3
$\begingroup$

Context: I want to simulate globular clusters in a simple way, just to display the positions of stars.

Assuming isotropy, what would be a reasonable model of the stellar number density as a function or r, the distance from the center of the cluster?

I'm assuming that such a model would have some free parameters as well.

$\endgroup$
4
$\begingroup$

The usual thing is a King model.

There are indeed free parameters. These are the central density, the "core radius" and a tidal truncation radius.

The background and rationale for these models is given in the link. They provide a pretty good representation of the surface density of globular clusters (or indeed open clusters). They require a numerical scheme to "deproject" from the plane of the sky to 3D.

If you find the nitty-gritty of Abel integrals too tricky in the deprojection, then you could always approximate with a Plummer model. This is analytically and computationally easier to deal with, but lacks a bit of physical realism. Central density and a characteristic radius are free parameters here.

$\endgroup$
  • $\begingroup$ My needs are pretty simple. I will use the Plummer model. $\endgroup$ – John O May 21 '15 at 11:39
4
$\begingroup$

Check out the MASSCLEAN package, it can be used to generate artificial/synthetic clusters of arbitrary metallicities, ages, mass, radius (based on a King profile distribution) and even includes field stars contamination.

Here's an example of a cluster generated with the code (right) imitating a known cluster (NGC 3603, left):

enter image description here

See the original article for a good description of the capabilities of the code.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.