Show simple item record

dc.contributor.authorGarratt, T. K.
dc.contributor.authorCoppin, K. E. K.
dc.contributor.authorGeach, J. E.
dc.contributor.authorAlmaini, O.
dc.contributor.authorHartley, W. G.
dc.contributor.authorMaltby, D. T.
dc.contributor.authorSimpson, C. J.
dc.contributor.authorWilkinson, A.
dc.contributor.authorConselice, C. J.
dc.contributor.authorFranco, M.
dc.contributor.authorIvison, R. J.
dc.contributor.authorKoprowski, M. P.
dc.contributor.authorLovell, C. C.
dc.contributor.authorPope, A.
dc.contributor.authorScott, D.
dc.contributor.authorWerf, P. van der
dc.date.accessioned2021-06-03T15:30:01Z
dc.date.available2021-06-03T15:30:01Z
dc.date.issued2021-05-05
dc.identifier.citationGarratt , T K , Coppin , K E K , Geach , J E , Almaini , O , Hartley , W G , Maltby , D T , Simpson , C J , Wilkinson , A , Conselice , C J , Franco , M , Ivison , R J , Koprowski , M P , Lovell , C C , Pope , A , Scott , D & Werf , P V D 2021 , ' Cosmic evolution of the H2 mass density and the epoch of molecular gas ' , The Astrophysical Journal , vol. 912 , no. 1 , 62 . https://doi.org/10.3847/1538-4357/abec81
dc.identifier.issn0004-637X
dc.identifier.otherPURE: 24855005
dc.identifier.otherPURE UUID: 7663286a-3da5-4280-9af0-1c9c19ab1bcc
dc.identifier.otherArXiv: http://arxiv.org/abs/2103.08613v1
dc.identifier.otherORCID: /0000-0002-0729-2988/work/95000538
dc.identifier.otherORCID: /0000-0002-3560-8599/work/95000621
dc.identifier.urihttp://hdl.handle.net/2299/24552
dc.description© 2021. The American Astronomical Society. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.3847/1538-4357/abec81
dc.description.abstractWe present new empirical constraints on the evolution of $\rho_{\rm H_2}$, the cosmological mass density of molecular hydrogen, back to $z\approx2.5$. We employ a statistical approach measuring the average observed $850\mu{\rm m}$ flux density of near-infrared selected galaxies as a function of redshift. The redshift range considered corresponds to a span where the $850\mu{\rm m}$ band probes the Rayleigh-Jeans tail of thermal dust emission in the rest-frame, and can therefore be used as an estimate of the mass of the interstellar medium (ISM). Our sample comprises of ${\approx}150,000$ galaxies in the UKIDSS-UDS field with near-infrared magnitudes $K_{\rm AB}\leq25$ mag and photometric redshifts with corresponding probability distribution functions derived from deep 12-band photometry. With a sample approximately 2 orders of magnitude larger than in previous works we significantly reduce statistical uncertainties on $\rho_{\rm H_2}$ to $z\approx2.5$. Our measurements are in broad agreement with recent direct estimates from blank field molecular gas surveys, finding that the epoch of molecular gas coincides with the peak epoch of star formation with $\rho_{\rm H_2}\approx2\times10^7\,{\rm M_\odot}\,{\rm Mpc^{-3}}$ at $z\approx2$. We demonstrate that $\rho_{\rm H_2}$ can be broadly modelled by inverting the star-formation rate density with a fixed or weakly evolving star-formation efficiency. This 'constant efficiency' model shows a similar evolution to our statistically derived $\rho_{\rm H_2}$, indicating that the dominant factor driving the peak star formation history at $z\approx2$ is a larger supply of molecular gas in galaxies rather than a significant evolution of the star-formation rate efficiency within individual galaxies.en
dc.format.extent14
dc.language.isoeng
dc.relation.ispartofThe Astrophysical Journal
dc.rightsOpen
dc.subjectastro-ph.GA
dc.titleCosmic evolution of the H2 mass density and the epoch of molecular gasen
dc.contributor.institutionCentre for Astrophysics Research
dc.contributor.institutionSchool of Physics, Engineering & Computer Science
dc.contributor.institutionCentre of Data Innovation Research
dc.contributor.institutionCentre for Climate Change Research
dc.contributor.institutionDepartment of Physics, Astronomy and Mathematics
dc.contributor.institutionSchool of Health and Social Work
dc.contributor.institutionCentre for Research in Public Health and Community Care
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.description.statusPeer reviewed
dc.relation.schoolSchool of Physics, Engineering & Computer Science
dc.relation.schoolSchool of Health and Social Work
dc.description.versiontypeFinal Accepted Version
dcterms.dateAccepted2021-05-05
rioxxterms.versionAM
rioxxterms.versionofrecordhttps://doi.org/10.3847/1538-4357/abec81
rioxxterms.licenseref.uriUnspecified
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue
herts.rights.accesstypeOpen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record