ORCID Profile
0000-0002-6301-5870
Current Organisation
University of Nottingham
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Publisher: American Astronomical Society
Date: 30-12-2008
Publisher: Oxford University Press (OUP)
Date: 17-06-2017
Publisher: Oxford University Press (OUP)
Date: 10-2004
Publisher: Oxford University Press (OUP)
Date: 02-2004
Publisher: EDP Sciences
Date: 14-12-2012
Publisher: Oxford University Press (OUP)
Date: 11-03-2009
Publisher: Oxford University Press (OUP)
Date: 04-2007
Publisher: Cambridge University Press (CUP)
Date: 03-2004
Publisher: Oxford University Press (OUP)
Date: 11-12-2020
Abstract: Galaxy cluster outskirts are described by complex velocity fields induced by diffuse material collapsing towards filaments, gas, and galaxies falling into clusters, and gas shock processes triggered by substructures. A simple scenario that describes the large-scale tidal fields of the cosmic web is not able to fully account for this variety, nor for the differences between gas and collisionless dark matter. We have studied the filamentary structure in zoom-in resimulations centred on 324 clusters from the threehundred project, focusing on differences between dark and baryonic matter. This paper describes the properties of filaments around clusters out to five R200, based on the diffuse filament medium where haloes had been removed. For this, we stack the remaining particles of all simulated volumes to calculate the average profiles of dark matter and gas filaments. We find that filaments increase their thickness closer to nodes and detect signatures of gas turbulence at a distance of ${\\sim}2 \\rm {{{~h^{-1}\\,{\\rm Mpc}}}}$ from the cluster. These are absent in dark matter. Both gas and dark matter collapse towards filament spines at a rate of ${\\sim}200 \\,\\rm {km ~ s^{-1}\\, h^{-1}}$. We see that gas preferentially enters the cluster as part of filaments, and leaves the cluster centre outside filaments. We further see evidence for an accretion shock just outside the cluster. For dark matter, this preference is less obvious. We argue that this difference is related to the turbulent environment. This indicates that filaments act as highways to fuel the inner regions of clusters with gas and galaxies.
Publisher: American Astronomical Society
Date: 21-10-2009
Publisher: EDP Sciences
Date: 2013
Publisher: EDP Sciences
Date: 11-2005
Publisher: Oxford University Press (OUP)
Date: 21-06-2007
Publisher: Oxford University Press (OUP)
Date: 03-2021
Abstract: Inferring line-of-sight distances from redshifts in and around galaxy clusters is complicated by peculiar velocities, a phenomenon known as the ‘Fingers of God’ (FoG). This presents a significant challenge for finding filaments in large observational data sets as these artificial elongations can be wrongly identified as cosmic web filaments by extraction algorithms. Upcoming targeted wide-field spectroscopic surveys of galaxy clusters and their infall regions, such as the WEAVE Wide-Field Cluster Survey, motivate our investigation of the impact of FoG on finding filaments connected to clusters. Using zoom-in resimulations of 324 massive galaxy clusters and their outskirts from the three hundred project, we test methods typically applied to large-scale spectroscopic data sets. This paper describes our investigation of whether a statistical compression of the FoG of cluster centres and galaxy groups can lead to correct filament extractions in the cluster outskirts. We find that within 5R200 (∼15 h−1 Mpc) statistically correcting for FoG elongations of virialized regions does not achieve reliable filament networks compared to reference filament networks based on true positions. This is due to the complex flowing motions of galaxies towards filaments in addition to the cluster infall, which overwhelm the signal of the filaments relative to the volume that we probe. While information from spectroscopic redshifts is still important to isolate the cluster regions, and thereby reduce background and foreground interlopers, we expect future spectroscopic surveys of galaxy cluster outskirts to rely on 2D positions of galaxies to extract cosmic filaments.
