A radio continuum survey of the southern sky at 1420 MHz. Observations and data reduction

We describe the equipment, observational method and reduction procedure of an absolutely calibrated radio continuum survey of the South Celestial Hemisphere at a frequency of 1420 MHz. These observations cover the area 0h < R.A. < 24h for declinations less than -10 degree. The sensitivity is about 50 mK T_B (full beam brightness) and the angular resolution (HPBW) is 35.4', which matches the existing northern sky survey at the same frequency.Comment: 9 pages with 9 figures, A&A, in pres

Evaluation of the School Administration Manager Project

Examines the results to date of a Wallace-supported project to help principals delegate some administrative and managerial tasks to school administration managers and spend more time interacting with teachers, students and others on instructional matters

A Search for Sub-Millisecond Pulsars

We have conducted a search of 19 southern Galactic globular clusters for sub-millisecond pulsars at 660 MHz with the Parkes 64-m radio telescope. To minimize dispersion smearing we used the CPSR baseband recorder, which samples the 20 MHz observing band at the Nyquist rate. By possessing a complete description of the signal we could synthesize an optimal filterbank in software, and in the case of globular clusters of known dispersion measure, much of the dispersion could be removed using coherent techniques. This allowed for very high time resolution (25.6 us in most cases), making our searches in general sensitive to sub-millisecond pulsars with flux densities greater than about 3 mJy at 50 cm. No new pulsars were discovered, placing important constraints on the proportion of pulsars with very short spin periods in these clusters.Comment: 8 pages, 3 figures, to appear in Ap

Does tiny-scale atomic structure exist in the interstellar medium ?

We report on preliminary results from the recent multi-epoch neutral hydrogen absorption measurements toward three pulsars, B0823+26, B1133+16 and B2016+28, using the Arecibo telescope. We do not find significant variations in optical depth profiles over periods of 0.3 and 9--10 yr, or on spatial scales of 10--20 and 70--85 AU. The large number of non detections of the tiny scale atomic structure suggests that the AU-sized structure is not ubiquitous in the interstellar medium and could be quite a rare phenomenon.Comment: Accepted by ApJ Letters, 5 pages, 2 figure

A Limit on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales

A ground-based polarimeter, PIQUE, operating at 90 GHz has set a new limit on the magnitude of any polarized anisotropy in the cosmic microwave background. The combination of the scan strategy and full width half maximum beam of 0.235 degrees gives broad window functions with average multipoles, l = 211+294-146 and l = 212+229-135 for the E- and B-mode window functions, respectively. A joint likelihood analysis yields simultaneous 95% confidence level flat band power limits of 14 and 13 microkelvin on the amplitudes of the E- and B-mode angular power spectra, respectively. Assuming no B-modes, a 95% confidence limit of 10 microkelvin is placed on the amplitude of the E-mode angular power spectrum alone.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter

Is self always prioritised? Attenuating the ownership self-reference effect in memory

The current study demonstrates the abolishment of the Ownership Self Reference Effect (OSRE) when elaborate details of a distant other-referent are provided. In a 2 (High versus Low information) × 2 (Self versus Other) experimental design, we tested the capacity for the SRE to be modulated with social saliency. Using a well-established ownership paradigm (Collard et al., 2020; Cunningham et al., 2008; Sparks et al., 2016), when the other was made socially salient (i.e. details and characteristics about the other were provided to the participant prior to encoding), no SRE emerged, such that self-owned and other-owned items were recalled with comparable accuracy. In contrast, when the other was not salient (i.e., no details about them were provided), participants accurately recalled a higher proportion of self-owned items, demonstrating a typical SRE in source memory. The degree of self- or other- referencing was not related to measured variables of closeness, similarity or shared traits with the other. Although the SRE is an established and robust effect, the findings of the current study illustrate critical circumstances in which the self is no longer prioritised above the other. In line with our predictions, we suggest that the self has automatic attributed social salience (e.g. through ownership) and that enhancing social salience by elaborating details of the other, prioritisation can expand to encapsulate an other beyond the self and influence incidental memory. [Abstract copyright: Crown Copyright © 2022. Published by Elsevier Inc. All rights reserved.

