Rethinking CMB foregrounds: systematic extension of foreground parameterizations

Future high-sensitivity measurements of the cosmic microwave background (CMB) anisotropies and energy spectrum will be limited by our understanding and modeling of foregrounds. Not only does more information need to be gathered and combined, but also novel approaches for the modeling of foregrounds, commensurate with the vast improvements in sensitivity, have to be explored. Here, we study the inevitable effects of spatial averaging on the spectral shapes of typical foreground components, introducing a moment approach, which naturally extends the list of foreground parameters that have to be determined through measurements or constrained by theoretical models. Foregrounds are thought of as a superposition of individual emitting volume elements along the line of sight and across the sky, which then are observed through an instrumental beam. The beam and line of sight averages are inevitable. Instead of assuming a specific model for the distributions of physical parameters, our method identifies natural new spectral shapes for each foreground component that can be used to extract parameter moments (e.g., mean, dispersion, cross-terms, etc.). The method is illustrated for the superposition of power-laws, free-free spectra, gray-body and modified blackbody spectra, but can be applied to more complicated fundamental spectral energy distributions. Here, we focus on intensity signals but the method can be extended to the case of polarized emission. The averaging process automatically produces scale-dependent spectral shapes and the moment method can be used to propagate the required information across scales in power spectrum estimates. The approach is not limited to applications to CMB foregrounds but could also be useful for the modeling of X-ray emission in clusters of galaxies.Comment: 19 pages, 8 figures, accepted by MNRAS, minor revision

Prospects for Measuring Cosmic Microwave Background Spectral Distortions in the Presence of Foregrounds

Measurements of cosmic microwave background spectral distortions have profound implications for our understanding of physical processes taking place over a vast window in cosmological history. Foreground contamination is unavoidable in such measurements and detailed signal-foreground separation will be necessary to extract cosmological science. We present MCMC-based spectral distortion detection forecasts in the presence of Galactic and extragalactic foregrounds for a range of possible experimental configurations, focusing on the Primordial Inflation Explorer (PIXIE) as a fiducial concept. We consider modifications to the baseline PIXIE mission (operating 12 months in distortion mode), searching for optimal configurations using a Fisher approach. Using only spectral information, we forecast an extended PIXIE mission to detect the expected average non-relativistic and relativistic thermal Sunyaev-Zeldovich distortions at high significance (194$\sigma$ and 11$\sigma$, respectively), even in the presence of foregrounds. The $\Lambda$CDM Silk damping $\mu$-type distortion is not detected without additional modifications of the instrument or external data. Galactic synchrotron radiation is the most problematic source of contamination in this respect, an issue that could be mitigated by combining PIXIE data with future ground-based observations at low frequencies ($\nu < 15-30$GHz). Assuming moderate external information on the synchrotron spectrum, we project an upper limit of $|\mu| < 3.6\times 10^{-7}$ (95\% c.l.), slightly more than one order of magnitude above the fiducial $\Lambda$CDM signal from the damping of small-scale primordial fluctuations, but a factor of $\simeq 250$ improvement over the current upper limit from COBE/FIRAS. This limit could be further reduced to $|\mu| < 9.4\times 10^{-8}$ (95\% c.l.) with more optimistic assumptions about low-frequency information. (Abridged)Comment: (16 pages, 11 figures, submitted to MNRAS. Fisher code available at https://github.com/mabitbol/sd_foregrounds. Updated with published version.

The transition to fatherhood: Exploration of fathers\u27 understandings and perceptions of their experiences of fatherhood

At the beginning of the 21st century, the face of fatherhood is a dynamic and complex reality. The aim of this study was to explore father\u27s perceptions regarding their own experiences during the transition to fatherhood. More specifically, this study aimed at exploring the adjustment to fatherhood and the resources and support systems that the fathers utilised in managing their adjustment to fatherhood. A qualitative research design, specifically an approach based on grounded theory was employed. A total often white Caucasian fathers, with own biological children under the age of five participated in this study and were interviewed using a set of semi-structured questions to assess the elements of the research questions. The interview was recorded, transcribed verbatim and analysed using thematic content analysis. A total of four dominant themes and nine sub-themes were identified: (1) perceptions about being and becoming a father (role perception, adjustment, influences); (2) father-child interaction (child- management issues and concerns, family-work conflict); (3) relationships (family, social networks); (4) resources and support systems (resources and support currently used, resources required). The findings provide insight into the experiences and the certain changes that the fathers experienced during their transition to fatherhood. Furthermore, this study contributes towards the understanding of how to effectively engage and empower men during their transition to fatherhood and to the development of programs that cater to the needs, strengths and personal development of fathers

