Chris Lovell

Our conference photo

Will Handley going very easy on me in English Pool at one of our social hours

Thanks to @chrislovell.bsky.social and Sotiria Fotopoulou for organizing a fantastic SBI & Galaxy Evolution workshop, and inviting me to speak!

Learned a ton and am so glad I got to finally visit the UK (and Bristol in particular).

🔭☄️🧪 #AstroSci

#extragalactic ☄️

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First Light And Reionization Epoch Simulations (FLARES) -- XIX: Supermassive black hole mergers in the early Universe and their environmental dependence The upcoming space-based gravitational wave (GW) observatory, LISA, is expected to detect GW signals from supermassive black hole (SMBH) mergers occurring at high redshifts. However, understanding the...

Couple of neat new FLARES papers out recently, including predictions for LISA from supermassive black hole mergers in the early Universe from the amazing Shihong Liao!

arxiv.org/abs/2505.12591
arxiv.org/abs/2505.05257

is the take here "people shouldn't be expected to actually read papers before citing them" ?

* hides *

Wait... there's been a misunderstanding

👀

Very proud to be a part of this excellent review on "The Spectral Energy Distributions of Galaxies", part of the Encyclopedia of Astrophysics.

Kartheik has made some absolutely stunning figures, example below. Go check it out!

arxiv.org/abs/2502.17680

appears to be down again today, is there somewhere we can get live updates on outages?

I want one!

Microsoft Probing If DeepSeek-Linked Group Improperly Obtained OpenAI Data Microsoft Corp. and OpenAI are investigating whether data output from OpenAI’s technology was obtained in an unauthorized manner by a group linked to Chinese artificial intelligence startup DeepSeek, ...

Oh no, the Chinese plagiarism machine might have plagiarized the American plagiarism machine

search.app/gLKPBELL2weQ...

Come join us in Bristol in May for our meeting on Simulation Based Inference for Galaxy Evolution!

We've got some very exciting speakers lined up (stay tuned), abstract submission deadline February 1st

sbi-galev.github.io/2025/

#astronomy #astro #extragalactic #astrocode

Fantastic work from Sophie, and some potentially big implications for the modelling of stellar populations in the early Universe..!

Check out the models here, including some nice interactive notebooks to get you started: sophie-newman.github.io/cloudy-maras...

#astronomy #extragalactic #astrocode

Quote from Beatrice Tinsley's Ph.D thesis. "The evolution of a galaxy should, ideally, be deduced by following its history either backwards in time from a known population of stars and gas, or forwards from primeval gas. The former method is not feasible because observable integrated features do not give enough details. The latter is also subject to great uncertainties, especially as to whether the primeval gas contained Helium (Peebles, 1966), and as to the nature of first generation stars."

Beatrice Tinsley's Ph.D thesis, 1967. Has anything changed? :)

(except maybe the uncertainties on primordial Helium abundance...)

#astronomy #extragalactic #histsci

Institute of Cosmology & Gravitation - Portsmouth Join the conversation

Follow the (growing) Starter Pack for the Institute of Cosmology & Gravitation (ICG) - Find out about our investigations into Gravity, Galaxies, Sonification & more at the University of Portsmouth, UK 🌌🔭 go.bsky.app/SScAL4f

Professional astrophysicist at the U. Portsmouth

yes

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There is still work to do in order to apply this pipeline to observations directly (which we're working on..) but these results suggest that there is interesting cosmological information in galaxy star formation and metal enrichment histories, and subsequently the observables ✨

We also explore the feature importance, and find that it is the colour distributions that drive the tight constraints on omega_m and sigma_8

We then perform Simulation Based Inference (SBI) on the luminosity functions and colour distributions, and find interesting results for sigma-8, describing the clustering of matter - this is despite the lack of any spatial information in these distributions

We believe (!) that this dataset represents the largest catalogue of synthetic photometry based on hydrodynamic galaxy formation simulations produced to date.

We first forward model the UV-NIR rest- and observer-frame photometry from over 200 million sources in the CAMELS simulations. These catalogues are now publicly available:

camels.readthedocs.io/en/latest/ph...

Learning the Universe: Cosmological and Astrophysical Parameter Inference with Galaxy Luminosity Functions and Colours We perform the first direct cosmological and astrophysical parameter inference from the combination of galaxy luminosity functions and colours using a simulation based inference approach. Using the Sy...

Hi Bluesky 👋 here's an arXiv announcement for ya

Our new Learning the Universe paper is on the arXiv today, using luminosity functions and colours to perform simulation based inference on cosmological and astrophysical parameters

arxiv.org/abs/2411.13960
learning-the-universe.org