Swift satellite images a galaxy ablaze with starbirth

Feb 26, 2008
Swift satellite images a galaxy ablaze with starbirth
Image credit: NASA/Swift Science Team/Stefan Immler

Combining 39 individual frames taken over 11 hours of exposure time, NASA astronomers have created this ultraviolet mosaic of the nearby "Triangulum Galaxy." "This is the most detailed ultraviolet image of an entire galaxy ever taken," says Stefan Immler of NASA's Goddard Space Flight Center in Greenbelt, Md. Immler used NASA's Swift satellite to take the images, and he then assembled them into a mosaic that seamlessly covers the entire galaxy.

The Triangulum Galaxy is also called M33 for being the 33rd object in Charles Messier's sky catalog. It is located about 2.9 million light-years from Earth in the constellation Triangulum. It is a member of our Local Group, the small cluster of galaxies that includes our Milky Way Galaxy and the Andromeda Galaxy (M31). Despite sharing our Milky Way's spiral shape, M33 has only about one-tenth the mass. M33's visible disk is about 50,000 light-years across, half the diameter of our galaxy.

Swift's Ultraviolet/Optical Telescope (UVOT) took the images through three separate ultraviolet filters from December 23, 2007 to January 4, 2008. The mosaic showcases UVOT's high spatial resolution. Individual star clusters and star-forming gas clouds are clearly resolved, even in the crowded nucleus of the galaxy. The image also includes Milky Way foreground stars and much more distant galaxies shining through M33.

Young, hot stars are prodigious producers of ultraviolet light, which heat up the surrounding gas clouds to such high temperatures that they radiate brightly in ultraviolet light. The image shows the giant star-forming region NGC 604 as a bright spot to the lower left of the galaxy's nucleus. With a diameter of 1,500 light-years (40 times that of the Orion Nebula), NGC 604 is the largest stellar nursery in the Local Group.

"The ultraviolet colors of star clusters tell us their ages and compositions," says Swift team member Stephen Holland of NASA Goddard. "With Swift's high spatial resolution, we can zero in on the clusters themselves and separate out nearby stars and gas clouds. This will enable us to trace the star-forming history of the entire galaxy."

"The entire galaxy is ablaze with starbirth," adds Immler. "Despite M33's small size, it has a much higher star-formation rate than either the Milky Way or Andromeda. All of this starbirth lights up the galaxy in the ultraviolet."

Larger image: www.nasa.gov/images/content/214434main_M33_UVOT.jpg

Source: Goddard Space Flight Center, by Robert Naeye

Explore further: Short, sharp shocks let slip the stories of supernovae

Related Stories

Galaxy's snacking habits revealed

May 20, 2015

A team of Australian and Spanish astronomers have caught a greedy galaxy gobbling on its neighbours and leaving crumbs of evidence about its dietary past.

Hubble catches a stellar exodus in action

May 14, 2015

Using NASA's Hubble Space Telescope, astronomers have captured for the first time snapshots of fledgling white dwarf stars beginning their slow-paced, 40-million-year migration from the crowded center of ...

Recommended for you

What are extrasolar planets?

4 hours ago

For countless generations, human beings have looked out at the night sky and wondered if they were alone in the universe. With the discovery of other planets in our solar system, the true extent of the Milky ...

A curious family of giant exoplanets

5 hours ago

There are 565 exoplanets currently known that are as massive as Jupiter or bigger, about one third of the total known, confirmed exoplanet population. About one quarter of the massive population orbits very ...

Astrobiology students explore alien environment on Earth

5 hours ago

Sonny Harman never thought he'd be able to travel far enough to do field work. That's because the Penn State doctoral student studies atmospheres on other planets. But to his surprise, Harman recently stepped ...

NASA image: Hubble revisits tangled NGC 6240

6 hours ago

Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Nikola
5 / 5 (1) Feb 26, 2008
I can't wait until the James Webb Telescope goes into orbit in 2013. Hubble is scheduled for major upgrades this fall which will hold us over until then.
gopher65
5 / 5 (1) Feb 26, 2008
JWST will image a different section of the spectrum that either Hubble or Swift. So it's not a replacement for either of them, it's a complementary telescope. Herschel will also be up this year (3.5 metre mirror) for sub-millimetre and far infrared stuff.

http://en.wikiped...ervatory

There are many different wavelengths to observe, and one telescope can't do them all. You need many different telescopes to see in every wavelength.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.