{"id":97354,"date":"2025-10-01T17:35:12","date_gmt":"2025-10-01T17:35:12","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/97354\/"},"modified":"2025-10-01T17:35:12","modified_gmt":"2025-10-01T17:35:12","slug":"infant-universe-was-warm-rather-than-cold-before-it-lit-up-astronomers-say","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/97354\/","title":{"rendered":"Infant Universe Was Warm, Rather than Cold, before It Lit Up, Astronomers Say"},"content":{"rendered":"

Using the Murchison Widefield Array (MWA) telescope at CSIRO\u2019s Murchison Radio-Astronomy Observatory, astronomers are searching for the elusive Epoch of Reionization, a period early in the Universe\u2019s history that is predicted by theory but is yet to be detected using radio telescopes; it signifies the end of the Cosmic Dark Ages, roughly a billion years after the Big Bang, when the gas between galaxies shifted from opaque to transparent, allowing light from the first stars and galaxies to travel throughout the Universe.<\/strong><\/p>\n

\"A<\/a><\/p>\n

A small part of the sky seen in radio waves by the Murchison Widefield Array. Image credit: Nunhokee et al. \/ ICRAR \/ Curtin University.<\/p>\n

\u201cOur research was conducted over two phases,\u201d said Dr. Ridhima Nunhokee, an astronomer with the Curtin University node at the International Centre for Radio Astronomy Research (ICRAR) and ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D).<\/p>\n

\u201cDuring the initial research, we obtained our first evidence of heating of the intergalactic medium, the gas between galaxies, 800 million years after the Big Bang.\u201d<\/p>\n

\u201cTo study this early period of the Universe, we must isolate the faint signal from the Epoch of Reionization, identify and remove every other source of radio waves in the Universe from their observations.\u201d<\/p>\n

\u201cThese include emissions from nearby stars and galaxies, interference from the Earth\u2019s atmosphere, and even noise generated by telescope itself.\u201d<\/p>\n

\u201cOnly after carefully subtracting these \u2018foreground signals\u2019 will the remaining data reveal signals from the Epoch of Reionization.\u201d<\/p>\n

\u201cFrom this research, we have developed<\/a> methods to deal with the foreground contamination, and subtract the signals we don\u2019t want, but also better understand our telescope and come up with a clean signal.\u201d<\/p>\n

\u201cWe\u2019ve also been able to integrate<\/a> about ten years of MWA data together, to observe the sky for longer than we ever have before.\u201d<\/p>\n

\u201cThat\u2019s the other reason we\u2019ve come closer than ever to detecting the signal.\u201d<\/p>\n

According to the team, the quality and quantity of this new dataset are what made this discovery possible.<\/p>\n

A cold Universe would produce a signal which would have been visible in the new data.<\/p>\n

The lack of that signal rules out such a \u2018cold start\u2019 to reionization, and means the Universe must have been \u2018pre-heated\u2019 before reionization happened.<\/p>\n

\u201cAs the Universe evolved, the gas between galaxies expands and cools, so we would expect it to be very, very cold,\u201d said Professor Cathryn Trott, an astronomer with the Curtin University node at ICRAR, ASTRO 3D and the Curtin Institute of Radio Astronomy.<\/p>\n

\u201cOur measurements show that it is at least heated by a certain amount. Not by a lot, but it tells us that very cold reionization is ruled out. That\u2019s really interesting.\u201d<\/p>\n

\u201cThe research suggests this heating is likely driven by the energy from early sources of X-rays from early black holes and stellar remnants spreading through the Universe.\u201d<\/p>\n

The results appear in two papers in the Astrophysical Journal<\/a>.<\/p>\n

_____<\/p>\n

C.D. Nunhokee et al. 2025. Limits on the 21 cm Power Spectrum at z = 6.5\u20137.0 from Murchison Widefield Array Observations. ApJ 989, 57; doi: 10.3847\/1538-4357\/adda45<\/p>\n

Cathryn M. Trott et al. 2025. Improved Limits on the 21 cm Signal at z = 6.5\u20137.0 with the Murchison Widefield Array Using Gaussian Information. ApJ 991, 211; doi: 10.3847\/1538-4357\/adff80<\/p>\n","protected":false},"excerpt":{"rendered":"Using the Murchison Widefield Array (MWA) telescope at CSIRO\u2019s Murchison Radio-Astronomy Observatory, astronomers are searching for the elusive…\n","protected":false},"author":2,"featured_media":97355,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[270],"tags":[62335,9697,18,62336,19,17,62337,29167,133,451,5610],"class_list":{"0":"post-97354","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-csiro","9":"tag-early-universe","10":"tag-eire","11":"tag-epoch-of-reionization","12":"tag-ie","13":"tag-ireland","14":"tag-murchison-widefield-array","15":"tag-radio-signal","16":"tag-science","17":"tag-space","18":"tag-universe"},"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/97354","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=97354"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/97354\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/97355"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=97354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=97354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=97354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}