JWST's "too massive" galaxy problem solved?! | A non-universal IMF

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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:    • JWST has found MASSIVE galaxies in th...  

** REFERENCES **
Steinhardt et al. (2023; new IMF for early universe) -https://arxiv.org/pdf/2208.07879.pdf
Boylan-Kolchin (2023; massive galaxies tension with λ CDM) - https://arxiv.org/pdf/2208.01611.pdf
Sneppen et al. (2022; temperature dependent IMF) - https://iopscience.iop.org/article/10...
Labbé et al. (2023; 6 massive galaxies in JWST data) - https://arxiv.org/pdf/2207.12446.pdf
Rana (1987; the initial mass function of stars) - https://articles.adsabs.harvard.edu/p...
Smith (2020; review on varying IMFs) - https://www.annualreviews.org/doi/pdf...
Hopkins (2018; review on how IMF is measured) - https://arxiv.org/pdf/1807.09949.pdf
Kroupa & Weidner (2003; Milky Way and local galaxies IMF) - https://iopscience.iop.org/article/10...

JWST observing schedules: https://www.stsci.edu/jwst/science-ex...
JWST data archive (with public access!): https://mast.stsci.edu/portal/Mashup/...
Twitter bot for JWST current observations:   / 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


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👩🏽‍💻 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
https://rebeccasmethurst.co.uk