Publications (71)
Detection of extended gamma-ray emission around the Geminga pulsar with H.E.S.S
H. E. S. S. Collaboration, :, F. Aharonian +165
Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar was discovered by…
Giant Lobes of Centaurus A Radio Galaxy Observed with the Suzaku X-ray Satellite
L. Stawarz, Y. T. Tanaka, G. Madejski +15
[abridged] We report on Suzaku observations of selected regions within the Southern giant lobe of the radio galaxy Centaurus A. We focus on distinct X-ray features likely associate…
EWOCS-V: Is Wd1-72 a recent post-interaction WR+O binary?
C. J. K. Larkin, J. Mackey, H. Jin +14
The evolutionary origin of Wolf-Rayet (WR) stars at Solar metallicity is unclear. Single-star evolution from massive O stars, possibly via a Luminous Blue Variable phase, is challe…
Constraining the nature of the most extreme Galactic particle accelerator. H.E.S.S. observations of the microquasar V4641 Sgr
A. Acharyya, F. Aharonian, H. Ashkar +131
Microquasars have emerged as promising candidates to explain the cosmic-ray flux at petaelectronvolt energies. LHAASO observations revealed V4641~Sgr as the most extreme example so…
An in situ comparison of electron acceleration at collisionless shocks under differing upstream magnetic field orientations
A. Masters, A. H. Sulaiman, Å. Stawarz +6
A leading explanation for the origin of Galactic cosmic rays is acceleration at high-Mach number shock waves in the collisionless plasma surrounding young supernova remnants. Evide…
Environmental limits on the non-resonant cosmic-ray current-driven instability
B. Reville, J. G. Kirk, P. Duffy +1
We investigate the so-called non-resonant cosmic-ray streaming instability, first discussed by Bell (2004). The extent to which thermal damping and ion-neutral collisions reduce th…
Time-resolved fast turbulent dynamo in a laser plasma
A. F. A. Bott, P. Tzeferacos, L. Chen +25
Understanding magnetic-field generation and amplification in turbulent plasma is essential to account for observations of magnetic fields in the universe. A theoretical framework a…
Science Prospects for the Southern Wide-field Gamma-ray Observatory: SWGO
SWGO Collaboration, P. Abreu, R. Alfaro +303
Ground-based gamma-ray astronomy is now well established as a key observational approach to address critical topics at the frontiers of astroparticle physics and high-energy astrop…
Evidence for gamma-ray emission from the remnant of Kepler's supernova based on deep H.E.S.S. observations
H. E. S. S. Collaboration, F. Aharonian, F. Ait Benkhali +157
Observations with imaging atmospheric Cherenkov telescopes (IACTs) have enhanced our knowledge of nearby supernova (SN) remnants with ages younger than 500 years by establishing Ca…
A current driven instability in parallel, relativistic shocks
B. Reville, J. G. Kirk, P. Duffy
Recently, Bell has reanalysed the problem of wave excitation by cosmic rays propagating in the pre-cursor region of a supernova remnant shock front. He pointed out a strong, non-re…
HESS J1809193: a halo of escaped electrons around a pulsar wind nebula?
