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dc.contributor.authorHani, Maan H
dc.contributor.authorSparre, Martin
dc.contributor.authorEllison, Sara L
dc.contributor.authorTorrey, Paul A.
dc.contributor.authorVogelsberger, Mark
dc.date.accessioned2020-11-10T21:43:03Z
dc.date.available2020-11-10T21:43:03Z
dc.date.issued2017-12
dc.date.submitted2017-12
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.urihttps://hdl.handle.net/1721.1/128442
dc.description.abstractGalaxies are surrounded by sizeable gas reservoirs which host a significant amount of metals: the circum-galactic medium (CGM). The CGM acts as a mediator between the galaxy and the extragalactic medium. However, our understanding of how galaxy mergers, a major evolutionary transformation, impact the CGM remains deficient. We present a theoretical study of the effect of galaxy mergers on the CGM. We use hydrodynamical cosmological zoom-in simulations of a major merger selected from the Illustris project such that the z = 0 descendant has a halo mass and stellar mass comparable to the Milky Way. To study the CGM we then re-simulated this system at a 40 times better mass resolution, and included detailed post-processing ionization modelling. Our work demonstrates the effect the merger has on the characteristic size of the CGM, its metallicity, and the predicted covering fraction of various commonly observed gas-phase species, such as HI, CIV, and OVI. We show that merger-induced outflows can increase the CGM metallicity by 0.2-0.3 dex within 0.5 Gyr post-merger. These effects last up to 6 Gyr post-merger. While the merger increases the total metal covering fractions by factors of 2-3, the covering fractions of commonly observed UV ions decrease due to the hard ionizing radiation from the active galactic nucleus, which we model explicitly. Our study of the single simulated major merger presented in this work demonstrates the significant impact that a galaxy interaction can have on the size, metallicity, and observed column densities of the CGM.en_US
dc.description.sponsorshipNASA (Grants NNX17AG29G and HST-HF2- 51384.001-A)en_US
dc.language.isoen
dc.publisherOxford University Press (OUP)en_US
dc.relation.isversionofhttp://dx.doi.org/10.1093/mnras/stx3252en_US
dc.rightsCreative Commons Attribution-Noncommercial-Share Alikeen_US
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/4.0/en_US
dc.sourcearXiven_US
dc.titleGalaxy mergers moulding the circum-galactic medium – I. The impact of a major mergeren_US
dc.typeArticleen_US
dc.identifier.citationHani, Maan H. et al. "Galaxy mergers moulding the circum-galactic medium – I. The impact of a major merger." Monthly Notices of the Royal Astronomical Society 475, 1 (December 2017): 1160–1176 © 2017 The Author(s)en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Physicsen_US
dc.contributor.departmentMIT Kavli Institute for Astrophysics and Space Researchen_US
dc.relation.journalMonthly Notices of the Royal Astronomical Societyen_US
dc.eprint.versionAuthor's final manuscripten_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dc.date.updated2019-06-11T11:53:15Z
dspace.date.submission2019-06-11T11:53:17Z
mit.journal.volume475en_US
mit.journal.issue1en_US


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