Born from the wind -- unique multi-wavelength portrait of star birth

October 08, 2008

Telescopes on the ground and in space have teamed up to compose a colourful image that offers a fresh look at the history of the star-studded region NGC 346. This new, ethereal portrait, in which different wavelengths of light swirl together like watercolours, reveals new information about how stars form.

The picture combines infrared, visible and X-ray light from NASA's Spitzer Space Telescope, ESO's New Technology Telescope (NTT) and the European Space Agency's XMM-Newton orbiting X-ray telescope, respectively. The NTT visible-light images allowed astronomers to uncover glowing gas in the region and the multi-wavelength image reveals new insights that appear only thanks to this unusual combination of information.

NGC 346 is the brightest star-forming region in the Small Magellanic Cloud, an irregular dwarf galaxy that orbits the Milky Way at a distance of 210 000 light-years.

"NGC 346 is a real astronomical zoo," says Dimitrios Gouliermis of the Max Planck Institute for Astronomy in Heidelberg, Germany, and lead author of the paper describing the observations. "When we combined data at various wavelengths, we were able to tease apart what's going on in different parts of this intriguing region."

Small stars are scattered throughout the NGC 346 region, while massive stars populate its centre. These massive stars and most of the small ones formed at the same time out of one dense cloud, while other less massive stars were created later through a process called "triggered star formation". Intense radiation from the massive stars ate away at the surrounding dusty cloud, triggering gas to expand and create shock waves that compressed nearby cold dust and gas into new stars. The red-orange filaments surrounding the centre of the image show where this process has occurred.

But another set of younger low-mass stars in the region, seen as a pinkish blob at the top of the image, couldn't be explained by this mechanism. "We were particularly interested to know what caused this seemingly isolated group of stars to form," says Gouliermis.

By combining multi-wavelength data of NGC 346, Gouliermis and his team were able to pinpoint the trigger as a very massive star that blasted apart in a supernova explosion about 50 000 years ago. Fierce winds from the massive dying star, and not radiation, pushed gas and dust together, compressing it into new stars, bringing the isolated young stars into existence. While the remains of this massive star cannot be seen in the image, a bubble created when it exploded can be seen near the large, white spot with a blue halo at the upper left (this white spot is actually a collection of three stars).

The finding demonstrates that both wind- and radiation-induced triggered star formation are at play in the same cloud. According to Gouliermis, "the result shows us that star formation is a far more complicated process than we used to think, comprising different competitive or collaborative mechanisms."

The analysis was only possible thanks to the combination of information obtained through very different techniques and equipments. It reveals the power of such collaborations and the synergy between ground- and space-based observatories.
-end-


ESO

Related Star Formation Articles from Brightsurf:

Low-metallicity globular star cluster challenges formation models
On the outskirts of the nearby Andromeda Galaxy, researchers have unexpectedly discovered a globular cluster (GC) - a massive congregation of relic stars - with a very low abundance of chemical elements heavier than hydrogen and helium (known as its metallicity), according to a new study.

Astronomers turn up the heavy metal to shed light on star formation
Astronomers from The University of Western Australia's node of the International Centre for Radio Astronomy Research (ICRAR) have developed a new way to study star formation in galaxies from the dawn of time to today.

New observations of black hole devouring a star reveal rapid disk formation
When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole.

How galaxies die: New insights into the quenching of star formation
Astronomers studying galaxy evolution have long struggled to understand what causes star formation to shut down in massive galaxies.

The cosmic commute towards star and planet formation
Interconnected gas flows reveal how star-forming gas is assembled in galaxies.

Star formation project maps nearby interstellar clouds
Astronomers have captured new, detailed maps of three nearby interstellar gas clouds containing regions of ongoing high-mass star formation.

Scientists discover pulsating remains of a star in an eclipsing double star system
Scientists from the University of Sheffield have discovered a pulsating ancient star in a double star system, which will allow them to access important information on the history of how stars like our Sun evolve and eventually die.

Distant milky way-like galaxies reveal star formation history of the universe
Thousands of galaxies are visible in this radio image of an area in the Southern Sky, made with the MeerKAT telescope.

Cascades of gas around young star indicate early stages of planet formation
What does a gestating baby planet look like? New research in Nature by a team including Carnegie's Jaehan Bae investigated the effects of three planets in the process of forming around a young star, revealing the source of their atmospheres.

Massive exoplanet orbiting tiny star challenges planet formation theory
Astronomers have discovered a giant Jupiter-like exoplanet in an unlikely location -- orbiting a small red dwarf star.

Read More: Star Formation News and Star Formation Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.