A5075169225- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Radiation Detection and Scintillator Technologies
- Radiation Therapy and Dosimetry
- Cosmology and Gravitation Theories
- Atomic and Subatomic Physics Research
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Particle Accelerators and Free-Electron Lasers
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Computational Physics and Python Applications
- Scientific Research and Discoveries
- Advanced Fiber Optic Sensors
- Neural dynamics and brain function
- Photocathodes and Microchannel Plates
- Radioactive Decay and Measurement Techniques
- Noncommutative and Quantum Gravity Theories
Université de Haute-Alsace
2015-2025
Institut Pluridisciplinaire Hubert Curien
2020-2025
Los Alamos National Laboratory
2016-2024
Centre National de la Recherche Scientifique
2018-2024
Université de Strasbourg
2016-2024
Parc Científic de la Universitat de València
2024
Istituto Nazionale di Fisica Nucleare
2024
Aix-Marseille Université
2024
University of Amsterdam
2024
HUN-REN Wigner Research Centre for Physics
2023-2024
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...
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 $\lesssim$...
The main objectives of the KM3NeT Collaboration are (i) discovery and subsequent observation high-energy neutrino sources in Universe (ii) determination mass hierarchy neutrinos. These strongly motivated by two recent important discoveries, namely: (1) astrophysical signal reported IceCube (2) sizable contribution electron neutrinos to third eigenstate as Daya Bay, Reno others. To meet these objectives, plans build a new Research Infrastructure consisting network deep-sea telescopes...
The γ-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, a residual all-sky component commonly called isotropic background (IGRB). IGRB comprises all extragalactic emissions too faint or resolved in given survey, as well any foregrounds that are approximately isotropic. first measurement Large Area Telescope (LAT) on board Fermi Gamma-ray Space (Fermi) used 10 months sky-survey...
Satellite galaxies of the Milky Way are among most promising targets for dark matter searches in gamma rays. We present a search consisting weakly interacting massive particles, applying joint likelihood analysis to 10 satellite with 24 months data Fermi Large Area Telescope. No signal is detected. Including uncertainty distribution, robust upper limits placed on annihilation cross sections. The 95% confidence level range from about 10(-26) cm3 s(-1) at 5 GeV 5×10(-23) 1 TeV, depending final...
The dwarf spheroidal satellite galaxies of the Milky Way are some most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack astrophysical backgrounds, widely considered be among promising targets for indirect detection via $\ensuremath{\gamma}$ rays. Here we report on $\ensuremath{\gamma}$-ray observations 25 based 4 years Fermi Large Area Telescope (LAT) data. None significantly detected in rays, present flux upper limits between 500 MeV GeV. We...
The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on Gamma-ray Space (Fermi) mission, is an imaging, wide field-of-view, high-energy γ-ray telescope, covering energy range from 20 MeV to more than 300 GeV. During first years of LAT team has gained considerable insight into in-flight performance instrument. Accordingly, we have updated analysis used reduce data for public release as well response functions (IRFs), description provided analysis. In this paper,...
Exotic origin for cosmic positrons Several cosmic-ray detectors have found more arriving at Earth than expected. Some researchers interpret this as a signature of exotic physics, such the annihilation dark matter particles. Others prefer mundane explanation that involves positron generation pulsars followed by diffusion to Earth. Abeysekara et al. detected extended emission gamma rays around two nearby pulsars, generated high-energy electrons and positrons. The size was used calculate how...
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...
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...
ABSTRACT We search for excess γ -ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using six years data from Fermi Large Area Telescope (LAT). Our sample 45 stellar systems includes 28 kinematically dark-matter-dominated dwarf spheroidal (dSphs) 17 recently discovered that have photometric characteristics consistent population known dSphs. For each these targets, relative predicted flux due to dark matter annihilation is taken kinematic...
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...
The Crab Nebula is the brightest TeV gamma-ray source in sky and has been used for past 25 years as a reference astronomy, calibration verification of new instruments. High Altitude Water Cherenkov Observatory (HAWC), completed early 2015, to observe at high significance across nearly full spectrum energies which HAWC sensitive. unique its wide field-of-view, 2 sr any instant, high-energy reach, up 100 TeV. HAWC's sensitivity improves with energy. Above $\sim$1 driven by best background...
