TY  - GEN
A1  - Abdalla, Hassan E.
A1  - Adam, Remi
A1  - Aharonian, Felix A.
A1  - Benkhali, Faical Ait
A1  - Angüner, Ekrem Oǧuzhan
A1  - Arakawa, Masanori
A1  - Arcaro, C
A1  - Armand, Catherine
A1  - Armstrong, T.
A1  - Egberts, Kathrin
T1  - Very high energy γ-ray emission from two blazars of unknown redshift and upper limits on their distance
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - We report on the detection of very high energy (VHE; E > 100 GeV) gamma-ray emission from the BL Lac objects KUV 00311-1938 and PKS 1440-389 with the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. observations were accompanied or preceded by multiwavelength observations with Fermi/LAT, XRT and UVOT onboard the Swift satellite, and ATOM. Based on an extrapolation of the Fermi/LAT spectrum towards the VHE gamma-ray regime, we deduce a 95 per cent confidence level upper limit on the unknown redshift of KUV 00311-1938 of z < 0.98 and of PKS 1440-389 of z < 0.53. When combined with previous spectroscopy results, the redshift of KUV 00311-1938 is constrained to 0.51 <= z < 0.98 and of PKS 1440-389 to 0.14 (sic) z < 0.53.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1202 
KW  - BL Lacertae objects: individual
KW  - galaxies: high-redshift
KW  - gamma-rays: general
KW  - Resolved and unresolved sources as a function of wavelength
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-526000
SN  - 1866-8372
IS  - 4
ER  - 
TY  - CHAP
A1  - Reimer, O.
A1  - Aharonian, Felix A.
A1  - Hinton, J.
A1  - Hofmann, W.
A1  - Hoppe, S.
A1  - Raue, M.
A1  - Reimer, A.
T1  - VHE gamma-rays from Westerlund 2 and implications for the inferred energetics
N2  - The H.E.S.S. collaboration recently reported the discovery of VHE γ-ray emission coincident with the young stellar cluster Westerlund 2. This system is known to host a population of hot, massive stars, and, most particularly, the WR binary WR 20a. Particle acceleration to TeV energies in Westerlund 2 can be accomplished in several alternative scenarios, therefore we only discuss energetic constraints based on the total available kinetic energy in the system, the actual mass loss rates of respective cluster members, and implied gamma-ray production from processes such as inverse Compton scattering or neutral pion decay. From the inferred gammaray luminosity of the order of 1035erg/s, implications for the efficiency of converting available kinetic energy into non-thermal radiation associated with stellar winds in the Westerlund 2 cluster are discussed under consideration of either the presence or absence of wind clumping.
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18172
ER  -