The galaxy M33, seen by Japan's Subaru Telescope. No other high-resolution image has covered M33 so widely and deeply. Larger image (new window)
Stars are the leading lights in a new galaxy picture
14 Mar 2009
Japan's giant Subaru Telescope in Hawai'i has produced a beautiful high-resolution view of the nearby galaxy M33 that reveals fine structure in its spiral shape.
The image, which covers an area of sky roughly equivalent to eight full Moons, shows details in a region measuring 90,000 x 60,000 light-years across, revealing the distribution of stars, star clusters, and star-forming regions in M33.
This galaxy, which lies about 2.5 million light-years away in the constellation Triangulum, is one of the closest galaxies to our own Milky Way. That proximity—plus its nearly face-on view—makes M33 a suitable target for the detailed study of spiral galaxy structure. There have been no other high-resolution images that cover M33 so widely and deeply.
The Subaru image of M33 was made by an international research group of astronomers from the National Astronomical Observatory of Japan, the Institute of Physics of Lithuania, the Gunma Astronomical Observatory, and other institutes in Japan, France and the UK.
< Japan's giant Subaru Telescope in Hawai'i
Most of M33's light comes from stars in its main, flattened part, called the disc. While many spiral galaxies, including the Milky Way, boast central structures called bulges, M33 does not seem to have one. Instead, it appears that the central region of the galaxy has a rich history of star-birth activity. One burst of star formation took place in M33's central region approximately 10 million years ago. Out in the disc, away from the central areas of star birth, there are numerous star clusters and star-forming regions containing massive young stars.
Analysis of high-resolution images of this galaxy makes it very straightforward to map the spatial distribution of stars formed at different eras of M33's evolution. For example, over time the star-forming activity in the disc seems to have shifted from the central part to the outer disc.
In addition, this galaxy is surrounded by a halo containing a sparse distribution of stars and globular (round shaped) star clusters. A detailed analysis of M33 reveals that old halo stars are spread all over the place.
There is also a difference in M33's globular cluster population. While globulars in the Milky Way are older than 10 billion years, those in M33 are estimated to be a few billion years younger, suggesting that there was a different formation history for clusters in M33 than those belonging to the Milky Way. Such differences may arise from the fact that the mass of M33 is an order of magnitude less than the Milky Way.
Adapted from information issued by Subaru.
LATEST HEADLINES & TOP STORIES:
> Stars are the leading lights in a new galaxy image
> Aussie scientists study stars with NASA
> Hubble: new evidence for dark matter
> Cassini spacecraft gets it's back up
> Watch the space station on webcam!
> Texas telescope to help spot Earth-like planets
> Tantalising signs of water activity on Mars
> Mars probe's computer rebooted
> Shuttle mission delayed by fuel leak
> A close-up look at Mars' moon Deimos
> Telescopes team up for 3D view of galaxies
> Teaming up to find new Earths
> Satellite spots the start of a cosmic explosion
> Build your own space station!
> DOWN TO EARTH: Ice in the Sea of Okhotsk
> Mars rover has to take the long way 'round
> Study hints at water—and life—under a martian volcano
> DOWN TO EARTH: "Cloud streets" near Greenland
> Kepler rockets into space to find other Earths
> All systems go for shuttle launch this week
> The ups and downs of a Mars rover
> DOWN TO EARTH: Snowbound US east coast
> Astronomers hope to find lots of planets
> MAIN NEWS PAGE…
Search SpaceInfo…
