The Atomic and Molecular Environments of AGN
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Transcript of The Atomic and Molecular Environments of AGN
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)