{"id":6199,"date":"2022-02-16T18:04:45","date_gmt":"2022-02-16T17:04:45","guid":{"rendered":"https:\/\/www.sciencefocus.com\/?p=111769"},"modified":"2022-02-16T18:25:10","modified_gmt":"2022-02-16T17:25:10","slug":"new-perspective-of-supermassive-black-hole-confirms-30-year-old-prediction","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/rss_feed\/new-perspective-of-supermassive-black-hole-confirms-30-year-old-prediction\/","title":{"rendered":"New perspective of supermassive black hole confirms 30-year-old prediction"},"content":{"rendered":"

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By Jason Goodyer\n \t\t<\/p>

Published: Wednesday, 16 February 2022 at 12:00 am<\/p>

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Since they were first spotted in the 1950s, active galactic nuclei, or AGNs have puzzled astronomers. In the night sky, an AGN is a bright, compact region at the centre of a galaxy that gives off much more light than would be expected to be produced by stars.<\/p>\n

The source of this luminosity is in fact thought to be supermassive black holes<\/a>, or more precisely the matter that swirls around their edges at close to the speed of light before getting sucked into the event horizon.<\/p>\n

Although it\u2019s thought that supermassive black holes are the source of all AGNs, it\u2019s not clear why some are less energetic (bright) than others. But now astronomers have their answer, thanks to some observations of a supermassive black hole in a galaxy not so far away<\/p>\n

The Unified Model of AGNs, which was theorised 30 years ago, states that although some AGNs appear to emit radio bursts, others visible light and others still X-rays, they all consist of supermassive black holes surrounded by a ring of cosmic dust that emit electromagnetic radiation not originating from stars.<\/p>\n

The difference in appearance is simply caused by the orientation at which we can see the black hole through the ring from Earth \u2013 some are more obscured by the dust than others.<\/p>\n

Close-up observations taken by the European Southern Observatory\u2019s Very Large Telescope Interferometer (ESO\u2019s VLTI) located in Chile\u2019s Atacama Desert, have provided evidence to support this model.<\/p>\n

The model states that although some AGNs appear to emit radio bursts and others visible light, they all consist of supermassive black holes surrounded by a ring of cosmic dust.<\/p>\n

The difference in appearance is simply caused by the orientation at which we can see the black hole through the ring from Earth \u2013 some are more obscured by the dust than others.<\/p>\n

The team made the discovery by studying Messier 77, a spiral galaxy situated 47 million light-years from Earth in the constellation Cetus, using the Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE).<\/p>\n

By mapping out the changes in dust temperature \u2013 which vary from room temperature to a blistering 1200\u00b0C \u2013 caused by the radiation emitted by the black hole, they were able to piece together a picture showing where it must lie.<\/p>\n

What they found was exactly as predicted by the Unified Model \u2013 a supermassive black hole surrounded by a thick disc of cosmic dust<\/a>.<\/p>\n

\u201cThe real nature of the dust clouds and their role in both feeding the black hole and determining how it looks when viewed from Earth have been central questions in AGN studies over the last three decades,\u201d said lead researcher Violeta G\u00e1mez Rosas from Leiden University in the Netherlands.<\/p>\n

\u201cWhilst no single result will settle all the questions we have, we have taken a major step in understanding how AGNs work.\u201d<\/p>\n

The researchers are now looking to use ESO\u2019s VLTI to further confirm the Unified Model of AGNs by observing a larger number of galaxies.<\/p>\n

\u201cOur results should lead to a better understanding of the inner workings of AGNs,\u201d said G\u00e1mez Rosas. \u201cThey could also help us better understand the history of the Milky Way, which harbours a supermassive black hole at its centre that may have been active in the past.\u201d<\/p>\n