{"id":5842,"date":"2026-09-30T09:26:05","date_gmt":"2026-09-30T09:26:05","guid":{"rendered":"https:\/\/netguide.io\/news\/2026\/09\/30\/mourir-radio-galaxies-fade-plus-rapide-que-la-pensee\/"},"modified":"2026-09-30T09:26:05","modified_gmt":"2026-09-30T09:26:05","slug":"mourir-radio-galaxies-fade-plus-rapide-que-la-pensee","status":"publish","type":"post","link":"https:\/\/netguide.io\/news\/fr\/2026\/09\/30\/mourir-radio-galaxies-fade-plus-rapide-que-la-pensee\/","title":{"rendered":"Mourir Radio Galaxies Fade plus rapide que la pens\u00e9e"},"content":{"rendered":"<div id=\"netgu-3800750736\" class=\"netgu-before-content netgu-entity-placement\"><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-6258556257245998\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-6258556257245998\" \ndata-ad-slot=\"3494115342\" \ndata-ad-format=\"auto\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div>\n<p class=\"wp-block-paragraph\"><strong>Lorsque les jets d&#8217;un trou noir supermassif tombent silencieux, une galaxie radio entre dans une vie apr\u00e8s-vie brillante &#8211; et cette phase semble beaucoup plus courte et plus turbulente que ce que l&#8217;on suppose. Ainsi rapporte une \u00e9quipe dirig\u00e9e par Sushant Dutta de l&#8217;Universit\u00e9 du Cap et l&#8217;Institut IDIA dans la revue Mensuel Notices of the Royal Astronomical Society.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ce que l&#8217;on appelle les galaxies radio restantes se forment lorsqu&#8217;un noyau actif d&#8217;une galaxie s&#8217;\u00e9teint et que ses lobes radio g\u00e9ants ne sont plus aliment\u00e9s par une \u00e9nergie fra\u00eeche. Ils sont un outil cl\u00e9 pour mesurer les cycles de travail sur et hors service des noyaux galactiques actifs &#8211; mais ils sont notoirement difficiles \u00e0 d\u00e9tecter.<\/p><div id=\"netgu-3246506751\" class=\"netgu-content netgu-entity-placement\"><aside class=\"deals-top deals-top--compact\">\n\n\t\t\t<h3 class=\"deals-top__title\">Top-Deals<\/h3>\n\t\n\t\t\t<ul class=\"deals-top__list\">\n\t\t\t\t\t\t\t<li class=\"deals-top__item\">\n\t\t\t\t\t<a class=\"deals-top__link\" href=\"https:\/\/netguide.io\/deals\/de\/deals\/moon-knight-digital-watch-face-fuer-wear-os-4\/\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<img class=\"deals-top__image\" src=\"https:\/\/netguide.io\/news\/wp-content\/uploads\/sites\/15\/2026\/09\/deal-27-150x150.png\" alt=\"\" width=\"52\" height=\"52\" loading=\"lazy\" \/>\n\t\t\t\t\t\t\n\t\t\t\t\t\t<span class=\"deals-top__body\">\n\t\t\t\t\t\t\t<span class=\"deals-top__name\">MOON KNIGHT Digital Watch Face f\u00fcr Wear OS 4+<\/span>\n\n\t\t\t\t\t\t\t<span class=\"deals-top__meta\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-top__price\">Gratis<\/span>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<s>0.89 \u20ac<\/s>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-discount\">-100%<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\n\t\t\t\t\t\t<span class=\"deals-top__temperature\">\n\t\t\t\t\t\t\t55\u00b0\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/li>\n\t\t\t\t\t\t\t<li class=\"deals-top__item\">\n\t\t\t\t\t<a class=\"deals-top__link\" href=\"https:\/\/netguide.io\/deals\/de\/deals\/train-sim-world-7-starter-pack-kostenlos-fuer-ps4-ps5-xbox-pc\/\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<img class=\"deals-top__image\" src=\"https:\/\/netguide.io\/news\/wp-content\/uploads\/sites\/15\/2026\/09\/capsule_616x353-11-150x150.jpg\" alt=\"\" width=\"52\" height=\"52\" loading=\"lazy\" \/>\n\t\t\t\t\t\t\n\t\t\t\t\t\t<span class=\"deals-top__body\">\n\t\t\t\t\t\t\t<span class=\"deals-top__name\">Train Sim World 7: Starter Pack kostenlos f\u00fcr PS4, PS5, Xbox, PC<\/span>\n\n\t\t\t\t\t\t\t<span