SUPER STAR CLUSTERS IN THE ANTENNAE GALAXIES
This new NASA Hubble Space Telescope image of the Antennae galaxies is
the sharpest yet of this merging pair of galaxies. During the course of
the collision, billions of stars will be formed. The brightest and most
compact of these star birth regions are called super star clusters.
The two spiral galaxies started to interact a few hundred million years
ago, making the Antennae galaxies one of the nearest and youngest examples
of a pair of colliding galaxies. Nearly half of the faint objects in the
Antennae image are young clusters containing tens of thousands of stars.
The orange blobs to the left and right of image center are the two cores
of the original galaxies and consist mainly of old stars criss-crossed
by filaments of dust, which appears brown in the image. The two galaxies
are dotted with brilliant blue star-forming regions surrounded by
glowing hydrogen gas, appearing in the image in pink.
The new image allows astronomers to better distinguish between the stars
and super star clusters created in the collision of two spiral galaxies.
By age dating the clusters in the image, astronomers find that only
about 10 percent of the newly formed super star clusters in the Antennae
will survive beyond the first 10 million years. The vast majority of the
super star clusters formed during this interaction will disperse, with
the individual stars becoming part of the smooth background of the
galaxy. It is however believed that about a hundred of the most massive
clusters will survive to form regular globular clusters, similar to the
globular clusters found in our own Milky Way galaxy.
The Antennae galaxies take their name from the long antenna-like “arms” extending far out from the nuclei of the two galaxies, best seen by ground-based telescopes. These “tidal tails” were formed during the initial encounter of the galaxies some 200 to 300 million years ago. They give us a preview of what may happen when our Milky Way galaxy will collide with the neighboring Andromeda galaxy in several billion years.
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration
B. Whitmore (Space Telescope Science Institute)