H. E. S. S. Collaboration, :, F. Aharonian +151
Context. HESS J1809193 is an unassociated very-high-energy -ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J…
Scrutinizing the 2020 multiwavelength outburst of PKS 0903-57 through observations with H.E.S.S
A. Acharyya, F. Aharonian, F. Ait Benkhali +138
The blazar PKS 0903-57 has recently been classified as a flat spectrum radio quasar at a redshift of . In March and April 2020, Fermi-LAT and AGILE reported tremendous ac…
Cosmic-ray current-driven instabilities -- revisiting environmental conditions
B. Reville, G. Giacinti, R. Scott
The growth of magneto-hydrodynamic fluctuations relevant to cosmic ray confinement in and near their sources, and the effects of local plasma conditions is revisited. We consider c…
Time-resolved hadronic particle acceleration in the recurrent Nova RS Ophiuchi
H. E. S. S. Collaboration, F. Aharonian, F. Ait Benkhali +171
Recurrent Novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated by e…
Inefficient magnetic-field amplification in supersonic laser-plasma turbulence
A. F. A. Bott, L. Chen, G. Boutoux +17
We report a laser-plasma experiment that was carried out at the LMJ-PETAL facility and realized the first magnetized, turbulent, supersonic plasma with a large magnetic Reynolds nu…
Diffusive shock acceleration at laser driven shocks: studying cosmic-ray accelerators in the laboratory
B. Reville, A. R. Bell, G. Gregori
The non-thermal particle spectra responsible for the emission from many astrophysical systems are thought to originate from shocks via a first order Fermi process otherwise known a…
Temporal structure of attosecond pulses from laser-driven coherent synchrotron emission
S. Cousens, B. Reville, B. Dromey +1
The microscopic dynamics of laser-driven coherent synchrotron emission transmitted through thin foils are investigated using particle-in-cell simulations. For normal incidence inte…
Cherenkov Telescope Array Contributions to the 35th International Cosmic Ray Conference (ICRC2017)
F. Acero, B. S. Acharya, V. AcÃn Portella +1137
List of contributions from the Cherenkov Telescope Array Consortium presented at the 35th International Cosmic Ray Conference, July 12-20 2017, Busan, Korea.
Experimental observation of a current-driven instability in a neutral electron-positron beam
J. Warwick, T. Dzelzainis, M. E. Dieckmann +16
We report on the first experimental observation of a current-driven instability developing in a quasi-neutral matter-antimatter beam. Strong magnetic fields ( 1 T) are measur…
Generation of a neutral, high-density electron-positron plasma in the laboratory
G. Sarri, K. Poder, J. Cole +17
We report on the laser-driven generation of purely neutral, relativistic electron-positron pair plasmas. The overall charge neutrality, high average Lorentz factor ($γ_{e/p} \appr…
Deciphering the gamma-ray emission in the Cygnus region
L. Haerer, T. Vieu, F. Schulze +2
The Cygnus region is a vast star-forming complex harbouring a population of powerful objects, including massive star clusters and associations, Wolf-Rayet stars, pulsars, and super…
Transport of high-energy charged particles through spatially-intermittent turbulent magnetic fields
L. E. Chen, A. F. A. Bott, P. Tzeferacos +22
Identifying the sources of the highest energy cosmic rays requires understanding how they are deflected by the stochastic, spatially intermittent intergalactic magnetic field. Here…
Search for long-term variability of HESS J1745-290
H. E. S. S. Collaboration, :, A. Acharyya +116
At the center of our Galaxy lies the bright γ-ray point-like source HESS J1745-290, which is compatible in position with Sgr A star, although an association between the two remain…
Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis
F. Aharonian, F. Ait Benkhali, J. Aschersleben +158
The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy rays from…
A pulsar wind nebula origin of the LHAASO-detected UHE gamma-ray sources
M. Breuhaus, B. Reville, J. A. Hinton
The recent measurement by LHAASO of gamma-ray emission extending up to 100s of TeV from multiple Galactic sources represents a major observational step forward in the search for th…
H.E.S.S. programme searching for VHE gamma rays associated with FRBs
F. Aharonian, A. Archaryya, J. Aschersleben +127
