A5022809978- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Particle Accelerators and Free-Electron Lasers
- Astronomical Observations and Instrumentation
- Radiation Detection and Scintillator Technologies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- Astro and Planetary Science
- Nuclear Physics and Applications
- Superconducting and THz Device Technology
- Radiation Therapy and Dosimetry
- Calibration and Measurement Techniques
Universität Hamburg
2015-2024
Max Planck Institute for Nuclear Physics
2002-2024
Universitat de Barcelona
2024
Institut d'Estudis Espacials de Catalunya
2024
Universidad de Zaragoza
2015-2023
Campbell Collaboration
2009-2022
Quantum (Australia)
2022
University of the Free State
2022
Center for Teaching Thinking
2022
University of Tübingen
2006-2021
The Crab nebula was observed with the H.E.S.S. stereoscopic Cherenkov-telescope array between October 2003 and January 2005 for a total of 22.9 hours (after data quality selection). Observations were made three operational telescopes in late complete 4 telescope - February 2004 2005. observations are discussed used as an example to detail flux spectral analysis procedures H.E.S.S., evaluate systematic uncertainties measurements. spectrum gamma-rays from source calculated on run-by-run...
The high-frequency peaked BL Lac PKS 2155-304 at redshift z = 0.116 is a well-known VHE (>100 GeV) γ-ray emitter. Since 2002 its flux has been monitored using the H.E.S.S. stereoscopic array of imaging atmospheric Cerenkov telescopes in Namibia. During 2006 July dark period, average was measured to be more than 10 times typical values observed from object. This article focuses solely on an extreme outburst detected early hours 28 (MJD 53,944). during this I(>200 (1.72 ± 0.05stat 0.34syst) ×...
The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon or satellite based instruments in the detection very-high-energy (>600 GeV) cosmic-ray electrons. Here we present electron spectrum derived from data taken with High Energy Stereoscopic System (H.E.S.S.) imaging atmospheric Cherenkov telescopes. In this measurement, first type, are able to extend measurement beyond range accessible direct measurements. We find evidence for...
We report on a survey of the inner part Galactic Plane in very high energy gamma-rays, with H.E.S.S. Cherenkov telescope system. The between +-30deg longitude and +-3deg latitude relative to Centre was observed 500 pointings for total 230 hours, reaching an average flux sensitivity 2% Crab Nebula at energies above 200 GeV. Fourteen previously unknown sources were detected significance level greater than 4 sigma after accounting all trials involved search. Initial results eight most...
The measurement of an excess in the cosmic-ray electron spectrum between 300 and 800 GeV by ATIC experiment has - together with PAMELA detection a rise positron fraction up to 100 motivated many interpretations terms dark matter scenarios; alternative explanations assume nearby source like pulsar or supernova remnant. Here we present H.E.S.S. starting at 340 GeV. While overall flux measured is consistent data within statistical systematic errors, exclude pronounced peak as suggested for...
We report the detection of a point-like source very high energy (VHE) gamma-rays coincident within 1' Sgr A*, obtained with H.E.S.S. array Cherenkov telescopes. The exhibit power-law spectrum spectral index -2.2 +/- 0.09 0.15 and flux above 165 GeV threshold (1.82 0.22) * 10^-7 m^-2 s^-1. measured differ substantially from recent results reported in particular by CANGAROO collaboration.
We present the results of most comprehensive survey Galactic plane in very high-energy (VHE) gamma-rays, including a public release sky maps, catalog VHE sources, and discovery 16 new sources gamma-rays. The High Energy Spectroscopic System (H.E.S.S.) (HGPS) was decade-long observation program carried out by H.E.S.S. I array Cherenkov telescopes Namibia from 2004 to 2013. observations amount nearly 2700 h data, covering at longitudes l = 250 deg 65 latitudes |b| < 3 deg. In addition...
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...
