Publications (39)
Discovery of VHE gamma-rays from the BL Lac object PKS 0548-322
H. E. S. S. collaboration, :, F. Aharonian +168
PKS 0548-322 (z=0.069) is a ``high-frequency-peaked'' BL Lac object and a candidate very high energy (VHE, E>100 GeV) gamma-ray emitter, due to its high X-ray and radio flux. Obser…
VHE Gamma Rays from PKS 2155-304
P. M. Chadwick, K. Lyons, T. J. L. McComb +5
The X-ray selected BL Lac PKS 2155-304 has been observed using the University of Durham Mark 6 very high energy gamma ray telescope during 1998. We find no evidence for TeV emissio…
H.E.S.S. constraints on Dark Matter annihilations towards the Sculptor and Carina Dwarf Galaxies
HESS Collaboration, A. Abramowski, F. Acero +192
The Sculptor and Carina Dwarf spheroidal galaxies were observed with the H.E.S.S. Cherenkov telescope array between January 2008 and December 2009. The data sets consist of a total…
Correlation between the TeV gamma ray and X-ray emission from an accreting X-ray binary
P. M. Chadwick, K. Lyons, T. J. L. McComb +6
This paper has been withdrawn by the authors.
H.E.S.S. observations of the globular clusters NGC 6388 and M 15 and search for a Dark Matter signal
HESS Collaboration, A. Abramowski, F. Acero +195
Observations of the globular clusters NGC 6388 and M 15 were carried out by the H.E.S.S. array of Cherenkov telescopes for a live time of 27.2 and 15.2 hours respectively. No gamma…
Very-high-energy gamma-ray emission from the direction of the Galactic globular cluster Terzan 5
HESS Collaboration, A. Abramowski, F. Acero +194
The H.E.S.S. very-high-energy (VHE, E > 0.1 TeV) gamma-ray telescope system has discovered a new source, HESS J1747-248. The measured integral flux is (1.2 +/- 0.3) \times 10^-12 c…
HESS J1943+213: a candidate extreme BL Lacertae object
H. E. S. S. Collaboration, :, A. Abramowski +200
We report on a newly detected point-like source, HESS J1943+213 located in the Galactic plane. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which w…
TeV Measurements of Young Pulsars and Supernova Remnants
P. M. Chadwick, K. Lyons, T. J. L. McComb +6
Observations have been made with the University of Durham Mark 6 telescope of a number of supernova remnants and young pulsars (Vela pulsar, PSR B1055-52, PSR J1105-6107, PSR J0537…
Search for Lorentz Invariance breaking with a likelihood fit of the PKS 2155-304 flare data taken on MJD 53944
HESS Collaboration, A. Abramowski, F. Acero +193
Several models of Quantum Gravity predict Lorentz Symmetry breaking at energy scales approaching the Planck scale (10^{19} GeV). With present photon data from the observations of d…
Geomagnetic Effects on the Performance of Atmospheric Cerenkov Telescopes
P. M. Chadwick, K. Lyons, T. J. L. McComb +5
Atmospheric Cerenkov telescopes are used to detect electromagnetic showers from primary gamma rays of energy > 300 GeV and to discriminate these from cascades due to hadrons using…
Discovery of VHE γ-ray emission and multi-wavelength observations of the BL Lac object 1RXS J101015.9-311909
HESS Collaboration, A. Abramowski, F. Acero +191
1RXS J101015.9-311909 is a galaxy located at a redshift of z=0.14 hosting an active nucleus belonging to the class of bright BL Lac objects. Observations at high (HE, E > 100 MeV)…
Search for a Dark Matter annihilation signal from the Galactic Center halo with H.E.S.S
H. E. S. S. Collaboration, :, A. Abramowski +193
A search for a very-high-energy (VHE; >= 100 GeV) gamma-ray signal from self-annihilating particle Dark Matter (DM) is performed towards a region of projected distance r ~ 45-150 p…
Revisiting the Westerlund 2 Field with the H.E.S.S. Telescope Array
The HESS Collaboration, A. Abramowski, F. Acero +194
Aims. Previous observations with the H.E.S.S. telescope array revealed the existence of extended very-high-energy (VHE; E>100 GeV) γ-ray emission, HESS J1023-575, coincident with…
TeV Gamma Ray Emission from Cen X-3
P. M. Chadwick, K. Lyons, T. J. L. McComb +5
Cen X-3 is a well-studied high-mass accreting X-ray binary and a variable source of high energy gamma rays from 100 MeV to 1 TeV. The object has been extensively monitored with the…
A new SNR with TeV shell-type morphology: HESS J1731-347
HESS Collaboration, A. Abramowski, F. Acero +195
The recent discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731-347 has motivated further obser…
The Uuniversity of Durham Mark 6 Gamma Ray Telescope
P. Armstrong, P. M. Chadwick, P. J. Cottle +18
The design, construction and operation of the University of Durham ground-based gamma ray telescope is discussed. The telescope has been designed to detect gamma rays in the < 200…
Correlation between the X-ray and TeV Gamma Ray Emission from an Accreting X-ray Binary
P. M. Chadwick, K. Lyons, T. J. L. McComb +6
This paper has been withdrawn by the authors.
