How "Little Red Dots" Broke the Universe (and how we're unbreaking it)

Event Date:
2025-10-27T16:00:00
2025-10-27T17:00:00
Event Location:
HENN 318
Speaker:
David Setton, Princeton University
Related Upcoming Events:
Astronomy Colloquia
Intended Audience:
Everyone
Local Contact:

Allison Man (aman@phas.ubc.ca) and Brett Gladman (gladman@astro.ubc.ca)

All are welcome to this event!

Event Information:

Abstract: 

One of the biggest mysteries of the early era of JWST's operation has been "Little Red Dots," compact sources with strange V shaped spectral energy distributions and broad emission lines. These sources have been incredibly hard to model, and over the course of three years, leading theories have ranged from over-massive and over-abundant galaxies that assembled Milky Way levels of stellar mass in the first Gyr of cosmic time to over-massive and over-abundant luminous active galactic nuclei that defy models of black hole assembly. 

I will walk through the brief history of discovery for these sources, demonstrating how we have slowly been getting closer to understanding Little Red Dots by leveraging JWST, ALMA, and several other observatories to constrain their panchromatic spectral energy distribution and bolometric output. I will discuss our current best understanding of these sources, and how we might move forward to incorporate them into our picture of galaxy and black hole assembly.
 

Bio: 


I am a Brinson Prize Fellow at the Princeton University Department of Astrophysical Sciences studying massive galaxies as a part of the SQuIGGLE, RUBIES, and UNCOVER surveys. My research focuses on understanding the physical mechanism that drives the shutdown of star formation in massive galaxies by placing constraints on the star formation histories, structures, and number densities of recently quenched systems. I am also very interested in Little Red Dots and understanding their strange "V"-shaped spectral energy distributon. When I'm not doing science, I am usually watching movies, playing guitar for my band, or watching football. 
 

Learn More: 

Links:

Add to Calendar 2025-10-27T16:00:00 2025-10-27T17:00:00 How "Little Red Dots" Broke the Universe (and how we're unbreaking it) Event Information: Abstract:  One of the biggest mysteries of the early era of JWST's operation has been "Little Red Dots," compact sources with strange V shaped spectral energy distributions and broad emission lines. These sources have been incredibly hard to model, and over the course of three years, leading theories have ranged from over-massive and over-abundant galaxies that assembled Milky Way levels of stellar mass in the first Gyr of cosmic time to over-massive and over-abundant luminous active galactic nuclei that defy models of black hole assembly.  I will walk through the brief history of discovery for these sources, demonstrating how we have slowly been getting closer to understanding Little Red Dots by leveraging JWST, ALMA, and several other observatories to constrain their panchromatic spectral energy distribution and bolometric output. I will discuss our current best understanding of these sources, and how we might move forward to incorporate them into our picture of galaxy and black hole assembly.  Bio:  I am a Brinson Prize Fellow at the Princeton University Department of Astrophysical Sciences studying massive galaxies as a part of the SQuIGGLE, RUBIES, and UNCOVER surveys. My research focuses on understanding the physical mechanism that drives the shutdown of star formation in massive galaxies by placing constraints on the star formation histories, structures, and number densities of recently quenched systems. I am also very interested in Little Red Dots and understanding their strange "V"-shaped spectral energy distributon. When I'm not doing science, I am usually watching movies, playing guitar for my band, or watching football.   Learn More:  About "little red dots": https://www.cfa.harvard.edu/news/new-theory-may-explain-mysterious-little-red-dots-early-universe https://www.nature.com/articles/d41586-025-03352-6 https://www.science.org/content/article/early-universe-s-little-red-dots-may-be-black-hole-stars About the co-evolution of galaxies and black holes: https://www.science.org/content/article/start-black-hole-then-add-stars About surveys: SQuIGGLE: https://squigglesurvey.github.io/ RUBIES: https://arxiv.org/abs/2506.05459 UNCOVER: https://jwst-uncover.github.io/  Links: David Setton's personal github page: https://davidjsetton.github.io/ David Setton's faculty page from Princeton University Department of Astrophysical Sciences: https://web.astro.princeton.edu/people/david-setton  Event Location: HENN 318