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dc.contributor.authorJackson, Ryan A.
dc.contributor.authorMartin, Garreth
dc.contributor.authorKaviraj, Sugata
dc.contributor.authorLaigle, Clotilde
dc.contributor.authorDevriendt, Julien
dc.contributor.authorDubois, Yohan
dc.contributor.authorPichon, Christophe
dc.date.accessioned2020-07-24T00:06:31Z
dc.date.available2020-07-24T00:06:31Z
dc.date.issued2020-06-01
dc.identifier.citationJackson , R A , Martin , G , Kaviraj , S , Laigle , C , Devriendt , J , Dubois , Y & Pichon , C 2020 , ' Why do extremely massive disc galaxies exist today? ' , Monthly Notices of the Royal Astronomical Society , vol. 494 , no. 4 , pp. 5568–5575 . https://doi.org/10.1093/mnras/staa970
dc.identifier.issn0035-8711
dc.identifier.otherPURE: 22366993
dc.identifier.otherPURE UUID: 1240283b-f98b-473e-89c3-e47783949c11
dc.identifier.otherArXiv: http://arxiv.org/abs/2004.00023v1
dc.identifier.otherORCID: /0000-0002-5601-575X/work/77850181
dc.identifier.otherScopus: 85090002637
dc.identifier.urihttp://hdl.handle.net/2299/22987
dc.descriptionThis article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, Volume 494, Issue 4, June 2020, Pages 5568–5575, https://doi.org/10.1093/mnras/staa970. ©: 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
dc.description.abstractGalaxy merger histories correlate strongly with stellar mass, largely regardless of morphology. Thus, at fixed stellar mass, spheroids and discs share similar assembly histories, both in terms of the frequency of mergers and the distribution of their mass ratios. Since mergers are the principal drivers of disc-to-spheroid morphological transformation, and the most massive galaxies typically have the richest merger histories, it is surprising that discs exist at all at the highest stellar masses (e.g. beyond the knee of the mass function). Using Horizon-AGN, a cosmological hydro-dynamical simulation, we show that extremely massive (M*> 10^11.4 MSun) discs are created via two channels. In the primary channel (accounting for ~70% of these systems and ~8% of massive galaxies) the most recent, significant merger (stellar mass ratio > 1:10) between a massive spheroid and a gas-rich satellite `spins up' the spheroid by creating a new rotational stellar component, leaving a massive disc as the remnant. In the secondary channel (accounting for ~30% of these systems and ~3% of massive galaxies), a system maintains a disc throughout its lifetime, due to an anomalously quiet merger history. Not unexpectedly, the fraction of massive discs is larger at higher redshift, due to the Universe being more gas-rich. The morphological mix of galaxies at the highest stellar masses is, therefore, a strong function of the gas fraction of the Universe. Finally, these massive discs have similar black-hole masses and accretion rates to massive spheroids, providing a natural explanation for why a minority of powerful AGN are surprisingly found in disc galaxies.en
dc.format.extent8
dc.language.isoeng
dc.relation.ispartofMonthly Notices of the Royal Astronomical Society
dc.rightsOpen
dc.subjectastro-ph.GA
dc.titleWhy do extremely massive disc galaxies exist today?en
dc.contributor.institutionSchool of Physics, Astronomy and Mathematics
dc.contributor.institutionCentre for Astrophysics Research
dc.contributor.institutionCentre of Data Innovation Research
dc.description.statusPeer reviewed
dc.description.versiontypeFinal Published version
dcterms.dateAccepted2020-06-01
rioxxterms.versionVoR
rioxxterms.versionofrecordhttps://doi.org/10.1093/mnras/staa970
rioxxterms.licenseref.uriUnspecified
rioxxterms.typeJournal Article/Review
herts.preservation.rarelyaccessedtrue
herts.rights.accesstypeOpen


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