It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies seen here — known as NGC 3921 — is one of these systems.
NGC 3921 — found in the constellation of Ursa Major (The Great Bear) — is an interacting pair of disk galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger.
The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1,000 bright, young star clusters bursting to life at the heart of the galaxy pair.
Image credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt
Text credit: European Space Agency
Last Updated: Sep. 18, 2015
Editor: Ashley Morrow
Hubble Looks at Stunning Spiral
This little-known galaxy, officially named J04542829-6625280, but most often referred to as LEDA 89996, is a classic example of a spiral galaxy. The galaxy is much like our own galaxy, the Milky Way. The disk-shaped galaxy is seen face on, revealing the winding structure of the spiral arms. Dark patches in these spiral arms are in fact dust and gas — the raw materials for new stars. The many young stars that form in these regions make the spiral arms appear bright and bluish.
The galaxy sits in a vibrant area of the night sky within the constellation of Dorado (The Swordfish), and appears very close to the Large Magellanic Cloud — one of the satellite galaxies of the Milky Way.
The observations were carried out with the high resolution channel of Hubble’s Advanced Camera for Surveys.
Image credit: ESA/Hubble & NASA, Acknowledgement: Flickr user C. Claude
Text credit: European Space Agency
Last Updated: July 31, 2015
Editor: Ashley Morrow
Hubble Sees a Galactic Sunflower
The arrangement of the spiral arms in the galaxy Messier 63, seen here in an image from the NASA/ESA Hubble Space Telescope, recall the pattern at the center of a sunflower. So the nickname for this cosmic object — the Sunflower Galaxy — is no coincidence.
Discovered by Pierre Mechain in 1779, the galaxy later made it as the 63rd entry into fellow French astronomer Charles Messier’s famous catalogue, published in 1781. The two astronomers spotted the Sunflower Galaxy’s glow in the small, northern constellation Canes Venatici (the Hunting Dogs). We now know this galaxy is about 27 million light-years away and belongs to the M51 Group — a group of galaxies, named after its brightest member, Messier 51, another spiral-shaped galaxy dubbed the Whirlpool Galaxy.
Galactic arms, sunflowers and whirlpools are only a few examples of nature’s apparent preference for spirals. For galaxies like Messier 63 the winding arms shine bright because of the presence of recently formed, blue–white giant stars and clusters, readily seen in this Hubble image.
Image credit: ESA/Hubble & NASA
Text credit: European Space Agency
Last Updated: Sep. 11, 2015
Editor: Ashley Morrow
What Hubble Observed
No comments:
Post a Comment