A5063309589- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Cosmology and Gravitation Theories
- Particle Detector Development and Performance
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Galaxies: Formation, Evolution, Phenomena
- Radiation Detection and Scintillator Technologies
- Astronomical Observations and Instrumentation
- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Radioactivity and Radon Measurements
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Noncommutative and Quantum Gravity Theories
- Radioactive Decay and Measurement Techniques
- Plasma Diagnostics and Applications
- Inorganic Fluorides and Related Compounds
- Magnetic confinement fusion research
- Nuclear Physics and Applications
Istituto Nazionale di Fisica Nucleare, Sezione di Torino
2015-2021
Université Paris Cité
2014-2019
Centre National de la Recherche Scientifique
2014-2019
Sorbonne Paris Cité
2019
Délégation Paris 7
2019
CEA Paris-Saclay
2014-2019
Université Paris-Saclay
2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2014-2019
Astrophysique, Instrumentation et Modélisation
2014-2019
Istituto Nazionale di Fisica Nucleare
2014-2018
The continuum high-energy gamma-ray emission between 1 GeV and 100 TeV from the Crab Nebula has been measured for first time in overlapping energy bands by Fermi large-area telescope (Fermi/LAT) below ~ ground-based imaging air Cherenkov telescopes (IACTs) above 60 GeV. To follow up on phenomenological approach suggested Hillas et al. (1998), broad band spectral spatial measurement (from radio to low-energy gamma-rays < GeV) is used extract shape of electron spectrum. While this model per...
The Cherenkov Telescope Array (CTA) is a project for next-generation observatory very high energy (GeV-TeV) ground-based gamma-ray astronomy, currently in its design phase, and foreseen to be operative few years from now. Several tens of telescopes 2-3 different sizes, distributed over large area, will allow sensitivity about factor 10 better than current instruments such as H.E.S.S, MAGIC VERITAS, an coverage GeV several TeV, field view up deg. In the following study, we investigate...
The Large Area Telescope (LAT) aboard the Fermi satellite allows us to study high-energy gamma-ray sky with unprecedented sensitivity. However, origin of 31% detected sources remains unknown. This population unassociated may contain new object classes, among them photons from self-annihilating or decaying non-baryonic dark matter. Fermi-LAT might be capable detect up a few these matter subhalos as faint and moderately extended temporally steady emission. After applying corresponding...
The Cherenkov Telescope Array (CTA) will have a unique chance of discovery for large range masses in Weakly Interacting Massive Particles models dark matter. principal target matter searches with CTA is the centre Galactic Halo. best strategy to perform observations within few degrees Centre, Centre itself and most intense diffuse emission regions removed from analysis. Assuming cuspy density profile Milky Way, 500 hours this region provide sensitivities below thermal cross-section...
The standard paradigm of hierarchical structure formation in a LambdaCDM universe predicts the presence dark matter subhaloes, hosted by Milky Way-sized galaxies. Anticipated subhalo masses range from 10^{10} down to cut-off mass between 10^{-3} and 10^{-11} solar masses. If is composed heavy self-annihilating or decaying particles, these subhaloes could be visible gamma-ray band as faint temporally constant sources without astrophysical counterparts. Based upon realistic models current...
The Cherenkov Telescope Array (CTA) will have a unique chance of discovery for large range masses in Weakly Interacting Massive Particles models dark matter. principal target matter searches with CTA is the centre Galactic Halo. best strategy to perform observations within few degrees Centre, Centre itself and most intense diffuse emission regions removed from analysis. Assuming cuspy density profile Milky Way, 500 hours this region provide sensitivities below thermal cross-section...
The source-count distribution as a function of their flux, dN/dS, is one the main quantities characterizing gamma-ray source populations. We employ statistical properties Fermi Large Area Telescope (LAT) photon counts map to measure composition extragalactic sky at high latitudes (|b|>30 deg) between 1 GeV and 10 GeV. present new method, generalizing use standard pixel-count statistics, decompose total observed emission into (a) point-source contributions, (b) Galactic foreground...
ABSTRACT Statistical properties of photon count maps have recently been proven as a new tool to study the composition gamma-ray sky with high precision. We employ 1-point probability distribution function six years Fermi -LAT data measure source-count dN / dS and diffuse components high-latitude energy. To that aim, we analyze emission in five adjacent energy bands between 1 171 GeV. It is demonstrated flux compatible broken power law up energies ∼50 The index below break 1.95 2.0. For...
The global contribution of unresolved gamma-ray point sources to the extragalactic background has been recently measured down fluxes lower than those reached with standard source detection techniques, and by employing statistical properties observed counts. We investigate exploit complementarity information brought one-point statistics photon counts (using more 10 years Fermi-LAT data) recent measurement angular power spectrum (based on 8 data). determine, under assumption that source-count...
Dark Matter (DM) is a fundamental ingredient of our Universe and structure formation, yet its nature elusive to astrophysical probes.Information on the physical properties WIMP (neutralino) DM (the leading candidate for cosmologically relevant DM) can be obtained by studying signals their annihilation/decay.Among various e.m. signals, secondary electrons produced neutralino annihilation generate synchrotron emission in magnetized atmosphere galaxy clusters galaxies which could observed as...
Gamma-ray searches for new physics such as dark matter are often driven by investigating the composition of extragalactic gamma-ray background (EGB). Classic approaches to EGB decomposition manifest in resolving individual point sources and dissecting intensity spectrum remaining unresolved component. Furthermore, statistical methods have recently been proven outperform sensitivity classic source detection algorithms finding point-source populations flux regime. In this article, we employ...
In this article, the capability of present (H.E.S.S., MAGIC, VERITAS) and planned (CTA) ground-based Cherenkov telescope systems for detecting angular anisotropies in diffuse gamma-ray background is investigated. Following up on a study impact instrumental characteristics (effective area, field view, resolution, rejection efficiency), first part examines influence different observational strategies, i.e. whether single deep observation or splitting over multiple shallow fields preferred....
Abstract The Fermi Large Area Telescope (LAT) Collaboration has recently released the Third Catalog of Hard -LAT Sources (3FHL), which contains 1556 sources detected above 10 GeV with seven years Pass 8 data. Building upon 3FHL results, we investigate flux distribution at high Galactic latitudes ( <?CDATA $| b| \gt 20^\circ $?> ), are mostly blazars. We use two complementary techniques: (1) a source-detection efficiency correction method and (2) an analysis pixel photon count statistics...
Recently, a new measurement of the auto- and cross-correlation angular power spectrum (APS) isotropic gamma-ray background was performed, based on 81 months data Fermi Large-Area Telescope (LAT). Here, we fit, for first time, APS with model describing emission unresolved blazars. These sources are expected to dominate anisotropy signal. The employ in our analysis reproduces well blazars resolved by LAT. When considering obtained masking listed 3FGL catalog, find that underproduce measured...
Common extensions of the Standard Model particle physics predict existence a ``hidden'' sector that comprises particles with vanishing or very weak coupling to (visible sector). For light ($m<{10}^{\ensuremath{-}14}\text{ }\text{ }\mathrm{eV}$) hidden U(1) gauge bosons (hidden photons), broadband radio spectra compact sources could be modified due kinetic mixing photons. Here, search methods are developed and their sensitivity discussed, specific emphasis on effect coherence length...
Extensions of the standard model particle physics, in particular those based on string theory, often predict a new U(1) gauge symmetry hidden sector. The corresponding boson, called photon, naturally interacts with ordinary photon via kinetic mixing, leading to - oscillations. In this framework, one expects disappearance as function mass and mixing angle, loosely constrained from theory. Several experiments have been carried out or are planned constrain mass-mixing plane. contribution we...
Dark Matter (DM) is a fundamental ingredient of our Universe and structure formation, yet its nature elusive to astrophysical probes. Information on the physical properties WIMP (neutralino) DM (the leading candidate for cosmologically relevant DM) can be obtained by studying signals their annihilation/decay. Among various e.m. signals, secondary electrons produced neutralino annihilation generate synchrotron emission in magnetized atmosphere galaxy clusters galaxies which could observed as...
An updated model for the synchrotron and inverse Compton emission from a population of high energy electrons Crab Nebula is used to reproduce measured spectral distribution radio gamma-rays. By comparing predicted component with recent Fermi measurements nebula's emission, it possible determine average magnetic field in nebula derive underlying electron distribution. The calculation can then be cross calibrate observations ground based air shower measurements. resulting calibration factors...
Predicted by hierarchical structure formation, Milky Way-type galaxies are anticipated to host numerous dark matter subhalos with masses between 10^{10} and a cut-off of 10^{-6} solar masses, or even less. In self-annihilating scenarios, these objects could be visible in the gamma-ray band as faint non-variable sources without astrophysical counterpart. accordance realistic subhalo models current observational constraints on matter, we predict that about one massive Galactic may have already...
Very high-energy gamma-rays (VHE; E>100 GeV) have been detected from the direction of Galactic Centre up to energies E>10 TeV. Up now, origin this emission is unknown due limited positional accuracy observing instruments. One counterpart candidates super-massive black hole (SMBH) Sgr A*. If VHE produced within ~10^{15} cm ~1000 r_G (r_G=G M/c^2 Schwarzschild radius) SMBH, a decrease photon flux in energy range 100--300 GeV expected whenever an early type or giant star approaches line sight ~...
Photon counts statistics have been shown to provide a sensitive tool for characterizing gamma-ray source populations and the composition of sky. In this contribution, we extend use standard 1-point probability distribution function (1pPDF) decompose high-latitude flux observed with Fermi-LAT into emission from point sources, Galactic foreground, diffuse isotropic background. To that aim, perform an energy-binned analysis data between 1 171 GeV. We measure source-count...