Difference between revisions of "User:Tohline/Appendix/Ramblings/ForPaulFisher"

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==Overview of Dissertation==
[https://digitalcommons.lsu.edu/gradschool_disstheses/6940/ Paul Fisher's (1999) doctoral dissertation] (accessible via the LSU Digital Commons) is titled, ''Nonaxisymmetric Equilibrium Models for Gaseous Galaxy Disks.''  Its abstract reads, in part:
[https://digitalcommons.lsu.edu/gradschool_disstheses/6940/ Paul Fisher's (1999) doctoral dissertation] (accessible via the LSU Digital Commons) is titled, ''Nonaxisymmetric Equilibrium Models for Gaseous Galaxy Disks.''  Its abstract reads, in part:


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<font color="darkgreen">Three-dimensional hydrodynamic simulations show that, in the absence of self-gravity, an axisymmetric, gaseous galaxy disk whose angular momentum vector is initially tipped at an angle, <math>~i_0</math>, to the symmetry axis of a fixed spheroidal dark matter halo potential does not settle to the equatorial plane of the halo.  Instead, the disk settles to a plane that is tipped at an angle, <math>~\alpha = \tan^{-1}[q^2 \tan i_0]</math>, to the equatorial plane of the halo, where <math>~q</math> is the axis ratio of the halo equipotential surfaces.  The equilibrium configuration to which the disk settles appears to be flat but it exhibits distinct nonaxisymmetric features.  .</font>
<font color="darkgreen">Three-dimensional hydrodynamic simulations show that, in the absence of self-gravity, an axisymmetric, gaseous galaxy disk whose angular momentum vector is initially tipped at an angle, <math>~i_0</math>, to the symmetry axis of a fixed spheroidal dark matter halo potential does not settle to the equatorial plane of the halo.  Instead, the disk settles to a plane that is tipped at an angle, <math>~\alpha = \tan^{-1}[q^2 \tan i_0]</math>, to the equatorial plane of the halo, where <math>~q</math> is the axis ratio of the halo equipotential surfaces.  The equilibrium configuration to which the disk settles appears to be flat but it exhibits distinct nonaxisymmetric features.  .</font>
</td></tr></table>
</td></tr></table>
All three-dimensional hydrodynamic simulations employ Richstone's (1980) time-independent "axisymmetric logarithmic potential" that is prescribed by the expression,
<table border="0" cellpadding="5" align="center">
<tr>
  <td align="right">
<math>~\Phi(x, y, z)</math>
  </td>
  <td align="center">
<math>~=</math>
  </td>
  <td align="left">
<math>~
\frac{v_0^2}{2}~ \ln\biggl[x^2 + y^2 + \frac{z^2}{q^2} \biggr] \, .
</math>
  </td>
</tr>
</table>


=See Also=
=See Also=

Revision as of 22:31, 29 March 2021

For Paul Fisher

Whitworth's (1981) Isothermal Free-Energy Surface
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Overview of Dissertation

Paul Fisher's (1999) doctoral dissertation (accessible via the LSU Digital Commons) is titled, Nonaxisymmetric Equilibrium Models for Gaseous Galaxy Disks. Its abstract reads, in part:

Three-dimensional hydrodynamic simulations show that, in the absence of self-gravity, an axisymmetric, gaseous galaxy disk whose angular momentum vector is initially tipped at an angle, <math>~i_0</math>, to the symmetry axis of a fixed spheroidal dark matter halo potential does not settle to the equatorial plane of the halo. Instead, the disk settles to a plane that is tipped at an angle, <math>~\alpha = \tan^{-1}[q^2 \tan i_0]</math>, to the equatorial plane of the halo, where <math>~q</math> is the axis ratio of the halo equipotential surfaces. The equilibrium configuration to which the disk settles appears to be flat but it exhibits distinct nonaxisymmetric features. .

All three-dimensional hydrodynamic simulations employ Richstone's (1980) time-independent "axisymmetric logarithmic potential" that is prescribed by the expression,

<math>~\Phi(x, y, z)</math>

<math>~=</math>

<math>~ \frac{v_0^2}{2}~ \ln\biggl[x^2 + y^2 + \frac{z^2}{q^2} \biggr] \, . </math>

See Also


Whitworth's (1981) Isothermal Free-Energy Surface

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Recommended citation:   Tohline, Joel E. (2021), The Structure, Stability, & Dynamics of Self-Gravitating Fluids, a (MediaWiki-based) Vistrails.org publication, https://www.vistrails.org/index.php/User:Tohline/citation