Studying the Effects of Galactic and Extragalactic Foregrounds on Cosmic Microwave Background Observations

Cosmic microwave background observations have been fundamental in forming the standard model of cosmology. Ongoing and upcoming cosmic microwave background experiments aim to confirm this model and push the boundaries of our knowledge to the very first moments of the Universe. Non-cosmological microwave radiation from the Galaxy and beyond, called foregrounds, obscures and contaminates these measurements. Understanding the sources and effects of foregrounds and removing their imprint in cosmic microwave background observations is a major obstacle to making cosmological inferences. This thesis contains my work studying these foregrounds. First, I will present observations of a well-known but poorly understood foreground called anomalous microwave emission. Second, I will present results forecasting the capability of a next-generation satellite experiment to detect cosmic microwave background spectral distortions in the presence of foregrounds. Third, I will present results studying the effect of foregrounds on the cosmic microwave background self-calibration method, which allows experiments to calibrate the telescope polarization angle using the cosmic microwave background itself. Fourth, I will present my analysis characterizing the performance of and producing maps for the E and B Experiment. Fifth, I will present my research contributions to the readout system that used in the laboratory to operate kinetic inductance detectors, which are being developed for cosmic microwave background observations. Lastly, I will conclude with future prospects in the field of foregrounds and cosmic microwave background cosmology

Constraining the Anomalous Microwave Emission Mechanism in the S140 Star Forming Region with Spectroscopic Observations Between 4 and 8 GHz at the Green Bank Telescope

Anomalous microwave emission (AME) is a category of Galactic signals that cannot be explained by synchrotron radiation, thermal dust emission, or optically thin free-free radiation. Spinning dust is one variety of AME that could be partially polarized and therefore relevant for ongoing and future cosmic microwave background polarization studies. The Planck satellite mission identified candidate AME regions in approximately $1^\circ$ patches that were found to have spectra generally consistent with spinning dust grain models. The spectra for one of these regions, G107.2+5.2, was also consistent with optically thick free-free emission because of a lack of measurements between 2 and 20 GHz. Follow-up observations were needed. Therefore, we used the C-band receiver (4 to 8 GHz) and the VEGAS spectrometer at the Green Bank Telescope to constrain the AME mechanism. For the study described in this paper, we produced three band averaged maps at 4.575, 5.625, and 6.125 GHz and used aperture photometry to measure the spectral flux density in the region relative to the background. We found if the spinning dust description is correct, then the spinning dust signal peaks at $30.9 \pm 1.4$ GHz, and it explains the excess emission. The morphology and spectrum together suggest the spinning dust grains are concentrated near S140, which is a star forming region inside our chosen photometry aperture. If the AME is sourced by optically thick free-free radiation, then the region would have to contain HII with an emission measure of $5.27^{+2.5}_{-1.5}\times 10^8$ $\rm{cm^{-6}\,pc}$ and a physical extent of $1.01^{+0.21}_{-0.20} \times 10^{-2}\,\rm{pc}$. This result suggests the HII would have to be ultra or hyper compact to remain an AME candidate.Comment: 21 pages, 14 figures. Submitted to Ap

The Role of Public Relations in Social Capital and Civic Engagement

Public relations scholars have increasingly argued for the broader role of public relations and strategic communication in society (e.g., Taylor, 2010). That is, how can knowledge of public relations be used to make society better rather than simply making organizations more effective? This study examines how different types of public relations and strategic communication efforts contribute to citizens’ social capital and civic engagement. Specifically, this study uses data from the 2010 Pew Internet and American Life Project ‘Social Side of the Internet’ survey to examine the relationship between various strategic communication efforts by social, civic, professional, and religious organizations and individuals’ social capital and civic engagement. Overall, the analyses suggest that organizations’ face-to-face meetings with their members foster interpersonal trust and both social-oriented and private-oriented civic engagement, and that organizations’ strategic communication via social media boosts both social-oriented and private-oriented civic engagement, whereas strategic communication via email, blogs and websites decreases social-oriented civic engagement. Theoretical and practical implications of the findings for the larger role of public relations and strategic communication in social capital and civic engagement are discussed

