The Standard Cosmological Model and CMB Anisotropies

This is a course on cosmic microwave background (CMB) anisotropies in the standard cosmological model, designed for beginning graduate students and advanced undergraduates. ``Standard cosmological model'' in this context means a Universe dominated by some form of cold dark matter (CDM) with adiabatic perturbations generated at some initial epoch, e.g., Inflation, and left to evolve under gravity alone (which distinguishes it from defect models). The course is primarily theoretical and concerned with the physics of CMB anisotropies in this context and their relation to structure formation. Brief presentations of the uniform Big Bang model and of the observed large--scale structure of the Universe are given. The bulk of the course then focuses on the evolution of small perturbations to the uniform model and on the generation of temperature anisotropies in the CMB. The theoretical development is performed in the (pseudo--)Newtonian gauge because it aids intuitive understanding by providing a quick reference to classical (Newtonian) concepts. The fundamental goal of the course is not to arrive at a highly exact nor exhaustive calculation of the anisotropies, but rather to a good understanding of the basic physics that goes into such calculations.Comment: Course given at the International School of Space Science: 3K Cosmology, held in L'Aquila, Italy, September 1998. 44 pages with 4 figure

Microwave dosimeter - A concept

Dosimeter determines time-integrated radiation dosage to which an individual is exposed. Integration is measured chemically in proportion to radiation detected. Wearer receives an exposure measurement representing an average of the dose over the entire body

Metabolic simulation chamber

Metabolic simulation combustion chamber was developed as subsystem for breathing metabolic simulator. Entire system is used for evaluation of life support and resuscitation equipment. Metabolism subsystem simulates a human by consuming oxygen and producing carbon dioxide. Basic function is to simulate human metabolic range from rest to hard work

Measuring cluster masses with CMB lensing: a statistical approach

We present a method for measuring the masses of galaxy clusters using the imprint of their gravitational lensing signal on the cosmic microwave background (CMB) temperature anisotropies. The method first reconstructs the projected gravitational potential with a quadratic estimator and then applies a matched filter to extract cluster mass. The approach is well-suited for statistical analyses that bin clusters according to other mass proxies. We find that current experiments, such as Planck, the South Pole Telescope and the Atacama Cosmology Telescope, can practically implement such a statistical methodology, and that future experiments will reach sensitivities sufficient for individual measurements of massive systems. As illustration, we use simulations of Planck observations to demonstrate that it is possible to constrain the mass scale of a set of 62 massive clusters with prior information from X-ray observations, similar to the published Planck ESZ-XMM sample. We examine the effect of the thermal (tSZ) and kinetic (kSZ) Sunyaev-Zeldovich (SZ) signals, finding that the impact of the kSZ remains small in this context. The stronger tSZ signal, however, must be actively removed from the CMB maps by component separation techniques prior to reconstruction of the gravitational potential. Our study of two such methods highlights the importance of broad frequency coverage for this purpose. A companion paper presents application to the Planck data on the ESZ-XMM sample.Comment: 9 pages, 5 figures, version accepted for publication in A&

Point Source Confusion in SZ Cluster Surveys

We examine the effect of point source confusion on cluster detection in Sunyaev-Zel'dovich (SZ) surveys. A filter matched to the spatial and spectral characteristics of the SZ signal optimally extracts clusters from the astrophysical backgrounds. We calculate the expected confusion (point source and primary cosmic microwave background [CMB]) noise through this filter and quantify its effect on the detection threshold for both single and multiple frequency surveys. Extrapolating current radio counts, we estimate that confusion from sources below 100 microJy limits single-frequency surveys to 1-sigma detection thresholds of Y 3.10^{-6} arcmin^2 at 30 GHz and Y 10^{-5} arcmin^2 at 15 GHz (for unresolved clusters in a 2 arcmin beam); these numbers are highly uncertain, and an extrapolation with flatter counts leads to much lower confusion limits. Bolometer surveys must contend with an important population of infrared point sources. We find that a three-band matched filter with 1 arcminute resolution (in each band) efficiently reduces confusion, but does not eliminate it: residual point source and CMB fluctuations contribute significantly the total filter noise. In this light, we find that a 3-band filter with a low-frequency channel (e.g, 90+150+220 GHz) extracts clusters more effectively than one with a high frequency channel (e.g, 150+220+300 GHz).Comment: Accepted for publication in Astronomy & Astrophysics; Updated grant information in acknowledgement

Temperature and humidity control of simulated human breath

Subsystem was developed for breathing metabolic simulator which adjusts temperature and humidity of air to levels of human exhaled breath. Temperature-humidity subsystem is described, consisting of aluminum enclosure with 400 watt heat sheet glued to bottom, vertical separators, inlet connection, and check valve

‘The intoxicated co-witness: How alcohol and discussion affect eyewitness memory reports.

Intoxicated witnesses are routinely encountered by law enforcement officers (Evans, Schreiber Compo & Russano, 2009). Such witnesses may have discussed details of the crime with each other prior to having their statement taken (Skagerberg & Wright, 2008). In order to understand the consequences of co-witness discussion on intoxicated witnesses, three studies were conducted investigating the effect of intoxication on misinformation when (a) the source of misinformation is a written statement from a seemingly intoxicated source in an online study; (b) when two intoxicated dyad partners engage in a face to face discussion in a laboratory based, alcohol administration study; and (c) when an intoxicated person encounters post event information from a sober video witness in the field. The results suggest that intoxication does not influence the tendency to report misinformation. This is consistent when the source of misinformation is perceived to be intoxicated and the recipient is sober, both co-witnesses are intoxicated, or the recipient of misinformation is intoxicated whilst the source is sober. Intoxication also does not influence source monitoring ability. That is, both sober and intoxicated participants are equally able to identify the source of their memory recall. The results also add to the current literature on the effect of intoxication on eyewitness memory at an individual level. They demonstrate that at moderate doses, whilst accuracy is not impaired, intoxication may reduce the completeness of recall and the confidence a witness has in their memory. At higher doses however, in addition to the detrimental effects of alcohol on confidence and completeness, accuracy is also impaired. The findings have implications for the criminal justice system given that intoxicated witnesses usually complete their evidential interview at a later date when sober (Crossland, Kneller & Wilcock, 2018). Witnesses who were intoxicated at the time of the crime and who engaged in co-witness discussion are no more prone than their sober counterparts to report co-witness information and are equally able to identify the source of the information that they report. Additionally, an intoxicated witness may report fewer details, and the accuracy of their statement may be influenced by their degree of intoxication. As such, breathalysing witnesses at the scene of the crime should be encouraged in order to understand the likely effect intoxication will have on their testimony