class=\"deals-top__meta\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-top__price\">Gratis<\/span>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\n\t\t\t\t\t\t<span class=\"deals-top__temperature\">\n\t\t\t\t\t\t\t55\u00b0\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/li>\n\t\t\t\t\t\t\t<li class=\"deals-top__item\">\n\t\t\t\t\t<a class=\"deals-top__link\" href=\"https:\/\/netguide.io\/deals\/de\/deals\/ml2u-watchfaces-fuer-wearos-im-google-play-store-2\/\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<img class=\"deals-top__image\" src=\"https:\/\/netguide.io\/news\/wp-content\/uploads\/sites\/15\/2026\/09\/2844734_1-150x150.webp\" alt=\"\" width=\"52\" height=\"52\" loading=\"lazy\" \/>\n\t\t\t\t\t\t\n\t\t\t\t\t\t<span class=\"deals-top__body\">\n\t\t\t\t\t\t\t<span class=\"deals-top__name\">ML2U Watchfaces f\u00fcr WearOS im Google Play Store<\/span>\n\n\t\t\t\t\t\t\t<span class=\"deals-top__meta\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-top__price\">Gratis<\/span>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<s>1.39 \u20ac<\/s>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-discount\">-100%<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\n\t\t\t\t\t\t<span class=\"deals-top__temperature\">\n\t\t\t\t\t\t\t54\u00b0\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/li>\n\t\t\t\t\t\t\t<li class=\"deals-top__item\">\n\t\t\t\t\t<a class=\"deals-top__link\" href=\"https:\/\/netguide.io\/deals\/de\/deals\/kostenloses-dlc-bundle-fuer-gears-of-war-e-day-liquid-death-bundle\/\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<img class=\"deals-top__image\" src=\"https:\/\/netguide.io\/news\/wp-content\/uploads\/sites\/15\/2026\/09\/2844571_1-150x150.webp\" alt=\"\" width=\"52\" height=\"52\" loading=\"lazy\" \/>\n\t\t\t\t\t\t\n\t\t\t\t\t\t<span class=\"deals-top__body\">\n\t\t\t\t\t\t\t<span class=\"deals-top__name\">Kostenloses DLC-Bundle f\u00fcr Gears of War E-Day \u2013 Liquid Death Bundle<\/span>\n\n\t\t\t\t\t\t\t<span class=\"deals-top__meta\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-top__price\">Gratis<\/span>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\n\t\t\t\t\t\t<span class=\"deals-top__temperature\">\n\t\t\t\t\t\t\t54\u00b0\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/li>\n\t\t\t\t\t\t\t<li class=\"deals-top__item\">\n\t\t\t\t\t<a class=\"deals-top__link\" href=\"https:\/\/netguide.io\/deals\/de\/deals\/kostenlose-emote-im-clash-royale-store\/\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<img class=\"deals-top__image\" src=\"https:\/\/netguide.io\/news\/wp-content\/uploads\/sites\/15\/2026\/09\/share-image-clashroyale-150x150.jpg\" alt=\"\" width=\"52\" height=\"52\" loading=\"lazy\" \/>\n\t\t\t\t\t\t\n\t\t\t\t\t\t<span class=\"deals-top__body\">\n\t\t\t\t\t\t\t<span class=\"deals-top__name\">Kostenlose Emote im Clash Royale-Store<\/span>\n\n\t\t\t\t\t\t\t<span class=\"deals-top__meta\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"deals-top__price\">Gratis<\/span>\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\n\t\t\t\t\t\t<span class=\"deals-top__temperature\">\n\t\t\t\t\t\t\t54\u00b0\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/li>\n\t\t\t\t\t<\/ul>\n\n\t\t\t\t\t<p class=\"deals-top__more\">\n\t\t\t\t<a href=\"https:\/\/netguide.io\/deals\/\">Alle Deals ansehen \u2192<\/a>\n\t\t\t<\/p>\n\t\t\t<\/aside>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Douze restes confirm\u00e9s<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">L&#8217;\u00e9quipe a \u00e9tudi\u00e9 14 candidats dans le domaine de l&#8217;enqu\u00eate approfondie XMM\u2013LSS. Ils ont combin\u00e9 des donn\u00e9es provenant du t\u00e9lescope MeerKAT d&#8217;Afrique du Sud (le projet MIGHTEE), de l&#8217;Inde, de GMRT (superMIGHTEE), de LOFAR, de GMRT et de Jansky Very Large Array, qui s&#8217;\u00e9tendaient ensemble de 144 MHz \u00e0 1,5 GHz. La mod\u00e9lisation spectrale a confirm\u00e9 douze objets en tant que v\u00e9ritables restes; deux se sont av\u00e9r\u00e9s encore actifs.