Unveiling the Baryon Cycle Through Cosmic Time
Abstract
Galaxy evolution is governed by the baryon cycle: gas accreted from the cosmic web and circumgalactic medium condenses into molecular gas, forms stars, and is redistributed by stellar and AGN feedback. Tracing the molecular phase is therefore essential to understanding how galaxies acquire, consume, and eject their baryons. Yet current molecular-gas surveys remain limited by sensitivity, area, cosmic variance, and spectral bandwidth. ALMA2040 would combine a ∼10× sensitivity improvement with ≳512 GHz simultaneous frequency coverage, delivering ∼100× faster mapping at fixed depth and a further ≳25× gain in instantaneous bandwidth. Together, these advances would increase spectroscopic survey speed by orders of magnitude, enabling tiered ``wedding-cake'' strategies: an ultra-deep ∼4-5 arcmin2 field probing faint and high-redshift reservoirs, a ∼0.25 deg2 survey reaching molecular-line sensitivities comparable to current ultra-deep fields over a much larger cosmological volume, and thousands of independent pointings minimizing cosmic variance. Broad spectral coverage would simultaneously detect multiple CO transitions, [CI], H2O, feedback tracers, far-IR fine-structure lines, and dust continuum, constraining molecular gas, ISM conditions, obscured star formation, and gas flows within the same observations. Every targeted observation would also become a molecular deep field, extending these measurements to serendipitous galaxies. Together with future HI, optical, and near-IR surveys, ALMA2040 would enable a population-resolved view of the baryon cycle across cosmic time and stringent tests of galaxy formation models.
Related
- SAGE26 Paper I: Modelling the baryon cycle from cosmic dawn to the present day
- And Then There WEre Baryons (ATWEB): The Baryon Budget of the Universe in Halos and the IGM over 13 Billion Years of Cosmic Time
- Tracing the Cosmic web across Cosmic time through SKA observations of radio galaxies
- Direct measures of black hole masses through cosmic time
- Tracing small-scale structure formation through cosmic time with strong gravitational lensing: A case for a next-generation sub-millimetre/millimetre interferometer
BibTeX
@misc{aravena2026unveiling,
title = {{Unveiling the Baryon Cycle Through Cosmic Time}},
author = {Manuel Aravena and Leindert A. Boogaard and Jorge González-López and Ryan Keenan and Chiara Circosta and Pierre Cox and Roberto Decarli and Tanio Díaz-Santos and Andreas Faisst and Román Fernández-Aranda and Jonathan Freundlich and Carlotta Gruppioni and Mahmoud Hamed and Gareth Jones and Melanie Kaasinen and Adarsh Kumar and Ivanna Langan and Andrea Lapi and Daizhong Liu and Umberto Maio and Chiara Mazzucchelli and Dieu Nguyen and Mamta Pandey-Pommier and Prachi Prajapati and Gergö Popping and Dominik Riechers and Matus Rybak and Irene Shivaei and Lucie Rowland and Livia Vallini and Julie Wardlow},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20885},
eprint = {2610.20885},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.20885},
}
RIS
TY - UNPB
TI - Unveiling the Baryon Cycle Through Cosmic Time
AU - Manuel Aravena
AU - Leindert A. Boogaard
AU - Jorge González-López
AU - Ryan Keenan
AU - Chiara Circosta
AU - Pierre Cox
AU - Roberto Decarli
AU - Tanio Díaz-Santos
AU - Andreas Faisst
AU - Román Fernández-Aranda
AU - Jonathan Freundlich
AU - Carlotta Gruppioni
AU - Mahmoud Hamed
AU - Gareth Jones
AU - Melanie Kaasinen
AU - Adarsh Kumar
AU - Ivanna Langan
AU - Andrea Lapi
AU - Daizhong Liu
AU - Umberto Maio
AU - Chiara Mazzucchelli
AU - Dieu Nguyen
AU - Mamta Pandey-Pommier
AU - Prachi Prajapati
AU - Gergö Popping
AU - Dominik Riechers
AU - Matus Rybak
AU - Irene Shivaei
AU - Lucie Rowland
AU - Livia Vallini
AU - Julie Wardlow
PY - 2026
DA - 2026/10/14
PB - arXiv
DO - 10.48550/arxiv.2610.20885
UR - https://arxiv.org/abs/2610.20885
AB - Galaxy evolution is governed by the baryon cycle: gas accreted from the cosmic web and circumgalactic medium condenses into molecular gas, forms stars, and is redistributed by stellar and AGN feedback. Tracing the molecular phase is therefore essential to understanding how galaxies acquire, consume, and eject their baryons. Yet current molecular-gas surveys remain limited by sensitivity, area, cosmic variance, and spectral bandwidth. ALMA2040 would combine a ∼10× sensitivity improvement with ≳512 GHz simultaneous frequency coverage, delivering ∼100× faster mapping at fixed depth and a further ≳25× gain in instantaneous bandwidth. Together, these advances would increase spectroscopic survey speed by orders of magnitude, enabling tiered ``wedding-cake'' strategies: an ultra-deep ∼4-5 arcmin^2 field probing faint and high-redshift reservoirs, a ∼0.25 deg^2 survey reaching molecular-line sensitivities comparable to current ultra-deep fields over a much larger cosmological volume, and thousands of independent pointings minimizing cosmic variance. Broad spectral coverage would simultaneously detect multiple CO transitions, [CI], H_2O, feedback tracers, far-IR fine-structure lines, and dust continuum, constraining molecular gas, ISM conditions, obscured star formation, and gas flows within the same observations. Every targeted observation would also become a molecular deep field, extending these measurements to serendipitous galaxies. Together with future HI, optical, and near-IR surveys, ALMA2040 would enable a population-resolved view of the baryon cycle across cosmic time and stringent tests of galaxy formation models.
ER -