Discovering cosmic dust clusters inside the Milky Way galaxy

An unprecedented map of the area inside the Milky Way has been revealed by astronomers. Our picture of the Milky Way galaxy is littered with thousands of cold cosmic dust clusters. This may be the place where new stars begin to form. Observed results from the APEX telescope in Chile released the map of the largest dust clusters to date. The map is also extremely valuable for observations to be made by the ALMA telescope, as well as the recently launched new telescope of the European space agency Herschel.

The study, called ATLASGAL, shows a picture of the Milky Way in light below a millimeter wavelength (between infrared light and radio waves (1)). The cosmic image taken at these wavelengths is very significant for studying the birth place of new stars and the central structure of the Milky Way.

Frederic Schuller from the Max Planck Radio Astronomy Institute, head of the ATLASGAL research team said, 'Thanks to ATLASGAL, we have a new look at the Milky Way galaxy. This study not only investigates the formation of a series of stars but also gives us an overview of the wider structure of the Milky Way galaxy where our planet exists. '

This new millimeter-scale map covers an area of ​​95 square meters. This region is a long and narrow strip along the Milky Way's surface, which is 2 degrees wide (4 times the width of the Moon) and 40 degrees long. This 16000 pixel long map is made possible by a camera under wavelength LABOCA on the APEX telescope. APEX is located at 5100 meters above sea level, on the Chajnantor arid plateau in the Andes, Chile. This position allows the most optimal observations within a millimeter. Today, people still do not know much about the universe at wavelengths below the millimeter by extremely dry atmospheric conditions . Moreover, to be able to do this requires advanced detection technology.

Color image capturing RCW120 in ATLASGAL study. RCW120 is the area where a cluster of ionized air bubbles spreads about 10 light-years across, making matter around it shrink into dense blocks of matter. This is where new stars are formed. (Photo: European Space Agency)

The interstellar medium - matter between stars - is made up of a mixture of cosmic dust and gas, which is relatively like sand and soot. However, the gas is mainly hydrogen and quite difficult to detect. So astronomers often detect these dense areas by searching for heat light emitted from cosmic dust.

Light below a millimeter allows astronomers to see these dust clouds glowing, although they obscure our cosmic vision at the wavelength of visible light. Accordingly, the ATLASGAL map includes the most dense central areas of the Milky Way, in the direction of the constellation Sagittarius. This is a huge black hole, hidden behind a cloud of veil of dust.

This new map also reveals thousands of dense clumps of dust that we have never seen, marking places where a series of stars can be born in the future. These clumps of dust are several light-years in size and have a mass of about 10 or several thousand times the mass of the Sun. In addition, ATLASGAL also captured images of beautiful silk structures and air bubbles in the interstellar environment, blown by supernovae and bright stars.

Some of the important highlights of the map include the Milky Way galaxy center, the massive and massive molecular gas cloud named B2 Centaur and the spreading air bubble area called RCW120, in the surrounding area. These bubbles are shrinking and forming new stars.

Mr. Leonardo Testi from European Space Agency ESO, member of ATLASGAL and ALMA project said: 'In the next year, we will expand this map size to cover the entire surface of the Milky Way galaxy . We will combine observations from the APEX telescope on the Chajnantor plateau as well as infrared observations from the European Space Agency Observatory Herschel. "

(1) Map built from observations through APEX telescope at 870 µm wavelength (0.87 mm)

Document:
Frederic Schuller et al.ATLASGAL% u2014 The APEX Telescope Large Area Survey of the Galaxy at 870 µm.Astronomy & Astrophysics.