Astronomers rarely find a double nucleus in a nearby cocoon galaxy, The so-called “Cocoon Galaxy” not only has a unique shape, but also a rare structure with two nuclei.
A team of astronomers examined data from optical and radio telescopes on Earth and in space and found that a galaxy known as NGC 4490 (also called the “cocoon galaxy” because of its shape) “has a clear dual-core structure” according to his paper. now the astronomers rarely find a double nucleus in a nearby cocoon galaxy.
One core can be seen in optical wavelengths. Others are hidden in dust and can only be seen in infrared and radio waves. The discovery documents are now online and have been accepted for publication in the Astrophysical Journal.
The first author is Alan Lawrence, who holds a Masters in Astronomy from the American University of Iowa in 2018 and continues to work with Iowa astronomers.
Co-authors are Charles Curton of Iowa, assistant professor of physics and astronomy; and Curtis Struck, professor of physics and astronomy; and Beverly Smith from East Tennessee State University, professor of physics and astronomy. the astronomers rarely find a double nucleus in a nearby cocoon galaxy.
Lawrence began his research in 2013 when he took an astronomy course at the University of Wisconsin-Madison. He had the opportunity to study one of the two galaxy systems and choose NGC 4490, which interacts with a smaller galaxy, NGC 4485.
This system is about 20% the size of the Milky Way in the northern hemisphere and about 30 million light years from Earth.
“I saw a dual core about seven years ago,” Lawrence said. “Never observed – or nobody ever did anything about it.” Some astronomers might have seen the nucleus with their optical telescopes. Others might have seen others with their radio telescopes.
But he said the two groups never compared notes to observe and describe multiple nuclei.
The new paper says that both nuclei have the same size, mass and luminosity. Both mass and luminosity are said to resemble the nuclei observed in other interacting galactic pairs.
And he said the structure of the double nucleus could also explain why the galactic system is surrounded by large piles of hydrogen.
“The most direct interpretation of the observations is that NGC 4490 itself is a remnant of the final stage of fusion,” a collision far earlier between the two galaxies the author wrote.
A fusion can encourage and prolong the formation of stars as high as needed to produce such a large hydrogen cloud.
Astronomers say that there are other reasons that make studying this system interesting.
Batches examining colliding galaxies say double nucleus galaxies are very rare, especially in small galaxies like this. And he said that astronomers believed that the double nucleus could contribute to the accumulation of supermassive black holes at the centers of several galaxies. And Curton, who studies star formation, said, “This project shows that using several wavelengths of cosmic and terrestrial observations together can really help us understand certain objects.”