Exponential disk. Rotation velocity

[Astaroth.]

Hello
I have been modeling the rotation curves of galaxies.
Can help in calculating the rotation velocity for a thin exponential disk.
I use the method of Kent S.
http://articles.adsabs.harvard.edu//full/1986AJ...91.1301K/0001310.000.html

My implementation in C # https://www.physicsforums.com/attachment.php?attachmentid=41286&stc=1&d=1322342344



Sorry for my english.

 

[AndyW]

Hello,

Thank you for sharing your work on modeling the rotation curves of galaxies. This is a very interesting and important topic in astrophysics. I am familiar with the method of Kent S. and have used it in my own research as well. I would be happy to assist you in calculating the rotation velocity for a thin exponential disk.

First, I would recommend checking the validity of your implementation in C# by comparing it to the results in the paper by Kent S. If there are any discrepancies, it would be helpful to troubleshoot and make sure all the equations and parameters are correctly implemented.

Once you have validated your implementation, we can move on to calculating the rotation velocity for a thin exponential disk. This can be done by using the following equation:

V(r) = V(max) * [1 - exp(-r/h)]

where V(max) is the maximum rotation velocity, r is the distance from the center of the galaxy, and h is the scale length of the disk. This equation assumes a flat rotation curve, which is a common assumption for thin exponential disks.

To calculate V(max), you will need to use the observed velocity at a certain radius, typically at the edge of the disk. This can be obtained from observational data or by fitting the rotation curve with a model. Then, using the scale length of the disk, you can calculate the rotation velocity at any distance from the center.

I hope this helps in your calculations. If you have any further questions, please don't hesitate to ask. Good luck with your research!