L. Pacciani
A5071934797- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Nuclear Physics and Applications
- Neutrino Physics Research
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Particle physics theoretical and experimental studies
- SAS software applications and methods
- Astronomical Observations and Instrumentation
- Radiation Detection and Scintillator Technologies
- Astronomy and Astrophysical Research
- Superconducting Materials and Applications
- CCD and CMOS Imaging Sensors
- Astro and Planetary Science
- Ionosphere and magnetosphere dynamics
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Spacecraft Design and Technology
Institute for Space Astrophysics and Planetology
2013-2024
National Institute for Astrophysics
2012-2023
University of Rijeka
2019
Kyoto University
2019
Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata
2016
Astronomical Observatory of Rome
2009-2015
Mars Space (United Kingdom)
2014
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2002-2012
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
1995-2011
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2009-2011
<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...
Abstract Most of the light from blazars, active galactic nuclei with jets magnetized plasma that point nearly along line sight, is produced by high-energy particles, up to around 1 TeV. Although are known be ultimately powered a supermassive black hole, how particles accelerated such high energies has been an unanswered question. The process must related magnetic field, which can probed observations polarization jets. Measurements radio optical polarization—the only range available until...
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...
Abstract Particle acceleration mechanisms in supermassive black hole jets, such as shock acceleration, magnetic reconnection, and turbulence, are expected to have observable signatures the multiwavelength polarization properties of blazars. The recent launch Imaging X-Ray Polarimetry Explorer (IXPE) enables us, for first time, use X-ray band (2–8 keV) probe jet synchrotron emission high-synchrotron-peaked BL Lac objects (HSPs). We report discovery linear (degree Π x = 15% ± 2% electric...
Abstract The lower-energy peak of the spectral energy distribution blazars has commonly been ascribed to synchrotron radiation from relativistic particles in jets. Despite consensus regarding jet emission processes, particle acceleration mechanism is still debated. Here, we present first X-ray polarization observations PG 1553+113, a high-synchrotron-peak blazar observed by Imaging Polarimetry Explorer (IXPE). We detect an degree (10 ± 2)% along electric-vector position angle ψ X = 86° 8°....
Abstract We report the first >99% confidence detection of X-ray polarization in BL Lacertae. During a recent X-ray/ γ -ray outburst, 287 ks observation (2022 November 27–30) was taken using Imaging Polarimetry Explorer (IXPE), together with contemporaneous multiwavelength observations from Neil Gehrels Swift observatory and XMM-Newton soft X-rays (0.3–10 keV), NuSTAR hard (3–70 optical Calar Alto Perkins Telescope observatories. Our data suggest that IXPE energy band is at crossover...
Abstract Observations of linear polarization in the 2–8 keV energy range with Imaging X-ray Polarimetry Explorer (IXPE) explore magnetic field geometry and dynamics regions generating nonthermal radiation relativistic jets blazars. These jets, particularly blazars whose spectral distribution peaks at energies, emit X-rays via synchrotron from high-energy particles within jet. IXPE observations X-ray-selected BL Lac–type blazar 1ES 1959+650 on 2022 May 3–4 showed a significant degree Π x =...
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...
Aims. We aim to probe the magnetic field geometry and particle acceleration mechanism in relativistic jets of supermassive black holes. Methods. conducted a polarimetry campaign from radio X-ray wavelengths high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging Polarimetry Explorer (IXPE) measurements 2022 December 6–8. During IXPE observation, we also monitored 421 using Swift -XRT obtained single observation with XMM-Newton improve spectral analysis. The time-averaged polarization...