出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The BL Lac object RGB J0152+017 (z = 0.080) was predicted to be a very high-energy (VHE;
> 100GeV) g -ray source, due to its high X-ray and radio fluxes.
We report recent observations of this source made in late October and November 2007 with the
H.E.S.S. array consisting of four imaging atmospheric ˇCerenkov telescopes. Contemporaneous
observations were made in X-rays with the Swift and RXTE satellites, in the optical band with the
ATOM telescope, and in the radio band with the Nançay Radio Telescope.
As a result, RGB J0152+017 is discovered as a source of VHE g -rays by H.E.S.S. A signal of
173 g -ray photons corresponding to a statistical significance of 6.6s was found in the data. The
energy spectrum of the source can be described by a powerlaw with a spectral index of G = 2.95-
±0.36stat±0.20syst. The integral flux above 300GeV corresponds to ∼2% of the flux of the Crab
nebula. The source spectral energy distribution (SED) can be described using a two-component
(extended jet and blob in jet) non-thermal synchrotron self-Compton (SSC) leptonic model, plus
a thermal host galaxy component. The parameters that are found are very close to those found for
TeV blazars in similar SSC studies.
The location of its synchrotron peak, as derived from the SED in Swift data, allows clear classification
as a high-frequency-peaked BL Lac (HBL).