Multi-wavelength Observations of H 2356-309
HESS Collaboration, A. Abramowski, F. Acero +184
AIMS: The properties of the broad-band emission from the high-frequency peaked BL Lac H 2356-309 (z=0.165) are investigated. METHODS: Very High Energy (VHE; E > 100 GeV) observatio…
Discovery of extended VHE γ-ray emission from the vicinity of the young massive stellar cluster Westerlund 1
HESS Collaboration, A. Abramowski, F. Acero +198
Results obtained in very-high-energy (VHE; E > 100 GeV) γ-ray observations performed with the H.E.S.S. telescope array are used to investigate particle acceleration processes in t…
Discovery and follow-up studies of the extended, off-plane, VHE gamma-ray source HESS J1507-622
H. E. S. S. Collaboration, F. Acero, F. Aharonian +167
Context: The detection of gamma-rays in the very-high-energy (VHE) range (100 GeV-100 TeV) offers the possibility of studying the parent population of ultrarelativistic particles f…
Simultaneous multi-wavelength campaign on PKS 2005-489 in a high state
The H. E. S. S. Collaboration, the Fermi LAT Collaboration, : +345
The high-frequency peaked BL Lac object PKS 2005-489 was the target of a multi-wavelength campaign with simultaneous observations in the TeV gamma-ray (H.E.S.S.), GeV gamma-ray (Fe…
First detection of VHE gamma-rays from SN 1006 by H.E.S.S
HESS Collaboration, F. Acero, F. Aharonian +175
Recent theoretical predictions of the lowest very high energy (VHE) luminosity of SN 1006 are only a factor 5 below the previously published H.E.S.S. upper limit, thus motivating f…
Very high energy gamma-rays from Centaurus X-3: indications and implications
A. M. Atoyan, P. M. Chadwick, M. K. Daniel +7
A timing analysis of VHE gamma-ray observations of Cen X-3 taken with the University of Durham Mark 6 telescope was performed, using both Rayleigh and Bayesian statistics. Data fro…
A Search for VHE Gamma Rays from AGNs Visible from the Southern Hemisphere
P. M. Chadwick, K. Lyons, T. J. L. McComb +5
Observations have been made, using the University of Durham Mark 6 gamma ray telescope, of the very high energy gamma ray emission from a number of active galactic nuclei visible f…
VHE Gamma Rays from PKS 2155-304
P. M. Chadwick, K. Lyons, T. J. L. McComb +6
The close X-ray selected BL Lac PKS 2155-304 has been observed using the University of Durham Mark 6 very high energy (VHE) gamma ray telescope during 1996 September/October/Novemb…
The energy spectra of TeV sources measured with the Durham Mark 6 Telescope
P. M. Chadwick, K. Lyons, T. J. L. McComb +5
A programme of detailed simulations of the response of the Durham Mark 6 atmospheric Cherenkov telescope is in progress. The effective collecting area for triggering by gamma-ray s…
PKS 2155-304 - a source of VHE gamma-rays
P. M. Chadwick, K. Lyons, T. J. L. McComb +7
The close X-ray selected BL Lac PKS 2155--304 has been observed using the University of Durham Mark 6 very high energy (VHE) gamma ray telescope during 1996 September/October/Novem…
Centaurus X-3 - A Source of High Energy Gamma Rays
P. M. Chadwick, M. R. Dickinson, N. A. Dipper +8
Centaurus X-3 is a well-studied high-mass accreting X-ray binary and a variable source of high energy gamma rays with energies from 100 MeV to 1 TeV. Previous results have suggeste…
TeV gamma rays from PSR 1706-44
