A radio telescope in Western Australia has captured a spectacular new view of the center of the Milky Way galaxy. A photo from the Murchison Widefield Array (MWA) telescope shows what our galaxy would look like if human eyes could see radio waves.
Astrophysicist Dr. Natasha Hurley-Walker from the Curtin University node at the International Center for Radio Astronomy Research (ICRAR) created images using the Pawsey Supercomputing Center in Perth. "This new view records low-frequency radio wave emissions from our galaxy, looking in both small details and larger structures," she said. "Our images look directly at the center of the Milky Way toward the region that astronomers call the center of the galaxy."
Test data are from the MWA GaLactic and Extragalactic All-sky studies, or GLEAM for short. The test has a resolution of two minutes of arc (roughly the same as the human eye) and maps the sky using radio waves at frequencies between 72 and 231 MHz (FM radio is close to 100 MHz).
"It's the strength of this wide frequency range that allows us to untangle different overlapping objects when looking at the complexity of the galactic center," said Dr. Hurley-Walker.
"Basically, different objects have different" radio colors "so we can use them to determine what physics are in the game."
Using images, Dr. Hurley-Walker and her colleagues discovered the remains of 27 massive stars that exploded into supernovae at the end of their lives. These stars would be eight or more times more massive than our Sun before their dramatic destruction thousands of years ago.
Younger and nearer supernova remnants or those in very dense environments are easy to detect, and 295 are already known. Unlike other instruments, MWA can find those that are older, distant or very empty.
Dr. Hurley-Walker said that one of the newly discovered supernova remnants lies in such an empty space of space, far from the plane of our galaxy, so despite being quite young, it is also very weak. "These are the remains of a star who died less than 9,000 years ago, which means that the explosion could have been visible to Native Australian people at that time," she said.
Cultural astronomy specialist Professor Duane Hamacher of the University of Melbourne said some Aboriginal traditions describe bright new stars appearing in the sky, but we don't know any definitive traditions describing this particular event. "But now that we know when and where this supernova has appeared in the sky, we can work with indigenous elders to see if any of their traditions describe this cosmic event. If it existed, it would be extremely exciting, "he said.
Dr. Hurley-Walker said that the two discovered supernova remnants are quite unusual "orphans" found in a region of the sky where there are no massive stars, which means that future searches in other such regions may be more effective than astronomers expected. She said that other supernova remnants found in research are very old. "It is very exciting for us because it is difficult to find supernova remnants in this phase of life – they allow us to look back in time in the Milky Way."
The MWA telescope is a precursor to the world's largest radio telescope, Square Kilometer Array, to be built in Australia and South Africa from 2021. "MWA is ideal for searching for these objects, but has limited sensitivity and resolution," said Dr. Hurley-Walker. "The low-frequency part of the SKA that will be built in the same place as the MWA will be thousands of times more sensitive and will have a much better resolution, so they should find thousands of supernova remnants that have formed over the last 100,000 years, even on the other side Milky way. "
Australian desert telescope surveying the sky in radio technicolor
"New candidate supernova radio residues detected in the GLEAM study over 345 ° www.icrar.org/wp-content/uploa… etected_in_GLEAM.pdf
"Remains of candidates after supernova radio observed in the GLEAM study over 345 ° www.icrar.org/wp-content/uploa… /gleam-survey-ii.pdf
GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) II study: Galactic Plane 345 ° www.icrar.org/wp-content/uploa… erved_by_GLEAM-1.pdf
International Center for Radio Astronomy Research
The capture telescope captures the center of the Milky Way, uncovers the remains of dead stars (2019, November 20)
was recovered on November 20, 2019
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