- Mon 6th Feb 2017
Although physically very small, black holes can decide the fate of galaxies. They have only two properties, mass and spin, with masses that range from a few times the mass of the Sun to over ten billion times that mass. Just about all galaxies have a supermassive black hole at the centre, with a mass proportional to that of the central spheroidal bulge of stars. In the case of the most massive galaxies this bulge corresponds to the total stellar mass. The correlation can arise because massive black holes, in accreting gas from the host galaxy, emit enough energy in radiation, winds and jets to expel all the gas from the galaxy and thereby shut off star formation as well as the accretion. Unless more gas comes along, the galaxy is effectively red and dead. In other words, the final stellar mass of a galaxy is determined by the black hole at its centre, even though the black hole is only one billionth of the size of the galaxy. How this happens will be illustrated and discussed.
Andy Fabian is Acting Director of the Institute of Astronomy and researches black holes and clusters of galaxies using orbiting X-ray telescopes such as Chandra, XMM and NuSTAR. He is a Fellow of the Royal Society and a Foreign Associate of the US National Academy of Sciences. He was President of the Royal Astronomical Society from 2008-2010 and was Vice-Master of Darwin College from 1997-2012. He has been awarded the RAS Gold Medal and the Bruno Rossi and Dannie Heineman prizes of the AAS.
“Superlative in all respects. Intelligible to a general audience and excellent responses to questions. One of the best I have heard at CSAR in 30 years.”
“Master class in Black holes and how they may work Fascinating and wide ranging Q&A Follow up conversation interesting in the bar All in all first-rate speaker and very well attended event.”
“Superb evening. Lecturer spoke with clarity and had some stunning images.”
Professor Andy Fabian, OBE, FRS, Institute of Astronomy, University of Cambridge