7 research outputs found

    Hosts of Type II Quasars: an HST Study

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    Type II quasars are luminous Active Galactic Nuclei whose centers are obscured by large amounts of gas and dust. In this contribution we present 3-band HST images of nine type II quasars with redshifts 0.25<z<0.4 selected from the Sloan Digital Sky Survey based on their emission line properties. The intrinsic luminosities of these quasars are thought to be in the range -24>M_B>-26, but optical obscuration implies that host galaxies can be studied unencumbered by bright nuclei. Each object has been imaged in three filters (`red', `green' and `blue') placed between the strong emission lines. The spectacular, high quality images reveal a wealth of details about the structure of the host galaxies and their environments. Most galaxies in the sample are ellipticals, but strong deviations from de Vaucouleurs profiles are found, especially in the blue band. We argue that most of these deviations are due to the light from the nucleus scattered off interstellar material in the host galaxy. This scattered component can make a significant contribution to the broad-band flux and complicates the analysis of the colors of the stellar populations in the host galaxy. This extended component can be difficult to notice in unobscured luminous quasars and may bias the results of host galaxy studies.Comment: 6 pages including 2 color figures; proceedings of the 'QSO host galaxies: evolution and environment' conference, Leiden, August 200

    Opening up dialogues and airways: using vignettes in research to enrich asthma understandings in sport and exercise

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    This article explores the lived experience of asthma in a specific population of sport and exercise participants, drawing on an approach currently under-utilised in studies of asthma: vignettes. These were used as an elicitation technique in research with19 frequent exercisers and sports participants with asthma, eight of whom responded to vignettes. We describe and evaluate this approach as deployed in relation to a phenomenological study of the lived experience of asthma, and consider how employing vignette-based research can encourage people with asthma to reflect critically on their experiences and ways of being-in-the-world. This was found to be a powerful way of challenging taken-for-granted assumptions, and stimulating consideration of behaviour change. The findings we report here cohere around two principal themes that emerged as salient: 1) somatic empathy; and 2) the power of sharing stories and opening up dialogues. Understanding the complexity of asthma experiences can, we argue, be of great practical value both to those with asthma and also to healthcare and exercise professionals in tailoring more effective treatments
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