities inner Nebula, their properties crucial for theoretical studies efficient particle acceleration up 10^15 eV. Here we study very rapid flux spectral evolution that reached April 16, 2011 record-high peak F = (26 +/- 5)...
ABSTRACT We report the results of an extensive search through AGILE data for a gamma-ray counterpart to LIGO gravitational-wave (GW) event GW150914. Currently in spinning mode, has potential cover 80% sky with its instrument, more than 100 times day. It turns out that came within minute time observing accessible GW150914 localization region. Interestingly, detector exposed ∼65% this region during s intervals centered at −100 and +300 from time. determine 2 σ flux upper limit band 50 MeV–10...
Fast radio bursts (FRBs) are short (millisecond) pulses originating from enigmatic sources at extragalactic distances so far lacking a detection in other energy bands. Magnetized neutron stars (magnetars) have been considered as the powering FRBs, but connection is controversial because of differing energetics and lack X-ray detections with similar characteristics two classes. We report here by AGILE satellite on April 28, 2020 an burst coincidence very bright Galactic magnetar SGR...
Abstract Gamma-ray emission in the MeV–GeV range from explosive cosmic events is of invaluable relevance to understanding physical processes related formation neutron stars and black holes. Here we report on detection by AGILE satellite energy remarkable long-duration gamma-ray burst GRB 221009A. The onboard detectors have good exposure 221009A during its initial crucial phases. Hard X-ray/MeV prompt phase lasted hundreds seconds, with brightest radiation being emitted between 200 300 s...
We derive quantitative predictions of the optical and X-ray luminosity functions for quasars in redshift range z ≲ 3. Based on accreting black holes as primary sources quasar outputs, we investigate how accretion is controlled by surrounding structures, these grow hierarchically from formation host galaxies to their assemblage into poor eventually rich groups. argue that < 3 efficient hole fueling triggered encounters a gas-rich with its companions group; destabilize gas induce accretion,...
[Abridged] We report on a multiwavelength observation of the blazar 3C 454.3 (which we dubbed "crazy diamond") carried out November 2007 by means astrophysical satellites AGILE, INTEGRAL, Swift, WEBT Consortium, and optical-NIR telescope REM. is detected at $\sim 19-σ$ level during 3-week observing period, with an average flux above 100 MeV $F_{\rm E>100MeV} = (170 \pm 13) \times 10^{-8}$ \phcmsec. The gamma-ray spectrum can be fit single power-law photon index $Γ_{\rm GRID} 1.73 0.16$...
We report the first blazar detection by AGILE. AGILE detected 3C 454.3 during a period of strongly enhanced optical emission in 2007 July. observed source with dedicated repointing July 24-30 its two co-aligned imagers, Gamma-Ray Imaging Detector and hard X-ray imager Super-AGILE sensitive 30 MeV to 50 GeV 18-60 keV ranges, respectively. Over entire period, γ-ray from at significance level 13.8 σ an average flux (E > 100 MeV) (280 ± 40) × 10-8 photons cm-2 s-1. The appears be variable toward...
Cygnus X-1 is the archetypal black hole (BH) binary system in our Galaxy. We report main results of an extensive search for transient gamma-ray emission from carried out energy range 100 MeV - 3 GeV by AGILE satellite, during period 2007 July 2009 October. The total exposure time about 300 days, which source was "hard" X-ray spectral state. divided observing intervals 2 or 4 week periods, and searched persistent emission. episode significant detected on 2009, October 16 a position compatible...