A team of astronomers has taken a stunning new picture of the central region of our Milky Way, revealing the complex network of filaments of cosmic gas in unprecedented detail.
Received from the ALMA radio telescope (Atacama Large Millimeter/Submillimeter Array), this rich dataset will allow the astronomical community to delve deeper into the lives of the stars present in the most extreme region of our galaxy, near the supermassive black hole at its center.
“This is a place of extremes, invisible to our eyes, but now revealed in extraordinary detail,” he declares. Ashley Barnesastronomer at the European Southern Observatory (ESO) in Germany, who is part of the team that obtained the new data.
It is a place of extremes, invisible to our eyes, but now revealed in extraordinary detail
Ashley Barnes, IT
The observations provide a unique view of the cold gas (the raw material from which stars are formed) within the so-called Central molecular zone (CMZ) of our galaxy. This is the first time that the cold gas of this entire area has been studied in such detail.
Data are presented in five articles accepted for publication in Monthly Notices of the Royal Astronomical Society.
The area is more than 650 light years
The region shown in the new image spans over 650 light years. It contains dense clouds of gas and dust surrounding it a supermassive black hole which is at the center of our galaxy.
“This is the only galactic nucleus close enough to Earth that we can study it in such detail,” says Barnes. The data set shows CMZ like never before, from structure of Art gas with a diameter of tens of light years to small clouds of gas around individual stars.
In particular, the gas studied using ACES (abbreviation from ALMA CMZ Exploration SurveyCentral Molecular Zone Probe with ALMA) is a cold molecular gas. The survey unravels the convoluted chemistry of the CMZ and reveals dozens of different moleculesfrom simple ones such as silicon monoxide to more complex organic ones such as methanol, acetone or ethanol.
The CMZ is home to some of the most massive stars known in our galaxy, many of which live quickly and die young, ending their lives in powerful supernova and even hypernova explosions.
Steve Longmore, John Moores University
Cold molecular gas flows along filaments that feed clumps of matter from which stars can grow. On the outskirts of the Milky Way it is known how this process occurs, but in the central region the events are much more extreme.
“The CMZ is home to some of the most massive stars known in our galaxy, many of which live fast and die young, ending their lives in powerful supernova and even hypernova explosions,” says ACES chief, Steve LongmoreProfessor of Astrophysics at Liverpool John Moores University (UK).
Stars in extreme conditions
With ACES, the astronomical community hopes to better understand how these phenomena affect star birth and whether our theories of star formation hold up under extreme conditions.
This is the first time such a large area has been scanned with this instrument, making it ALMA’s largest ever image
“By studying how stars are born in the CMZ, we can also gain a clearer picture of how galaxies grew and evolved,” adds Longmore. “We believe that the region has many common characteristics with galaxies of the early universewhere stars formed under chaotic and extreme conditions.’
To collect this new data set, the team used ALMA, a facility operated by ESO and its partners in Atacama Desertin Chile. In fact, this is the first time such a large area has been scanned with this instrument, making it ALMA’s largest image yet. In the sky, the mosaic (obtained by combining many individual observations, like putting together the pieces of a puzzle) is as long as three full moons placed side by side.
“The upcoming upgrade of ALMA’s broadband sensitivity, together with ESO’s Extremely Large Telescope, will soon allow us to delve even deeper into this region to discern finer structures, trace more complex chemical processes, and probe interactions between stars, gas and black holes with unprecedented clarity,” Barnes concludes. “In many ways, this is just the beginning.”
rights: Creative Commons.
