498 research outputs found

    Communicating climate risk: a handbook

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    The Distance to the Cygnus Loop from Hubble Space Telescope Imaging of the Primary Shock Front

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    We present a Hubble Space Telescope/WFPC2 narrow-band H-alpha image of a region on the northeastern limb of the Cygnus Loop supernova remnant. This location provides a detailed example of where the primary blast wave first encounters the surrounding interstellar medium. The filament structure is seen in exquisite detail in this image, which was obtained primarily as an EARLY ACQuisition image for a follow-up spectroscopic program. We compare the HST image to a digitized version of the POSS-I red plate to measure the proper motion of this filament. By combining this value for the proper motion with previous measurements of the shock velocity at this position we find that the distance to the Cygnus Loop is 440 (+130, -100) pc, considerably smaller than the canonical value of 770 pc. We briefly discuss the ramifications of this new distance estimate for our understanding of this prototypical supernova remnant.Comment: 18 pages, 3 Figures (2 JPEG and one Postscript

    What Hubble really meant by late and early type: simply more or less complex in appearance

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    It is widely written and believed that Edwin Hubble introduced the terms `early' and `late types' to suggest an evolutionary sequence for galaxies. This is incorrect. Hubble took these terms from spectral classification of stars to signify a sequence related to complexity of appearance, albeit based on images rather than spectra. The temporal connotations of the terms had been abandoned prior to his 1926 paper on classification of galaxies.Comment: 3 pages, 2 figures, using MNRAS style file; to appear in different style in RAS journal Astronomy & Geophysics (A&G), scheduled for October 2008 issue, A&G journal page is at http://www.blackwellpublishing.com/journal.asp?ref=1366-878

    Climate change is the elephant in every room

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    An HST/WFPC Survey of Bright Young Clusters in M31. II. Photometry of Less Luminous Clusters in the Fields

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    We report on the properties of 89 low mass star clusters located in the vicinity of luminous young clusters (blue globulars) in the disk of M31. 82 of the clusters are newly detected. We have determined their integrated magnitudes and colors, based on a series of Hubble Space Telescope Wide Field/Planetary Camera 2 exposures in blue and red (HST filters F450W and F814W). The integrated apparent magnitudes range from F450W = 17.5 to 22.5, and the colors indicate a wide range of ages. Stellar color-magnitude diagrams for all clusters were obtained and those with bright enough stars were fit to theoretical isochrones to provide age estimates. The ages range from 12 Myr to >500 Myr. Reddenings, which average E(F450 - F814) = 0.59 with a dispersion of 0.21 magnitudes, were derived from the main sequence fitting for those clusters. Comparison of these ages and integrated colors with single population theoretical models with solar abundances suggests a color offset of 0.085 magnitudes at the ages tested. Estimated ages for the remaining clusters are based on their measured colors. The age-frequency diagram shows a steep decline of number with age, with a large decrease in number per age interval between the youngest and the oldest clusters detected.Comment: 20 pages, 9 figure

    The luminosities of the brightest cluster galaxies and brightest satellites in SDSS groups

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    We show that the distribution of luminosities of Brightest Cluster Galaxies in an SDSS-based group catalog suggests that BCG luminosities are just the statistical extremes of the group galaxy luminosity function. This latter happens to be very well approximated by the all-galaxy luminosity function (restricted to Mr<-19.9), provided one uses a parametrization of this function that is accurate at the bright end. A similar analysis of the luminosity distribution of the Brightest Satellite Galaxies suggests that they are best thought of as being the second brightest pick from the same luminosity distribution of which BCGs are the brightest. I.e., BSGs are not the brightest of some universal satellite luminosity function, in contrast to what Halo Model analyses of the luminosity dependence of clustering suggest. However, we then use mark correlations to provide a novel test of these order statistics, showing that the hypothesis of a universal luminosity function (i.e. no halo mass dependence) from which the BCGs and BSGs are drawn is incompatible with the data, despite the fact that there was no hint of this in the BCG and BSG luminosity distributions themselves. We also discuss why, since extreme value statistics are explicitly a function of the number of draws, the consistency of BCG luminosities with extreme value statistics is most clearly seen if one is careful to perform the test at fixed group richness N. Tests at, e.g., fixed total group luminosity Ltot, will generally be biased and may lead to erroneous conclusions.Comment: 12 pages, 9 figures; v2 -- Revised to match version accepted in MNRAS. Includes a new section on using mark correlations to test extreme value statistic

    Improving negative emotion recognition in young offenders reduces subsequent crime

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    Development Psychopathology in context: clinical setting

    Deep CFHT Photometric Survey of the Entire M33 Galaxy I: Catalogue of 36000 Variable Point Sources

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    We have conducted a variability survey of the local group galaxy M33 using g', r', and i' observations from 27 nights spanning 17 months made with the MegaPrime/MegaCam instrument on the 3.6 m CFHT telescope. We identify more than 36000 variable sources with g',r',i' < 24 out of approximately 2 million point sources in a one square degree field of view. This increases the number of known variables in this galaxy by more than a factor of 20. In this paper we provide a brief description of the data and a general overview of the variable star population which includes more than 800 candidate variable blue and red supergiant stars, more than 2000 Cepheids, and more than 19000 long period variable AGB and RGB stars.Comment: Submitted to MNRAS. 20 pages, 16 figures. Catalogue and light curves are available at http://www.astro.livjm.ac.uk/~dfb/M33/ animations associated with this paper are available at http://www.cfa.harvard.edu/~jhartman/M33_Movie.html a version of the paper with full-resolution images is available at http://www.astro.livjm.ac.uk/~dfb/M33/M33_fullres.ps.g

    Respectable Drinkers, Sensible Drinking, Serious Leisure: Single-Malt Whisky Enthusiasts and the Moral Panic of Irresponsible Others

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    In the public discourse of policy-makers and journalists, drinkers of (excessive) alcohol are portrayed either as irresponsible, immoral deviants or as gullible victims. In other words, the public discourse engenders a moral panic about alcohol-crazed individuals, who become what Cohen [1972. Folk devil and moral panics. London: Routledge] identifies as folk devils: the Other, abusing alcohol to create anti-social disorder. However, alcohol-drinking was, is and continues to be an everyday practice in the leisure lives of the majority of people in the UK. In this research article, I want to explore the serious leisure of whisky-tasting to provide a counter to the myth of the alcohol-drinker as folk devil, to try to construct a new public discourse of sensible drinking. I will draw on ethnographic work at whisky-tastings alongside interviews and analysis of on-line discourses. I show that participation in whisky-tasting events creates a safe space in which excessive amounts of alcohol are consumed, yet the norms of the particular habitus ensure that such drinking never leads to misbehaviour. In doing so, however, I will note that the respectability of whisky-drinking is associated with its masculine, white, privileged habitus – the folk devil becomes someone else, someone Other
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