Fast Radio Bursts (FRBs) are highly energetic, extremely short-lived bursts of radio flashes. Despite extensive research, the exact cause of these outbursts remains speculative. Th…
Modified Friedmann equations via conformal Bohm -- De Broglie gravity
G. Gregori, B. Reville, B. Larder
We use an alternative interpretation of quantum mechanics, based on the Bohmian trajectory approach, and show that the quantum effects can be included in the classical equation of…
The second H.E.S.S. gamma-ray burst catalogue: 15 years of observations with the H.E.S.S. telescopes
A. Acharyya, F. Aharonian, C. Arcaro +143
Recent observational efforts using imaging atmospheric Cherenkov telescopes (IACTs) have led to firm detections of very-high-energy (VHE) signals from bright gamma-ray bursts (GRBs…
Laboratory evidence of dynamo amplification of magnetic fields in a turbulent plasma
P. Tzeferacos, A. Rigby, A. Bott +27
Magnetic fields are ubiquitous in the Universe. Extragalactic disks, halos and clusters have consistently been shown, via diffuse radio-synchrotron emission and Faraday rotation me…
Strong suppression of heat conduction in a laboratory replica of galaxy-cluster turbulent plasmas
J. Meinecke, P. Tzeferacos, J. S. Ross +32
Galaxy clusters are filled with hot, diffuse X-ray emitting plasma, with a stochastically tangled magnetic field whose energy is close to equipartition with the energy of the turbu…
Very-high-energy -ray emission from young massive star clusters in the Large Magellanic Cloud
F. Aharonian, F. Ait Benkhali, J. Aschersleben +129
The Tarantula Nebula in the Large Magellanic Cloud is known for its high star formation activity. At its center lies the young massive star cluster R136, providing a significant am…
A filamentation instability for streaming cosmic-rays
B. Reville, A. R. Bell
We demonstrate that cosmic rays form filamentary structures in the precursors of supernova remnant shocks due to their self-generated magnetic fields. The cosmic-ray filamentation…
Unveiling extended gamma-ray emission around HESS J1813-178
F. Aharonian, F. Ait Benkhali, J. Aschersleben +147
HESS J1813178 is a very-high-energy -ray source spatially coincident with the young and energetic pulsar PSR J18131749 and thought to be associated with its pulsar wind n…
A deep spectromorphological study of the -ray emission surrounding the young massive stellar cluster Westerlund 1
F. Aharonian, H. Ashkar, M. Backes +156
Young massive stellar clusters are extreme environments and potentially provide the means for efficient particle acceleration. Indeed, they are increasingly considered as being res…
Laboratory realization of relativistic pair-plasma beams
C. D. Arrowsmith, P. Simon, P. Bilbao +26
Relativistic electron-positron plasmas are ubiquitous in extreme astrophysical environments such as black holes and neutron star magnetospheres, where accretion-powered jets and pu…
CTA Contributions to the 34th International Cosmic Ray Conference (ICRC2015)
The CTA Consortium, :, A. Abchiche +1305
List of contributions from the CTA Consortium presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.
Generating ultra-dense pair beams using 400 GeV/c protons
C. D. Arrowsmith, N. Shukla, N. Charitonidis +14
A previously unexplored experimental scheme is presented for generating low-divergence, ultra-dense, relativistic, electron-positron beams using 400 GeV/c protons available at faci…
High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S
F. Aharonian, F. Ait Benkhali, J. Aschersleben +144
Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators an…
Gamma-Ray Constraints on Heavy Axion-Like-Particle Decays from Fermi-LAT and H.E.S.S. Blazar Spectra
A. Acharyya, F. Aharonian, M. Backes +117
The propagation of very-high-energy (VHE; GeV) gamma rays from extragalactic sources is affected by interactions with photons of the extragalactic background light…
Detection of very-high-energy gamma-ray emission from Eta Carinae during its 2020 periastron passage
H. E. S. S. Collaboration, F. Aharonian, F. Ait Benkhali +137
The colliding-wind binary system Carinae has been identified as a source of high-energy (HE, below 100\,GeV) and very-high-energy (VHE, above 100\,GeV) gamma rays…
