Planck satellite sees giant filaments of cold dust stretching through our galaxy

PARIS - A new image from ESA’s (European Space Agency’s) Planck satellite has revealed giant filaments of cold dust stretching through our Galaxy.

The image shows the filamentary structure of dust in the solar neighbourhood - within about 500 light-years of the Sun.

The local filaments are connected to the Milky Way, which is the pink horizontal feature near the bottom of the image.

Here, the emission is coming from much further away, across the disc of our Galaxy.

The image has been colour coded to discern different temperatures of dust. White-pink tones show dust of a few tens of degrees above absolute zero, whereas the deeper colours are dust at around -261 degree Celsius, only about 12 degrees above absolute zero.

The warmer dust is concentrated into the plane of the Galaxy whereas the dust suspended above and below is cooler.

“What makes these structures have these particular shapes is not well understood,” said Jan Tauber, ESA Project Scientist for Planck.

The denser parts are called molecular clouds while the more diffuse parts are ‘cirrus’.

They consist of both dust and gas, although the gas does not show up directly in this image.

There are many forces at work in the Galaxy to help shape the molecular clouds and cirrus into these filamentary patterns.

For example, on large scales the Galaxy rotates, creating spiral patterns of stars, dust, and gas.

Gravity exerts an important influence, pulling on the dust and gas.

Radiation and particle jets from stars push the dust and gas around, and magnetic fields also play a role, although to what extent is presently unclear.

Bright spots in the image are dense clumps of matter where star formation may take place.

As the clumps shrink, they become denser and better at shielding their interiors from light and other radiation.

This allows them to cool more easily and collapse faster.

ESA’s Herschel space telescope can be used to study such regions in detail, but only Planck can find them all over the sky.

The new image is a combination of data taken with Planck’s High Frequency Instrument (HFI), at wavelengths of 540 micrometres and 350 micrometres, and a 100-micrometre image taken in 1983 with the IRAS satellite. (ANI)