In the center of our galaxy, gigantic, balloon-like structures of high-energy radiation extend thousands of light-years above and below the Milky Way\u2019s plane. Known as the Fermi bubbles, the massive lobes may have been the result of a violent outburst in our galaxy\u2019s recent past. A new discovery of cold hydrogen clouds embedded inside the bubbles adds another level of mystery to the objects, suggesting they\u2019re only a few million years old\u2014practically brand-new, by cosmic standards.<\/p>\n
Using the National Science Foundation\u2019s Green Bank Telescope in West Virginia, a team of scientists discovered something extremely odd. Lurking inside the hot Fermi bubbles are clouds of cold gas that shouldn\u2019t be there, forcing scientists to wonder how the cooler gas manages to survive in the superheated, extreme environment. The new findings, published<\/a> in The Astrophysical Journal Letters, shed light on how galaxies evolve over time.<\/p>\n The Fermi bubbles were discovered in 2010 by NASA\u2019s Fermi Gamma-ray Space Telescope. The two orbs form an hourglass structure, one stretching above and another below the center of the Milky Way. Each lobe is around 25,000 light-years tall, made up of gamma rays and high-energy cosmic rays.<\/p>\n \u201cFermi bubbles are a relatively recent discovery \u2013 they were first identified by telescopes that \u2018see\u2019 gamma rays in 2010 \u2013 there are different theories about how it happened, but we do know that it was an extremely sudden and violent event, like a volcanic eruption but on a massive scale,\u201d Rongmon Bordoloi, associate professor of physics at North Carolina State University and co-author of the research, said in a statement<\/a>.<\/p>\n The team behind the study was observing the Fermi bubbles to gather high-resolution data about the composition of the hot gas within the structure. The majority of gas inside the Fermi bubbles is super-hot, measuring at around 1 million degrees Kelvin. Surprisingly, the team also found clouds of neutral hydrogen gas dotted within the bubbles around 12,000 light-years above the center of the galaxy and as massive as several thousand Suns.<\/p>\n The gas in the clouds, however, is relatively cold compared to the rest of the gas in the bubbles. \u201cThey\u2019re around 10,000 degrees Kelvin, so cooler than their surroundings by at least a factor of 100,\u201d Andrew Fox, astronomer at the Space Telescope Science Institute and coauthor of the paper, said in a statement. \u201cFinding those clouds within the Fermi bubble is like finding ice cubes in a volcano.\u201d<\/p>\n Considering their extreme environment, the clouds of hydrogen should have been destroyed, a process that would take over a few million years. This means that the Fermi bubbles are much younger than expected. \u201cIt wouldn\u2019t be possible for the clouds to be present at all if the Fermi bubbles were 10 million years old or older,\u201d Bordoloi said.<\/p>\n The scientists behind the study believe that the clouds were swept up from the center of the Milky Way and carried by the hot wind that formed the Fermi bubbles. Jay Lockman, an astronomer at the Green Bank Observatory and coauthor of the paper, compared the system to a more familiar phenomenon: \u201cJust as you can\u2019t see the motion of the wind on Earth unless there are clouds to track it, we can\u2019t see the hot wind from the Milky Way but can detect radio emission from the cold clouds it carries along.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"In the center of our galaxy, gigantic, balloon-like structures of high-energy radiation extend thousands of light-years above and…\n","protected":false},"author":3,"featured_media":75381,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[5163,16814,159,783,67,132,68],"class_list":{"0":"post-75380","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-black-holes","9":"tag-milky-way","10":"tag-science","11":"tag-space","12":"tag-united-states","13":"tag-unitedstates","14":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/114879973551651108","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/75380","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=75380"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/75380\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/75381"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=75380"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=75380"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=75380"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}