Numerical modeling of laser-driven experiments aiming to demonstrate magnetic field amplification via turbulent dynamo
P. Tzeferacos, A. Rigby, A. Bott +29
The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and…
X-ray Spectral Analysis of the Jet Termination Shock in Pictor A on Sub-Arcsecond Scales with Chandra
R. Thimmappa, L. Stawarz, J. Neilsen +2
Hotspots observed at the edges of extended radio lobes in high-power radio galaxies and quasars mark the position of mildly-relativistic termination shock, where the jet bulk kinet…
Cosmic ray acceleration at oblique shocks
A. R. Bell, K. M. Schure, B. Reville
We show that the diffusion approximation breaks down for particle acceleration at oblique shocks with velocities typical of young supernova remnants. Higher order anisotropies flat…
Search for gamma-ray spectral lines from dark matter annihilation with the H.E.S.S. Inner Galaxy Survey
H. E. S. S. Collaboration, F. Aharonian, H. Ashkar +115
Spectral gamma-ray line features are expected as key signatures from dark matter (DM) annihilations of TeV-scale particle DM. Observations of the Galactic Centre with atmospheric C…
Contributions of the Cherenkov Telescope Array (CTA) to the 6th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2016)
The CTA Consortium, :, A. Abchiche +1387
List of contributions from the Cherenkov Telescope Array (CTA) Consortium presented at the 6th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2016), July 11-15,…
Energetic particle-mediated interplanetary shocks observed by Solar Orbiter
D. Trotta, D. Lario, B. Reville +10
Context: In collisionless shocks, energetic particles can carry sufficient pressure to modify the upstream plasma and the shock structure itself, a regime often invoked in theories…
Measurement of ion acceleration and diffusion in a laser-driven magnetized plasma
J. T. Y. Chu, J. W. D. Halliday, C. Heaton +25
Here we present results from an experiment performed at the GSI Helmholtz Centre for Heavy Ion Research. A mono-energetic beam of chromium ions with initial energies of …
Gamma-ray and X-ray constraints on non-thermal processes in Carinae
R. White, M. Breuhaus, R. Konno +3
The binary system Carinae is a unique laboratory in which to study particle acceleration to high energies under a wide range of conditions, including extremely high densities…
The transport of cosmic rays in self-excited magnetic turbulence
B. Reville, S. O'Sullivan, P. Duffy +1
The process of diffusive shock acceleration relies on the efficacy with which hydromagnetic waves can scatter charged particles in the precursor of a shock. The growth of self-gene…
Searching for TeV gamma-ray emission from SGR\,1935+2154 during its 2020 X-ray and radio bursting phase
H. E. S. S. Collaboration, :, H. Abdalla +251
Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRB) -- enigmatic powerful radio pulses with durations of several milliseconds and high brightness te…
CTA contributions to the 33rd International Cosmic Ray Conference (ICRC2013)
The CTA Consortium, :, O. Abril +1102
Compilation of CTA contributions to the proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), which took place in 2-9 July, 2013, in Rio de Janeiro, Brazil
Stochastic particle acceleration in the lobes of giant radio galaxies
S. O'Sullivan, B. Reville, A. M. Taylor
We investigate the acceleration of particles via the second-order Fermi process in the lobes of giant radio galaxies. Such sites are candidates for the accelerators of ultra-high e…
Curvature in the very-high energy gamma-ray spectrum of M87
H. E. S. S. Collaboration, F. Aharonian, F. Ait Benkhali +132
The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of…
Dynamic shocks powered by a wide, relativistic, super-Eddington outflow launched by an accreting neutron star in the mid-20th century
F. J. Cowie, R. P. Fender, I. Heywood +11
Accreting systems can launch powerful outflows which interact with the surrounding medium. We combine new radio observations of the accreting neutron star X-ray binary (XRB) Circin…
The microphysics of collisionless shock waves
A. Marcowith, A. Bret, A. Bykov +12
Collisionless shocks, that is shocks mediated by electromagnetic processes, are customary in space physics and in astrophysics. They are to be found in a great variety of objects a…
