Galaxies Gone Wild On A Saturday Night
This is satisfying to watch. 25 gas discs embedded in dark matter halos being thrown into the chaotic environment that is a galaxy cluster. And they all survive pretty much intact !
All of the discs have the same initial conditions, though the movie for each one uses slightly different display parameters (brightness, field of view, etc.) since some of them are more disrupted than others. Each movie tracks the disc through the cluster. The harassing galaxies are not shown since the interaction times are very short. I actually ran 27 simulations, but 27 isn't a square number.
The hypothesis I'm testing is that dark galaxies could survive better than the "tidal debris" explanation that's used for several otherwise mysterious starless clouds of hydrogen seen in the Virgo cluster. Other simulations I've been running strongly suggest that producing clouds similar to those observed by removing gas from galaxies is almost impossible. Thus far, the dark galaxies hypothesis is coming up trumps.
There's still a huge amount of work to do here though. The next step, which will probably complete all the data I need for a publication, will be to try using smaller clouds with less dark matter. The ones shown here are using the largest possible sizes for the clouds allowed by observations, which also means the highest dark matter content.
A much more serious limitation of the current work is the lack of intracluster medium / ram pressure stripping. As the galaxies move through the hot gas inside the cluster itself, their gas gets removed. Combine that with the gravitational harassment and it might be possible to create something that looks like a dark galaxy but actually isn't. It's very hard to guess the result, but we have to take things one step at a time.
Cool. I like the way u created this simulation
ReplyDeleteThat was unfair and harsh to 27.
ReplyDelete27 is not square - it's cubic. And 3x9 would be perfect for our preferred device screen (according to Intel, The device is a mobile phone. Even for us poor souls having a job).
Previously, I automatically assumed that a galaxy was a disc but even galaxies have 3 dimensions to them. It is also true that there is more matter in or near a black hole than astronomers are taking into account (unlike star formation).
ReplyDeleteThe evidence of that is that, when they detected gravitational waves, they also detected a gamma ray burst, from the same location, four seconds after the fluctuation in distance was detected and they were surprised because they didn't think there was enough mass present within or near the black holes.
I was not surprised because I had predicted that there would be a lot more room and matter contained within or near a black hole, depending on how a black hole is defined.
Gravitational lensing and now gravitational waves have the effect of substantiating the theory of general relativity and it means there is a lot of space near a black hole which is from here almost to infinity because distance gets smaller and smaller until there is no distance at the point of singularity, if that is ever attained and that is a lot of room for a lot of mass.
(You simply can't measure a galaxy from one end to the other - Gravitational lensing and gravitational waves confirm it. The size is almost infinite, when there is a black hole there.)
ReplyDeleteNice pics, BTW.
ReplyDeleteOff topic somewhat: You just made galaxy simulations (Rhys Taylor ) and I just made four "crystal batteries" that have been putting out just under 3 volts with a load of three LEDs. It is kind of unsettling because they just keep on burning bright day and night.
ReplyDeleteThat is really pretty, Rhys Taylor . Was all this done in Blender? The galaxy M27 is the "Dumbbell" nebula, Jargon-wise. Wink wink. catch my drift, nudge nudge?
ReplyDeleteFred Beckhusen The simulations are run in an SPH code call gf, but visualised in Blender.
ReplyDeleteYes, I believe I understand your reference. :)