875 research outputs found

    The galaxy-halo connection from a joint lensing, clustering and abundance analysis in the CFHTLenS/VIPERS field

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    We present new constraints on the relationship between galaxies and their host dark matter halos, measured from the location of the peak of the stellar-to-halo mass ratio (SHMR), up to the most massive galaxy clusters at redshift z0.8z\sim0.8 and over a volume of nearly 0.1~Gpc3^3. We use a unique combination of deep observations in the CFHTLenS/VIPERS field from the near-UV to the near-IR, supplemented by 60000\sim60\,000 secure spectroscopic redshifts, analysing galaxy clustering, galaxy-galaxy lensing and the stellar mass function. We interpret our measurements within the halo occupation distribution (HOD) framework, separating the contributions from central and satellite galaxies. We find that the SHMR for the central galaxies peaks at Mh,peak=1.90.1+0.2×1012MM_{\rm h, peak} = 1.9^{+0.2}_{-0.1}\times10^{12} M_{\odot} with an amplitude of 0.0250.025, which decreases to 0.001\sim0.001 for massive halos (Mh>1014MM_{\rm h} > 10^{14} M_{\odot}). Compared to central galaxies only, the total SHMR (including satellites) is boosted by a factor 10 in the high-mass regime (cluster-size halos), a result consistent with cluster analyses from the literature based on fully independent methods. After properly accounting for differences in modelling, we have compared our results with a large number of results from the literature up to z=1z=1: we find good general agreement, independently of the method used, within the typical stellar-mass systematic errors at low to intermediate mass (M<1011M{M}_{\star} < 10^{11} M_{\odot}) and the statistical errors above. We have also compared our SHMR results to semi-analytic simulations and found that the SHMR is tilted compared to our measurements in such a way that they over- (under-) predict star formation efficiency in central (satellite) galaxies.Comment: 31 pages, 18 figures, 4 table. Accepted for publication in MNRAS. Online material available at http://www.cfhtlens.or

    The galaxy-halo connection from a joint lensing, clustering and abundance analysis in the CFHTLenS/VIPERS field

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    We present new constraints on the relationship between galaxies and their host dark matter haloes, measured from the location of the peak of the stellar-to-halo mass ratio (SHMR), up to the most massive galaxy clusters at redshift z∼0.8 and over a volume of nearly 0.1Gpc3. We use a unique combination of deep observations in the CFHTLenS/VIPERS field from the near-UV to the near-IR, supplemented by ∼60 000 secure spectroscopic redshifts, analysing galaxy clustering, galaxy-galaxy lensing and the stellar mass function. We interpret our measurements within the halo occupation distribution (HOD) framework, separating the contributions from central and satellite galaxies. We find that the SHMR for the central galaxies peaks at Mh,peak=1.90.1+0.2×1012MM_{\rm h, peak} = 1.9^{+0.2}_{-0.1}\times 10^{12}{\,{\rm M}_{{\odot }}} with an amplitude of 0.025, which decreases to ∼0.001 for massive haloes (Mh>1014M{{{M}_{\rm h}}}> 10^{14} {\,{\rm M}_{{\odot }}}). Compared to central galaxies only, the total SHMR (including satellites) is boosted by a factor of 10 in the high-mass regime (cluster-size haloes), a result consistent with cluster analyses from the literature based on fully independent methods. After properly accounting for differences in modelling, we have compared our results with a large number of results from the literature up to z=1: we find good general agreement, independently of the method used, within the typical stellar-mass systematic errors at low to intermediate mass (M<1011M{{{M}_{\rm \star }}}<10^{11} {\,{\rm M}_{{\odot }}}) and the statistical errors above. We have also compared our SHMR results to semi-analytic simulations and found that the SHMR is tilted compared to our measurements in such a way that they over- (under-) predict star formation efficiency in central (satellite) galaxie

    Please mind the gap: students’ perspectives of the transition in academic skills between A-level and degree level geography

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    This paper explores first-year undergraduates’ perceptions of the transition from studying geography at pre-university level to studying for a degree. This move is the largest step students make in their education, and the debate about it in the UK has been reignited due to the government’s planned changes to A-level geography. However, missing from most of this debate is an appreciation of the way in which geography students themselves perceive their transition to university. This paper begins to rectify this absence. Using student insights, we show that their main concern is acquiring the higher level skills required for university learning

    Constructing Memories of Holmfirth through 'Last of the Summer Wine'

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    Last of the Summer Wine (BBC, 1973-2010) was filmed in Holmfirth, West Yorkshire, UK for 37 years. Its presence in the town has affected collective memories of the space and place of the region. In examining Summer Wine’s continued presence in Holmfirth even after it has ceased production, we investigate how the series as a text, institution and brand serves to spatially inform Holmfirth and construct, embed and inform cultural memory

    Hopes and Fears: Community cohesion and the ‘White working class’ in one of the ‘failed spaces’ of multiculturalism

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    Since 2001, community cohesion has been an English policy concern, with accompanying media discourse portraying a supposed failure by Muslims to integrate. Latterly, academia has foregrounded White majority attitudes towards ethnic diversity, particularly those of the ‘White working class’. Whilst questioning this categorisation, we present data on attitudes towards diversity from low income, mainly White areas within Dewsbury, West Yorkshire, a town portrayed in media discourse as one of the ‘failed spaces’ of multiculturalism. Drawing on mixed methods research, we present and discuss data that provide a complex message, seemingly confirming pessimistic analyses around ethnic diversity and predominantly White neighbourhoods but also highlighting an appetite within the same communities for greater and more productive inter-ethnic contact. Furthermore, anxieties about diversity and integration have largely failed to coalesce into broad support for organised anti-minority politics manifest in groups such as the English Defence League

    Education policy as an act of white supremacy: whiteness, critical race theory and education reform

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    The paper presents an empirical analysis of education policy in England that is informed by recent developments in US critical theory. In particular, I draw on ‘whiteness studies’ and the application of Critical Race Theory (CRT). These perspectives offer a new and radical way of conceptualising the role of racism in education. Although the US literature has paid little or no regard to issues outside North America, I argue that a similar understanding of racism (as a multifaceted, deeply embedded, often taken-for-granted aspect of power relations) lies at the heart of recent attempts to understand institutional racism in the UK. Having set out the conceptual terrain in the first half of the paper, I then apply this approach to recent changes in the English education system to reveal the central role accorded the defence (and extension) of race inequity. Finally, the paper touches on the question of racism and intentionality: although race inequity may not be a planned and deliberate goal of education policy neither is it accidental. The patterning of racial advantage and inequity is structured in domination and its continuation represents a form of tacit intentionality on the part of white powerholders and policy makers. It is in this sense that education policy is an act of white supremacy. Following others in the CRT tradition, therefore, the paper’s analysis concludes that the most dangerous form of ‘white supremacy’ is not the obvious and extreme fascistic posturing of small neonazi groups, but rather the taken-for-granted routine privileging of white interests that goes unremarked in the political mainstream

    Expected proton signal sizes in the PRaVDA Range Telescope for proton Computed Tomography

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    Proton radiotherapy has demonstrated benefits in the treatment of certain cancers. Accurate measurements of the proton stopping powers in body tissues are required in order to fully optimise the delivery of such treaments. The PRaVDA Consortium is developing a novel, fully solid state device to measure these stopping powers. The PRaVDA Range Telescope (RT), uses a stack of 24 CMOS Active Pixel Sensors (APS) to measure the residual proton energy after the patient. We present here the ability of the CMOS sensors to detect changes in the signal sizes as the proton traverses the RT, compare the results with theory, and discuss the implications of these results on the reconstruction of proton tracks
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