A radio telescope in the Western Australian Outback has taken a spectacular new view of the center of the galaxy galaxy. The image from the Murchison Widefield Array (MWA) telescope shows what our galaxy would look like if human eyes could see radio waves.
The astrophysicist dr. Natasha Hurley-Walker from the Curtin University node of the International Center for Radio Astronomy Research (ICRAR) created the images with the Pawsey Supercomputing Center in Perth. "This new view captures our galaxy's low-frequency radio emission, looking at both detailed and larger structures," she said. "Our pictures look directly into the middle of the Milky Way, towards a region that astronomers call the galactic center."
Data for the research are from the GaLactic and Extragalactic All-Sky MWA Survey, GLEAM for short. The survey has a resolution of two arc minutes (approximately the same as the human eye) and maps the sky with radio waves at frequencies between 72 and 231 MHz (FM radio is near 100 MHz).
"This is the strength of this broad frequency range, which allows us to unravel various overlapping objects while looking at the complexity of the galactic center," Dr. Hurley-Walker] The 27 newly discovered supernova remnants – the remnants of stars that died thousands to hundreds of thousands of years ago in massive stellar explosions. The radio images trace the edges of the explosions as they continue to expand into the interstellar space. [Some are huge, larger than the full moon, and others are small and hard to spot in the complexity of the Milky Way.] Picture credits: Dr. med. Natasha Hurley-Walker (ICRAR / Curtin) and the GLEAM team.
"In essence, different objects have different & # 39; radio colors & # 39 ;, so we can use it to figure out what kind of physics is involved."
Dr. Hurley-Walker and her colleagues used the images to discover the remains of 27 massive stars that exploded into supernovae at the end of their lives. These stars would have been eight times as massive as our sun before their dramatic destruction thousands of years ago.
Younger and denser remnants of supernova or those in very dense environments are easily recognized, and 295 are already known. Unlike other instruments, MWA can find older, more distant or very empty environments.
Dr. Hurley-Walker said that one of the newly discovered supernova remnants lies in such an empty region of space, far beyond our galaxy's plane, and therefore is also very weak, even though he is still quite young. "It's the remains of a star that died less than 9,000 years ago, which means the explosion could have been visible to Native Americans throughout Australia at the time."
An expert on cultural astronomy, Associate Professor Duane Hamacher of the University of Melbourne, some Aboriginal traditions describe new shining stars emerging in the sky. However, we do not know definitive traditions that describe this particular event. "Now that we know when and where this supernova appeared in the sky, we can work with indigenous elders to see if any of their traditions describe this cosmic event, if anything, it would be extremely exciting," he said. 19659016] Dr. med. According to Hurley-Walker, two of the discovered supernova remnants are quite unusual "orphans" found in a heavenly region where there are no massive stars. Other research supernova remnants discovered are very old, she said. "This is really exciting for us because it's hard to find supernova remnants in this phase of life – they give us a glimpse into the past in the Milky Way."
The MWA telescope is a forerunner of the world's largest radio "The MWA is perfect for finding these objects, but is limited in its sensitivity and resolution," Dr. Hurley Walker. "The low-frequency part of the SKA, built in the same place as the MWA, will be thousands of times more sensitive and have a much better resolution, so it should find the thousands of supernova remnants that have formed in the last 100,000 years on the other side of the Milky Way. "
The Australian desert telescope shows the sky in radio technology
& # 39; In the GLEAM survey over 345 °, new candidate remains of Radiosupernova were discovered. Www.icrar.org/wp-content/uploa…etected_in_GLEAM.pdf
International Center for Radio Astronomy Research
Outback telescope conquers the center of the Milky Way and discovers remains of dead stars (2019, 20 November)
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