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PKS 2005-489 at VHE: four years of monitoring with HESS and simultaneous multi-wavelength observations
(EDP Sciences, 2010)
Aims. Our aim is to study the very high energy (VHE; E>100 GeV) γ-ray emission from BL Lac objects and the evolution in time of their broad-band spectral energy distribution (SED).
Methods. VHE observations of the ...
Simultaneous multiwavelength observations of the second exceptional y-ray flare of PKS 2155-304 in July 2006
(EDP Sciences, 2009)
Aims. The X-ray-TeV connection and the evolution of the emitting particle population is studied in high-energy peaked BL Lac objects, by obtaining spectral information in both bands on sub-hour timescales.
Methods. ...
The 2010 very high energy γ-ray flare and 10 years of multi-wavelength observations of M 87
(IOP Publishing, 2012)
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 – 6) × 109 M☉) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) γ-ray ...
Upper limits from HESS active galactic nuclei observations in 2005-2007
(EDP Sciences, 2008)
Aims.Very high energy (VHE; GeV) γ-ray studies were performed for 18 active galactic nuclei (AGN) from a variety of AGN classes.
Methods.VHE observations of a sample of 14 AGN, considered candidate VHE emitters, were ...
Discovery of VHE gamma-rays from the high-frequency-peaked BL Lacertae object RGB J0152+017
(EDP Sciences, 2008)
Aims. The BL Lac object RGB J0152+017 (z=0.080) was predicted to be a very high-energy (VHE; >100 GeV) $\gamma$-ray source, due to its high X-ray and radio fluxes. Our aim is to understand the radiative processes by ...
Multi-wavelength observations of H 2356-309
(EDP Sciences, 2010)
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) observations of H 2356–309 were performed with ...
A multiwavelength view of the flaring state of PKS 2155-304 in 2006
(EDP Sciences, 2012)
Context: 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 GeV) occurred, provide a detailed ...
Simultaneous observations of PKS 2155-304 with HESS, FERMI, RXTE, and ATOM: spectral energy distributions and variability in a low state
(IOP Publishing, 2009)
We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155–304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and ...
Simultaneous multi-wavelength campaign on PKS 2005-489 in a high state
(EDP Science, 2011)
TeV γ-ray (H.E.S.S.), GeV γ-ray (Fermi/LAT), X-ray (RXTE, Swift), UV (Swift) and optical (ATOM, Swift) bands. This campaign was carried out during a high flux state in the synchrotron regime. The flux in the optical and ...
HESS J1943+213: a candidate extreme BL Lacertae object
(EDP Sciences, 2011)
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 was proposed to have radio and infrared ...