Image: Star formation and magnetic turbulence in the Orion Molecular Cloud

May 20, 2015, European Space Agency
Credit: ESA and the Planck Collaboration

With blue hues suggestive of marine paradises and a texture evoking the tranquil flow of sea waves, this image might make us daydream of sandy beaches and exotic holiday destinations. Instead, the subject of the scene is intense and powerful, because it depicts the formation of stars in the turbulent billows of gas and dust of the Orion Molecular Cloud.

The image is based on data from ESA's Planck satellite, which scanned the sky between 2009 and 2013 to study the , the most ancient light in the Universe's history. While doing so, Planck also detected foreground emission from material in the Milky Way, as well as from other galaxies.

Our Galaxy is pervaded by a diffuse mixture of gas and that occasionally becomes denser, creating giant gas clouds where stars can form. While present only in traces, dust is a crucial ingredient in these interstellar clouds. It also shines brightly at some of the wavelengths that were probed by Planck, so astronomers can use these data to learn more about the cradles of star formation.

In addition, dust grains have elongated shapes and tend to align their longest axis at right angles to the direction of the Galaxy's . This makes their emission partly 'polarised' – it vibrates in a preferred direction. Since Planck was equipped with polarisation-sensitive detectors, its scans also contain information about the direction of the magnetic field threading the Milky Way.

This image combines a visualisation of the total intensity of dust emission, shown in the colour scale, with an indication of the magnetic field's orientation, represented by the texture. Blue hues correspond to regions with little dust, while the yellow and red areas reflect denser (and mostly hotter) clouds containing larger amounts of dust, as well as gas.

The red clumps at the centre of the image are part of the Orion Molecular Cloud Complex, one of the closest large regions of , only about 1300 light-years from the Sun. The most prominent of the red clumps, to the lower left of centre, is the famous Orion Nebula, also known as M42. This is visible to the naked eye in the constellation Orion, just below the three stars forming the 'belt' of the mythological hunter. An annotated version of the image can be found here.

The magnetic field appears regular and organised in almost parallel lines in the upper part of the image: this is a result of the large-scale arrangement of the magnetic field along the Galactic plane, which is located above the top of this image. However, the field becomes less regular in the central and lower parts of the image, in the region of the Orion Molecular Cloud. Astronomers believe that the turbulent structure of the magnetic field observed in this and other star-forming clouds is related to the powerful processes taking place when stars are being born.

The emission from dust is computed from a combination of Planck observations at 353, 545 and 857 GHz, whereas the direction of the magnetic field is based on Planck polarisation data at 353 GHz. The image spans about 40º across.

Explore further: Image: The magnetic field along the galactic plane

Related Stories

Image: The magnetic field along the galactic plane

December 16, 2014

While the pastel tones and fine texture of this image may bring to mind brush strokes on an artist's canvas, they are in fact a visualisation of data from ESA's Planck satellite. The image portrays the interaction between ...

Researchers image the Milky Way's magnetic fingerprint

May 6, 2014

(Phys.org) —Our Galaxy's magnetic field is revealed in a new image from ESA's Planck satellite. This image was compiled from the first all-sky observations of 'polarised' light emitted by interstellar dust in the Milky ...

Embracing Orion

August 26, 2013

(Phys.org) —This new view of the Orion A star-formation cloud from ESA's Herschel space observatory shows the turbulent region of space that hugs the famous Orion Nebula.

Image: Hubble eyes galactic refurbishment

May 4, 2015

The smudge of stars at the center of this NASA/ESA Hubble Space Telescope image is a galaxy known as UGC 5797. UGC 5797 is an emission line galaxy, meaning that it is currently undergoing active star formation. The result ...

Recommended for you

Hunting molecules to find new planets

June 19, 2018

It's impossible to obtain direct images of exoplanets as they are masked by the high luminous intensity of their stars. However, astronomers led by UNIGE propose detecting molecules present in the exoplanet's atmosphere in ...

Exploring planetary plasma environments from your laptop

June 15, 2018

A new database of plasma simulations, combined with observational data and powerful visualisation tools, is providing planetary scientists with an unprecedented way to explore some of the Solar System's most interesting plasma ...

0 comments

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.