It has been collected by the Herschel Space Telescope

Oct 2, 2009 08:50 GMT  ·  By
Unprecedented, far-infrared detail of the Milky Way, obtained by combining SPIRE and PACS images
   Unprecedented, far-infrared detail of the Milky Way, obtained by combining SPIRE and PACS images

Two of the most advanced telescopes orbiting the planet or the Sun today were launched this year aboard an Ariane 5 delivery system by the European Space Agency (ESA). One of them is the Planck observatory, whose mission is to analyze the Cosmic Microwave Background (CMB), while the other is the flagship mission, the Herschel Space Telescope. It is able to photograph the Universe in the far-infrared wavelengths, and one of its first images is of the Milky Way, featuring unprecedented details. While taking the shot, Herschel was placed in a special scanning mode, the BBC News reports.

The main goal of the advanced observatory is to distinguish details about early star and galaxy formation that are invisible to other telescopes, such as the famous Hubble. In order to do that, it needs to be cooled close to absolute zero, and also to orbit the Sun in a Lagrangian point (L2), so that residual light coming in from the Moon, Earth and the Sun is kept away from its sensitive detectors. In its latest image, the spacecraft used its three infrared detectors to image collapsing clouds of gas that fell under their own gravitational pull to create young, blue stars.

The scanning mode Herschel was placed in meant that two of its cameras, the PACS (Photodetecting Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging Receiver), worked together to image the Milky Way. The former is an integral-field spectrograph, which is able to snap pictures in two sets of wavelengths (60–85/85–130 micrometers and 130–210 micrometers) at the same time. The latter is a low-resolution spectrometer covering the 194 to 672 micrometer wavelength. SPIRE also features a tri-band imaging camera, centered around 250, 350 and 500 micrometers.

“Our wavelength coverage is telling us details about the physics. Spire is particularly good at seeing the cold and extended material which might correspond, for instance, to the earliest stages of star formation. Pacs is slightly more sensitive to what we would call warmer material, although by any normal standards it is still extremely cold; and that material might be closer to regions where stars have already formed and have been heated up by the young stellar objects,” the Spire principal investigator, Cardiff University Professor Matt Griffin, from the United Kingdom, explains.