A5015439216- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Culinary Culture and Tourism
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Food Quality and Safety Studies
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Astronomical Observations and Instrumentation
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- High voltage insulation and dielectric phenomena
- Lightning and Electromagnetic Phenomena
- Nutrition, Health and Food Behavior
- Superconducting Materials and Applications
- Particle physics theoretical and experimental studies
- Ionosphere and magnetosphere dynamics
University of Rome Tor Vergata
2019
National Institute for Astrophysics
2010-2019
Institute for Space Astrophysics and Planetology
2011-2018
The Ohio State University
2011-2015
National Taiwan University of Science and Technology
2015
Universidade Católica Portuguesa
2015
University of Arkansas at Fayetteville
2013
Consorzio Interuniversitario Fisica Spaziale
2011
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...
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...
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...
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...
We present the AGILE-GRID (Astro-rivelatore Gamma a Immagini LEggero – Gamma-Ray Imaging Detector) monitoring of Cygnus X-3, during period between November 2007 and July 2009. report here whole X-3 in AGILE "pointing" mode data-taking, to confirm that γ-ray activity coincides with same repetitive pattern multiwavelength emission analyze depth overall spectrum by assuming both leptonic hadronic scenarios. Seven intense events were detected this period, typical event lasting one or two days....
We present the gamma-ray data of extraordinary flaring activity above 100 MeV from flat spectrum radio quasar 3C 454.3 detected by AGILE during month 2009 December. 454.3, which has been among most active blazars FSRQ type since 2007, in range with a progressively rising flux November 10. The reached value comparable that Vela pulsar on December 2. Remarkably, between 2 and 3, source more than doubled its emission became brightest sky peak Fγ,p = (2000 ± 400) × 10−8 ph cm−2 s−1 for 1 day...
Aims. We present the second AGILE-GRID Catalog (2AGL) of γ-ray sources in 100 MeV-10 GeV energy range. Methods. With respect to previous catalogs, current 2AGL is based on first 2.3 years science data from AGILE mission (the so called 'pointing mode') and incorporates more several analysis improvements, including better calibrations at event reconstruction level, an updated model for Galactic diffuse gamma-ray emission, a refined procedure point-like source detection, inclusion search...
Cygnus X-3 (Cyg X-3) is a well-known microquasar producing variable emission at all wavelengths. Cyg prominent X-ray binary relativistic jets, and studying its high energy crucial for the understanding of fundamental acceleration processes in accreting compact objects. Aims. Our goal to study extreme particle {\gamma}-ray production above 100 MeV during special spectral states X- 3 usually characterized by low hard flux enhanced soft states. We observed with AGILE satellite extended time...
We present the results of multi-year gamma-ray observations by AGILE satellite black hole binary system Cygnus X-1. In a previous investigation we focused on X-1 in hard state during period mid-2007/2009. Here monitoring 2010/mid-2012 carried out for which includes remarkably prolonged `soft state' phase (June 2010 -- May 2011). Previous 1--10 MeV Cyg this hinted at possible existence non-thermal particle component with substantial modifications Comptonized emission from inner accretion...
We report the extraordinary γ-ray activity (E > 100 MeV) of gravitationally lensed blazar PKS 1830–211 (z = 2.507) detected by AGILE between 2010 October and November. On 14, source experienced a factor ∼12 flux increase with respect to its average value remained brightest at this level (∼500 × 10−8 photons cm−2 s−1) for about four days. The one-month light curve across flare showed mean F(E 200 s−1, which resulted in enhancement value. Following flare, was observed near-IR (NIR)–optical...
The Imaging X-ray Polarimetry Explorer (IXPE) will expand the information space for study of cosmic sources, by adding polarization to properties (time, energy, and position) observed in x-ray astronomy. Selected 2017 January as a NASA Astrophysics Small (SMEX) mission, IXPE be launched into an equatorial orbit 2021. observatory includes three identical telescopes, each comprising 4-m-focal-length (grazing-incidence) mirror module assembly (MMA) polarization-sensitive (imaging) detector unit...
Identification of gamma-ray-emitting Galactic sources is a long-standing problem in astrophysics. One such source, 1AGL J2022+4032, coincident with the interior radio shell supernova remnant Gamma Cygni (SNR G78.2+2.1) Cygnus Region, has recently been identified by Fermi as gamma-ray pulsar, LAT PSR J2021+4026. We present long-term observations J2022+4032 AGILE telescope, measuring its flux and light curve. compare curve that J2021+3652 (PSR J2021+3651), showing variability appears to be...
Context: AGILE is a gamma-ray astrophysics mission which has been in orbit since 23 April 2007 and continues to operate reliably. The detector, AGILE-GRID, observed Galactic extragalactic sources, many of were collected the first Catalog. Aims: We present calibration AGILE-GRID using in-flight data Monte Carlo simulations, producing Instrument Response Functions (IRFs) for effective area A_eff), Energy Dispersion Probability (EDP), Point Spread Function (PSF), each as function incident...
Context. The detection and the characterization of highenergy emission component from individual gamma-ray bursts (GRBs) is one key science objectives currently operating satellite AGILE, launched in April 2007. In its first two years operation AGILE detected three GRBs with photons energy larger than 30 MeV. One more GRB was third year, while spinning mode.
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 underwent flux enhancement factor 15-30 in 6 years, ~10 six months. We interpret this flare-up terms transition an accretion-disk dominated emission to synchrotron-jet one. analysed Sloan Digital Sky Survey (SDSS) archival taken during period low source. estimated mass central...
Context.AGILE is a γ-ray astrophysics mission which has been in orbit since 23 April 2007 and continues to operate reliably.The detector, AGILE-GRID, observed Galactic extragalactic sources, many of were collected the first AGILE Catalog.Aims.We present calibration AGILE-GRID using in-flight data Monte Carlo simulations, producing Instrument Response Functions (IRFs) for effective area (A eff ), Energy Dispersion Probability (EDP), Point Spread Function (PSF), each as function incident...