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Redshift plus \u00e9lev\u00e9, plus courte lueur<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Les \u00e2ges spectraux mesur\u00e9s varient d&#8217;environ 8 \u00e0 42 millions d&#8217;ann\u00e9es, avec une m\u00e9diane proche de douze millions &#8211; remarquablement br\u00e8ve. Une tendance claire se d\u00e9gage : plus une galaxie est lointaine et ainsi redchang\u00e9e, plus son reste est jeune. Les chercheurs attribuent cela au fond du micro-ondes cosmique, sur lequel les \u00e9lectrons relativistes perdent de l&#8217;\u00e9nergie plus rapidement \u00e0 de plus grandes distances.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>14 candidats, 12 confirm\u00e9s comme restes<\/li>\n<li>\u00c2ges spectraux environ 8 \u00e0 42 millions d&#8217;ann\u00e9es (m\u00e9diane environ 12)<\/li>\n<li>Redshift z = 0,35 \u00e0 2,85 (m\u00e9diane 1,25)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Ce que cela signifie pour les trous noirs<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Les restes \u00e9loign\u00e9s ne restent donc visibles que bri\u00e8vement, ce qui fausse leur recensement et affecte les estimations de la dur\u00e9e de vie des jets. De futurs lev\u00e9s plus sensibles avec MeerKAT et le Square Kilomer Array actuellement en construction devraient r\u00e9v\u00e9ler beaucoup d&#8217;autres de ces g\u00e9ants qui s&#8217;affaiblissent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sources : <a href=\"https:\/\/academic.oup.com\/mnras\/article\/550\/4\/stag1328\/8734296\">Avis mensuels de la Soci\u00e9t\u00e9 royale d&#8217;astronomie<\/a> \u00b7 <a href=\"https:\/\/arxiv.org\/abs\/2607.09920\">arXiv<\/a> \u00b7 <a href=\"https:\/\/www.eurekalert.org\/news-releases\/1140488\">EurekAlert (Universit\u00e9 du Cap)<\/a><\/p>\n<div id=\"netgu-1568324530\" class=\"netgu-after-content netgu-entity-placement\"><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-6258556257245998\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-6258556257245998\" \ndata-ad-slot=\"4559785002\" \ndata-ad-format=\"auto\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Une \u00e9quipe dirig\u00e9e par Sushant Dutta a mesur\u00e9 douze galaxies radio mourantes. Leur vie apr\u00e8s la mort s&#8217;av\u00e8re \u00e9tonnamment br\u00e8ve, et les restes les plus \u00e9loign\u00e9s s&#8217;estompent encore plus vite que les restes voisins.<\/p>\n","protected":false},"author":1,"featured_media":1999,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[],"tags":[],"class_list":["post-5842","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry"],"brizy_media":[],"_links":{"self":[{"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/posts\/5842","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/comments?post=5842"}],"version-history":[{"count":1,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/posts\/5842\/revisions"}],"predecessor-version":[{"id":5843,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/posts\/5842\/revisions\/5843"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/media\/1999"}],"wp:attachment":[{"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/media?parent=5842"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/categories?post=5842"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/netguide.io\/news\/wp-json\/wp\/v2\/tags?post=5842"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}