Formation of a spiral galaxy

Cosmological simulation of the formation of a spiral galaxy. The data is extracted from a cosmological SPH simulation performed with the DEVA code. Mass resolution for baryonic particles is 2.8e6 solar masses. For the astrophysically inclined, the length scale is not correct, it should be twice the size shown on the left size. Hence, final radius of the disk is ~20kpc.

Finally details on this galaxy are available in paper form:
http://arxiv.org/abs/0906.1118
Galaxy 6795 in that paper

Category:

People & Blogs

Tags:

• galaxy
• spiral
• formation
• sph
• simulation

[arm2armcos]

Hi, what s happened with this paper on astroph??

Did you published? could you explain more about simulations?

[mambru37]

There is a small contribution to the meeting these simulations were made for, arXiv:0709.0818. Full paper with explanation of the method should be available on astro-ph once it is accepted (sooner than later).

[mambru37]

there you go!

arXiv:0804.3766

[kappazapata]

may i ask two more questions? 1. what is the mass resolution of you simulation? it seems you've got a quite large cosmo-box, but the spiral looks indeed quite detailed... did you re-simulate at different resolutions? 2. did you include any kind of feedback?

[mambru37]

Baryonic mass resolution is not that high: ~3e6 Msun, and yes, as it can be seen at the beginning of the movie, it's a resimulation; only the baryonic particles inside the virial radius of the final object are included (sort of). Energy feedback is not activated for this simulation. I don't understand very well its effects, moreover, it implies more free parameters. I guess it should be activated if you go to higher resolutions, but then you have to change your star formation efficiencies.

[pointmanzero]

The creationist nephilimfree claims that the inside of galaxies spin at the same rate as the outer arms. Is this true? Is it represented in your simulation.

[TheJesseLenney]

This is awesome.

What exactly is being rendered? Is it dark matter? And how did you render it like that (to show density)?

[deluxeassortment]

It seems like the accretion disc flattens out pretty fast, faster than I'd have expected. Any idea why they flatten out in this manner? I would have thought it would have been the result of a combination of gravity of surrounding particles and angular momentum over time, but I've never quite understood how accretion discs flatten.

[matty406]

oh, i wish i could do stuff like this...

I like the part when it almost rips apart, though. :D

[astrogrikor]

hahaha ...what ???? INTERESTING PHYSICS FOR SURE

[CACBCCCU]

Interesting. The paired-spiral states seem very transient compared to observations of various close-by sample galaxies. Could be my personal selection bias, I suppose. Also there is no suggestion of a ring phase that seems very common in real images of more-distant galaxies. I'd suggest multiplying Newtonian gravity by a cosine with a wavelength on a scale of the average disk-cluster radius. Call it a low-energy quantum gravity correction to Newton.