Uploads from Dr. Becky

Currently Playing: What is galactic archaeology?! #shorts

What is galactic archeology? Because At its heart, it's figuring out the Milky Way’s history by treating the stars as fossils. The shape of a galaxy can tell you a lot about how its evolved over time and what’s happened in its history. We know that when two galaxies collide and merge together, you scramble all the stars and gas and dust, and turn a nice flat spiral galaxy, into an elliptical galaxy, or a sphere of stars. The stars are all orbiting the centre still just on different planes. So the shape can tell us a lot, and for the Milky Way this is a bit more difficult than looking at other galaxies. We’re stuck inside it, so figuring out the overall shape requires a bit more work. But essentially what we do is record the positions and distances to stars to build up a 3D map of the Milky Way to reveal its shape. One of the things that pops out is something known as the sagittarius stream, a huge loop of stars that’s come from our merger with the Sagittarius dwarf galaxy, which we think has crashed through the Milky Way's disk a few times over the last six billion years. These impacts and interactions triggered big bursts of newly formed stars in the Milky Way, which fun fact: one of which we think might have formed the Sun and the solar system 4.5 billion years ago... 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