{"id":4550,"date":"2019-09-08T16:46:41","date_gmt":"2019-09-08T14:46:41","guid":{"rendered":"https:\/\/www.oa-cagliari.inaf.it\/seminari\/nuove-intuizioni-sugli-agn-attraverso-la-loro-emissione-radio\/"},"modified":"2025-09-22T22:57:26","modified_gmt":"2025-09-22T20:57:26","slug":"nuove-intuizioni-sugli-agn-attraverso-la-loro-emissione-radio","status":"publish","type":"seminari","link":"https:\/\/www.oa-cagliari.inaf.it\/en\/seminars\/nuove-intuizioni-sugli-agn-attraverso-la-loro-emissione-radio\/","title":{"rendered":"New insights into AGN, via their radio emission"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-1643\" src=\"https:\/\/www.oa-cagliari.inaf.it\/wp-content\/uploads\/2025\/09\/2019061309035002728-300x286.png\" alt=\"New insights into AGN, via their radio emission\" width=\"300\" height=\"286\" srcset=\"https:\/\/www.oa-cagliari.inaf.it\/wp-content\/uploads\/2025\/09\/2019061309035002728-300x286.png 300w, https:\/\/www.oa-cagliari.inaf.it\/wp-content\/uploads\/2025\/09\/2019061309035002728.png 500w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>Radio observations allow us to identify a wide range of active galactic nuclei (AGN), which play a significant role in the evolution of galaxies. In the first part of this talk, I will escribe a new sample of powerful radio-galaxies, whose bright emission is detected at low radio-frequencies by the Murchison Widefield Array (MWA). This covers 72-231 MHz, and the 20 flux-densities over this range enable their broad-band radio spectra to be studied. Doing so highlights \u2018restarted\u2019 radio-galaxies, relic radio lobes, and sources with a spectral turnover that is likely due to free-free absorption by ionised gas. Identification of host galaxies is now complete, making this a highly-valuable legacy dataset. For the remainder of my talk, I will present recent analysis of radio emission from \u2018radio-quiet\u2019 quasars (RQQs). Being at low radio-luminosities, it has been assumed that their emission is dominated by star formation. However, using multi-wavelength data for two samples, we find support that black-hole accretion makes a significant contribution to the total radio emission in RQQs. These studies have important implications for modelling AGN feedback, and for determining the accretion and star-formation histories of the Universe.<\/p>\n","protected":false},"template":"","class_list":["post-4550","seminari","type-seminari","status-publish","hentry","categorie_seminari-colloquium"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.oa-cagliari.inaf.it\/en\/wp-json\/wp\/v2\/seminari\/4550","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oa-cagliari.inaf.it\/en\/wp-json\/wp\/v2\/seminari"}],"about":[{"href":"https:\/\/www.oa-cagliari.inaf.it\/en\/wp-json\/wp\/v2\/types\/seminari"}],"wp:attachment":[{"href":"https:\/\/www.oa-cagliari.inaf.it\/en\/wp-json\/wp\/v2\/media?parent=4550"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}