by MarkBour » Thu Mar 05, 2020 9:42 pm
OB1Kubota wrote: ↑Thu Mar 05, 2020 4:24 am
Thanks Mark. Made my observation backwards. But question remains the same.
Yeah, sorry, it's easier to nitpick than to answer a deep question.
I guess I replied because I had been looking at them and thinking of very similar questions.
I'd love to get the software from one of the better galactic collision simulations and do some runs.
If I wasn't lazy, I'd write one, since I don't think it's hard, but the runs probably require supercomputer time.
However, to answer your question could probably be done with models containing just a thousand stars or less.
From what I've seen, when two grand spirals merge, regardless of rotation direction, they are very likely to hugely reduce each other's rotation. If they approach each other edge on, the net rotations are still very cancelling regardless of whether they matched or were opposite before merger. Often you get an elliptical, with low rotation. I think the main counter-example would be two galaxies that approached each other face-on to face-on and were rotating in the same direction.
Anyway, I'd love to hear an answer from someone who's actually done these sims, since I've only seen a modest number of publicized examples.
[quote=OB1Kubota post_id=300128 time=1583382294 user_id=142209]
Thanks Mark. Made my observation backwards. But question remains the same.
[/quote]
Yeah, sorry, it's easier to nitpick than to answer a deep question.
I guess I replied because I had been looking at them and thinking of very similar questions.
I'd love to get the software from one of the better galactic collision simulations and do some runs.
If I wasn't lazy, I'd write one, since I don't think it's hard, but the runs probably require supercomputer time.
However, to answer your question could probably be done with models containing just a thousand stars or less.
From what I've seen, when two grand spirals merge, regardless of rotation direction, they are very likely to hugely reduce each other's rotation. If they approach each other edge on, the net rotations are still very cancelling regardless of whether they matched or were opposite before merger. Often you get an elliptical, with low rotation. I think the main counter-example would be two galaxies that approached each other face-on to face-on and were rotating in the same direction.
Anyway, I'd love to hear an answer from someone who's actually done these sims, since I've only seen a modest number of publicized examples.