{"id":60000,"date":"2025-07-12T16:27:07","date_gmt":"2025-07-12T16:27:07","guid":{"rendered":"https:\/\/www.europesays.com\/us\/60000\/"},"modified":"2025-07-12T16:27:07","modified_gmt":"2025-07-12T16:27:07","slug":"radio-observations-hint-at-active-galactic-nucleus-in-nearby-spiral-galaxy-ngc-4527","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/60000\/","title":{"rendered":"Radio observations hint at active galactic nucleus in nearby spiral galaxy NGC 4527"},"content":{"rendered":"<p>            <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/07\/radio-observations-exp.jpg\" alt=\"Radio observations explore the nature of a nearby spiral galaxy\" title=\"NGC 4527: color scale shows 700 MHz (Band-4) emission from the naturally weighted image. White contours represent the 1,230 MHz (Band-5) emission from the naturally weighted image, with contour levels of 0.45, 4.3 and 8.2 mJy\/beam. Red markers indicate the positions of known supernovae in NGC 4527. The synthesized beams are shown in the bottom right corner. Credit: arXiv (2025). DOI: 10.48550\/arxiv.2507.02204\" width=\"800\" height=\"530\"\/><\/p>\n<p>                NGC 4527: color scale shows 700 MHz (Band-4) emission from the naturally weighted image. White contours represent the 1,230 MHz (Band-5) emission from the naturally weighted image, with contour levels of 0.45, 4.3 and 8.2 mJy\/beam. Red markers indicate the positions of known supernovae in NGC 4527. The synthesized beams are shown in the bottom right corner. Credit: arXiv (2025). DOI: 10.48550\/arxiv.2507.02204<\/p>\n<p>Argentinian astronomers have employed the upgraded Giant Metrewave Radio Telescope (uGMRT) to perform high-resolution radio observations of a nearby spiral galaxy designated NGC 4527. Results of the observational campaign, <a href=\"https:\/\/arxiv.org\/abs\/2507.02204\" target=\"_blank\" rel=\"noopener\">published<\/a> July 2 on the arXiv preprint server, shed more light on the nature of this galaxy, suggesting that it hosts an active galactic nucleus.<\/p>\n<p>Discovered in 1783, NGC 4527 is an edge-on <a href=\"https:\/\/phys.org\/tags\/spiral+galaxy\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">spiral galaxy<\/a> in the constellation Virgo, at a distance of some 49 million light years. It has an estimated size of 104,000 light years and is classified as a starburst galaxy due to its high infrared luminosity (about 26 billion solar luminosities) and <a href=\"https:\/\/phys.org\/tags\/star+formation+rate\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">star formation rate<\/a> at a level of three solar masses per year.<\/p>\n<p>Previous observations of NGC 4527 have detected three supernovae on the galaxy&#8217;s disk, providing evidence of recent massive star formation activity. Moreover, it turned out that the nuclear region of NGC 4527 harbors a massive molecular gas reservoir and exhibits kinematic signatures of a gravitationally unstable disk. However, this galaxy has an unusually low star formation efficiency when compared to classic starburst galaxies like M 82 and NGC 253.<\/p>\n<p>These peculiar properties of NGC 4527 suggest that it may be in a &#8220;pre-starburst&#8221; phase, where gas accumulation precedes an imminent star formation burst. A team of astronomers led by Camila Ailen Galante of the National University of La Plata in Buenos Aires, Argentina, decided to further investigate this matter using uGMRT.<\/p>\n<p>&#8220;This paper presents new radio continuum observations of NGC 4527 using the upgraded Giant Metrewave Radio Telescope (uGMRT) at 700 MHz (Band-4) and 1,230 MHz (Band5), complemented by archival infrared and X-ray data,&#8221; the researchers wrote.<\/p>\n<p>Galante&#8217;s team managed to explore the large-scale emissions and the central region of NGC 4527. It turned out that on a large scale, the radio emission at 700 and 1,230 MHz follows the stellar disk, with no evidence of a radio halo. The spectral index values across the disk point to the presence of polycyclic aromatic hydrocarbons (PAHs).<\/p>\n<p>When it comes to the central region of NGC 4527, the observations identified three compact radio sources. One of them was found at the center of the galaxy and exhibits a non-thermal spectral index. The two other sources appear to be symmetrically located along the galaxy&#8217;s major axis at a projected distance of approximately 1,300 light years, and they both display relatively flat spectral indices. The collected data also indicate PAH destruction in the more energetic zones of the galaxy.