The H.E.S.S. Survey of the Inner Galaxy in Very High Energy Gamma Rays
- F. Aharonian, A. Akhperjanian, S. Wagner
- Physics
- 13 October 2005
The distribution in Galactic latitude of the detected sources appears to be consistent with a scale height in the Galactic disk for the parent population smaller than 100 pc, consistent with expectations for supernova remnants and/or pulsar wind nebulae.
A low level of extragalactic background light as revealed by γ-rays from blazars
- F. Aharonian, A. Akhperjanian, S. Wagner
- PhysicsNature
- 2 August 2005
The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the…
The Potential of White Dwarf Cosmochronology
- G. Fontaine, P. Brassard, P. Bergeron
- Physics
- 1 April 2001
In the light of recent significant progress on both the observational and theoretical fronts, we review the status of white dwarf stars as cosmochronometers. These objects represent the end products…
Discovery of very-high-energy γ-rays from the Galactic Centre ridge
- F. Aharonian, A. Akhperjanian, S. Wagner
- PhysicsNature
- 9 February 2006
The source of Galactic cosmic rays (with energies up to 1015 eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the…
Optical and Ultraviolet Analyses of ZZ Ceti Stars and Study of the Atmospheric Convective Efficiency in DA White Dwarfs
- P. Bergeron, F. Wesemael, R. Lamontagne, G. Fontaine, R. Saffer, N. Allard
- Physics
- 1 August 1995
A COMPREHENSIVE SPECTROSCOPIC ANALYSIS OF DB WHITE DWARFS
- P. Bergeron, F. Wesemael, J. Liebert
- Physics
- 27 May 2011
We present a detailed analysis of 108 helium-line (DB) white dwarfs based on model atmosphere fits to high signal-to-noise optical spectroscopy. We derive a mean mass of 0.67 M☉ for our sample, with…
Energy spectrum of cosmic-ray electrons at TeV energies.
- F. Aharonian, A. Akhperjanian, A. Zech
- PhysicsPhysical Review Letters
- 24 November 2008
In this measurement, the first of this type, the High Energy Stereoscopic System is able to extend the measurement of the electron spectrum beyond the range accessible to direct measurements, finding evidence for a substantial steepening in the energy spectrum above 600 GeV compared to lower energies.
Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy
- M. Actis, G. Agnetta, C. Rulten
- Physics
- 23 November 2011
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a…
A New Population of Very High Energy Gamma-Ray Sources in the Milky Way
- F. Aharonian, A. Akhperjanian, S. Wagner
- PhysicsScience
- 25 March 2005
A first sensitive survey of the inner part of the Milky Way with the High Energy Stereoscopic System (HESS) reveals a population of eight previously unknown firmly detected sources of very high energy γ-rays.
On the Purity of the ZZ Ceti Instability Strip: Discovery of More Pulsating DA White Dwarfs on the Basis of Optical Spectroscopy
- P. Bergeron, G. Fontaine, M. Billères, S. Boudreault, E. Green
- Physics
- 17 September 2003
We report the discovery of two new ZZ Ceti pulsators, LP 133-144 and HE 1258+0123, selected on the basis of model atmosphere fits to optical spectroscopic data. The atmospheric parameters for LP…
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