In a new high-resolution image, we see the Tarantula Nebula — a luminous star-forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way — in a new light, with wispy gas clouds that provide insight into how massive stars shape this region.
This composite image shows the Tarantula Nebula. The background image, taken in the infrared, is itself a composite: it was captured by the HAWK-I instrument on ESO’s Very Large Telescope (VLT) and the Visible and Infrared Survey Telescope for Astronomy (VISTA), shows bright stars and light, pinkish clouds of hot gas. The bright red-yellow streaks that have been superimposed on the image come from radio observations taken by the ALMA, revealing regions of cold, dense gas which have the potential to collapse and form stars. The unique web-like structure of the gas clouds led astronomers to the nebula’s spidery nickname. Image credit: ESO / ALMA / NAOJ / NRAO / Wong et al. / M.-R. Cioni / VISTA Magellanic Cloud Survey / Cambridge Astronomical Survey Unit.
The Tarantula Nebula, also known as NGC 2070 or 30 Doradus, is located in the southern constellation of Dorado, about 170,000 light-years away in one of our closest galactic neighbors, the Large Magellanic Cloud.
At its heart are some of the most massive stars known, a few with more than 150 times the mass of our Sun, making the region perfect for studying how gas clouds collapse under gravity to form new stars.
“Fragmentary clouds in the new image may be the remains of once-larger clouds that have been shredded by the enormous energy being released by young and massive stars, a process dubbed feedback,” said Dr. Tony Wong, an astronomer at the University of Illinois at Urbana-Champaign.
Astronomers originally thought the gas in these areas would be too sparse and too overwhelmed by this turbulent feedback for gravity to pull it together to form new stars.
But the new data also reveal much denser filaments where gravity’s role is still significant.
“Our results imply that even in the presence of very strong feedback, gravity can exert a strong influence and lead to a continuation of star formation,” Professor Wong said.
“What makes 30 Doradus unique is that it is close enough for us to study in detail how stars are forming, and yet its properties are similar to those found in very distant galaxies, when the Universe was young,” added Dr. Guido De Marchi, an astronomer at ESA.
“Thanks to 30 Doradus, we can study how stars used to form 10 billion years ago when most stars were born.”
While most of the previous studies of the Tarantula Nebula have focused on its center, astronomers have long known that massive star formation is happening elsewhere too.
To better understand this process, the study authors conducted high-resolution observations covering a large region of the nebula.
Using the Atacama Large Millimeter/submillimeter Array (ALMA), they measured the emission of light from carbon monoxide gas.
This allowed them to map the large, cold gas clouds in the nebula that collapse to give birth to new stars — and how they change as huge amounts of energy are released by those young stars.
“We were expecting to find that parts of the cloud closest to the young massive stars would show the clearest signs of gravity being overwhelmed by feedback,” Professor Wong said.
“We found instead that gravity is still important in these feedback-exposed regions — at least for parts of the cloud that are sufficiently dense.”
The team’s results were published in the Astrophysical Journal.
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Tony Wong et al. 2022. The 30 Doradus Molecular Cloud at 0.4 pc Resolution with the Atacama Large Millimeter/submillimeter Array: Physical Properties and the Boundedness of CO-emitting Structures. ApJ 932, 47; doi: 10.3847/1538-4357/ac723a
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