Uploads from Dr. Becky

Currently Playing: Black hole at the centre of every galaxy? #shorts

How do we know there’s a supermassive black hole at the centre of every galaxy? Well let's rewind to the 1990s, with the launch of the Hubble Space Telescope at the beginning of the decade which revealed that the centres of some galaxies contained very bright objects, often outshining the entire galaxy of stars. These were dubbed active galactic nuclei, or AGN. To get something as bright as an AGN, you need an object very energetic, or massive, to power it. Something like a supermassive black hole, one that has material around it accelerated to such huge speeds that it glows in everything from X-rays, to visible light and infrared light. That was an idea that had been around since the 1960s, the problem was we needed observational evidence for massive objects in the centres of galaxies. Now I’ve done a whole video before on how we now know there’s a supermassive black hole at the centre of each galaxy, starting from all the way back to the 1900s. To cut a long story short, through the 1980s and 1990s with Hubble people were measuring the speed that stars were orbiting the centre of nearby galaxies. A speed that needed them to be orbiting around objects millions of times heavier than the Sun, in a very small region of space, that we couldn’t see. These would be dubbed “massive dark objects” at first, before all the evidence came together in the early 2000s for consensus to be reached that they were supermassive black holes. Now my own research is on how they grow so supermassive. And my latest YouTube video is on the latest research paper published by me and my PhD student and our collaborators on how black holes are growing to be supermassive in galaxies that have never merged together with another galaxy. According to our best theories for how galaxies and supermassive black holes evolve together, these should be tiny, and yet we find they’re not. They’re still supermassive. To find out more about how these black holes have grown so supermassive, check out my latest video, and subscribe, so you don’t miss out on not just what we know in space, but how we know it. Previous videos: https://www.youtube.com/watch?v=QCv87K_y97w Video filmed on a Sony ⍺7 IV Video edited by Martino Gasparrini: martino.freelance@gmail.com Video produced by Marina Hui & Dr Becky Smethurst --- 📚 My book, "A Brief History of Black Holes", out NOW in hardback, paperback, e-book and audiobook (which I narrated myself!): http://lnk.to/DrBecky --- 👕 My merch, including JWST designs, are available here (with worldwide shipping!): https://dr-becky.teemill.com/ --- 🎧 Royal Astronomical Society Podcast that I co-host: podfollow.com/supermassive --- 🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video! --- 👩🏽‍💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford. I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars. http://drbecky.uk.com