BibTex format
@article{Halder:2026:mnras/stag1590,
author = {Halder, A and Peiris, HV and Thorp, S and Leistedt, B and Mortlock, DJ and Jagwani, G and Tudorache, MN and Deger, S and VandenBussche, B and Leja, J and Wright, AH},
doi = {mnras/stag1590},
journal = {Monthly Notices of the Royal Astronomical Society},
title = {<tt>pop-cosmos</tt> : redshifts and physical properties of KiDS-1000 galaxies},
url = {http://dx.doi.org/10.1093/mnras/stag1590},
volume = {551},
year = {2026}
}
RIS format (EndNote, RefMan)
TY - JOUR
AB - <jats:title>ABSTRACT</jats:title> <jats:p>Principled Bayesian inference of galaxy properties has not previously been performed for wide-area weak-lensing surveys with millions of sources. We address this gap by applying the pop-cosmos generative model to perform spectral energy distribution (SED) fitting for 4 million KiDS (Kilo-Degree Survey)-1000 galaxies. Calibrated on deep COSMOS2020 photometric data, pop-cosmos specifies a physically motivated prior over the galaxy population up to $z \simeq 6$ in stellar population synthesis (SPS) parameter space. Using the Speculator SPS emulator with GPU (graphics processing unit)-accelerated Markov Chain Monte Carlo sampling, we perform full posterior inference at 8.2 GPU seconds per galaxy, obtaining joint constraints on galaxy redshifts and physical properties. We validate photometric redshifts against $\sim \!185\,\!000$ KiDS galaxies cross-matched to Dark Energy Spectroscopic Instrument Data Release 1 spectroscopic samples, achieving low bias ($2\times 10^{-3}$), scatter ($\sigma _{\mathrm{MAD}}=0.03$), and outlier fraction (3.2 per cent) for the Bright Galaxy Survey, with comparable performance (bias $3\times 10^{-2}$, $\sigma _{\mathrm{MAD}}=0.05$, 1.0 per cent outliers) for luminous red galaxies (LRGs). Within the LRG sample, we identify massive, dusty, star-forming contaminants at $z \simeq 0.4$ satisfying standard colour selections for quenched populations. We infer trends in stellar mass, star formation, metallicity, and dust across five tomographic redshift bins consistent with established scaling relations. Using specific star formation rate constraints, we identify $\sim$7 per cent of KiDS-1000 galaxies as quenched, versus 37 per cent implied by conservative colour cuts. This enables the construction of weak-lensing samples defined by physical properties while mitigating intrinsic alignment systematics and preserving statist
AU - Halder,A
AU - Peiris,HV
AU - Thorp,S
AU - Leistedt,B
AU - Mortlock,DJ
AU - Jagwani,G
AU - Tudorache,MN
AU - Deger,S
AU - VandenBussche,B
AU - Leja,J
AU - Wright,AH
DO - mnras/stag1590
PY - 2026///
SN - 0035-8711
TI - <tt>pop-cosmos</tt> : redshifts and physical properties of KiDS-1000 galaxies
T2 - Monthly Notices of the Royal Astronomical Society
UR - http://dx.doi.org/10.1093/mnras/stag1590
UR - https://doi.org/10.1093/mnras/stag1590
VL - 551
ER -