M. Breuhaus
A5025789612- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Particle Accelerators and Free-Electron Lasers
- Galaxies: Formation, Evolution, Phenomena
- Nuclear Physics and Applications
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Astrophysics and Star Formation Studies
- High-Energy Particle Collisions Research
- History and Developments in Astronomy
- CCD and CMOS Imaging Sensors
- Atmospheric Ozone and Climate
- Radiation Therapy and Dosimetry
- Computational Physics and Python Applications
- Seismology and Earthquake Studies
Centre de physique des particules de Marseille
2024-2025
Aix-Marseille Université
2024-2025
Centre National de la Recherche Scientifique
2024-2025
Max Planck Institute for Nuclear Physics
2019-2024
University of the Free State
2022
Heidelberg University
2022
Max Planck Institute for Astronomy
2022
Campbell Collaboration
2022
Berlin Heart (Germany)
2021
Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, associated with stellar core collapse events. We report the detection very-high-energy (VHE) GRB 190829A, between 4 and 56 hours after trigger, using High Energy Stereoscopic System (H.E.S.S.). The low luminosity redshift 190829A reduce both internal external absorption, allowing determination its intrinsic energy spectrum. Between energies 0.18 3.3 tera-electron...
SS 433 is a microquasar, stellar binary system that launches collimated relativistic jets. We observed in gamma rays using the High Energy Stereoscopic System (H.E.S.S.) and found an energy-dependent shift apparent position of gamma-ray emission from parsec-scale These observations trace energetic electron population indicate inverse Compton scattering mechanism rays. Our modeling morphology constrains location particle acceleration requires abrupt deceleration jet flow. infer presence...
The detection of cosmic neutrinos with energies above a teraelectronvolt (TeV) offers unique exploration into astrophysical phenomena1–3. Electrically neutral and interacting only by means the weak interaction, are not deflected magnetic fields rarely absorbed interstellar matter: their direction indicates that origin might be from farthest reaches Universe. High-energy can produced when ultra-relativistic cosmic-ray protons or nuclei interact other matter photons, observation could...
Recurrent Novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to accretion fresh material from a binary companion. The shock generated by ejected slamming into companion star's wind, accelerates particles very-high-energies. We report very-high-energy (VHE, $\gtrsim100$\,GeV) gamma rays recurrent nova RS\,Ophiuchi up month after its 2021 outburst, using High Energy Stereoscopic System. VHE emission has similar temporal profile lower-energy GeV emission,...
Magnetic fields in galaxies and galaxy clusters are believed to be the result of amplification intergalactic seed during formation large-scale structures universe. However, origin, strength, morphology this magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) IGMF can obtained from observations high-energy gamma rays distant blazars. Gamma interact with extragalactic background light produce electron-positron pairs, which subsequently initiate electromagnetic...
GRB221009A is the brightest gamma-ray burst ever detected. To probe very-high-energy (VHE, $>$\!100 GeV) emission, High Energy Stereoscopic System (H.E.S.S.) began observations 53 hours after triggering event, when brightness of moonlight no longer precluded observations. We derive differential and integral upper limits using H.E.S.S. data from third, fourth, ninth nights initial GRB detection, applying atmospheric corrections. The combined yield an energy flux limit $\Phi_\mathrm{UL}^{95\%}...
Dwarf spheroidal galaxy satellites of the Milky Way are prime targets for indirect detection dark matter with gamma rays due to their proximity, high content, and absence nonthermal emission processes. Recently, Dark Energy Survey (DES) revealed existence new ultrafaint dwarf galaxies in southern-hemisphere sky, therefore ideally located ground-based observations imaging atmospheric Cherenkov telescope array H.E.S.S. We present a search very-high-energy ($E\ensuremath{\gtrsim}100\text{...
The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations very-high-energy γ rays from have provided important constraints modelling its broadband emission. We present first fully self-consistent analysis Nebula’s -ray emission between 1 GeV ∼100 TeV, that is, over five orders magnitude in energy. Using open-source software package G AMMAPY , we combined 11.4 yr data Fermi Large Area Telescope 80 h High...
KM3NeT/ARCA is a Cherenkov neutrino telescope under construction in the Mediterranean sea, optimised for detection of astrophysical neutrinos with energies above ∼1 TeV. In this work, using Monte Carlo simulations including all-flavour neutrinos, integrated and differential sensitivities are presented considering case diffuse flux as well extended point-like sources. This analysis applied to Starburst Galaxies demonstrating that detector has capability tracing TeV from these Remarkably,...
Abstract The KM3NeT/ARCA neutrino detector is currently under construction at 3500 m depth offshore Capo Passero, Sicily, in the Mediterranean Sea. main science objectives are detection of high-energy cosmic neutrinos and discovery their sources. Simulations were conducted for full detector, instrumenting a volume 1 km $$^3$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mn>3</mml:mn> </mml:mmultiscripts> </mml:math> , to estimate sensitivity...
