Y. Mizumura, J. Kushida, K. Nishijima, G. V. Bicknell, R. W. Clay, P. G. Edwards, S. Gunji, S. Hara, S. Hayashi, S. Kabuki, F. Kajino, A. Kawachi, T. Kifune, R. Kiuchi, K. Kodani, Y. Matsubara, T. Mizukami, Y. Mizumoto, M. Mori, H. Muraishi, T. Naito, M. Ohishi, T. Yoshida, T. Yoshikoshi
We have searched for very high energy (VHE) gamma rays from four blazars
using the CANGAROO-III imaging atmospheric Cherenkov telescope. We report the
results of the observations of H 2356-309, PKS 2155-304, PKS 0537-441, and 3C
279, performed from 2005 to 2009, applying a new analysis to suppress the
effects of the position dependence of Cherenkov images in the field of view. No
significant VHE gamma ray emission was detected from any of the four blazars.
The GeV gamma-ray spectra of these objects were obtained by analyzing Fermi/LAT
archival data. Non-simultaneous wide range (radio to VHE gamma-ray bands)
spectral energy distributions (SEDs) including CANGAROO-III upper limits, GeV
gamma-ray spectra, and archival data are discussed using a one-zone synchrotron
self-Compton (SSC) model in combination with a external Compton (EC) radiation.
The HBLs (H 2356-309 and PKS 2155-304) can be explained by a simple SSC model,
and PKS 0537-441 and 3C 279 are well modeled by a combination of SSC and EC
model. We find a consistency with the blazar sequence in terms of strength of
magnetic field and component size.
View original:
http://arxiv.org/abs/1202.2181
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