Astronomers at the Green Bank Observatory have used the radio telescope to look at the most famous star-forming region in the galaxy and they observed a 50-light-year-long ammonia nebula.
The observations are part of an ambitious observational campaign to map the ammonia in several star-forming regions. The team has released the first results, as reported in the Astrophysical Journal, and the data collected is providing new insights into star formation.
"We still don't understand in detail how large clouds of gas in our galaxy collapse to form new stars," lead author Rachel Friesen, one of the collaboration's co-principal investigators, said in a statement.
"But ammonia is an excellent tracer of dense, star-forming gas, and these large ammonia maps will allow us to track the motions and temperature of the densest gas. This is critical to assessing whether gas clouds and filaments are stable, or are undergoing collapse on their way to forming new stars."
Stars form in dense molecular clouds and it’s very difficult to see exactly what goes on under the cover of the gas. For this reason, astronomers have been using different instruments to peer through the clouds.
The different instruments allow researchers to see the emissions of different elements. Radio, in this case, is being used to look at ammonia. By studying how the gas moves, its temperature, and its density researchers are hoping to work out exactly how the gas collapses into a star.
The particular target discussed here is part of the Orion Nebula, which is located over 1,200 light-years away in the homonymous constellation and it’s one of the closest star-forming regions to Earth. It is estimated to be 24 light-years across and has 2,000 times the mass of the Sun. It is part of the so-called Gould Belt, a ring of stars and nebulae we see in the sky.
This belt has interested stellar astronomers in particular because all the nearby low-mass star formation appears to be forming in the confines of this region.
The international collaboration called this project GAS, Green Bank Ammonia Survey. The first data release contains an analysis of B18 in Taurus, NGC 1333 in Perseus, L1688 in Ophiuchus, as well as Orion A North from, obviously, Orion.In the future GAS will look at more regions as well as establishing the structure and stability of the gas cloud. Understanding how star-formation happens nearby might tell us how it happens everywhere across the universe.
