1/9/2023 0 Comments Ram pressure stripping mass![]() ![]() In this work, the authors investigate whether these stripped galaxies are more likely to have an AGN in their centres. This process is known as ram-pressure stripping. ![]() As galaxies sail through this ocean, drag forces from the ICM can cause gas in the galaxies to be stripped away, leading to tails of gas streaming out in their wake. Between these is a sea of hot gas, the intracluster medium (ICM). Galaxy clusters are huge objects containing up to several thousand galaxies. Today’s paper explores one mechanism, which could be responsible for switching on AGN in galaxy clusters. But, like all engines, AGN need an ignition: a trigger that can cause a dormant supermassive black hole to start accreting material and become an AGN. As a result, AGN emit huge amounts of light, and are some of the brightest objects in the Universe. Around 10% of the mass that is accreted by an AGN is converted into energy (this efficiency is about 0.7% in nuclear fusion, and just one billionth of a percent in typical combustion ). Credit: NASA/JPL-Caltech.ĪGN are incredibly efficient engines. Some AGN emit narrow, powerful jets of material - this can be seen above the black hole. A supermassive black hole surrounded by an accretion disk is known as an Active Galactic Nucleus, or AGN, as shown by the artist’s impression in Figure 1.įigure 1: Artist’s impression of an AGN, with a central black hole surrounded by a flat, rotating accretion disk. If enough material is present, it can form an accretion disk - an incredibly hot structure that feeds material into a black hole and converts this mass into energy, which is emitted as light. Consequently, material that is pulled towards a supermassive black hole can be accelerated almost to the speed of light. With their enormous density and gravitational fields, black holes are some of the most extreme objects in the Universe. This theory was bolstered in 2019, when the Event Horizon Telescope took the first ever photograph of a black hole in the centre of the nearby elliptical galaxy M87, and in 2020, when Reinhard Genzel and Andrea Ghez were awarded the Nobel Prize in Physics for discovering a supermassive black hole at the centre of our own galaxy. Status: Accepted for publication in the Astrophysical Journal, available on arXivĬurrent theories suggest that most galaxies - if not all - contain a supermassive black hole in their centre, with masses anywhere from millions to billions of times that of our Sun. Jaffé, Jacob Crossett, Marco Gullieuszik, Jacopo Fritz, Alessandro Ignestiįirst Author’s Institution: INAF-Padova Astronomical Observatory, Padova, Italy Poggianti, Alessia Moretti, Mario Radovich, Rory Smith, Yara L. Title: Exploring the AGN-ram pressure stripping connection in local clustersĪuthors: Giorgia Peluso, Benedetta Vulcani, Bianca M. ![]()
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