Publications (35)
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…
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…
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…
A new analysis method for very high definition Imaging Atmospheric Cherenkov Telescopes as applied to the CAT telescope
S. Le Bohec, B. Degrange, M. Punch +33
A new method of shower-image analysis is presented which appears very powerful as applied to those Cherenkov Imaging Telescopes with very high definition imaging capability. It pro…
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…
Detection of the BL Lac object 1ES1426+428 in the Very High Energy gamma-ray band by the CAT Telescope from 1998-2000
A. Djannati-Atai, B. Khelifi, S. Vorobiov +14
The BL Lac Object 1ES 1426+428, at a red-shift of z=0.129, has been monitored by the CAT telescope from February 1998 to June 2000. The accumulation of 26 hours of observations sho…
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…
The CAT Imaging Telescope
A. Barrau, R. Bazer-Bachi, H. Cabot +33
The VHE gamma-ray imaging telescope CAT started taking data in October 1996. Located at the Themis solar site in southern France, it features a 17.7 m^2 Davies-Cotton mirror equipp…
Temporal and spectral gamma-ray properties of Mkn421 above 250 GeV from CAT observations between 1996 and 2000
F. Piron, A. Djannati-Atai, M. Punch +22
The gamma-ray emission above 250 GeV from the BL Lac object Markarian 421 was observed by the CAT Cherenkov imaging telescope between December, 1996, and June, 2000. In 1998, the s…
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…
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…
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…
Detection of Vhe Gamma-Rays from MRK 501 with the Cat Imaging Telescope
A. Barrau, R. Bazer-Bachi, H. Cabot +33
The CAT imaging telescope on the site on the former solar plant Themis has been observing gamma-rays from Mrk501 above 220 GeV in March and April 1997. This source is shown to be h…
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…
The CAT Imaging Telescope for Very-High-Energy Gamma-Ray Astronomy
A. Barrau, R. Bazer-Bachi, E. Beyer +49
The CAT (Cherenkov Array at Themis) imaging telescope, equipped with a very-high-definition camera (546 fast phototubes with 0.12 degrees spacing surrounded by 54 larger tubes in t…
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…
On the nature of HESS J1503-582 revealed by the H.E.S.S. experiment: Coincidence with a FVW?
M. Renaud, P. Goret, R. C. G. Chaves
The H.E.S.S. survey of the inner Galaxy in the very-high-energy gamma-ray domain has led to the discovery of many extended sources, some of which do not appear to be associated wit…
Performances of the CAT imaging telescope and some preliminary results on Mkn 180 and the Crab
A. Barrau, R. Bazer-Bachi, H. Cabot +33
The CAT imaging telesope, which uses the Atmospheric Cherenkov Technique to observe TeV gamma-ray sources, has been operating since September 1996. Located in southern France, it f…
High-energy particles in the wind nebula of pulsar B1509-58 as seen by INTEGRAL
M. Forot, W. Hermsen, M. Renaud +5
We present observations with the INTEGRAL/IBIS telescope of the wind nebula powered by the young pulsar B1509-58 and we discuss the spatial and spectral properties of the unpulsed…
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…
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…
Spectrum and Variability of Mrk501 as observed by the CAT Imaging Telescope
A. Barrau, R. Bazer-Bachi, H. Cabot +33
The CAT Imaging Telescope has observed the BL Lac object Markarian 501 between March and August 1997. We report here on the variability over this time including several large flare…
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…
Observation of the Crab Nebula Gamma-Ray Emission Above 220 Gev by the Cat Cherenkov Imaging Telescope
A. Barrau, R. Bazer-Bachi, H. Cabot +33
The CAT imaging telescope, recently built on the site of the former solar plant Themis (French Pyrenees), observed gamma-rays from the Crab nebula from October 1996 to March 1997.…
Very High Energy Gamma-ray spectral properties of Mrk 501 from CAT Cerenkov telescope observations in 1997
A. Djannati-Atai, F. Piron, A. Barrau +31
The BL Lac object Mrk 501 went into a very high state of activity during 1997, both in VHE gamma-rays and X-rays. We present here results from observations at energies above 250 Ge…
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…
Search for >= 400 GeV gamma-rays from the SNR Cas A
P. Goret, C. Gouiffes, E. Nuss +1
The recent detection of a hard X-ray component in the supernova remnant Cassiopeia A is interpreted as synchrotron emission from electrons accelerated to energies up to 40 TeV (All…