Abstract
Arcminute Microkelvin Imager observations towards CIZA J2242+5301, in comparison with observations of weak gravitational lensing and X-ray emission from the literature, are used to ...investigate the behaviour of non-baryonic dark matter (NBDM) and gas during the merger. Analysis of the Sunyaev–Zel'dovich (SZ) signal indicates the presence of high pressure gas elongated perpendicularly to the X-ray and weak-lensing morphologies, which, given the merger-axis constraints in the literature, implies that high pressure gas is pushed out into a linear structure during core passing. Simulations in the literature closely matching the inferred merger scenario show the formation of gas density and temperature structures perpendicular to the merger axis. These SZ observations are challenging for modified gravity theories in which NBDM is not the dominant contributor to galaxy-cluster gravity.
It has recently been argued that because the major two dimensions of perfectionism (perfectionistic strivings and perfectionistic concerns, PS and PC) can have opposing effects, the “combined effect” ...should be calculated to understand whether, overall, perfectionism is neutral, adaptive, or maladaptive. In this methodological note we revisit the task of disentangling the overall effects of PS and PC. In doing so, we illustrate a new and alternative approach – calculation of the total unique effect and the relative weights of PS and PC. The total unique effect is the simplest way of ascertaining whether perfectionism is neutral, adaptive, or maladaptive. However, like the combined effect, it does not convey information regarding the relative importance of PS and PC. Calculating the relative weights of PS and PC does so and provides a fuller account of the overall effect of perfectionism and the precise role of each dimension when predicting a given outcome. We close the paper by applying this approach to a range of outcomes reported in recent meta-analyses in this area. In doing so, perfectionism is revealed to be primarily maladaptive and rarely adaptive or neutral, with the relative contribution of perfectionistic concerns being the main reason why this is the case.
•Perfectionism includes dimensions that can have opposing effects.•A new approach to determining the overall effect of perfectionism is illustrated.•Perfectionism is revealed to be primarily maladaptive and rarely adaptive or neutral.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
ABSTRACT
We develop a Bayesian method of analysing Sunyaev–Zel’dovich measurements of galaxy clusters obtained from the Arcminute Microkelvin Imager (AMI) radio interferometer system and from the ...Planck satellite, using a joint likelihood function for the data from both instruments. Our method is applicable to any combination of Planck data with interferometric data from one or more arrays. We apply the analysis to simulated clusters and find that when the cluster pressure profile is known a priori, the joint data set provides precise and accurate constraints on the cluster parameters, removing the need for external information to reduce the parameter degeneracy. When the pressure profile deviates from that assumed for the fit, the constraints become biased. Allowing the pressure profile shape parameters to vary in the analysis allows an unbiased recovery of the integrated cluster signal and produces constraints on some shape parameters, depending on the angular size of the cluster. When applied to real data from Planck-detected cluster PSZ2 G063.80+11.42, our method resolves the discrepancy between the AMI and Planck Y-estimates and usefully constrains the gas pressure profile shape parameters at intermediate and large radii.
We report new cm-wave measurements at five frequencies between 15 and 18GHz of the continuum emission from the reportedly anomalous ‘region 4’ of the nearby galaxy NGC6946. We find that the emission ...in this frequency range is significantly in excess of that measured at 8.5GHz, but has a spectrum from 15 to 18GHz consistent with optically thin free–free emission from an ultracompact Hii region. In combination with previously published data, we fit four emission models containing different continuum components using the Bayesian spectrum analysis package radiospec. These fits show that, in combination with data at other frequencies, a model with a spinning dust component is slightly preferred to those that possess better-established emission mechanisms.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We present 25 arcsec resolution radio images of five Lynds Dark Nebulae (L675, L944, L1103, L1111 and L1246) at 16 GHz made with the Arcminute Microkelvin Imager (AMI) Large Array. These objects were ...previously observed with the AMI Small Array to have an excess of emission at microwave frequencies relative to lower frequency radio data. In L675, we find a flat spectrum compact radio counterpart to the 850 μm emission seen with Submillimetre Common-User Bolometer Array (SCUBA) and suggest that it is cm-wave emission from a previously unknown deeply embedded young protostar. In the case of L1246, the cm-wave emission is spatially correlated with 8 μm emission seen with Spitzer. Since the mid-infrared emission is present only in Spitzer band 4 we suggest that it arises from a population of polycyclic aromatic hydrocarbon molecules, which also give rise to the cm-wave emission through spinning dust emission.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
ABSTRACT
A new method is presented for modelling the physical properties of galaxy clusters. Our technique moves away from the traditional approach of assuming specific parameterized functional forms ...for the variation of physical quantities within the cluster, and instead allows for a ‘free-form’ reconstruction, but one for which the level of complexity is determined automatically by the observational data and may depend on position within the cluster. This is achieved by representing each independent cluster property as some interpolating or approximating function that is specified by a set of control points, or ‘nodes’, for which the number of nodes, together with their positions and amplitudes, are allowed to vary and are inferred in a Bayesian manner from the data. We illustrate our nodal approach in the case of a spherical cluster by modelling the electron pressure profile Pe(r) in analyses both of simulated Sunyaev–Zel’dovich (SZ) data from the Arcminute MicroKelvin Imager (AMI) and of real AMI observations of the cluster MACS J0744+3927 in the CLASH sample. We demonstrate that one may indeed determine the complexity supported by the data in the reconstructed Pe(r), and that one may constrain two very important quantities in such an analysis: the cluster total volume integrated Comptonization parameter (Ytot) and the extent of the gas distribution in the cluster (rmax). The approach is also well-suited to detecting clusters in blind SZ surveys, in the case where the population of radio sources is known in advance.
The Arcminute Microkelvin Imager (AMI) Galactic Plane Survey is a large-area survey of the outer Galactic plane to provide arcminute resolution images at milli-Jansky sensitivity in the ...centimetre-wave band. Here we present the first data release of the survey, consisting of 868 deg2 of the Galactic plane, covering the area 76°
170° between latitudes of |b|
5°, at a central frequency of 15.75 GHz (1.9 cm). We describe in detail the drift-scan observations which have been used to construct the maps, including the techniques used for observing, mapping and source extraction, and summarize the properties of the finalized data sets. These observations constitute the most sensitive Galactic plane survey of large extent at centimetre-wave frequencies greater than 1.4 GHz.
We present an analytic parametric model to describe the baryonic and dark matter distributions in clusters of galaxies with spherical symmetry. It is assumed that the dark matter density follows a ...Navarro-Frenk-White (NFW) profile and that the gas pressure is described by a generalized NFW profile. By further demanding hydrostatic equilibrium and that the local gas fraction is small throughout the cluster, one obtains unique functional forms, dependent on basic cluster parameters, for the radial profiles of all the properties of interest in the cluster. We show that these profiles are consistent with both numerical simulations and multiwavelength observations of clusters. We also use our model to analyse six simulated Sunyaev-Zel'dovich (SZ) clusters as well as A611 SZ data from the Arcminute Microkelvin Imager. In each case, we derive the radial profile of the enclosed total mass and the gas pressure and show that the results are in good agreement with our model prediction.
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