There's a spiral galaxy located 200 million light years from here that's not doing so well. See those intense blue streaks streaming away from it? Those are hot young stars that are being torn away from the galaxy by its surroundings as it moves through space.
This extraordinary new image was snapped by the Hubble Space Telescope. The galaxy, called ESO 137-001, is framed against a bright background as it moves through the heart of a galaxy cluster named Abell 3627. This cluster is violently ripping the spiral's contents out into deep space, leaving the bright blue streaks.
It's an effect caused by a process called ram pressure stripping. It's a drag force felt by an object as it moves through a fluid. It's like trying to walk as fast as you can in a pool of water. In this case, the fluid is a superheated gas, which tends to settle at the centers of galactic clusters. Eventually, the process will leave this galaxy with very little of the cold gas that's essential for star formation — rendering it incapable of forming new stars. So this galaxy is dying, and it will eventually whither away once its current set of stars all die out.
The process is also causing the curved appearance of the disc of gas and dust, a result of the forces exerted by the heated gas. The cluster is bending ESO 137-001, but the galaxy's gravitational pull is strong enough to hold on to the majority of its dust, though some displaced brown streaks of dust are visible.
A combined image showing a gigantic gas stream that's only visible in the X-ray part of the spectrum. Credit: NASA/ESA/CXC.
Check out this completely jaw-dropping zoom-in on ESO 137011; the sequence begins with a view of the night sky near the constellation of Triangulum Australe (The Southern Triangle):
[ Hubble ]