Spiral Galaxies in Collision
Billions of years from now, only of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that about peaked 40 million years ago, the smaller galaxy is swinging around counter-clockwise, and is now slightly behind the larger galaxy. The space between stars is so vast that when galaxies collide, the stars in them usually do not collide.
Image Credit: Debra Meloy Elmegreen (Vassar College) et al., & the Hubble Heritage Team (AURA/STScl/NASA)
two lost souls swimming in a fishbowl: Pluto and Charon, photographed by Hubble Space Telescope, June 2010.
This study also aimed to image the smaller Plutonian moons Nyx and Hydra. If you look very closely, there appear to be two extremely faint objects that track with Pluto and Charon (at about the 9 and 7 o’clock positions) which might fit the bill.
This composite image of VV 340 contains X-ray data from Chandra and optical data from Hubble. The two galaxies shown here are in the early stage of an interaction that will eventually lead to them merging in millions of years. The Chandra data shows that the northern galaxy contains a rapidly growing supermassive black hole that is heavily obscured by dust and gas. Data from other wavelengths shows that the two interacting galaxies are evolving at different rates.
Image Credit: X-ray NASA/CXC/IfA/D.Sanders et al; Optical NASA/STScl/NRAO/A.Evans et al
Galaxies don’t normally look like this. NGC 6745 actually shows the results of two galaxies that have been colliding for only hunderds of million of years. Just off the above digitally sharpened photograph to the lower right is the smaller galaxy, moving away. The larger galaxy, pictured above, used to be a spiral galaxy but now is damaged and appear peculiar. Gravity has distorted the shapes of the galaxies. Although it is likely that no stars in the two galaxies direclty collided, the gas, dust, and ambient magnetic fields do interact directly. In fact, a knot of gas pulled off the larger galaxy on the lower right has now begun to form stars. NGC 6745 spans about 80 thousand light-years across and is located about 200 million light-years away.
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScl/AURA)-ESA/Hubble Collaboration Acknowledgment: Roger Lynds (KPNO/NOAO) et al.