The Role of Public Relations in Social Capital

Public relations research has traditionally focused on how public relations efforts make organizations more effective. Recently, scholars have argued for the broader role of public relations in society. That is, how can public relations be used to improve society rather than simply making organizations more effective? Existing studies have emphasized the relationship between internal public relations and organizational social capital. Lack of scholarly attention has been paid to how public relations efforts affect citizens’ social capital in general. To fill the gap in this area, this study examines how different types of public relations efforts contribute to citizens’ social capital. Specifically, this study uses data from the 2010 Pew Internet and American Life Project ‘Social Side of the Internet’ survey to examine the influence of public relations efforts by various organizations in individuals’ social capital. Overall, the analyses suggest that organizations’ face-to-face meetings with their members enhance interpersonal trust and civic engagement, and that organizations’ strategic use of social media boosts civic engagement, whereas strategic communication via email, blogs, and websites decreases civic engagement. This study provides empirical evidence and practical implications for the important role of strategic social media use and interpersonal communication in enhancing social capital

Rational Choice Theory: conceptual structure and recent evolution.

This article hopes to facilitate dialogue within political studies by presenting a general description of the conceptual structure of Rational Choice Theory, RCT. The main goal is to present precisely and concretely the basic precepts of RCT both on its original formulation and on the adjustments that have been adopted in reply to internal and external critiques.Thus, it presents a brief discussion about how the acknowledgement of the theory’s limitations has guided some aspects of its recent evolution. The article concludes with some brief reflections on the usefulness of RCT in political science, not aimed at discussing the applicability of RCT in the social sciences, a discussion beyond the scope of the paper, but to initiate a discussion about how RCT constitutes itself as a theoretical framework that facilitates dialogue within the discipline.Rational choice theory, expected utility, symbolic utility, evidentially expected utility, causally expected utility, decisional value, rationality

The Role of Connexin and Pannexin Large-Pore Channels in Hearing

Connexin and pannexin large-pore channels allow the regulated passage of small molecules at sites of cell-cell contacts, and from the cytosol to the extracellular milieu, respectively. Since it has been known for many years that Cx26 and Cx30 gap junction proteins are crucial in hearing we propose that Cx43 might also be important in hearing. Here we used two different genetically modified mouse lines that contain systemic Cx43 gene mutations that reduces gap junctional intercellular communication (GJIC) to examine whether Cx43 is also important for proper hearing function. Furthermore, since pannexins have also been postulated to be involved in auditory function we used three different Panx global knock-out mice to evaluate their hearing profiles. We showed that Cx43 mutant mice that had severe loss of Cx43 channel function had hearing loss, while mutant mice with a modest loss of Cx43 function exhibited normal hearing. Surprisingly, Panx1-/-, Panx3-/-, and double knock-out (dKO) mice did not have hearing loss, suggesting that pannexins do not play an important role in hearing. To evaluate whether large-pore channels played a role in noise-induced hearing loss (NIHL), we challenged Cx43 mutant and pannexin knock-out mice with a loud noise-exposure and examined their permanent hearing loss. Interestingly, only Panx3-/- and Panx dKO mice were slightly protected against permanent hearing damage. Finally, organotypic cochlear cultures from Cx43 mutant mice and a CRISPR Cas9 Cx43 ablated cochlear-derived cell line, revealed that GJIC does not exacerbate drug-induced hearing loss but does cause supporting cell reorganization. Collectively, our results highlight the importance of Cx43 GJIC in hearing function, but not noise- or drug-induced ototoxicity. Furthermore, our studies support the notion that Panxs are not involved in baseline hearing, but loss of Panx3 may lead to slight protection against permanent NIHL