P. M. Chadwick, M. R. Dickinson, N. A. Dipper +9
Observations made with the University of Durham Mark 6 atmospheric Cerenkov telescope confirm that PSR B1706-44 is a very high energy gamma-ray emitter. There is no indication from…
Search for Dark Matter Annihilation Signals from the Fornax Galaxy Cluster with H.E.S.S
HESS Collaboration, A. Abramowski, F. Acero +195
The Fornax galaxy cluster was observed with the High Energy Stereoscopic System (H.E.S.S.) for a total live time of 14.5 hours, searching for very-high-energy (VHE, E>100 GeV) gamm…
Measurements of Flux Limits for TeV Emission from AGNs
P. M. Chadwick, K. Lyons, T. J. L. McComb +6
The University of Durham Mark 6 Telescope has been used to make observations of a number of AGNs visible from the Southern Hemisphere. Results are presented for limits to VHE gamma…
The 2010 very high energy gamma-ray flare & 10 years of multi-wavelength observations of M 87
The H. E. S. S. Collaboration, :, A. Abramowski +442
Abridged: The giant radio galaxy M 87 with its proximity, famous jet, and very massive black hole provides a unique opportunity to investigate the origin of very high energy (VHE;…
VHE gamma-ray emission of PKS 2155-304: spectral and temporal variability
HESS Collaboration, A. Abramowski, F. Acero +185
Observations of very high energy gamma-rays from blazars provide information about acceleration mechanisms occurring in their innermost regions. Studies of variability in these obj…
Discovery of the source HESS J1356-645 associated with the young and energetic PSR J1357-6429
HESS Collaboration, A. Abramowski, F. Acero +195
Several newly discovered very-high-energy (VHE; E > 100 GeV) gamma-ray sources in the Galaxy are thought to be associated with energetic pulsars. Among them, middle-aged (> 1E+4 yr…
Detection of very-high-energy gamma-ray emission from the vicinity of PSR B1706-44 and G343.1-2.3 with H.E.S.S
H. E. S. S. Collaboration, :, A. Abramowski +198
The gamma-ray pulsar PSR B1706-44 and the adjacent supernova remnant (SNR) candidate G343.1-2.3 were observed by H.E.S.S. during a dedicated observation campaign in 2007. As a resu…
A multiwavelength view of the flaring state of PKS 2155-304 in 2006
HESS Collaboration, A. Abramowski, F. Acero +208
Multiwavelength (MWL) observations of the blazar PKS 2155-304 during two weeks in July and August 2006, the period when two exceptional flares at very high energies (VHE, E>= 100 G…
Discovery of VHE emission towards the Carina arm region with the H.E.S.S. telescope array: HESS J1018-589
HESS Collaboration, A. Abramowski, F. Acero +195
The observational coverage with HESS of the Carina region in VHE gamma-rays benefits from deep exposure (40 h) of the neighboring open cluster Westerlund 2. The observations have r…
Geomagnetic effects on atmospheric Cerenkov images
P. M. Chadwick, K. Lyons, T. J. L. McComb +6
Atmospheric Cerenkov telescopes are used to detect electromagnetic showers from primary gamma rays of energy ~300 GeV - ~10 TeV and to discriminate these from cascades due to hadro…
Discovery of hard-spectrum γ-ray emission from the BL Lac object 1ES 0414+009
The HESS Collaboration, A. Abramowski, F. Acero +199
1ES 0414+009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high energy (VHE, E>100 GeV) gamma-rays due to its…