292 research outputs found

    Land-use planning, inequality and the problem of 'left-behind places' - A 'provocation' for the UK2070 Commission

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    The problems of so-called 'left-behind' places - typically former industrial regions have figured prominently in voting patterns over the last five years in the UK, and also the USA and Europe. This paper examines the following issues: the political economy of 'left-behind' regions; the new policy prescriptions for 'left-behind' regions; and the kinds of institutions that are required to create a new economic future in such disadvantaged places

    Nova Sagittarii 1994 #1 (V4332 Sagittarii): The Discovery and Evolution of an Unusual Luminous Red Variable Star

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    We report photometry and spectroscopy of the evolution of Nova Sagittarii 1994 #1 (V4332 Sagittarii) during outburst. We compare the photometric and spectral evolution of this outburst to known classes of outbursts -- including classical novae and outbursts occurring on symbiotic stars -- and find this object does NOT conform to any known class of outburst. The closest match to the behavior of this unusual object is M31 RV, an extremely luminous and red variable object discovered in the bulge of M31 in 1988. However, the temporal behavior and maximum luminosity of the two events differ by several orders of magnitude, requiring substantial intrinsic variation if these two events are members the same type of outburst. Our model of the spectroscopic evolution of this outburst shows that the effective temperature cooled from 4400 K to 2300 K over the three month span of our observations. In combination with line diagnostics in our later spectra, including [OI] lambda 5577 and the dramatic increase in the Halpha to Hbeta ratio, we infer the existence of a cool, dense (N_e ~ 10^{8-9} cm^{-3}) envelope that is optically thick in the Hydrogen Balmer recombination lines (case C). We suggest that a nuclear event in a single star, in which a slow shock drove the photosphere outwards, can power the observed luminosity evolution and the emission spectrum.Comment: Accepted for publication in AJ. 24 pages including 8 embedded postscript figures. Also available at http://www.astronomy.ohio-state.edu/~martini/pub

    Photometric Confirmation of MACHO Large Magellanic Cloud Microlensing Events

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    We present previously unpublished photometry of three Large Magellanic Cloud (LMC) microlensing events and show that the new photometry confirms the microlensing interpretation of these events. These events were discovered by the MACHO Project alert system and were also recovered by the analysis of the 5.7 year MACHO data set. This new photometry provides a substantial increase in the signal-to-noise ratio over the previously published photometry and in all three cases, the gravitational microlensing interpretation of these events is strengthened. The new data consist of MACHO-Global Microlensing Alert Network (GMAN) follow-up images from the CTIO 0.9 telescope plus difference imaging photometry of the original MACHO data from the 1.3m "Great Melbourne" telescope at Mt. Stromlo. We also combine microlensing light curve fitting with photometry from high resolution HST images of the source stars to provide further confirmation of these events and to show that the microlensing interpretation of event MACHO-LMC-23 is questionable. Finally, we compare our results with the analysis of Belokurov, Evans & Le Du who have attempted to classify candidate microlensing events with a neural network method, and we find that their results are contradicted by the new data and more powerful light curve fitting analysis for each of the four events considered in this paper. The failure of the Belokurov, Evans & Le Du method is likely to be due to their use of a set of insensitive statistics to feed their neural networks.Comment: 29 pages with 8 included postscript figures, accepted by the Astrophysical Journa

    Difference image photometry with bright variable backgrounds

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    Over the last two decades the Andromeda Galaxy (M31) has been something of a test-bed for methods aimed at obtaining accurate time-domain relative photometry within highly crowded fields. Difference imaging methods, originally pioneered towards M31, have evolved into sophisticated methods, such as the Optimal Image Subtraction (OIS) method of Alard & Lupton (1998), that today are most widely used to survey variable stars, transients and microlensing events in our own Galaxy. We show that modern difference image (DIA) algorithms such as OIS, whilst spectacularly successful towards the Milky Way bulge, may perform badly towards high surface brightness targets such as the M31 bulge. Poor results can occur in the presence of common systematics which add spurious flux contributions to images, such as internal reflections, scattered light or fringing. Using data from the Angstrom Project microlensing survey of the M31 bulge, we show that very good results are usually obtainable by first performing careful photometric alignment prior to using OIS to perform point-spread function (PSF) matching. This separation of background matching and PSF matching, a common feature of earlier M31 photometry techniques, allows us to take full advantage of the powerful PSF matching flexibility offered by OIS towards high surface brightness targets. We find that difference images produced this way have noise distributions close to Gaussian, showing significant improvement upon results achieved using OIS alone. We show that with this correction light-curves of variable stars and transients can be recovered to within ~10 arcseconds of the M31 nucleus. Our method is simple to implement and is quick enough to be incorporated within real-time DIA pipelines. (Abridged)Comment: 12 pages. Accepted for publication in MNRAS. Includes an expanded discussion of DIA testing and results, including additional lightcurve example

    Austerity states, institutional dismantling and the governance of sub-national economic development: the demise of the regional development agencies in England

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    Austerity states, institutional dismantling and the governance of sub-national economic development: the demise of the regional development agencies in England. Territory, Politics, Governance. Contributing to interpretations of the governance geographies of austerity, the paper explains how, why and in what forms austerity states are constructed by actors in particular political-economic contexts and geographical and temporal settings, how and by whom they are articulated and pursued, and how they are worked through public policy and institutional and territorial architectures. Empirically, the focus is explaining the UK Government and its abolition and closure of the regional development agencies in England. First, a more qualitative and plural conception of austerity states is developed to question singular and/or monolithic notions of state types and their transitions, and to better reflect the particularities of how state projects are configured and unfolded by actors within political-economic variegations of capitalism. Second, a more geographically sensitive approach and appreciation of (re)scaling are detailed to incorporate and extend beyond the predominantly national frame and decentralizing narratives deployed in current accounts. Last, a historically literate interpretation of institutional dismantling is advanced better to explain the politics and restructuring of institutional landscapes by actors within austerity states

    M31N 2005-09c: a fast FeII nova in the disk of M31

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    Classical novae are quite frequent in M~31. However, very few spectra of M31 novae have been studied to date, especially during the early decline phase. Our aim is to study the photometric and spectral evolution of a M31 nova event close to outburst. We present photometric and spectroscopic observations of M31N 2005-09c, a classical nova in the disk of M31, using the 1.3m telescope of the Skinakas Observatory in Crete (Greece), starting on the 28th September, i.e. about 5 days after outburst, and ending on the 5th October 2005, i.e. about 12 days after outburst. We also have supplementary photometric observations from the La Sagra Observatory in Northern Andalucia, Spain, on September 29 and 30, October 3, 6 and 9 and November 1, 2005. The wavelength range covered by the spectra is from 3565 A to 8365 A. The spectra are of high S/N allowing the study of the evolution of the equivalent widths of the Balmer lines, as well as the identification of non-Balmer lines. The nova displays a typical early decline spectrum that is characterized by many weak FeII multiplet emissions. It is classified as a Pfe_{fe} nova. From the nova light curve, we have also derived its speed class, t=14+-2.5 days. As the nova evolved the Balmer lines became stronger and narrower. The early decline of the expansion velocity of the nova follows a power law in time with an exponent of \~-0.2
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