spitzer reveals activities of supermassive black holes in elliptical galaxies

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Spitzer Reveals Activities of Supermassive Black Holes in Elliptical Galaxies. Qiusheng Gu Nanjing University in collaboration with J.-S. Huang (CfA), G. Wilson (SSC), G. G. Fazio (CfA). SMBHs in Elliptical Galaxies. Ferrarese & Merritt, 2000, ApJ, 539, L9 - PowerPoint PPT Presentation

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  • Spitzer Reveals Activities of Supermassive Black Holes in Elliptical GalaxiesQiusheng Gu Nanjing University

    in collaboration with

    J.-S. Huang (CfA), G. Wilson (SSC), G. G. Fazio (CfA)

  • SMBHs in Elliptical GalaxiesFerrarese & Merritt, 2000, ApJ, 539, L9Gebhardt et al., 2000, ApJ, 539, L13.

  • SMBHs in Elliptical Galaxies

  • SMBHs in Elliptical GalaxiesAll galaxies contain supermassive black holes.The mass of SMBH is tightly correlated with the mass of the bulge.

  • SMBHs in Elliptical GalaxiesBower et al. 1998, ApJ, 492, L111D = 17 Mpc,1 = 82 pc.

  • SMBHs in Elliptical GalaxiesBower et al. 1998, ApJ, 492, L111

  • SMBHs in Elliptical Galaxies An S-shape velocity curve with a peak amplitude of 400 km s-1 at 0.1(8 pc) from the nucleus. A thin Keplerian disk fits the observed gas kinematics very well if the rotation axis of the gas disk is aligned with the radio jet axis. A nuclear compact mass of 1.5109Mwith an uncertainty of (0.9-2.6)109M

  • Es: QSOs hosts at high zRadio-Loud QSOsExclusively in elliptical hostsRadio-Quiet QSOsMB
  • SMBHs in local EllipticalsIn the Palomar sample, 57 Es 26 with pure absorption nuclei 4 Seyferts + 21 LINERs + 6 Transition

  • Spitzer: Powerful IR Telescope IR bands less affected by extinction

    Possible to detect the nuclear component as IR re-processed emission from a dusty torus (when stellar components properly removed)

  • MotivationWilson et al. (2006): at z ~1, 1/3 EROs are detected at 24 um;Pozzi et al. (2006): at 0.9
  • MotivationWilson et al. 2006

  • Ks image with 24m contours (40" x40" )Redshift: 0.9< z< 2.08(Mignoli et al. 04)

  • 6/8 EXTENDED de Vaucouleurs profile No AGN signature

  • Our GoalTo find the infrared indicator of SMBH activities in local elliptical galaxies;To understand the origin of infrared emission in elliptical galaxies.All Es in Hos sample with Spitzer IRAC observations.We detected infrared-red cores in 6(24) Es

  • One example: NGC 315

  • IRAC Color Distributions

  • After removing stellar population

  • NGC 315

  • Another example: NGC 5322

  • What is behind ?The strength of SMBHs activities ?The dust mass ?IR emission mechanism: dust reradiation optical-UV-soft X-ray photons (AGNs/Starburst) --- dust --- infrared

  • Emission Line

  • Hubble WFPC2 image of NGC 315Central Dust Structures

  • Hubble WFPC2 image of NGC 4374Central Dust Structures

  • Hubble WFPC2 image of NGC 4278Hubble WFPC2 image of NGC 5322Adopt from Lauer et al., 2005, AJ, 129, 2138

  • NGC 5077Exception: Central Dust

  • NGC 4125NGC 4552NGC 7626NGC 5813Elliptical Galaxies without an Infrared-red Core

  • Origin of Dust in EsInternal origin : stellar mass loss

    External origin: minor merger of small gas-rich satelliate system (Indications: off-set clouds , polar discs)

  • Origin of Dust in EsMergering remnants; gaseous morphologyMHI/LBGaseous kinematics: For fast-rotating galaxies, gas and stars are co-rotating, closely linked internal; For slow-rotating (rounder and more triaxial) Es, no alignment between gas and stars external accretion (Sarzi et al. 2006).

  • SummaryWe detected an infrared-red core in ~1/4 elliptical galaxies;Es with infrared-red cores always contain significant dust in the central regions;The infrared-red core is due to the dust reradiation heated by central AGNs.We will investigate how the central dust in Es originate from HI contents and gaseous kinematics.

  • AGNs Host Galaxies

  • Schade et al. 2000