Direct detection of CO(3-2) at z=7.31 in REBELS-25 gives M_mol ~ 10^11 M_sun with f_gas ~0.95, confirming a massive molecular reservoir and showing low-J CO remains detectable in the Epoch of Reionization.
Deriving a multivariate CO-to-H$_2$ conversion function using the [CII]/CO(1-0) ratio and its application to molecular gas scaling relations
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
We present Herschel PACS observations of the [CII] 158 micron emission line in a sample of 24 intermediate mass (9<logM$_\ast$/M$_\odot$<10) and low metallicity (0.4< Z/Z$_\odot$<1.0) galaxies from the xCOLD GASS survey. Combining them with IRAM CO(1-0) measurements, we establish scaling relations between integrated and molecular region [CII]/CO(1-0) luminosity ratios as a function of integrated galaxy properties. A Bayesian analysis reveals that only two parameters, metallicity and offset from the star formation main sequence, $\Delta$MS, are needed to quantify variations in the luminosity ratio; metallicity describes the total dust content available to shield CO from UV radiation, while $\Delta$MS describes the strength of this radiation field. We connect the [CII]/CO luminosity ratio to the CO-to-H$_2$ conversion factor and find a multivariate conversion function $\alpha_{CO}$, which can be used up to z~2.5. This function depends primarily on metallicity, with a second order dependence on $\Delta$MS. We apply this to the full xCOLD GASS and PHIBSS1 surveys and investigate molecular gas scaling relations. We find a flattening of the relation between gas mass fraction and stellar mass at logM$_\ast$/M$_\odot$<10. While the molecular gas depletion time varies with sSFR, it is mostly independent of mass, indicating that the low L$_{CO}$/SFR ratios long observed in low mass galaxies are entirely due to photodissociation of CO, and not to an enhanced star formation efficiency.
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astro-ph.GA 3years
2026 3representative citing papers
A JWST survey of eight gravitationally lensed galaxies at z=2-4 resolves 10-200 pc star-forming clumps and finds early evidence of recently quenched, post-starburst clumps.
Corrected empirical limits show the most massive galaxies never exceed the theoretical baryonic maximum of 0.16 times halo virial mass, keeping observations consistent with LambdaCDM at all redshifts.
citing papers explorer
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Direct detection of cool molecular gas in a star-forming galaxy at $z=7.31$
Direct detection of CO(3-2) at z=7.31 in REBELS-25 gives M_mol ~ 10^11 M_sun with f_gas ~0.95, confirming a massive molecular reservoir and showing low-J CO remains detectable in the Epoch of Reionization.
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LEGGOS I: The JWST LEGGOS Survey -- LEnsing and Galaxy Growth: Observing Substructures -- Unpacks the Nature of Clumpy Star Formation and Quenching in Gravitationally Lensed Galaxies beyond Cosmic Noon
A JWST survey of eight gravitationally lensed galaxies at z=2-4 resolves 10-200 pc star-forming clumps and finds early evidence of recently quenched, post-starburst clumps.
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Empirical estimates of how massive galaxies can be in {\Lambda}CDM
Corrected empirical limits show the most massive galaxies never exceed the theoretical baryonic maximum of 0.16 times halo virial mass, keeping observations consistent with LambdaCDM at all redshifts.