<\/p>\n<p>The astronomers concluded that the observed properties of NGC 4527 suggest that it contains a circumnuclear star-forming ring. Furthermore, they noted that the PAH destruction, non-thermal radio emission and also the recent detection of X-rays in the central region of this galaxy can be explained by the presence of an <a href=\"https:\/\/phys.org\/tags\/active+galactic+nucleus\/\" rel=\"tag noopener\" class=\"textTag\" target=\"_blank\">active galactic nucleus<\/a> (AGN).<\/p>\n<p>&#8220;Moreover, the AGN scenario offers a plausible mechanism for the formation of the circumnuclear ring: if the accretion flow is\u2014or was\u2014super-Eddington and driving a dense wind that fails to escape the galaxy&#8217;s gravitational potential, the fallback of material onto the disk could inject fresh gas a few hundred parsecs from the center, triggering star formation in a ring-like structure,&#8221; the researchers explained.<\/p>\n<p>However, the authors of the paper underlined that variability studies and higher-resolution observations of the innermost central region of NGC 4527 are required in order to confirm the presence of an AGN.<\/p>\n<p>\n    Written for you by our author <a href=\"https:\/\/sciencex.com\/help\/editorial-team\/#authors\" target=\"_blank\" rel=\"noopener\">Tomasz Nowakowski<\/a>,<br \/>\n    edited by <a href=\"https:\/\/sciencex.com\/help\/editorial-team\/\" target=\"_blank\" rel=\"noopener\">Stephanie Baum<\/a>, and fact-checked and reviewed by <a href=\"https:\/\/sciencex.com\/help\/editorial-team\/\" target=\"_blank\" rel=\"noopener\">Robert Egan<\/a>\u2014this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive.<br \/>\n    If this reporting matters to you,<br \/>\n    please consider a <a href=\"https:\/\/sciencex.com\/donate\/?utm_source=story&amp;utm_medium=story&amp;utm_campaign=story\" target=\"_blank\" rel=\"noopener\">donation<\/a> (especially monthly).<br \/>\n    You&#8217;ll get an <b>ad-free<\/b> account as a thank-you.\n    <\/p>\n<p><strong>More information:<\/strong><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tC. A. Galante et al, High resolution radio analysis of the starburst galaxy NGC 4527: signatures of an AGN core, arXiv (2025). <a data-doi=\"1\" href=\"https:\/\/dx.doi.org\/10.48550\/arxiv.2507.02204\" target=\"_blank\" rel=\"noopener\">DOI: 10.48550\/arxiv.2507.02204<\/a><\/p>\n<p>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<strong>Journal information:<\/strong><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\/journals\/arxiv\/\" target=\"_blank\" rel=\"noopener\">arXiv<\/a><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"icon_open\" href=\"http:\/\/arxiv.org\/\" 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<\/p>\n<p class=\"article-main__note mt-4\">\n\t\t\t\t\t\t\t\t\t\t\t\t  \u00a9 2025 Science X Network\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\t<strong>Citation<\/strong>:<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tRadio observations hint at active galactic nucleus in nearby spiral galaxy NGC 4527 (2025, July 10)<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tretrieved 12 July 2025<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tfrom https:\/\/phys.org\/news\/2025-07-radio-hint-galactic-nucleus-nearby.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":"NGC 4527: color scale shows 700 MHz (Band-4) emission from the naturally weighted image. White contours represent the&hellip;\n","protected":false},"author":3,"featured_media":60001,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[493,494,492,489,159,490,158,491,67,132,68],"class_list":{"0":"post-60000","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-united-states","17":"tag-unitedstates","18":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/114841206487208300","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/60000","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=60000"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/60000\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/60001"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=60000"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=60000"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=60000"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}