Ten milliparsec-scale structure of the nucleus region in Centaurus A

Abstract

We present the results of a VLBI Space Observatory Programme (VSOP) observation of the subparsec structure in Centaurus A at 4.9 GHz. Owing to its proximity, our Centaurus A space-VLBI image is one of the highest spatial resolution images of an AGN ever made -- 0.01 pc per beam. The elongated core region is resolved into several components over 10 milli-arcseconds long (0.2 pc) including a compact component of brightness temperature 2.2x10^10K. We analyze the jet geometry in terms of collimation. Assuming the strongest component to be the core, the jet opening angle at ~ 5,000 r_s (Schwarzchild radii) from the core is estimated to be ~ 12 degree, with collimation of the jet to ~ 3 degree continuing out to ~ 20,000 r_s. This result is consistent with previous studies of the jet in M87, which favor MHD disk outflow models. Future space VLBI observations at higher frequencies will probably be able to image the collimation region, within 1,000 r_s of the center of Centaurus A, together with the accretion disk itself.

12 pages, 6 figures, accepted for publication in PASJ, Vol.57 No.6, VSOP special issue

Cited by in corpus (46)

• Discovery of very high energy gamma-ray emission from Centaurus A with H.E.S.S
• Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
• Ultra High Energy Cosmic Rays from Black Hole Jets of Radio Galaxies
• Resolving the innermost parsec of Centaurus A at mid-infrared wavelengths
• TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry I. First-Epoch 8.4 GHz Images
• A synchrotron self-Compton scenario for the very high energy gamma-ray emission of the radiogalaxy M87
• TANAMI monitoring of Centaurus A: The complex dynamics in the inner parsec of an extragalactic jet
• Centaurus A: morphology and kinematics of the atomic hydrogen
• Hot self-similar relativistic MHD flows
• Internal entrainment and the origin of jet-related broad-band emission in Centaurus A
• Ultra-high energy Neutrinos from Centaurus A and the Auger hot spot
• The $\gamma$-ray spectrum of the core of Centaurus A as observed with H.E.S.S. and Fermi-LAT
• Dual-frequency VLBI study of Centaurus A on sub-parsec scales
• Multifrequency Polarimetry of the Nrao 140 Jet: Possible Detection of a Helical Magnetic Field and Constraints on its Pitch Angle
• Twelve and a Half Years of Observations of Centaurus A with RXTE
• Evidence for nuclear radio jet and its structure down to <100 Schwarzschild radii in the center of the Sombrero galaxy (M 104, NGC 4594)
• VHE Gamma-Ray Induced Pair Cascades in the Radiation Fields of Dust Tori of AGN: Application to Cen A
• Disentangling the circumnuclear environs of Centaurus A: I. High resolution molecular gas imaging
• The millimeter-wave continuum spectrum of Centaurus A and its nucleus
• Gamma-ray fluxes from the core emission of Centaurus A: A puzzle solved
• Neutrino, $\gamma$-ray and cosmic ray fluxes from the core of the closest radio galaxies
• The jet/wind outflow in Centaurus A: a local laboratory for AGN feedback
• Ultra-High Energy Cosmic-Ray Acceleration in the Jet of Centaurus A
• Disentangling the circumnuclear environs of Centaurus A: II. On the nature of the broad absorption line
• High Resolution Radio Astronomy Using Very Long Baseline Interferometry
• Correlation of $\gamma$-ray and high-energy cosmic ray fluxes from the giant lobes of Centaurus A
• Stellar Disruption and the Quasar Radio Dichotomy
• Relativistic spine jets from Schwarzschild black holes: "Application to AGN radioloud sources"
• Discovery of Limb Brightening in the Parsec-scale Jet of NGC 315 through Global Very Long Baseline Interferometry Observations and Its Implications for Jet Models
• Gamma-rays from the IC $e^{\pm }$ pair cascade in the radiation field of an accretion disk: Application to CenA
• Influence of the jet opening angle on the derived kinematical parameters of blazar jets having uniform and stratified bulk motion
• Parsec-scale shocks in the kiloparsec-scale jet of Centaurus A
• Inverse Compton scattering of starlight in the kiloparsec-scale jet in Centaurus A: The origin of excess TeV $\gamma$-ray emission
• Study of the PeV Neutrino, $\gamma$-rays and UHECRs around The Lobes of Centaurus A
• Theoretical overview on high-energy emission in microquasars
• The 1.4 mm core of Centaurus A: First VLBI results with the South Pole Telescope
• Radiation Pattern of Radio and Optical Components of Extended Radio Sources
• Time dependent gamma-ray production in the anisotropic IC $e^{\pm }$ pair cascade initiated by electrons in active galaxies
• IceCube Science
• Interpreting correlated observations of cosmic rays and gamma-rays from Centaurus A with a proton blazar inspired model
• Physical Conditions and Particle Acceleration in the Kiloparsec Jet of Centaurus A
• Spatial variations of magnetic field along active galactic nuclei jets on sub-pc to Mpc scales
• The Subparsec-scale Structure and Evolution of Centaurus A. III. A Multi-Epoch Spectral And Polarimetric VLBA Study
• The influence of the jet opening angle on the appearance of relativistic jets
• Implications of pc and kpc jet asymmetry to the cosmic ray acceleration
• The influence of collimation on the appearance of relativistic jets