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_74
Publisher: Springer-Verlag
Date: 2005
DOI: 10.1007/10995020_116
Publisher: American Astronomical Society
Date: 20-03-2002
DOI: 10.1086/338763
Publisher: EDP Sciences
Date: 29-06-2004
Publisher: Oxford University Press (OUP)
Date: 04-2008
Publisher: Oxford University Press (OUP)
Date: 27-01-2017
DOI: 10.1093/MNRAS/STX228
Publisher: Oxford University Press (OUP)
Date: 06-08-2018
Publisher: Oxford University Press (OUP)
Date: 13-10-2011
Publisher: Oxford University Press (OUP)
Date: 08-11-2011
Publisher: EDP Sciences
Date: 27-10-2009
Publisher: Oxford University Press (OUP)
Date: 23-04-2015
DOI: 10.1093/MNRAS/STV670
Publisher: Oxford University Press (OUP)
Date: 11-2005
Publisher: EDP Sciences
Date: 06-2013
Publisher: Oxford University Press (OUP)
Date: 03-02-2020
Abstract: In the outer regions of a galaxy cluster, galaxies either may be falling into the cluster for the first time or have already passed through the cluster centre at some point in their past. To investigate these two distinct populations, we utilize TheThreeHundred project, a suite of 324 hydrodynamical resimulations of galaxy clusters. In particular, we study the ‘backsplash population’ of galaxies: those that have passed within R200 of the cluster centre at some time in their history, but are now outside of this radius. We find that, on average, over half of all galaxies between R200 and 2R200 from their host at $z$ = 0 are backsplash galaxies, but that this fraction is dependent on the dynamical state of a cluster, as dynamically relaxed clusters have a greater backsplash fraction. We also find that this population is mostly developed at recent times ($z$ ≲ 0.4), and is dependent on the recent history of a cluster. Finally, we show that the dynamical state of a given cluster, and thus the fraction of backsplash galaxies in its outskirts, can be predicted based on observational properties of the cluster.
Publisher: Oxford University Press (OUP)
Date: 11-03-2009
Publisher: Oxford University Press (OUP)
Date: 15-12-2009
Publisher: Oxford University Press (OUP)
Date: 03-2007
Publisher: Oxford University Press (OUP)
Date: 05-2003
Publisher: Cambridge University Press (CUP)
Date: 07-2004
Publisher: Oxford University Press (OUP)
Date: 05-09-2007
Publisher: Oxford University Press (OUP)
Date: 23-04-2020
Abstract: Upcoming wide-field surveys are well suited to studying the growth of galaxy clusters by tracing galaxy and gas accretion along cosmic filaments. We use hydrodynamic simulations of volumes surrounding 324 clusters from The ThreeHundred project to develop a framework for identifying and characterizing these filamentary structures and associating galaxies with them. We define three-dimensional reference filament networks reaching 5R200 based on the underlying gas distribution and quantify their recovery using mock galaxy s les mimicking observations such as those of the WEAVE Wide-Field Cluster Survey. Since massive galaxies trace filaments, they are best recovered by mass-weighting galaxies or imposing a bright limit (e.g. & L*) on their selection. We measure the transverse gas density profile of filaments, derive a characteristic filament radius of ≃ 0.7–1 h−1Mpc, and use this to assign galaxies to filaments. For different filament extraction methods, we find that at R & R200, ∼15–$20{{\\ \\rm per\\ cent}}$ of galaxies with M* & 3 × 109M⊙ are in filaments, increasing to $\\sim 60{{\\ \\rm per\\ cent}}$ for galaxies more massive than the Milky Way. The fraction of galaxies in filaments is independent of cluster mass and dynamical state and is a function of cluster-centric distance, increasing from ∼13 per cent at 5R200 to ∼21 per cent at 1.5R200. As a bridge to the design of observational studies, we measure the purity and completeness of different filament galaxy selection strategies. Encouragingly, the overall three-dimensional filament networks and ∼67 per cent of the galaxies associated with them are recovered from two-dimensional galaxy positions.
Publisher: American Astronomical Society
Date: 22-09-2009
Publisher: American Astronomical Society
Date: 03-06-2009
Publisher: Oxford University Press (OUP)
Date: 22-05-2015
DOI: 10.1093/MNRAS/STV779
Publisher: Springer Science and Business Media LLC
Date: 2003
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Meghan Gray.