Dr. Becky | JWST's "too massive" galaxy problem solved?! | A non-universal IMF @DrBecky | Uploaded 1 year ago | Updated 2 hours ago
Go to brilliant.org/drbecky to get a 30-day free trial and the first 200 people will get 20% off their annual subscription.
Remember those overmassive galaxies that JWST found that people claimed proved "the big bang never happened?" when in reality it was just that we couldn't explain how they'd got so big? Well, turns out those galaxies probably aren't that massive after all. In this video we're chatting about one assumption (called the Initial Mass Function of stars) used to calculate their masses needed a bit of a tweak...
#jwst #astrophysics #bigbang
My previous video on these massive galaxies when they were first found: youtu.be/hmkyF1tNFc4
** REFERENCES **
Steinhardt et al. (2023; new IMF for early universe) -arxiv.org/pdf/2208.07879.pdf
Boylan-Kolchin (2023; massive galaxies tension with λ CDM) - arxiv.org/pdf/2208.01611.pdf
Sneppen et al. (2022; temperature dependent IMF) - iopscience.iop.org/article/10.3847/1538-4357/ac695e/pdf
Labbé et al. (2023; 6 massive galaxies in JWST data) - arxiv.org/pdf/2207.12446.pdf
Rana (1987; the initial mass function of stars) - https://articles.adsabs.harvard.edu/pdf/1987A%26A...184..104R
Smith (2020; review on varying IMFs) - annualreviews.org/doi/pdf/10.1146/annurev-astro-032620-020217
Hopkins (2018; review on how IMF is measured) - arxiv.org/pdf/1807.09949.pdf
Kroupa & Weidner (2003; Milky Way and local galaxies IMF) - iopscience.iop.org/article/10.1086/379105/pdf
JWST observing schedules: https://www.stsci.edu/jwst/science-execution/observing-schedules
JWST data archive (with public access!): https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html
Twitter bot for JWST current observations: twitter.com/JWSTObservation
00:00 - Introduction
00:56 - Our best model of the Universe
03:14 - JWST's overmassive "impossible" galaxies
04:12 - How we measure the mass of galaxies
06:15 - The initial mass function
08:59 - How the IMF affects JWST's overmassive galaxies
11:16 - Is the IMF different in the early Universe?
13:43 - New estimates for the masses of these galaxies
16:33 - What's next?
17:33 - Brilliant
18:42 - Bloopers
---
📚 My new book, "A Brief History of Black Holes", out NOW in hardback, e-book and audiobook (which I narrated myself!): http://hyperurl.co/DrBecky
---
📚 "The Year In Space" celebrating all things space in 2022 from me and the rest of the Supermassive Podcast team: geni.us/jNcrw
---
👕 My new merch, including JWST designs, are available here (with worldwide shipping!): 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 (Christ Church). 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
rebeccasmethurst.co.uk
Go to brilliant.org/drbecky to get a 30-day free trial and the first 200 people will get 20% off their annual subscription.
Remember those overmassive galaxies that JWST found that people claimed proved "the big bang never happened?" when in reality it was just that we couldn't explain how they'd got so big? Well, turns out those galaxies probably aren't that massive after all. In this video we're chatting about one assumption (called the Initial Mass Function of stars) used to calculate their masses needed a bit of a tweak...
#jwst #astrophysics #bigbang
My previous video on these massive galaxies when they were first found: youtu.be/hmkyF1tNFc4
** REFERENCES **
Steinhardt et al. (2023; new IMF for early universe) -arxiv.org/pdf/2208.07879.pdf
Boylan-Kolchin (2023; massive galaxies tension with λ CDM) - arxiv.org/pdf/2208.01611.pdf
Sneppen et al. (2022; temperature dependent IMF) - iopscience.iop.org/article/10.3847/1538-4357/ac695e/pdf
Labbé et al. (2023; 6 massive galaxies in JWST data) - arxiv.org/pdf/2207.12446.pdf
Rana (1987; the initial mass function of stars) - https://articles.adsabs.harvard.edu/pdf/1987A%26A...184..104R
Smith (2020; review on varying IMFs) - annualreviews.org/doi/pdf/10.1146/annurev-astro-032620-020217
Hopkins (2018; review on how IMF is measured) - arxiv.org/pdf/1807.09949.pdf
Kroupa & Weidner (2003; Milky Way and local galaxies IMF) - iopscience.iop.org/article/10.1086/379105/pdf
JWST observing schedules: https://www.stsci.edu/jwst/science-execution/observing-schedules
JWST data archive (with public access!): https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html
Twitter bot for JWST current observations: twitter.com/JWSTObservation
00:00 - Introduction
00:56 - Our best model of the Universe
03:14 - JWST's overmassive "impossible" galaxies
04:12 - How we measure the mass of galaxies
06:15 - The initial mass function
08:59 - How the IMF affects JWST's overmassive galaxies
11:16 - Is the IMF different in the early Universe?
13:43 - New estimates for the masses of these galaxies
16:33 - What's next?
17:33 - Brilliant
18:42 - Bloopers
---
📚 My new book, "A Brief History of Black Holes", out NOW in hardback, e-book and audiobook (which I narrated myself!): http://hyperurl.co/DrBecky
---
📚 "The Year In Space" celebrating all things space in 2022 from me and the rest of the Supermassive Podcast team: geni.us/jNcrw
---
👕 My new merch, including JWST designs, are available here (with worldwide shipping!): 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 (Christ Church). 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
rebeccasmethurst.co.uk