Cosmological and astrophysical observations suggest that 85% of the total matter Universe is made Dark Matter (DM). However, its nature remains one most challenging fundamental open questions particle physics. Assuming DM, this exotic form cannot consist Standard Model (SM) particles. Many models have been developed to attempt unraveling DM such as Weakly Interacting Massive Particles (WIMPs), favored candidates. WIMP annihilations decay could produce SM particles which in turn hadronize...
It is generally held that >100 TeV emission from astrophysical objects unambiguously demonstrates the presence of PeV protons or nuclei, due to unavoidable Klein-Nishina suppression inverse Compton electrons. However, in dominated cooling, hard high-energy electron spectra are possible. We show environmental requirements for such can naturally be met spiral arms, and particular regions enhanced star formation activity, natural locations most promising accelerators: powerful young pulsars....
In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-ray (by factor 10) and optical 5) bands remained this low state throughout 2022. Similarly, polarization source vanished, resulting spectrum being fully explained through steady of accretion disk broad-line region. Unlike aforementioned bands, very-high-energy X-ray fluxes did not exhibit from year to year. This suggests that steady-state originate different emission region than vanished parts jet fluxes....
Abstract The measurement of the flux muons produced in cosmic ray air showers is essential for study primary rays. Such measurements are important extensive shower detectors to assess energy spectrum and chemical composition flux, complementary information provided by fluorescence detectors. Detailed simulations carried out, using codes such as CORSIKA, estimate muon at sea level. These based on choice hadronic interaction models, which improvements have been implemented post-LHC era. In...
The identification of PeVatrons, hadronic particle accelerators reaching the knee cosmic ray spectrum (few $10^{15}$ eV), is crucial to understand origin rays in Galaxy. We provide an update on unidentified source HESS J1702-420, a promising PeVatron candidate. present new observations J1702-420 made with High Energy Stereoscopic System (H.E.S.S.), and processed using improved analysis techniques. configuration was optimized enhance collection area at highest energies. applied...
The recent measurement by LHAASO of gamma-ray emission extending up to hundreds TeV from multiple Galactic sources represents a major observational step forward in the search for origin cosmic rays. burning question is if this ultra-high-energy associated with acceleration protons and/or nuclei PeV energies, or it can be PeV-electron accelerators. A strong Klein-Nishina suppression inverse Compton at these energies unavoidable; nevertheless, we show here that provide natural explanation...
Context. HESS J1809$-$193 is an unassociated very-high-energy $\gamma$-ray source located on the Galactic plane. While it has been connected to nebula of energetic pulsar PSR J1809$-$1917, supernova remnants and molecular clouds present in vicinity also constitute possible associations. Recently, detection emission up energies $\sim$100 TeV with HAWC observatory led renewed interest J1809$-$193. Aims. We aim understand origin Methods. analysed 93.2 h data taken above 0.27 High Energy...
A bstract KM3NeT/ORCA is a water Cherenkov neutrino detector under construction and anchored at the bottom of Mediterranean Sea. The designed to study oscillations atmospheric neutrinos determine mass ordering. This paper focuses on an initial configuration ORCA, referred as ORCA6, which comprises six out foreseen 115 detection units photo-sensors. high-purity sample was extracted, corresponding exposure 433 kton-years. 5828 candidates analysed following binned log-likelihood method in...
Indirect dark matter detection methods are used to observe the products of annihilations or decays originating from astrophysical objects where large amounts thought accumulate. With neutrino telescopes, an excess neutrinos is searched for in nearby reservoirs, such as Sun and Galactic Centre, which could potentially produce a sizeable flux Standard Model particles. The KM3NeT infrastructure, currently under construction, comprises ARCA ORCA undersea \v{C}erenkov detectors located at two...
KM3NeT/ORCA is an underwater neutrino telescope under construction in the Mediterranean Sea. Its primary scientific goal to measure atmospheric oscillation parameters and determine mass ordering. ORCA can constrain $\Delta m^{2}_{31}$ $\theta_{23}$ by reconstructing arrival direction energy of multi-GeV neutrinos crossing Earth. Searches for deviations from Standard Model particle physics forward scattering inside Earth matter, produced Non-Standard Interactions, be conducted investigating...
Oscillations of atmospheric muon and electron neutrinos produce tau with energies in the GeV range, which can be observed by ORCA detector KM3NeT neutrino telescope Mediterranean Sea. First measurements ORCA6, an early subarray corresponding to about 5$\%$ final detector, are presented. A sample 5828 candidates has been selected from analysed exposure 433 kton-years. The $\nu_\tau$ normalisation, defined as ratio between number expected events, is measured $S_\tau = 0.48^{+0.5}_{-0.33}$....