The Birth of a Nursery

This image was recently pub­lished on the ESO website:

*

Here is the press release that accom­panied it:

Illus­trating the power of submillimetre-​wavelength astro­nomy, [the above] APEX image reveals how an expanding bubble of ionised gas about ten light-​years across is causing the sur­rounding material to collapse into dense clumps that are the birth­places of new stars. Sub­mil­li­metre light is the key to revealing some of the coldest material in the Universe, such as these cold, dense clouds.

The region, called RCW120, is about 4200 light years from Earth, towards the con­stel­la­tion of Scorpius. A hot, massive star in its centre is emitting huge amounts of ultra­vi­olet radi­ation, which ionises the sur­rounding gas, strip­ping the elec­trons from hydrogen atoms and pro­du­cing the char­ac­ter­istic red glow of so-​called H-​alpha emission.

As this ionised region expands into space, the asso­ci­ated shock wave sweeps up a layer of the sur­rounding cold inter­stellar gas and cosmic dust. This layer becomes unstable and col­lapses under its own gravity into dense clumps, forming cold, dense clouds of hydrogen where new stars are born. However, as the clouds are still very cold, with tem­per­at­ures of around –250˚ Celsius, their faint heat glow can only be seen at sub­mil­li­metre wavelengths. Sub­mil­li­metre light is there­fore vital in studying the earliest stages of the birth and life of stars.

The submillimetre-​wavelength data were taken with the LABOCA camera on the 12-​m Atacama Pathfinder Exper­i­ment (APEX) tele­scope, located on the 5000m high plateau of Chajn­antor in the Chilean Atacama desert. Thanks to LABOCA’s high sens­it­ivity, astro­nomers were able to detect clumps of cold gas four times fainter than pre­vi­ously possible. Since the bright­ness of the clumps is a measure of their mass, this also means that astro­nomers can now study the form­a­tion of less massive stars than they could before.

The plateau of Chajn­antor is also where ESO, together with inter­na­tional partners, is building a next gen­er­a­tion sub­mil­li­metre tele­scope, ALMA, the Atacama Large Millimeter/​submillimeter Array. ALMA will use over sixty 12-​m antennas, linked together over dis­tances of more than 16 km, to form a single, giant telescope.

APEX is a col­lab­or­a­tion between the Max-​Planck-​Institute for Radio Astro­nomy (MPIfR), the Onsala Space Obser­vatory (OSO) and ESO. The tele­scope is based on a pro­to­type antenna con­structed for the ALMA project. Oper­a­tion of APEX at Chajn­antor is entrusted to ESO.

This is a pho­to­graph of the afore­men­tioned Atacama Pathfinder Exper­i­ment (APEX):

A photograph of the Atacama Pathfinder Experiment

It looks like it would be a great place to work.