Posted on 12/10/2015 6:38:48 AM PST by SunkenCiv
Explanation: This dance is to the death. Along the way, as these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge itself is strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity. As further evidence, the face-on spiral galaxy on the right, also known as NGC 3808A, exhibits many young blue star clusters produced in a burst of star formation. The twisted edge-on spiral on the left (NGC 3808B) seems to be wrapped in the material bridging the galaxies and surrounded by a curious polar ring. Together, the system is known as Arp 87 and morphologically classified, technically, as peculiar. While such interactions are drawn out over billions of years, repeated close passages should ultimately result in the death of one galaxy in the sense that only one galaxy will eventually result. Although this scenario does look peculiar, galactic mergers are thought to be common, with Arp 87 representing a stage in this inevitable process. The Arp 87 pair are about 300 million light-years distant toward the constellation Leo. The prominent edge-on spiral at the far left appears to be a more distant background galaxy and not involved in the on-going merger.
(Excerpt) Read more at 129.164.179.22 ...
[Credit: NASA, ESA, Hubble Space Telescope; Processing: Douglas Gardner]
The night sky for those stars caught in the bridge must be spectacular.
If a galaxy meet a galaxy a-commin’ thru the sky................
Wow!
So what happens to the black hole that supposedly powers the centers of spiral galaxies?
Annihilation?
The black holes reestablish themselves at the center of the combined galaxy and merge into a single larger one. For a while it becomes an active nucleus as it gobbles up nebulae and star clusters, but eventually settles down as it clears its immediate neighborhood. There’s nothing really violent about the merging of black holes, since nothing can escape them; their event horizons just swallow each other. Well almost nothing—merging compact objects are supposed to release a lot of gravity waves according to Einstein’s general relativity. But so far we haven’t been able to find any with our current detectors.
Thanks for the new wallpaper. Beautiful!
The Big One is amazing.
Too bad we won’t be around to see the galaxies merge into one.
Thank you for another great APOD post, my friend.
:’) My pleasure!
Nice!
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