Investigating the source of Planck-detected AME: high resolution observations at 15 GHz

The Planck 28.5 GHz maps were searched for potential Anomalous Microwave Emission (AME) regions on the scale of $\sim3^{\circ}$ or smaller, and several new regions of interest were selected. Ancillary data at both lower and higher frequencies were used to construct spectral energy distributions (SEDs), which seem to confirm an excess consistent with spinning dust models. Here we present higher resolution observations of two of these new regions with the Arcminute Microkelvin Imager Small Array (AMI SA) between 14 and 18 GHz to test for the presence of a compact ($\sim$10 arcmin or smaller) component. For AME-G107.1+5.2, dominated by the {\sc Hii} region S140, we find evidence for the characteristic rising spectrum associated with the either the spinning dust mechanism for AME or an ultra/hyper-compact \textsc{Hii} region across the AMI frequency band, however for AME-G173.6+2.8 we find no evidence for AME on scales of $\sim 2-10$ arcmin.Comment: 13 pages, 8 figures, 4 tables. Submitted to Advances in Astronomy AME Special Issu

CLOVER - A new instrument for measuring the B-mode polarization of the CMB

We describe the design and expected performance of Clover, a new instrument designed to measure the B-mode polarization of the cosmic microwave background. The proposed instrument will comprise three independent telescopes operating at 90, 150 and 220 GHz and is planned to be sited at Dome C, Antarctica. Each telescope will feed a focal plane array of 128 background-limited detectors and will measure polarized signals over angular multipoles 20 < l < 1000. The unique design of the telescope and careful control of systematics should enable the B-mode signature of gravitational waves to be measured to a lensing-confusion-limited tensor-to-scalar ratio r~0.005.Comment: 4 pages, 5 figures. To appear in the proceedings of the XXXVIXth Rencontres de Moriond "Exploring the Universe

Galaxy Cluster Shapes and Systematic Errors in H0 Measured by the Sunyaev-Zel'dovich Effect

Imaging of the Sunyaev-Zel'dovich (SZ) effect in galaxy clusters combined with cluster plasma x-ray diagnostics can measure the cosmic distance scale to high redshift. Projecting the inverse-Compton scattering and x-ray emission along the cluster line-of-sight introduces systematic errors in the Hubble constant, H0, because the true shape of the cluster is not known. I present a study of the systematic errors in the value of H0, as determined by the x-ray and SZ properties of theoretical samples of triaxial isothermal ``beta'' model clusters, caused by projection effects and observer orientation. I calculate estimates for H0 for each cluster based on their large and small apparent angular core radii and their arithmetic mean. I demonstrate that the estimates for H0 for a sample of 25 clusters have 99.7% confidence intervals for the mean estimated H0 analyzing the clusters using either their large or mean angular core radius are within 14% of the ``true'' (assumed) value of H0 (and enclose it), for a triaxial beta model cluster sample possessing a distribution of apparent x-ray cluster ellipticities consistent with that of observed x-ray clusters. This limit on the systematic error in H0 caused by cluster shape assumes that each sample beta model cluster has fixed shape; deviations from constant shape within the clusters may introduce additional uncertainty or bias into this result.Comment: Accepted for publication in the Astrophysical Journal, 24 March 1998; 4 pages, 2 figure

Detection of Cosmic Microwave Background Structure in a Second Field with the Cosmic Anisotropy Telescope

We describe observations at frequencies near 15 GHz of the second 2x2 degree field imaged with the Cambridge Cosmic Anisotropy Telescope (CAT). After the removal of discrete radio sources, structure is detected in the images on characteristic scales of about half a degree, corresponding to spherical harmonic multipoles in the approximate range l= 330--680. A Bayesian analysis confirms that the signal arises predominantly from the cosmic microwave background (CMB) radiation for multipoles in the lower half of this range; the average broad-band power in a bin with centroid l=422 (theta = 51') is estimated to be Delta_T/T=2.1^{+0.4}_{-0.5} x 10^{-5}. For multipoles centred on l=615 (theta =35'), we find contamination from Galactic emission is significant, and constrain the CMB contribution to the measured power in this bin to be Delta_T/T <2.0 x 10^{-5} (1-sigma upper limit). These new results are consistent with the first detection made by CAT in a completely different area of sky. Together with data from other experiments, this new CAT detection adds weight to earlier evidence from CAT for a downturn in the CMB power spectrum on scales smaller than 1 degree. Improved limits on the values of H_0 and Omega are determined using the new CAT data.Comment: 5 pages, 5 figures (gif), submitted to MNRA

AMI SZ observation of galaxy-cluster merger CIZA J2242+5301: Perpendicular flows of gas and dark matter

© 2018 The Author(s). 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.STFC (ST/M001172/1) STFC (ST/K00333X/1) STFC (ST/M007065/1) STFC (ST/H008586/1) STFC (ST/J005673/1