We present the first catalog of TeV gamma-ray sources realized with recently completed High Altitude Water Cherenkov Observatory (HAWC). It is most sensitive wide field-of-view telescope currently in operation, a 1-year survey sensitivity ~5-10% flux Crab Nebula. With an instantaneous field view >1.5 sr and >90% duty cycle, it continuously surveys monitors sky for gamma ray energies between hundreds GeV tens TeV. HAWC located Mexico at latitude 19 degree North was March 2015. Here, we 2HWC...
The Fermi bubbles are two large structures in the gamma-ray sky extending to 55° above and below Galactic center. We analyze 50 months of Large Area Telescope data between 100 MeV 500 GeV 10° latitude derive spectrum morphology bubbles. thoroughly explore systematic uncertainties that arise when modeling diffuse emission through separate approaches. is well described by either a log parabola or power law with an exponential cutoff. exclude simple more than 7σ significance. cutoff has index...
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...
Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse background. Flux upper limits are presented for spectral from 7 200 GeV background 4.8 264 obtained two years of Fermi Large Area Telescope data integrated over most sky. We give cross-section lifetime lower dark models that spectrum, including proposed as explanations PAMELA cosmic-ray data.
We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in γ-ray spectrum of NGC 1275, central galaxy Perseus cluster. Using 6 years Fermi Large Area Telescope data, we find no evidence ALPs exclude couplings above 5×10^{-12} GeV^{-1} ALP masses 0.5≲m_{a}≲5 neV at 95% confidence. The limits are competitive with sensitivity planned laboratory experiments, and, together other bounds, strongly constrain possibility that can...
We report for the first time a gamma-ray and multi-wavelength nearly-periodic oscillation in an active galactic nucleus. Using Fermi Large Area Telescope (LAT) we have discovered apparent quasi-periodicity flux (E >100 MeV) from GeV/TeV BL Lac object PG 1553+113. The marginal significance of 2.18 +/-0.08 year-period cycle is strengthened by correlated oscillations observed radio optical fluxes, through data collected OVRO, Tuorla, KAIT, CSS monitoring programs Swift UVOT. appearing ~10 years...
We present the first catalog of gamma-ray sources emitting above 56 and 100 TeV with data from High Altitude Water Cherenkov (HAWC) Observatory, a wide field-of-view observatory capable detecting gamma rays up to few hundred TeV. Nine are observed TeV, all which likely Galactic in origin. Three continue past making this highest-energy source date. report integral flux each these objects. also spectra for three discuss possibility that they PeVatrons.
The event selection developed for the Fermi Large Area Telescope before launch has been periodically updated to reflect constantly improving knowledge of detector and environment in which it operates. Pass 7, released public August 2011, represents most recent major iteration this incremental process. In parallel, LAT team undertaken a coherent long-term effort aimed at radical revision entire event-level analysis, based on experience gained prime phase mission. This includes virtually every...
Due to their proximity, high dark-matter content, and apparent absence of non-thermal processes, Milky Way dwarf spheroidal satellite galaxies (dSphs) are excellent targets for the indirect detection dark matter. Recently, eight new dSph candidates were discovered using first year data from Dark Energy Survey (DES). We searched gamma-ray emission coincident with positions these objects in six years Fermi Large Area Telescope data. found no significant excesses emission. Under assumption that...
We report the discovery of four Fast Radio Bursts (FRBs) in ongoing SUrvey for Pulsars and Extragalactic at Parkes Telescope: FRBs 150610, 151206, 151230 160102. Our real-time discoveries have enabled us to conduct extensive, rapid multimessenger follow-up 12 major facilities sensitive radio, optical, X-ray, gamma-ray photons neutrinos on time-scales ranging from an hour a few months post-burst. No counterparts were found we provide upper limits afterglow luminosities. None seen repeat....
Abstract We present TeV gamma-ray observations of the Crab Nebula, standard reference source in ground-based astronomy, using data from High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy estimation methods that utilize extensive air shower variables such as core position, angle, and lateral distribution. contrast, previously published HAWC spectrum roughly estimated with only number photomultipliers triggered. This new methodology...