Galaxy-Scale Physics and Dark Matter Halos

[nkurinsky]

Is there a specific reason why options to add dark matter haloes are not included? I understand this is based on Newtonian gravity, but to a first order adding basic halo profiles (NFW, Einasto) and adding options to simulate little globs of DM based on a range of masses would be an incredible addition, especially for use at the college level to demonstrate the need for dark matter. I do think this would be worth the bit of extra work if it's doable, though it seems your focus is on solar-system scale physics so I understand this might be a bit ambitious. As someone in this field this would be really neat to see, you seem to have a great product thus far.

[ericjhilton]

Hi, we do include dark matter haloes! Go to Home-> Create -> Galaxy. Some of the presets include dark matter, or you can specify it yourself under 'Settings.' The default is numberDMParticles = 250, but you can increase that to get a more realistic rotation curve. This is done pure n-body, so the spiral arms aren't stable.

It's on my to-do list to revisit galaxies, and improve upon the way we procedurally generate them, likely in the next couple of months. I'd like to allow the user to specify the DM profile (as you mention), as well as provide a way to plot the rotation curve, which would really show off the difference between including DM and placing all the mass at the center.

Thanks for the comment, and please let me know if you have any more thoughts.

Cheers,
Eric

[BrandCollision]

Hi, we do include dark matter haloes! Go to Home-> Create -> Galaxy. Some of the presets include dark matter, or you can specify it yourself under 'Settings.' The default is numberDMParticles = 250, but you can increase that to get a more realistic rotation curve. This is done pure n-body, so the spiral arms aren't stable.

It's on my to-do list to revisit galaxies, and improve upon the way we procedurally generate them, likely in the next couple of months. I'd like to allow the user to specify the DM profile (as you mention), as well as provide a way to plot the rotation curve, which would really show off the difference between including DM and placing all the mass at the center.

Thanks for the comment, and please let me know if you have any more thoughts.

Cheers,
Eric

Hes probably wanting you to acully be able to spwn idividual dark matter halos, and not have to spawn an entire galexy, just sayin

[Gordon Freeman]

That'd be... odd.
I'm pretty sure she/he means "Why isn't there an "Add Dark Matter Halo" button for galaxies?".

Although I'll admit, a dispenser for dark matter clouds would be pretty awesome.