{"id":18013,"date":"2025-04-14T01:40:13","date_gmt":"2025-04-14T01:40:13","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/18013\/"},"modified":"2025-04-14T01:40:13","modified_gmt":"2025-04-14T01:40:13","slug":"do-completely-dark-dark-matter-halos-exist","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/18013\/","title":{"rendered":"Do &#8216;completely dark&#8217; dark matter halos exist?"},"content":{"rendered":"<p>            <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/04\/galaxy.jpg\" alt=\"galaxy\" title=\"Credit: Unsplash\/CC0 Public Domain\" width=\"800\" height=\"525\"\/><\/p>\n<p>                Credit: Unsplash\/CC0 Public Domain<\/p>\n<p>Every galaxy is thought to form at the center of a dark matter halo\u2014a region of gravitationally bound matter that extends far beyond the visible boundaries of a galaxy. Stars are formed when gravity within dark matter halos draws in gas, but astrophysicists don&#8217;t yet know whether star-free dark matter halos exist.<\/p>\n<p>Now Ethan Nadler, a computational astrophysicist at UC San Diego, has calculated the mass below which halos fail to form stars. This work was done using analytic predictions from galaxy formation theory and cosmological simulations.<\/p>\n<p>The study, titled <a href=\"https:\/\/iopscience.iop.org\/article\/10.3847\/2041-8213\/adbc6e\" target=\"_blank\" rel=\"noopener\">&#8220;The Impact of Molecular Hydrogen Cooling on the Galaxy Formation Threshold,&#8221;<\/a> was published in The Astrophysical Journal Letters and was led by Ethan Nadler.<\/p>\n<p>&#8220;Historically, our understanding of <a href=\"https:\/\/phys.org\/tags\/dark+matter\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">dark matter<\/a> has been linked to its behavior in galaxies. A detection of completely dark halos would open up a new window to study the universe,&#8221; stated Nadler.<\/p>\n<p>Previously, this threshold for <a href=\"https:\/\/phys.org\/tags\/star+formation\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">star formation<\/a> was thought to be between 100 million to 1 billion solar masses due to cooling of atomic hydrogen gas. Nadler&#8217;s research shows that star formation can occur in halos down to 10 million <a href=\"https:\/\/phys.org\/tags\/solar+masses\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">solar masses<\/a> through <a href=\"https:\/\/phys.org\/tags\/molecular+hydrogen\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">molecular hydrogen<\/a> cooling.<\/p>\n<p>With the Rubin Observatory coming online later this year and JWST already making unprecedented observations of our universe, there will soon be new data to test these predictions and reveal whether completely dark halos exist. This may have far-reaching consequences for cosmology and the nature of dark matter.<\/p>\n<p><strong>More information:<\/strong><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tThe Impact of Molecular Hydrogen Cooling on the Galaxy Formation Threshold, The Astrophysical Journal Letters (2025). <a data-doi=\"1\" href=\"https:\/\/dx.doi.org\/10.3847\/2041-8213\/adbc6e\" target=\"_blank\" rel=\"noopener\">DOI: 10.3847\/2041-8213\/adbc6e<\/a><\/p>\n<p>\n\t\t\t\t\t\t\t\t\t\t\t\t\tProvided by<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/phys.org\/partners\/university-of-california---san-diego\/\" target=\"_blank\" rel=\"noopener\">University of California &#8211; San Diego<\/a><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"icon_open\" href=\"http:\/\/www.ucsd.edu\/portal\/site\/ucsd\" target=\"_blank\" rel=\"nofollow noopener\"><\/p>\n<p>\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/p>\n<p>\n\t\t\t\t\t\t\t\t\t\t\t\t<strong>Citation<\/strong>:<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tDo &#8216;completely dark&#8217; dark matter halos exist? (2025, April 8)<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tretrieved 13 April 2025<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tfrom https:\/\/phys.org\/news\/2025-04-dark-halos.html\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n<p>\n\t\t\t\t\t\t\t\t\t\t\t This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no<br \/>\n\t\t\t\t\t\t\t\t\t\t\t part may be reproduced without the written permission. The content is provided for information purposes only.\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n","protected":false},"excerpt":{"rendered":"Credit: Unsplash\/CC0 Public Domain Every galaxy is thought to form at the center of a dark matter halo\u2014a&hellip;\n","protected":false},"author":2,"featured_media":18014,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3845],"tags":[75,76,74,71,70,72,53,73,16,15],"class_list":{"0":"post-18013","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-materials","9":"tag-nanotech","10":"tag-physics","11":"tag-physics-news","12":"tag-science","13":"tag-science-news","14":"tag-technology","15":"tag-technology-news","16":"tag-uk","17":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114333773497587531","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/18013","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=18013"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/18013\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/18014"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=18013"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=18013"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=18013"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}