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High-resolution observations of powerful radio sources

High-resolution observations of powerful radio sources. Monica Orienti Almudena Prieto. 13/12/2007 Monica Orienti – IAC. Outline. Powerful radio sources Hot-spot Young radio sources. 1.Powerful radio sources. L 1.4 GHz > 10 24 W/Hz

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High-resolution observations of powerful radio sources

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  1. High-resolution observations of powerful radio sources Monica Orienti Almudena Prieto 13/12/2007 Monica Orienti – IAC

  2. Outline • Powerful radio sources • Hot-spot • Young radio sources

  3. 1.Powerful radio sources • L1.4 GHz > 1024 W/Hz • Size: from pc to a few Mpc • Elliptical galaxies and quasars; • 10% of AGN population 1.04 Mpc

  4. 1. Powerful radio sources Radio morphology Cygnus A Lobe Hot spot Jet Hot spot Core Lobe

  5. 1. Powerful radio sources The central component e- P  E2B2   E2B B Synchrotron radiation

  6. 1. Powerful radio sources The external component • Reacceleration in the hot-spots • Electrons are deposited in the lobes where they age: tsyn  108 years • Transient phenomenon Lobe Hot-spot Jet

  7. 2. Hot-spot S S0.5 S br n br B E2 tsyn  br-1/2B-3/2

  8. 2. Hot-spot Sample selection - 9 hot-spots observed with VLA and VLT with high-resolution < 1” - All hot-spots are characterized by: • Low magnetic field • Low radio power

  9. 2. Hot-spot Results • 4 hot-spots (45%) detected • 3 hot-spots show extended optical emission

  10. 2. Hot-spot The goal What originates the extended features?

  11. 3. Young radio sources • LLS < 1 kpc; • P1.4 GHz > 1025 W/Hz; • t ~ 103 – 5 yr 300 pc

  12. 3. Young radio sources The ISM and the source growth Strong flux-density and arm- length asymmetries in compact (< 15 kpc) radio sources

  13. 3. Young radio sources The goal How the ambient medium influences the source growth? Evidence of jet-cloud interaction?

  14. Seyfert galaxies (A. Prieto, J. Acosta, J.A. Fernandez-Ontiveros) • Usually not powerful in radio • Unresolved non-thermal component in the centre • High-resolution radio observations to characterize the SED of the central region

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