Understanding Rotation Curves: A Study of Galactic Density and Derivatives

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SUMMARY

This discussion focuses on the calculation of rotation curves in galactic dynamics, referencing Casertano's 1982 formula for velocity squared, which involves a double integral of density functions. The density function is defined as p(r,z) = p0 * exp(-r/h) * [ch(z/z0)]^-2, and the derivative is provided as well. The main issue raised is the limitation of the double integral for accurate calculations, with a C# implementation shared for further exploration.

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Dan_
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Hello, I make the calculation of the curve rotation. Casertano(1982г.)
V^{2}=-8GR \int_{0}^{\infty}{r} \int_{0}^{\infty}{ [\frac {\partial p(r,z)} {\partial r}] \frac {K(p)-E(p)} {\sqrt{R r p}}}dzdr
p = x - \sqrt{x^{2}-1} x=(R^{2}+u^{2}+z^{2})/(2Rr)
Density
p(r,z) = p_{0} \exp(-r/h) [ch(z/z_{0})]^{-2}
Derivative
\frac {\partial p(u,z)} {\partial u} = \frac {-p_{0} \exp(-r/h) [ch(z/z_{0})]^{-2}} {h}
Original article http://articles.adsabs.harvard.edu//full/1983MNRAS.203..735C/0000737.000.html
The problem is this. Double integral should be limited. I do not know how.
 
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Calculation in C# http://pastebin.com/Dx4xkzYy
 

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