{"id":3111,"date":"2021-10-26T22:00:00","date_gmt":"2021-10-26T22:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=3111"},"modified":"2021-10-13T03:55:36","modified_gmt":"2021-10-13T03:55:36","slug":"a-mysterious-radio-source-from-our-galactic-center-leaves-astronomers-puzzled","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/a-mysterious-radio-source-from-our-galactic-center-leaves-astronomers-puzzled\/","title":{"rendered":"A Mysterious Radio Source from Our Galactic Center Leaves Astronomers Puzzled"},"content":{"rendered":"\n

The universe that you see when you look out the night sky isn\u2019t the complete picture. All the cosmic objects in the universe\u2014stars, black holes, galaxies, what have you\u2014shine with many forms of light, only some of which you can see. This is because \u201cvisible\u201d light only exists as a small sliver in the vast catalog known as the electromagnetic spectrum<\/em>.<\/p>\n\n\n\n

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The electromagnetic spectrum spans all possible wavelengths of light, from radio waves to gamma rays; the light we see is a small band within this whole spectrum, called the \u201cvisible spectrum.\u201d (Inductiveload\/NASA\/Wikimedia Commons, 2007) <\/figcaption><\/figure><\/div>\n\n\n\n

Most of the stuff in the sky shines in wavelengths either below or above what we can see. This applies to nearly all cosmic bodies. In fact, it\u2019s this fact that scientists in radio telescopes, like the one in the South Africa Radio Astronomy Observatory (SARAO), constantly take advantage of when viewing the sky. Oftentimes, astronomers actually manage to find the light that these bodies emit before they find the bodies themselves.<\/p>\n\n\n\n

This appears to be the case with a recent find by scientists from SARAO; together with the Commonwealth Scientific and Industrial Research Organization (CSIRO)\u2019s Australian Square Kilometer Array Pathfinder (ASKAP) and SARAO\u2019s MeerKAT radio telescope, scientists found a peculiar source of radio waves emanating from near the center of the Milky Way Galaxy, called the easy-to-remember ASKAP J173608.2-321635<\/em>. The study is currently available in preprint at arXiv.<\/p>\n\n\n\n

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An artist\u2019s rendition shows how the radio waves detected by scientists on Earth are transmitted through the cosmos from the peculiar radio source ASKAP J173608.2-321635. (Zentilomo, 2021) <\/figcaption><\/figure><\/div>\n\n\n\n

ASKAP\u2019s Variables and Slow Transients (VAST) survey actually found the odd radio source and detected it six (6) times, hence the name of the cosmic mystery. (The numbers trailing its name are its coordinates in the sky.) Astronomers then aimed SARAO\u2019s MeerKAT telescope at it for three months starting from November of 2020, at a 2-4-week interval.<\/p>\n\n\n\n

Ziteng Wang, Ph.D. student from the Sydney Institute for Astronomy (SIA) at the University of Sydney, CSIRO, and the ARC Center of Excellence for Gravitational Wave Discovery (OzGrav)\u2014together with a team of scientists\u2014screened the results obtained from aiming their radio telescopes at the peculiar ASKAP radio source, and couldn\u2019t find any matches with what the team expected from certain celestial bodies, like pulsars and supernovae. The team also tried identifying the source with visible light, yet still found nothing. <\/p>\n\n\n\n

Said Wang: \u201cThe strangest property of the signal […] is that it has a very high polarization<\/em> […] [meaning] its light oscillates in only one direction, but that direction rotates with time.\u201d Wang added: \u201cThe brightness of the object also varies dramatically, by a factor of 100, and the signal switches on and off apparently at random. We\u2019ve never seen anything like it.\u201d<\/p>\n\n\n\n

\u201cThis object was unique in that it started out invisible, became bright, faded away and then reappeared. This behavior was extraordinary,\u201d said SIA astronomer Prof. Tara Murphy, who\u2019s also from OzGrav. <\/p>\n\n\n\n

Prof. David Kaplan, from the University of Wisconsin-Milwaukee, noted that the find seems more aligned towards mysterious radio sources known as Galactic Center Radio Transients<\/em> (GCRTs).<\/p>\n\n\n\n

\u201cWhile […] ASKAP J173608.2-321635 does share some properties with GCRTs, there are also differences. And we don\u2019t really understand those sources, anyway, so this adds to the mystery.\u201d<\/p>\n\n\n\n

(For more mysterious space finds, some unexplained data from the XENON1T dark-matter detector might just be the evidence we\u2019re looking for in the search for dark energy<\/a>. For another, here\u2019s our piece on the \u201caccidental\u201d brown dwarf find that\u2019s zooming through the galaxy<\/a>.)<\/p>\n\n\n\n

References<\/h2>\n\n\n\n