Multi-Dimensional MHD simulations of young Core-Collapse Supernova Remnants
C. J. K. Larkin, J. Mackey, B. Reville +3
Supernova remnants (SNRs) play a central role in shaping the interstellar medium. Core-Collapse Supernova (CCSN) progenitors are massive stars, which produce a dense circumstellar…
The H.E.S.S. extragalactic sky survey with the first decade of observations
H. E. S. S. Collaboration, F. Aharonian, F. Ait Benkhali +140
The results of the first extragalactic gamma-ray survey by the High Energy Stereoscopic System (H.E.S.S.) are presented. The survey comprises 2720 hours of very high-energy gamma-r…
H.E.S.S. follow-up observations of GRB221009A
H. E. S. S. Collaboration, :, F. Aharonian +159
GRB221009A is the brightest gamma-ray burst ever detected. To probe the very-high-energy (VHE, \!100 GeV) emission, the High Energy Stereoscopic System (H.E.S.S.) began observat…
Universal behaviour of shock precursors in the presence of efficient cosmic-ray acceleration
B. Reville, A. R. Bell
The self-consistent interaction between energetic particles and self-generated hydromagnetic waves in a cosmic-ray pressure dominated plasma is considered. Using a three-dimensiona…
Insensitivity of a turbulent laser-plasma dynamo to initial conditions
A. F. A. Bott, L. Chen, P. Tzeferacos +18
It has recently been demonstrated experimentally that a turbulent plasma created by the collision of two inhomogeneous, asymmetric, weakly magnetised laser-produced plasma jets can…
Steady-State Solutions in Nonlinear Diffusive Shock Acceleration
B. Reville, J. G. Kirk, P. Duffy
Stationary solutions to the equations of non-linear diffusive shock acceleration play a fundamental role in the theory of cosmic-ray acceleration. Their existence usually requires…
Multi-dimensional simulations of the expanding supernova remnant of SN 1987A
T. M. Potter, L. Staveley-Smith, B. Reville +4
The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There are still a large number of outstanding questions, such…
Galactic gamma-ray and neutrino emission from interacting cosmic-ray nuclei
M. Breuhaus, J. A. Hinton, V. Joshi +2
We present a study of the expectations for very-high-energy (VHE) to ultra-high-energy (UHE) gamma-ray and neutrino emission from interacting cosmic rays in our Galaxy as well as a…
Neutrino-electron magnetohydrodynamics in an expanding Universe
L. M. Perrone, G. Gregori, B. Reville +2
We derive a new model for neutrino-plasma interactions in an expanding universe that incorporates the collective effects of the neutrinos on the plasma constituents. We start from…
On the Cosmic Ray Driven Firehose Instability
R. Scott, B. Reville, A. Spitkovsky
The role of the non-resonant firehose instability in conditions relevant to the precursors of supernova remnant shocks is considered. Using a second order tensor expansion of the V…
A cosmic ray current driven instability in partially ionised media
B. Reville, J. G. Kirk, P. Duffy +1
We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock. It is known that transverse waves propag…
On the maximum energy of shock-accelerated cosmic rays at ultra-relativistic shocks
B. Reville, A. R. Bell
The maximum energy to which cosmic rays can be accelerated at weakly-magnetised ultra-relativistic shocks is investigated. We demonstrate that for such shocks, in which the scatter…
H.E.S.S. detection of the PSR J0855-4644 nebula
F. Aharonian, H. Ashkar, M. Backes +131
HESS J0852-463 is a TeV γ-ray source located in the Galactic plane. The region consists of a supernova remnant (SNR, RX J0852.0-4622) with a shell-like morphology, commonly referr…
Constraints on the intergalactic magnetic field using Fermi-LAT and H.E.S.S. blazar observations
H. E. S. S., Fermi-LAT Collaborations, : +134
Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in th…
Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433
F. Aharonian, F. Ait Benkhali, J. Aschersleben +161
SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding a…
Ultra-high energy Inverse Compton emission from Galactic electron accelerators
M. Breuhaus, J. Hahn, C. Romoli +4
It is generally held that >100 TeV emission from astrophysical objects unambiguously demonstrates the presence of PeV protons or nuclei, due to the unavoidable Klein-Nishina suppre…