Joint Bayesian component separation and CMB power spectrum estimation

We describe and implement an exact, flexible, and computationally efficient algorithm for joint component separation and CMB power spectrum estimation, building on a Gibbs sampling framework. Two essential new features are 1) conditional sampling of foreground spectral parameters, and 2) joint sampling of all amplitude-type degrees of freedom (e.g., CMB, foreground pixel amplitudes, and global template amplitudes) given spectral parameters. Given a parametric model of the foreground signals, we estimate efficiently and accurately the exact joint foreground-CMB posterior distribution, and therefore all marginal distributions such as the CMB power spectrum or foreground spectral index posteriors. The main limitation of the current implementation is the requirement of identical beam responses at all frequencies, which restricts the analysis to the lowest resolution of a given experiment. We outline a future generalization to multi-resolution observations. To verify the method, we analyse simple models and compare the results to analytical predictions. We then analyze a realistic simulation with properties similar to the 3-yr WMAP data, downgraded to a common resolution of 3 degree FWHM. The results from the actual 3-yr WMAP temperature analysis are presented in a companion Letter.Comment: 23 pages, 16 figures; version accepted for publication in ApJ -- only minor changes, all clarifications. More information about the WMAP3 analysis available at http://www.astro.uio.no/~hke under the Research ta

Power Spectrum of Primordial Inhomogeneity Determined from the 4-Year COBE DMR Sky Maps

Fourier analysis and power spectrum estimation of the cosmic microwave background anisotropy on an incompletely sampled sky developed by Gorski (1994) has been applied to the high-latitude portion of the 4-year COBE DMR 31.5, 53 and 90 GHz sky maps. Likelihood analysis using newly constructed Galaxy cuts (extended beyond |b| = 20deg to excise the known foreground emission) and simultaneously correcting for the faint high latitude galactic foreground emission is conducted on the DMR sky maps pixelized in both ecliptic and galactic coordinates. The Bayesian power spectrum estimation from the foreground corrected 4-year COBE DMR data renders n ~ 1.2 +/- 0.3, and Q_{rms-PS} ~ 15.3^{+3.7}_{-2.8} microK (projections of the two-parameter likelihood). These results are consistent with the Harrison-Zel'dovich n=1 model of amplitude Q_{rms-PS} ~ 18 microK detected with significance exceeding 14sigma (dQ/Q < 0.07). (A small power spectrum amplitude drop below the published 2-year results is predominantly due to the application of the new, extended Galaxy cuts.)Comment: 9 pages of text in LaTeX, 1 postscript Table, 4 postscript figures (2 color plates), submitted to The Astrophysical Journal (Letters

Digital Deblurring of CMB Maps II: Asymmetric Point Spread Function

In this second paper in a series dedicated to developing efficient numerical techniques for the deblurring Cosmic Microwave Background (CMB) maps, we consider the case of asymmetric point spread functions (PSF). Although conceptually this problem is not different from the symmetric case, there are important differences from the computational point of view because it is no longer possible to use some of the efficient numerical techniques that work with symmetric PSFs. We present procedures that permit the use of efficient techniques even when this condition is not met. In particular, two methods are considered: a procedure based on a Kronecker approximation technique that can be implemented with the numerical methods used with symmetric PSFs but that has the limitation of requiring only mildly asymmetric PSFs. The second is a variant of the classic Tikhonov technique that works even with very asymmetric PSFs but that requires discarding the edges of the maps. We provide details for efficient implementations of the algorithms. Their performance is tested on simulated CMB maps.Comment: 9 pages, 13 Figure

An upper limit on anomalous dust emission at 31 GHz in the diffuse cloud [LPH96]201.663+1.643

[LPH96]201.663+1.643, a diffuse H{\sc ii} region, has been reported to be a candidate for emission from rapidly spinning dust grains. Here we present Cosmic Background Imager (CBI) observations at 26-36 GHz that show no evidence for significant anomalous emission. The spectral index within the CBI band, and between CBI and Effelsberg data at 1.4/2.7 GHz, is consistent with optically thin free-free emission. The best-fitting temperature spectral index from 2.7 to 31 GHz, $\beta=-2.06 \pm 0.03$, is close to the theoretical value, $\beta=-2.12$ for $T_{e}=9100$ K. We place an upper limit of 24% ~ (2\sigma) for excess emission at 31 GHz as seen in a 6\arcmin FWHM beam. Current spinning dust models are not a good fit to the spectrum of LPH96. No polarized emission is detected in the CBI data with an upper limit of 2% on the polarization fraction.Comment: 5 pages, 3 figures, submitted to ApJ