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Gas Disks and Supermassive Black Holes in Nearby Radio Galaxies

Gas Disks and Supermassive Black Holes in Nearby Radio Galaxies

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ema<strong>in</strong><strong>in</strong>g galaxies may be of particular <strong>in</strong>terest: NGC 4335 <strong>and</strong> NGC 5141 have the<br />

most settled observed velocity profiles out to 100 pc, however <strong>in</strong> both of these cases<br />

we f<strong>in</strong>d that no black hole is necessary to fit the observed k<strong>in</strong>ematics; <strong>in</strong> NGC 2329<br />

the central slope is very shallow compared to all rotat<strong>in</strong>g th<strong>in</strong> disk models, suggest<strong>in</strong>g<br />

that <strong>in</strong>flow could be important (Chapter 4).<br />

How is the gas organized <strong>in</strong> the central regions? In Chapter 5, we used<br />

weighted mean parameters with<strong>in</strong> 100 pc of the center of each nucleus to describe the<br />

k<strong>in</strong>ematic state of the gas.<br />

We showed that the po<strong>in</strong>t-to-po<strong>in</strong>t variations <strong>in</strong> the velocity profiles are largest<br />

perpendicular to the preferred plane of rotation <strong>in</strong> the nuclei, <strong>in</strong>dicat<strong>in</strong>g that these<br />

motions orig<strong>in</strong>ate from velocity components that have not settled <strong>in</strong>to a th<strong>in</strong> disk<br />

configuration. We found that the velocity dispersion is distributed fairly evenly <strong>in</strong> all<br />

orientations, so likely orig<strong>in</strong>ates from <strong>in</strong>tr<strong>in</strong>sically isotropic r<strong>and</strong>om motions. Even<br />

<strong>in</strong> face on systems we observe differences <strong>in</strong> the mean velocities on either side of the<br />

nucleus, <strong>in</strong>dicat<strong>in</strong>g we may be observ<strong>in</strong>g bulk motions of the disk. From this set of<br />

evidence we conclude that the gas disks are not <strong>in</strong>tr<strong>in</strong>sically settled <strong>and</strong> are probably<br />

not well settled <strong>in</strong>to the major plane of the galaxy potential (Chapter 5).<br />

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