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The Atomic and Molecular Environments of AGN

The Atomic and Molecular Environments of AGN. Alison Peck SAO/SMA Project. NGC 4261. Circumnuclear torus first seen in HST image. Also detected in absorption on one EVN baseline. Absorption appears only toward counterjet. First scientific observation

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The Atomic and Molecular Environments of AGN

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  1. The Atomic and Molecular Environments of AGN Alison Peck SAO/SMA Project

  2. NGC 4261 • Circumnuclear torus first seen in HST image • Also detected in absorption on one EVN baseline • Absorption appears only toward counterjet • First scientific observation processed at the new JIVE correlator image courtesy Ylva Pihlstroem

  3. NGC 4258 • Considered best evidence of • a supermassive black hole • Can estimate central mass • Can estimate distance to • host galaxy For recent work, see Humphreys talk Thursday and Modjaz poster 26 image courtesy Lincoln Greenhill (see Miyoshi et al 1995 Herrnstein et al 1999)

  4. Environment of AGNs Maseremission HI absorption Free-free absorption Faraday Rotation (Peck 1999)

  5. NGC 1052 Images courtesy Jim Braatz (See Claussen et al 1998, Braatz et al 2003)

  6. Mrk 348 (Peck et al 2003) (today…)

  7. Mrk 348 Jet Maser (Peck et al 2003)

  8. HIabsorption Hydra A • Optical Depth ~ 0.8 • FWHM = 80 km/s • NH = 1 x 1024 cm-2 • for Tspin = 8000 K • Mass ~ 2 x 107 Msun • for r=50 pc (Taylor 1996)

  9. HIabsorption2322-123 • Optical depth~ 0.26 • FWHM = 735 km/s • Column density: NH = 3 x 1024 cm-2 • for Tspin = 8000 K • Mass: 109 Msun for r=50 pc (Taylor et al 2000)

  10. HI absorption 1946+708 • Optical depth ~ 0.2 • FWHM = 350 km/s • NH = 3 x 1023 cm-2 for Tspin = 8000 K • Mass: ~ 108 Msun (Peck & Taylor 2001)

  11. Not All Absorption is Associated with the AGN (Peck 1999)

  12. CSOs – good sources for HI Absorption See Taylor poster 35 (Peck 1999)

  13. OH in IIIZw35 6 • Enclosed mass m~7x10 M solar • Masers lie in a ring of radius r~22pc • Velocity field confirms rotation • Absorption lies outside maser ring (Pihlstroem et al 2001)

  14. NGC 1275

  15. Free-Free Absorption 1946+708 • Spectral index map using 1.3 Global VLBI and 5 GHz VLBA observations • free-free optical depth: • tff ~ T-3/2 ne2n-2 d • Ne ~ 3 x 1022 cm-2 • ionization ~ 10% More free-free results – Kameno talk (Peck & Taylor 2001)

  16. 3C279 Polarization and Faraday Rotation Source Screen Observer (Zavala & Taylor 2003)

  17. Maseremission HI absorption Free-free absorption Faraday Rotation All regions detected

  18. HI absorption -- NGC 7674 Future Possibilities -- Sensitivity 5.3 pc • VLBA + Y27 + Arecibo • Beam=17 x 5 mas, PA 3o • Cont. rms noise: 30 mJy/beam • Line rms noise: 260 mJy/beam Momjian et al 2002

  19. Future Possibilities • Phase Referencing – more calibrators (talks on Wed afternoon, Thurs morning) • Weaker masers: more H2O jet masers and “kilomasers” OH Megamasers (Darling, Pihlstroem – today after coffee) • Higher frequency lines (SMA – testing currently >20% science observations)

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