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

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

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

Environment of AGNs Maser emission Free-free absorption Faraday Rotation HI absorption (Peck 1999)

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

Mrk 348 (Peck et al 2003) (today…)

Mrk 348 Jet Maser (Peck et al 2003)

H I absorption Hydra A  Optical Depth ~ 0.8  FWHM = 80 km/s  N H = 1 x cm -2 for T spin = 8000 K  Mass ~ 2 x 10 7 M sun for r=50 pc (Taylor 1996)

H I absorption  Optical depth ~ 0.26  FWHM = 735 km/s  Column density: N H = 3 x cm -2 for T spin = 8000 K  Mass: 10 9 M sun for r=50 pc (Taylor et al 2000)

 Optical depth ~ 0.2  FWHM = 350 km/s  N H = 3 x cm -2 for T spin = 8000 K  Mass: ~ 10 8 M sun H I absorption (Peck & Taylor 2001)

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

CSOs – good sources for H I Absorption (Peck 1999) See Taylor poster 35

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

NGC 1275

Free-Free Absorption Spectral index map using 1.3 Global VLBI and 5 GHz VLBA observations  free-free optical depth:   ff ~ T -3/2 n e 2 -2 d  N e ~ 3 x cm -2  ionization ~ 10% (Peck & Taylor 2001) More free-free results – Kameno talk

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

All regions detected Maser emission Free-free absorption Faraday Rotation HI absorption

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

Future Possibilities  Phase Referencing – more calibrators (talks on Wed afternoon, Thurs morning)  Weaker masers: more H 2 O jet masers and “kilomasers” OH Megamasers (Darling, Pihlstroem – today after coffee)  Higher frequency lines (SMA – testing currently >20% science observations)