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The Radio Continuum View of Centaurus Acentaurus A

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The Radio Continuum View of Centaurus Acentaurus A TheThe radioradio continuumcontinuum viewview ofof CentaurusCentaurus AA Ron Ekers CSIRO The Many Faces of Centaurus A Sydney, 29 June 2009 Ilana's composite Morganti et al. 1999 9° 10' Burns et al. xx image courtesy Norbert Junkes (MPIfR) WhyWhy CentaurusCentaurus AA isis specialspecial ■ the first extragalactic radio source ■ the brightest source in the Southern Hemisphere ■ the second double lobed source discovered ± after Cygnus A ■ the closest Radio Galaxy ■ the closest AGN ■ the closest SMBH ± VLBI resolution 0.01pc, 100 Rs ■ A spectacular galaxy EvolutionEvolution ofof thethe ModelsModels ■ Radio sources ± Static magnetic field 1960 ± Evolutionary sequence 1970 ± Continuous injection ± Continuous reacceleration ■ Energy source ± Galaxy collisions 1950's ± Nuclear accretions 1960- ± Accretion triggered by collisions 1980- CentaurusCentaurus AA thethe closestclosest AGNAGN ■ Distance 3.4Mpc ■ Next closest comparable AGN M87 17Mpc ! ■ Average distance to a L=1024 W Hz-1 radio galaxies ± 10Mpc ± So we are lucky (or influenced!) ■ Much easier to study at all wavelengths ■ Subtends a large angular size ± Good linear resolution ± Background probes SomeSome RadioRadio GalaxiesGalaxies Name Size Log Log (kpc) Luminosity Energy (ergs sec-1) (ergs) Centaurus A 470 41.7 59.9 Cygnus A 200 45.2 60.6 M87 80 42.0 58.6 M82 1 39.5 55.2 PolarizationPolarization inin CentaurusCentaurus AA Bracewell 1962 ■ April 1962 ■ Parkes 64m just completed ■ Discovered by Bracewell ± Published Cooper and Price ± Visitors Log ± Not a National Facilities yet! ■ Connie Mayer ± Found Cygnus A polarization a few weeks earlier NorthNorth GoobangGoobang PhilosophicalPhilosophical SocietySociety MarkMark PricePrice 19611961 DiscoveryDiscovery ofof FaradayFaraday RotationRotation CentaurusCentaurus AA -- ParkesParkes 64m64m ■ Cooper and Price ■ Nature Sep 1962 ■ 10 ± 20cm ■ Faraday Rotation o ± -120 CooperCooper PricePrice andand ColeCole 19651965 ■ Aust J Phys, 18, 589 (1965) ■ Parkes 64m ■ 11, 21, 31, 75cm ■ Spectral index -0.6 whole source ■ Polarization up to 40% ■ RM -36 to -84 rad m-2 HaslamHaslam 408MHz408MHz Haslam 408MHz HIPASSHIPASS ContinuumContinuum Preliminary continuum image, courtesy Mark Calabretta (CSIRO ATNF) HIHI ParkesParkes AllAll SkySky SurveySurvey BarnesBarnes etet al.al. 20012001 ■ Observations 1997 to 2000 ■ 8° scans of 9 minutes ■ Mark Calabretta (ATNF) processing continuum ■ incl. HI Zone of Avoidance Juraszek et al 2000 Preliminary continuum image, courtesy Mark Calabretta (CSIROFeain ATNF) 2009 ParkesParkes 6cm6cm NorbertNorbert JunkesJunkes Intensity Polarization 600kpc ??? CentaurusCentaurus AA ATCAATCA MosaicMosaic ■1.4GHz continuum ■ full polarization ■4 x 750m array configuration 600kpc ■406 pointings, hexagonal grid ■Σ FOV 45 deg2 ■Θ ~45'' ■ σ ~0.26mJy/beam (0.1K) ■Ilana Feain ± last talk! CentaurusCentaurus AA compositecomposite RadioRadio ±± OpticalOptical alignmentalignment Radio RadioRadio ±± OpticalOptical alignmentalignment Precession?Precession? Optical 150kpc 60kpc Cannon, UK Schmidt IIIaJ [How][How] doesdoes radioradio plasmaplasma couplecouple toto thethe IGM/ISM?IGM/ISM? CO blue stars Charmandaris+00 Graham & Fassett 02 30kpc Oosterloo+05 StarStar FormationFormation CentaurusCentaurus AA middlemiddle lobelobe Oosterloo Galex UV 15kpc ThermalThermal XrayXray inin thethe MiddleMiddle LobeLobe Oosterloo 15kpc Kraft et al ApJ 698 (2009) 2036 CentaurusCentaurus AA compositecomposite InnerInner doubledouble lobelobe VLAVLA 5GHz5GHz 7 kpc InnerInner doubledouble lobelobe 7 kpc CentaurusCentaurus AA compositecomposite CentaurusCentaurus AA thethe closestclosest AGNAGN jetjet ■ ATCA 5GHz ± Hardcastle 2003 ■ Chandra Xray 1 kpc ± Kraft 2002 ± 1º = 17pc CentaurusCentaurus AA thethe AsymmetryAsymmetry EnigmaEnigma 3pc ManyMany scalesscales ofof CentaurusCentaurus AA 600kpc600kpc ±± 0.01pc0.01pc == 10108 :: 11 ■ Mpc overall shape - modified by dynamical changes? ■ 100Kpc middle lobe - bubbles, star-formation, channels ± jet induced star formation ± We cant understand the physics of black hole regulation and feedback except in the very closest objects. ■ 10kpc - central double ■ 1kpc jet ± closest so best resolution ± Xray - radio ■ 0.01pc VLBI jet ± One sidedness ± Doppler, flip-flop, environment ± SMBH effects, accretion disk, BH merger kicks ParkesParkes NorbertNorbert JunkesJunkes 600kpc image courtesy Norbert JunkesFeain (MPIfR) 2009 JunkesJunkes toto FeainFeain 150kpc.
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