A5008052402- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Particle physics theoretical and experimental studies
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Quantum Chromodynamics and Particle Interactions
- Mechanics and Biomechanics Studies
- Astronomical Observations and Instrumentation
- High-pressure geophysics and materials
- Radiation Detection and Scintillator Technologies
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- CCD and CMOS Imaging Sensors
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Particle accelerators and beam dynamics
- Radiation Effects in Electronics
Istituto Nazionale di Fisica Nucleare, Sezione di Torino
2015-2024
University of Turin
2015-2024
Istituto Nazionale di Fisica Nucleare
2010-2024
Nevin Scrimshaw International Nutrition Foundation
2022-2023
Institute for Space Astrophysics and Planetology
2022
Osservatorio Astrofisico di Torino
2012-2021
Marshall Space Flight Center
2019-2021
University of Geneva
1993-2020
Max Planck Society
2018
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2016
We present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in 100 MeV–300 GeV range. Based on first 4 yr science data from Gamma-ray Space mission, it is deepest yet this energy Relative to Second LAT catalog, 3FGL incorporates twice as much data, well a number analysis improvements, including improved calibrations at event reconstruction level, an updated model for Galactic diffuse γ-ray emission, refined procedure detection, and methods associating with...
We present the fourth Fermi Large Area Telescope catalog (4FGL) of gamma-ray sources. Based on first eight years science data from Gamma-ray Space mission in energy range 50 MeV to 1 TeV, it is deepest yet this range. Relative 3FGL catalog, 4FGL has twice as much exposure well a number analysis improvements, including an updated model for Galactic diffuse emission, and two sets light curves (1-year 2-month intervals). The includes 5064 sources above 4 sigma significance, which we provide...
The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some most dark matter (DM) dominated objects known. We report on gamma-ray observations dSphs based 6 years Fermi Large Area Telescope data processed with new Pass 8 event-level analysis. None significantly detected in gamma rays, and we present upper limits DM annihilation cross section from a combined analysis 15 dSphs. These constraints among strongest robust to date lie below canonical thermal relic for mass $\lesssim$...
Using data collected at the Pierre Auger Observatory during past 3.7 years, we demonstrated a correlation between arrival directions of cosmic rays with energy above 6 × 10 19 electron volts and positions active galactic nuclei (AGN) lying within ∼75 megaparsecs. We rejected hypothesis an isotropic distribution these least 99% confidence level from prescribed priori test. The observed is compatible that highest-energy particles originate nearby extragalactic sources whose flux has not been...
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. objectives of Observatory are to probe origin and characteristics rays above $10^{17}$ eV study interactions these, most energetic particles observed nature. design features an array 1660 water-Cherenkov particle detector stations spread over 3000 km$^2$ overlooked by 24 air fluorescence telescopes. In addition, three elevation telescopes overlook 23.5 km$^2$,...
The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. spectral index gamma particle flux, J proportional, variantE;{-gamma}, energies between 4 eV and 10;{19} 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) higher energies. hypothesis a single power law rejected with significance greater than 6 standard deviations. data are consistent prediction by Greisen Zatsepin Kuz'min.
The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It based on (3FGL) sources between 100 MeV and 300 GeV with a Test Statistic (TS) greater than 25, 2008 August 4 2012 July 31. 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\deg}), 71% increase over second 2 years data. There are 28 duplicate associations, thus 1563 2192 high-latitude gamma-ray 3FGL AGNs. Most them (98%) blazars. About half newly blazars unknown type, i.e.,...
We describe the measurement of depth maximum, X{max}, longitudinal development air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed fluorescence detector Pierre Auger Observatory in coincidence with at least one surface station are selected for analysis. The average shower maximum was found to evolve energy a rate (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) this energy. measured shower-to-shower fluctuations decrease from about 55 26...
The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of emission towards Galactic centre (GC) in high-energy gamma-rays. This paper describes analysis data taken during first 62 months mission energy range 1-100 GeV from a $15^\circ \times 15^\circ$ region about direction GC, and implications for interstellar emissions produced by cosmic ray (CR) particles interacting with gas radiation fields inner Galaxy point sources detected. Specialised models (IEMs) are...
We report a study of the distributions depth maximum, ${X}_{\mathrm{max}}$, extensive air-shower profiles with energies above $1{0}^{17.8}\text{ }\text{ }\mathrm{eV}$ as observed fluorescence telescopes Pierre Auger Observatory. The analysis method for selecting data sample minimal sampling bias is described in detail well experimental cross-checks and systematic uncertainties. Furthermore, we discuss detector acceptance resolution ${X}_{\mathrm{max}}$ measurement provide parametrizations...
