CMB observations using the SKA

We examine the prospects for observations of CMB anisotropy with the SKA; we discuss the advantages of interferometric SKA imaging, observing strategies, calibration issues and the achievable sensitivity. Although the SKA will probably operate at cm wavelengths, where discrete source confusion dominates the CMB anisotropy, its extreme sensitivity to point sources will make it possible to subtract the source contamination at these wavelengths and thereby image the low surface brightness CMB anisotropies on small angular scales. The SKA, operating at 10-20 GHz, may usefully make high-l observations of the CMB anisotropy spectrum and survey the sky for Sunyaev-Zeldovich decrements.Comment: 4 pages. invited talk presented at the XXVIIth General Assembly of the URSI, 17-24 Aug 2002, Maastricht, The Netherland

An Exploration of Teachers’ and Mental Health First Aiders’ Constructs of Mental Health in Secondary Schools

The socio-political and educational context in which this current research is situated supports a neoliberal agenda and therefore contributes to the complex discourse around mental health (MH) in the UK. However, as MH has become a higher-profile priority for the UK government, over the last decade, initiatives have begun to focus on promoting mental health in educational contexts. As a result, schools have been recognised as having the potential to embed universal approaches for positive MH development. One such school-based MH initiative was announced in 2017 with the introduction of Youth Mental Health First Aid training (MHFA) for every secondary school in England. However, with the exception of an evaluative piece of research into the Youth MHFA programme, there is limited research into the views of secondary school practitioners’ interpretation of the term ‘mental health’ and perceived emotional availability to promote the MH of their students. Therefore, this study aimed to explore the ways in which a small group of Mental Health First Aiders and teachers working in mainstream schools constructed the term ‘mental health’. Data was gathered using semi-structured interviews and analysed using thematic analysis. Themes were explored and identified in relation to the practitioner’s understanding of the term ‘mental health’ and how available they feel, to promote their students’ mental health in school. Numerous themes were identified in relation to the practitioners’ conceptualisation of MH, and alongside referring to a biomedical model, there was reflection upon the complex interaction between psychological and social factors related to the development of MH difficulties. Further, the significance of the relationships between school staff and their students, parents and colleagues within the context of supporting CYP’s mental health emerged from the analysis. Findings also highlighted the ways in which school staff are available to promote their students’ MH, as well as the barriers which exist within this. For example, the impact of working in this field on school staffs’ wellbeing, which illustrates the importance of professional support, such as supervision, which it can be argued EPs are well placed to provide. In light of the current mental health challenges in the UK, the present study suggests that the introduction of specific interventions such as MHFA Champions need to be complemented by a wider whole-school systemic focus on MH and wellbeing which aims to connect CYP with their broader social and cultural worlds

Observations of the 57Fe+23 hyperfine transition in clusters of galaxies

We present a search for the hyperfine transition of the 57Fe+23 ion at 3.071 mm in clusters of galaxies with the ATNF Mopra telescope. The results are compared with a realistic estimate of the peak brightness temperature of the line in a cooling flow cluster A85, using the available X-ray data

ATLBS: the Australia Telescope Low-brightness Survey

We present a radio survey carried out with the Australia Telescope Compact Array. A motivation for the survey was to make a complete inventory of the diffuse emission components as a step towards a study of the cosmic evolution in radio source structure and the contribution from radio-mode feedback on galaxy evolution. The Australia Telescope low-brightness survey (ATLBS) at 1388 MHz covers 8.42 sq deg of the sky in an observing mode designed to yield images with exceptional surface brightness sensitivity and low confusion. The ATLBS radio images, made with 0.08 mJy/beam rms noise and 50" beam, detect a total of 1094 sources with peak flux exceeding 0.4 mJy/beam. The ATLBS source counts were corrected for blending, noise bias, resolution, and primary beam attenuation; the normalized differential source counts are consistent with no upturn down to 0.6 mJy. The percentage integrated polarization Pi_0 was computed after corrections for the polarization bias in integrated polarized intensity; Pi_0 shows an increasing trend with decreasing flux density. Simultaneous visibility measurements made with longer baselines yielded images, with 5" beam, of compact components in sources detected in the survey. The observations provide a measurement of the complexity and diffuse emission associated with mJy and sub-mJy radio sources. 10% of the ATLBS sources have more than half of their flux density in extended emission and the fractional flux in diffuse components does not appear to vary with flux density, although the percentage of sources that have complex structure increases with flux density. The observations are consistent with a transition in the nature of extended radio sources from FR-II radio source morphology, which dominates the mJy population, to FR-I structure at sub-mJy flux density. (Abridged)Comment: 18 pages, 8 figues, 6 tables, accepted for publication in MNRA

A deep survey of the low-surface-brightness radio sky

We have made a radio survey--the Australia Telescope Low Brightness Survey (ATLBS)--of 8.4 square degrees sky area, using the Australia Telescope Compact Array in the 20-cm band, in an observing mode designed to provide wide-field images with exceptional sensitivity in surface brightness, and thereby explore a new parameter space in radio source populations. The goals of this survey are to quantify the distribution in angular sizes, particularly at weak surface brightness levels: this has implications for the confusion in deep surveys with the SKA. The survey is expected to lead to a census of the radio emission associated with low-power radio galaxies at redshifts 1-3, without any missing extended emission, and hence a study of the cosmic evolution of low-power radio galaxies to higher redshift and a comprehensive study of the AGN feedback during the intense black hole growth phase during this redshift range.Comment: 5 pages, includes 2 figures and 1 table. To appear in the proceedings of "From Planets to Dark energy: the modern radio universe" in the online journal Proceedings of Science - Po