The Atomic and Molecular The Atomic and Molecular Environments of AGNEnvironments of AGN

Alison PeckAlison PeckSAO/SMA ProjectSAO/SMA Project

NGC 4261NGC 4261

Circumnuclear torus first seen in Circumnuclear torus first seen in HST imageHST image

Absorption appears only towardAbsorption appears only toward counterjetcounterjet

First scientific observationFirst scientific observation processed at the new JIVEprocessed at the new JIVE correlatorcorrelator

Also detected in absorption onAlso detected in absorption on one EVN baselineone EVN baseline

image courtesy Ylva Pihlstroem

NGC 4258NGC 4258

image courtesy Lincoln Greenhill(see Miyoshi et al 1995 Herrnstein et al 1999)

Can estimate central massCan estimate central mass

Considered best evidence ofConsidered best evidence of a supermassive black holea supermassive black hole

Can estimate distance toCan estimate distance to host galaxyhost galaxy

For recent work, seeHumphreys talk Thursdayand Modjaz poster 26

Environment of AGNs

Maser emission

Free-free absorptionFaraday Rotation

HI absorption

(Peck 1999)

NGC 1052NGC 1052

Images courtesy Jim Braatz

(See Claussen et al 1998, Braatz et al 2003)

Mrk 348Mrk 348

(Peck et al 2003) (today…)

Mrk 348 Jet MaserMrk 348 Jet Maser

(Peck et al 2003)

HHII absorption absorption Hydra AHydra 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)

HHII absorptionabsorption 2322-1232322-123

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)

Optical depth ~ 0.2

FWHM = 350 km/s

NH = 3 x 1023 cm-2

for Tspin = 8000 K

Mass: ~ 108 Msun

HHII absorption absorption 1946+7081946+708

(Peck & Taylor 2001)

Not All Absorption is Associated Not All Absorption is Associated with the AGNwith the AGN

(Peck 1999)

CSOs – good sources for HCSOs – good sources for HII Absorption Absorption

(Peck 1999)

See Taylor poster 35

OH in IIIZw35OH in IIIZw35

(Pihlstroem et al 2001)

Masers lie in a ring of radius Masers lie in a ring of radius rr~22pc~22pc

Velocity field confirms rotationVelocity field confirms rotation

Absorption lies outside maser Absorption lies outside maser ringring

Enclosed mass Enclosed mass mm~7x10 M~7x10 M66

solarsolar

NGC 1275

Free-Free Free-Free Absorption Absorption 1946+7081946+708

Spectral index map using 1.3 Global VLBI and 5 GHz VLBA observations

free-free optical depth:

ff ~ T-3/2 ne2 -2 d

Ne ~ 3 x 1022 cm-2

ionization ~ 10%

(Peck & Taylor 2001)More free-free results – Kameno talk

Polarization and Polarization and Faraday RotationFaraday Rotation

Source

Screen

Observer

(Zavala & Taylor 2003)

3C2793C279

All regions detectedAll regions detected

Maser emission

Free-free absorptionFaraday Rotation

HI absorption

HHII absorption -- NGC 7674 absorption -- NGC 7674

VLBA + Y27 + Arecibo

Momjian et al 2002

Beam=17 x 5 mas, PA 3o

Cont. rms noise: 30 Jy/beamLine rms noise: 260 Jy/beam

5.3 pc

Future Possibilities -- SensitivityFuture Possibilities -- Sensitivity

Future PossibilitiesFuture 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)