Abstract The region around the Galactic Center (GC) is now well established to be brighter at energies of a few GeV than what expected from conventional models diffuse gamma-ray emission and catalogs known sources. We study excess using 6.5 yr data Fermi Large Area Telescope. characterize uncertainty GC spectrum morphology due uncertainties in cosmic-ray source distributions propagation, distribution interstellar gas Milky Way, potential contribution bubbles. also evaluate properties...
We present an incremental version (4FGL-DR3, for Data Release 3) of the fourth Fermi-LAT catalog gamma-ray sources. Based on first twelve years science data in energy range from 50 MeV to 1 TeV, it contains 6658 The analysis improves that used 4FGL over eight data: more sources are fit with curved spectra, we introduce a robust spectral parameterization pulsars, and extend points TeV. parameters, distributions, associations updated all Light curves rebuilt yr intervals (not 2 month...
Dark matter in the Milky Way may annihilate directly into gamma rays, producing a monoenergetic spectral line. Therefore, detecting such signature would be strong evidence for dark annihilation or decay. We search lines Fermi Large Area Telescope observations of halo energy range 200 MeV to 500 GeV using analysis methods from our most recent line searches. The main improvements relative previous works are use 5.8 years data reprocessed with Pass 8 event-level and additional resulting...
We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in first 7 years data using Pass 8 event-level analysis. This is Third Catalog Hard Fermi-LAT Sources (3FHL), containing 1556 objects characterized - 2 TeV energy range. The sensitivity and angular resolution are improved factors 3 relative to previous LAT at same energies (1FHL). vast majority (79%) associated with extragalactic counterparts other wavelengths, including 16 located very high...
Using the data taken at Pierre Auger Observatory between December 2004 and 2012, we have examined implications of distributions depths atmospheric shower maximum (Xmax), using a hybrid technique, for composition hadronic interaction models. We do this by fitting with predictions from variety models variations in primary cosmic rays examining quality fit. Regardless what model is assumed, find that our are not well described mix protons iron nuclei over most energy range. Acceptable fits can...
The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area (4LAC) between 2008 August 4 and 2016 2 contains 2863 objects located at high Galactic latitudes (|b|>10{\deg}). It includes 85% more sources than previous 3LAC based on years data. AGNs represent least 79% high-latitude in Fermi-Large Source Catalog (4FGL), which covers energy range from 50 MeV to 1 TeV. In addition, 344 gamma-ray are found low latitudes. Most 4LAC blazars (98%),...
We present a catalog of sources detected above 50 GeV by the {\it Fermi}-Large Area Telescope (LAT) in 80 months data. The newly delivered Pass 8 event-level analysis allows detection and characterization GeV--2 TeV energy range. In this band, Fermi}-LAT has 360 sources, which constitute second hard (2FHL). improved angular resolution enables precise localization point ($\sim$1.7$'$ radius at 68 % C.~L.) spatially extended sources. find that 86 can be associated with counterparts other...
ABSTRACT Most of the celestial γ rays detected by Large Area Telescope (LAT) on board Fermi Gamma-ray Space originate from interstellar medium when energetic cosmic interact with nucleons and photons. Conventional point-source extended-source studies rely modeling this diffuse emission for accurate characterization. Here, we describe development Galactic Interstellar Emission Model (GIEM), which is standard adopted LAT Collaboration publicly available. This model based a linear combination...
We report a measurement of the proton-air cross section for particle production at center-of-mass energy per nucleon 57 TeV. This is derived from distribution depths shower maxima observed with Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing tail maxima, $[505\ifmmode\pm\else\textpm\fi{}22(\mathrm{stat}{)}_{\ensuremath{-}36}^{+28}(\mathrm{syst})]\text{ }\text{ }\mathrm{mb}$ found.
We present the first hybrid measurement of average muon number in air showers at ultra-high energies, initiated by cosmic rays with zenith angles between $62^\circ$ and $80^\circ$. The is based on 174 events recorded simultaneously Surface Detector array Fluorescence Pierre Auger Observatory. for each shower derived scaling a simulated reference profile lateral density distribution ground until it fits data. A $10^{19}$~eV angle $67^\circ$, which arrives an altitude 1450 m above sea level,...
On 2015 June 16, Fermi-LAT observed a giant outburst from the flat spectrum radio quasar 3C 279 with peak $>100$ MeV flux of $\sim3.6\times10^{-5}\;{\rm photons}\;{\rm cm}^{-2}\;{\rm s}^{-1}$ averaged over orbital period intervals. It is historically highest $\gamma$-ray source including past EGRET observations, isotropic luminosity reaching $\sim10^{49}\;{\rm erg}\;{\rm s}^{-1}$. During outburst, Fermi spacecraft, which has an 95.4 min, was operated in special pointing mode to optimize...