Astronomers from the United States and South Korea have made the first high-resolution, telescope radio observations of molecular clouds within a massive star forming the star of the outer Milky Way.
"This region is behind a cloud of dust and gas," says Charles Kerton, an associate professor of physics and astronomy at Iowa State University and a member of the study team. "The cloud blocks the light and therefore we need to use infrared or learning radios."
The Milky Way area is called CTB 102. It is about 14,000 light years from Earth. It is classified as a region of HII, which means it contains clouds of atomized-charged-hydrogen atoms. And, because of its distance from the Earth and dust and gas in between, it is difficult to study.
And so, "this region is very difficult to get out," Kerton said.
Astronomers described their first draft of a new, higher resolution map for the region in a paper recently accepted for publication in the Astrophysical Journal . The leading authors are Sung-ju Kang, a scientist at Korea Astronomy and Space Science Institute and a former student who graduated from Iowa State University; and Brandon Marshall, a former graduate student in Iowa State who received a faculty position at the University of Nebraska and Kearney. Other co-authors are Kerton and Youngsik Kim, Minho Choi and Miju Kang, all Korean Astronomy and Space Science Institute. Kim is also in the Daejeon Observatory in South Korea.
Kerton said astronomers used a newly commissioned radio telescope at the Taeduk Radio Astronomy Observatory in South Korea to obtain high resolution, carbon monoxide observations of the molecular clouds of the galactic region. [19659005"Sinasabinitosaaminangatistrakturangmatalsalsadaluygginterstellardoon"sinabiniKerton
Astronomers also compare their radio observations to existing infrared data from the Wide-Field Infrared Survey Explorer and the Two Micron All Sky Surveys. Infrared data allows them to classify the young stars forming within the region's molecular clouds.
Data yields three major observations, astronomers report on their role.
First, astronomers use radio data to illustrate the physical structure and character of the new molecular cloud map of the region-they are relatively large, about 180 light years across with mass equal to nearly 100,000 mass of our day. Next, they use infrared data to determine the young stellar contents within the clouds. And finally, they included two data streams to study the efficiency of star formation in the galaxy region.
They reported the development of the formation of the entire CTB 102 region was almost 5% to 10%, similar to other giant molecular clouds within the galaxy. However, they found a subregion of clouds with a star formation efficiency of 17% to 37% (depending on how much the subregion's mass was calculated). That's higher than expected for a subregion of its size. These refer to the subregion is the site of a massive cluster of young people, formation of stars embedded in the molecular cloud.
Why all the formation of the star in a subregion? Kerton said that a question for further study. Perhaps, he said, there is something special about the interstellar material in that subregion, which follows the huge HII region.
"This is our first look at all this," Kerton said. "Older data is some dots, some pixels. We can not isolate the relatively small region of the universe."
But now they can-with the help of the new South Korean radio observatory.
Observations of high-resolution studies, Kerton said, "is also a demonstration that the telescope is ideal for studying similar regions in our galaxy-many other potential targets . "
Multiwavelength formation of the region's constellation reveals dozens of new things in the sky
High Resolution Observations of Molecular Clouds Associated with Large HII Region CTB 102, arXiv: 1904.00529 [astro-ph.GA] arxiv.org/abs/1904.00529
Astronomers are first, high-resolution looking at the big stars that make up the Milky Way region (2019, April 15)
retrieved 15 April 2019
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