Radio galaxy Elliptical Fanaroff-Riley type I “Misaligned” BL Lac (~ 60  ) Distance 3.5 Mpc Parameter Value  (J2000) 201   (J2000) -43  Galaxy Size 18  14 arcmin Radio Source size 8  4 degrees Distance 3.5 Mpc Apparent Magnitude 7.96 mag Total galaxy mass (4  1)  M  Outer radio lobe 250 kpc Inner radio lobe 5 kpc Inner radio jet 1.35 kpc Relativistic nuclear jet 1.65 pc Radio core pc Dust lane radius 7 kpc Optical image of Centaurus A (ESO/MPG 2.2-m telescope with WFI) Outer lobes (408MHz) (20 o  20 o, Haslman 1982 ) Outer lobes 6.9cm(4.75GHz) (5 o  9 o, Junkes 1993) Blue : Radio jet Red : CO White : Atomic hydrogen gas Yellow : shell (32’  32’, Charmandaris 2000) 30 kpc ~ 0.3  Image size = 15  14 arcmin Radio VLA(6cm) 4.9GHz Far infrared IRAS  m Mid infrared Spitzer 3.6 to 8  m Visible DSS nm Near infrared 2MASS  m Ultraviolet GALEX nm Gamma CANGAROO-III Angular resolution X-ray Chandra 1-3 keV 0.25 o One event resolution 10% of galaxies  AGN AGN - Time variation (1000sec) - It is 100 or more times brighter than the stars of the whole galaxy. - A massive black hole (MBH) as its nuclei 10% of AGN  Jet (Blazar) Jet - Super luminal motion - Radio lobe - Hot spot - Knot Unified model of AGN Cen A 60° Double-peaked structure = synchrotron + inverse Compton (Synchrotron Self-Compton model) HBL LBL  ray Same cut as Crab ( L > 0.9 )  2 distribution Integral Flux 2-  upper limit  7% Crab Flux Our flux limit is 10 times lower than previous results. Possibility on HBL assumption Typical AGN model But Cen A… IC peak Synchrotron peak Radio Infrared / optical X ray Gamma (MeV) Gamma (TeV) Relativistic beaming effect Bai estimation CANGAROO-III Bai, J.M. et al 1999 F( TeV) = 6.4  erg cm -2 s -1 : Bai F(>530GeV) = 2.6  erg cm -2 s -1 : CANGAROO-III The day-by-day results of Cen A observation We cannot find any sign of bursts. The annihilation rate of the CDM can be written as The accelerator measurement on the fragmentation function is limited to lower energy of such as 100 MeV. The gamma-ray flux is written Cen A → Giant Galaxy 3.5 Mpc Search for Gamma-rays from the Active radio galaxy Centaurus A with CANGAROO-III telescopes We have observed the giant radio galaxy Centaurus A (Cen A) in the TeV energy region using the CANGAROOIII stereoscopic system. The system has been in operation since 2004 and is an array of four Imaging Atmospheric Cherenkov Telescopes (IACT) with about a 100 m spacing. The observations were carried out between March and April In total 20-hour data were obtained. No statistically significant gamma-ray signal has been found above 530 GeV and we obtain an integral flux upper limit of 3.2  cm -2 sec -1 (2-  level). This upper limit is less than 7 % of the gamma-ray flux from the Crab nebula. Although some groups reported detections of Cen A in the past, we give upper limits more than one-order of magnitude lower for this object. S. Kabuki (a), R. Enomoto (b), M. Mori (b) and CANGAROO collaborators (a) Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto , Japan (b) Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba , Japan Radio images of Centaurus A Multiwavelength images of Centaurus A Active Galactic Nuclei (AGN) Synchrotron self-Compton model Result of Analysis Estimation of Flux (burst) Upper limit on density of CDM In this paper, we showed the result of the first stereoscopic observation of Cen A with CANGAROO-III telescopes. The observation period was from March 16 to April and the total observation time was 1197 min. We could not detect a TeV gamma-ray signal and the 2-  upper limit was obtained to be 3.2  cm -2 sec -1 at energies greater than 530 GeV. This 2-  upper limit corresponds to be approximately 7 %-Crab flux. This is an order of magnitude lower than past results. We derived physical parameters for an HBL model using our upper limits and multi-wavelength spectra. Assuming a volume of the emission region to be that defined by our angular resolution, we obtained a limit on the magnetic field: B > 210  G (R/12 kpc) -1. Even using a size of an order of a light year, it exceeds one Gauss, a situation which can be hardly understood. We conclude that Cen A is not classified as a normal HBL. Conclusions Blazar  ~ 1/   ~  ~10  cos   Define beaming factor The flux can be written as F obs ＝  2+α F ＝  p F. If we see Mrk501 at 60 degrees inclination like Cen A, with typical values,  ~5 and p~3, the flux changes by  p = 1.3× If we assume Mrk501 is at the same distance of Cen A, (F Mrk501 /F CenA ) 2 = (z Mrk501 /z Cen A ) 2 = (0.034/0.0008) 2 = 1.8  10 4 Thus, even if its inclination is 60 degrees like Cen A, the gamma-ray signal could be detected. The gamma-ray signal was undetectable.  The problem of the inclination of the jet? H.E.S.S. limit (Aharonian et al, 2005).