Termination of DNA Replication in Prokaryotes

Most bacteria and archaea have circular chromosomes, in which DNA replication begins at a site known as an origin of replication. Double‐stranded DNA unwound at the origin creates two replication forks that are engaged by DNA polymerase complexes (replisomes) that advance each fork and proceed in opposite directions away from the origin, copying the original strands. Termination of DNA replication occurs when the two forks meet and fuse, creating two separate double‐stranded DNA molecules. In the well‐studied bacteria Escherichia coli and Bacillus subtilis, this occurs in the terminus region, which is situated diametrically opposite the origin. Failure to terminate chromosome replication correctly can lead to problems with genome function and stability, including DNA over‐replication. In contrast, some archaea have multi‐origin chromosomes and do not appear to specifically regulate the location of termination

AMI Observations of the Anomalous Microwave Emission in the Perseus Molecular Cloud

We present observations of the known anomalous microwave emission region, G159.6–18.5, in the Perseus molecular cloud at 16 GHz performed with the Arcminute Microkelvin Imager Small Array. These are the highest angular resolution observations of G159.6–18.5 at microwave wavelengths. By combining these microwave data with infrared observations between 5.8 and 160 μm from the Spitzer Space Telescope, we investigate the existence of a microwave-infrared correlation on angular scales of ~2'. We find that the overall correlation appears to increase toward shorter infrared wavelengths, which is consistent with the microwave emission being produced by electric dipole radiation from small, spinning dust grains. We also find that the microwave-infrared correlation peaks at 24 μm (6.7σ), suggesting that the microwave emission is originating from a population of stochastically heated small interstellar dust grains rather than polycyclic aromatic hydrocarbons

15 GHz Monitoring of Gamma-ray Blazars with the OVRO 40 Meter Telescope in Support of Fermi

We present results from the first two years of our fast-cadence 15 GHz gamma-ray blazar monitoring program, part of the F-GAMMA radio monitoring project. Our sample includes the 1158 blazars north of -20 degrees declination from the Candidate Gamma-Ray Blazar Survey (CGRaBS), which encompasses a significant fraction of the extragalactic sources detected by the Fermi Gamma-ray Space Telescope. We introduce a novel likelihood analysis for computing a time series variability amplitude statistic that separates intrinsic variability from measurement noise and produces a quantitative error estimate. We use this method to characterize our radio light curves. We also present results indicating a statistically significant correlation between simultaneous average 15 GHz radio flux density and gamma-ray photon flux.Comment: 5 pages, 7 figures; 2009 Fermi Symposium; eConf Proceedings C09112

The incidence, prevalence and mortality of granulomatosis with polyangiitis in the UK Clinical Practice Research Datalink

Objectives: To estimate the incidence, prevalence and mortality of Granulomatosis with polyangiitis (GPA) in the United Kingdom. Methods: We conducted a historical cohort study using data from the Clinical Practice Research Datalink and Hospital Episode Statistics (CPRD-HES). We calculated incidence rate ratios, adjusted for age, gender and ethnicity, using Poisson regression. Results: We identified 462 cases diagnosed between 1997 and 2013. Our overall estimate of incidence was 11.8 (95% CI 10.7-12.9)/million person-years. Incidence in children (aged <16 years) was 0.88 (95% CI 0.40-1.96), and adults 14.0 (95% CI 12.8-15.4). The incidence was lower in females (adjusted IRR 0.68; 95% CI 0.56-0.81) and highest in the 55-69 year age-group (adjusted IRR 9.5, 95% CI 6.9-13.0; reference group 0-39 years). Incidence was not significantly different in the Black / Minority Ethnic population compared to the white population (adjusted odds ratio 0.78, 95% CI 0.53-1.13, p=0.13). The prevalence in 2013 was 134.9 (121.3-149.6) /million. Mortality was 13.6% at 1-year, and higher in HES than CPRD-identified cases (Hazard ratio 3.16, 95% CI 2.19-4.56, p<0.001). Conclusions: By combining primary and secondary care datasets we have found the incidence and mortality of granulomatosis with polyangiitis to be higher than previously reported. We predict that at present each year in the UK there will be approximately 700 new cases of whom 95 will die within 12 months

First results from the Very Small Array -- IV. Cosmological parameter estimation

We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard inflationary LambdaCDM model. Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the VSA and COBE_DMR data alone produce the constraints Omega_tot = 1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 = 0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent confidence level. Adding in the type Ia supernovae constraints, we additionally find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}. These constraints are consistent with those found by the BOOMERanG, DASI and MAXIMA experiments. We also find that, by combining all the recent CMB experiments and assuming the HST key project limits for H_0 (for which the X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda= 0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres