A radio telescope located in outback Western Australia has observed a cosmic phenomenon with a striking resemblance to a jellyfish.<\/p>\n
Published today in The Astrophysical Journal<\/em>, an Australian-Italian team used the Murchison Widefield Array (MWA) telescope to observe a cluster of galaxies known as Abell 2877.<\/p>\n Lead author and PhD candidate Torrance Hodgson, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) in Perth, said the team observed the cluster for 12 hours at five radio frequencies between 87.5 and 215.5 megahertz.<\/p>\n \u201cWe looked at the data, and as we turned down the frequency, we saw a ghostly jellyfish-like structure begin to emerge,\u201d he said.<\/p>\n \u201cThis radio jellyfish holds a world record of sorts. Whilst it\u2019s bright at regular FM radio frequencies, at 200 MHz the emission all but disappears.<\/p>\n \u201cNo other extragalactic emission like this has been observed to disappear anywhere near so rapidly.\u201d<\/p>\n This uniquely steep spectrum has been challenging to explain. \u201cWe\u2019ve had to undertake some cosmic archaeology to understand the ancient background story of the jellyfish,\u201d said Hodgson.<\/p>\n \u201cOur working theory is that around 2 billion years ago, a handful of supermassive black holes from multiple galaxies spewed out powerful jets of plasma. This plasma faded, went quiet, and lay dormant.<\/p>\n \u201cThen quite recently, two things happened\u2014the plasma started mixing at the same time as very gentle shock waves passed through the system.<\/p>\n \u201cThis has briefly reignited the plasma, lighting up the jellyfish and its tentacles for us to see.\u201d<\/p>\n The jellyfish is over a third of the Moon\u2019s diameter when observed from Earth, but can only be seen with low-frequency radio telescopes.<\/p>\n \u201cMost radio telescopes can\u2019t achieve observations this low due to their design or location,\u201d said Hodgson.<\/p>\n The MWA\u2014a precursor to the Square Kilometre Array (SKA)\u2014is located at CSIRO\u2019s Murchison Radio-astronomy Observatory in remote Western Australia.<\/p>\n The site has been chosen to host the low-frequency antennas for the SKA, with construction scheduled to begin in less than a year.<\/p>\n Professor Johnston-Hollitt, Mr Hodgson\u2019s supervisor and co-author, said the SKA will give us an unparalleled view of the low-frequency Universe.<\/p>\n \u201cThe SKA will be thousands of times more sensitive and have much better resolution than the MWA, so there may be many other mysterious radio jellyfish waiting to be discovered once it\u2019s operational.<\/p>\n \u201cWe\u2019re about to build an instrument to make a high resolution, fast frame-rate movie of the evolving radio Universe. It will show us from the first stars and galaxies through to the present day,\u201d she said.<\/p>\n \u201cDiscoveries like the jellyfish only hint at what\u2019s to come, it\u2019s an exciting time for anyone seeking answers to fundamental questions about the cosmos.\u201d<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" A radio telescope located in outback Western Australia, the Murchison Widefield Array, has observed a cosmic phenomenon with a striking resemblance to a jellyfish.<\/p>\n","protected":false},"author":4373,"featured_media":12477,"template":"","meta":{"_acf_changed":false,"_oasis_is_in_workflow":0,"_oasis_original":0,"_oasis_task_priority":"","_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":"","wds_primary_category":0,"wds_primary_research-areas":0,"footnotes":""},"categories":[104,107,1],"tags":[],"research-areas":[],"class_list":["post-19686","media-release","type-media-release","status-publish","has-post-thumbnail","hentry","category-space-and-physics","category-space-exploration","category-uncategorised"],"acf":{"post_options":{"":null,"additional_content":{"title":"","content":"","image":false},"related_courses":false,"credits":{"author":"","photographer":"","media":false},"display_author":true,"banner":{"image":false}}},"featured_image":"https:\/\/www.curtin.edu.au\/news\/wp-content\/uploads\/2022\/07\/Jellyfish-1000x500.jpg","author_meta":{"first_name":"Vanessa","last_name":"Beasley","display_name":"Vanessa Beasley"},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/media-release\/19686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/media-release"}],"about":[{"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/types\/media-release"}],"author":[{"embeddable":true,"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/users\/4373"}],"version-history":[{"count":0,"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/media-release\/19686\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/media\/12477"}],"wp:attachment":[{"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/media?parent=19686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/categories?post=19686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/tags?post=19686"},{"taxonomy":"research-areas","embeddable":true,"href":"https:\/\/www.curtin.edu.au\/news\/wp-json\/wp\/v2\/research-areas?post=19686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}