Researchers from the University of Maryland led the study on capturing the first-ever high-resolution image of a star nursery in the Milky Way galaxy where stars are born.
The previous low-resolution image did not clearly show the expanding bubble of hot plasma did not clearly or reveal how the bubble expanded into the surrounding gas.
NASA's SOFIA Telescope
The team of researchers used the spatial and spectral resolution of NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA)and APEX telescopes.
SOFIA is a Boeing 747SP aircraft that s modified to carry the 2.7-meter (106-inch) reflecting telescope. It is also nicknamed the flying observatory, flying into the stratosphere at 38,000-45,000 feet which puts the aircraft above 99% of the infrared-blocking atmosphere of Earth, according to NASA.
Astronomers use SOFIA to study the Solar System and beyond in ways that are not possible when using ground-based telescopes. With its mobility, astronomers could observe the cosmos from almost anywhere in the world, which makes their research of transient events possible.
SOFIA has already undertaken studies about Pluto, and the Kuiper Belt Object MU69. Now, it has captured the luminous massive star-forming region of RCW 49 at high resolution.
Where Stars are Born
Based on the high-resolution captured by NASA's SOFIA telescope, researchers found a single, expanding bubble of warm gas that surrounds the Westerlund 2 star cluster, disproving earlier research that there might be two bubbles in the region, according to the university's news release via SciTech Daily.
Study lead author and postdoctoral associate Maitraiyee Tiwari of the UMD Department of Astronomy explained that extreme stellar winds are capable of blowing and shaping bubbles in the surrounding clouds of gas. Stellar winds are produced when massive stars eject protons, electrons, and atoms of heavy metal during their formation.
The researchers observed that such a bubble centered around the biggest cluster of stars in the Westerlund 2 star cluster. They were also able to measure its radius, mass, and speed at which it was expanding.
The expanding bubbles consist of dense gas of ionized carbon which forms an outer shell around the bubbles where new stars are believed to form. However, it is difficult to distinguish individual bubbles because they overlap and intermingle with clouds of the surrounding gas.
But researchers measured the radiation emitted from the cluster from high energy X-rays to low energy radio waves to create a clearer picture of the bubble that surrounds the Westerlund 2. they noted that they can use spectrometry to measure how fast the carbon is moving either towards or away from Earth, which uses the Doppler effect.
Researchers were able to create a 3D view of the expanding bubble of hot plasma surrounding Westerlund 2 by determining the direction of carbon ions and combining it with measurements from across the electromagnetic spectrum.
New stars Forming Inside the Bubble
Aside from discovering a single stellar wind-driven shell of the massive star-forming region of RCW 49, the team also found evidence of new stars forming in the shell of this bubble, UMD news release reported.
Analysis showed that the bubble expanded and broke into one side which released hot plasma and slowed the expansion of the shell. Then about 200,00 or 300,000 years ago, a brighter star in Westerlund 2 evolved and reinvigorated the expansion of the region. This indicates that stars will continue to be born in this shell for a long time.
They published the full findings of their study, "SOFIA FEEDBACK Survey: Exploring the Dynamics of the Stellar Wind-Driven Shell of RCW 49," in The Astrophysical Journal.
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