The inner region of the Milky Way halo harbors a large amount dark matter (DM). Given its proximity, it is one most promising targets to look for DM. We report on search annihilations DM particles using γ-ray observations towards 300 pc Way, with H.E.S.S. array ground-based Cherenkov telescopes. analysis based 2D maximum likelihood method Galactic Center (GC) data accumulated by over last 10 years (2004-2014), and does not show any significant signal above background. Assuming Einasto...
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....
A search for a very-high-energy (VHE; ≥100 GeV) γ-ray signal from self-annihilating particle dark matter (DM) is performed towards region of projected distance r∼45-150 pc the Galactic center. The background-subtracted spectrum measured with High Energy Stereoscopic System (H.E.S.S.) instrument in energy range between 300 GeV and 30 TeV shows no hint residual flux. Assuming conventional Navarro-Frenk-White Einasto density profiles, limits are derived on velocity-weighted annihilation cross...
Gamma-ray line signatures can be expected in the very-high-energy (${E}_{\ensuremath{\gamma}}>100\text{ }\text{ }\mathrm{GeV}$) domain due to self-annihilation or decay of dark matter (DM) particles space. Such a signal would readily distinguishable from astrophysical $\ensuremath{\gamma}$-ray sources that most cases produce continuous spectra span over several orders magnitude energy. Using data collected with H.E.S.S. instrument, upper limits on linelike emission are obtained energy range...
of the Technical Design Report for second stage "Any Light Particle Search" (ALPS-II) at DESY as submitted to PRC in August 2012 and reviewed November 2012.ALPS-II is a "Light Shining through Wall" experiment which searches photon oscillations into weakly interacting sub-eV particles.These are often predicted by extensions Standard Model motivated astrophysical phenomena.The first phases ALPS-II project were approved management on February 21st, 2013.
The long gamma-ray burst (GRB) 100621A, at the time brightest X-ray transient ever detected by Swift-XRT in $0.3\textrm{--}10$ keV range, has been observed with H.E.S.S. imaging air Cherenkov telescope array, sensitive to gamma radiation very-high-energy (VHE, $>100$ GeV) regime. Due its relatively small redshift of $z\sim0.5$, favourable position southern sky and short follow-up ($<700 \rm{s}$ after satellite trigger) observations, this GRB could be within sensitivity reach instrument....
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...
Following the detection of strong TeV γ-ray flares from BL Lac object 1ES 1959+650 with Whipple 10 m Cerenkov telescope on 2002 May 16 and 17, we performed intensive target opportunity radio, optical, X-ray, observations 18 to August 14. Observations X-ray Rossi X-Ray Timing Explorer HEGRA telescopes revealed several flares, enabling us sensitively test X-ray-γ-ray flux correlation properties. Although fluxes seemed be correlated in general, found an "orphan" flare that was not accompanied...
We report the discovery of very-high-energy (VHE) γ-ray emission binary system PSR B1259-63/SS 2883 a radio pulsar orbiting massive, luminous Be star in highly eccentric orbit.The observations around 2004 periastron passage were performed with four 13 m Cherenkov telescopes HESS experiment, recently installed Namibia and full operation since December 2003.Between February June 2004, signal from was detected total significance above 13σ.The flux found to vary significantly on timescales days...
X-ray binaries are composed of a normal star in orbit around neutron or stellar-mass black hole. Radio and x-ray observations have led to the presumption that some called microquasars behave as scaled-down active galactic nuclei. Microquasars resolved radio emission is thought arise from relativistic outflow akin nuclei jets, which particles can be accelerated large energies. Very high energy gamma-rays produced by interactions these been observed several Using High Energy Stereoscopic...
The detection of fast variations the tera-electron volt (TeV) (10(12) eV) gamma-ray flux, on time scales days, from nearby radio galaxy M87 is reported. These are about 10 times as those observed in any other wave band and imply a very compact emission region with dimension similar to Schwarzschild radius central black hole. We thus can exclude several sites processes production. observations confirm that TeV gamma rays emitted by extragalactic sources than blazars, where jets not...