1,007 research outputs found

    Examining collusion and voting biases between countries during the Eurovision song contest since 1957

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    The Eurovision Song Contest (ESC) is an annual event which attracts millions of viewers. It is an interesting activity to examine since the participants of the competition represent a particular country's musical performance that will be awarded a set of scores from other participating countries based upon a quality assessment of a performance. There is a question of whether the countries will vote exclusively according to the artistic merit of the song, or if the vote will be a public signal of national support for another country. Since the competition aims to bring people together, any consistent biases in the awarding of scores would defeat the purpose of the celebration of expression and this has attracted researchers to investigate the supporting evidence for biases. This paper builds upon an approach which produces a set of random samples from an unbiased distribution of score allocation, and extends the methodology to use the full set of years of the competition's life span which has seen fundamental changes to the voting schemes adopted. By building up networks from statistically significant edge sets of vote allocations during a set of years, the results display a plausible network for the origins of the culture anchors for the preferences of the awarded votes. With 60 years of data, the results support the hypothesis of regional collusion and biases arising from proximity, culture and other irrelevant factors in regards to the music which that alone is intended to affect the judgment of the contest.Comment: to be published in JASS

    A Deep 150 MHz GMRT Survey in Eridanus

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    We present results of a 150 MHz survey of a field centered on Epsilon Eridani, undertaken with the Giant Metrewave Radio Telescope (GMRT). The survey covers an area with a diameter of 2 deg, has a spatial resolution of 30" and a noise level of 3.1 mJy at the pointing centre. These observations provide a deeper and higher resolution view of the 150 MHz radio sky than the 7C survey (although the 7C survey covers a much larger area). A total of 113 sources were detected, most are point-like, but 20 are extended. We present an analysis of these sources, in conjunction with the NVSS (at 1.4 GHz) and VLSS (at 74 MHz). This process allowed us to identify 5 Ultra Steep Spectrum (USS) radio sources that are candidate high redshift radio galaxies (HzRGs). In addition, we have derived the dN/dS distribution for these observations and compare our results with other low frequency radio surveys.Comment: 12 pages, 11 figures, 3 tables, accepted for publication in MNRA

    The Sydney-AAO Multi-object Integral field spectrograph (SAMI)

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    We demonstrate a novel technology that combines the power of the multi-object spectrograph with the spatial multiplex advantage of an integral field spectrograph (IFS). The Sydney-AAO Multi-object IFS (SAMI) is a prototype wide-field system at the Anglo-Australian Telescope (AAT) that allows 13 imaging fibre bundles ("hexabundles") to be deployed over a 1-degree diameter field of view. Each hexabundle comprises 61 lightly-fused multimode fibres with reduced cladding and yields a 75 percent filling factor. Each fibre core diameter subtends 1.6 arcseconds on the sky and each hexabundle has a field of view of 15 arcseconds diameter. The fibres are fed to the flexible AAOmega double-beam spectrograph, which can be used at a range of spectral resolutions (R=lambda/delta(lambda) ~ 1700-13000) over the optical spectrum (3700-9500A). We present the first spectroscopic results obtained with SAMI for a sample of galaxies at z~0.05. We discuss the prospects of implementing hexabundles at a much higher multiplex over wider fields of view in order to carry out spatially--resolved spectroscopic surveys of 10^4 to 10^5 galaxies.Comment: 24 pages, 16 figures. Accepted by MNRA

    Formation of proto-globular cluster candidates in cosmological simulations of dwarf galaxies at z>4z>4

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    We perform cosmological hydrodynamical simulations to study the formation of proto-globular cluster candidates in progenitors of present-day dwarf galaxies (Mvir≈1010 M⊙(M_{\rm vir} \approx 10^{10}\, {\rm M}_\odot at z=0z=0) as part of the "Feedback in Realistic Environment" (FIRE) project. Compact (r1/2<30r_{1/2}<30 pc), relatively massive (0.5×105≲M⋆/M⊙≲5×1050.5 \times 10^5 \lesssim M_{\star}/{\rm M}_\odot \lesssim 5\times10^5), self-bound stellar clusters form at 11≳z≳511\gtrsim z \gtrsim 5 in progenitors with Mvir≈109 M⊙M_{\rm vir} \approx 10^9\,{\rm M}_\odot. Cluster formation is triggered when at least 107 M⊙10^7\,{\rm M}_\odot of dense, turbulent gas reaches Σgas≈104 M⊙ pc−2\Sigma_{\rm gas} \approx 10^4\, {\rm M}_\odot\, {\rm pc}^{-2} as a result of the compressive effects of supernova feedback or from cloud-cloud collisions. The clusters can survive for 2−3 Gyr2-3\,{\rm Gyr}; absent numerical effects, they would likely survive substantially longer, perhaps to z=0z=0. The longest-lived clusters are those that form at significant distance -- several hundreds of pc -- from their host galaxy. We therefore predict that globular clusters forming in progenitors of present-day dwarf galaxies will be offset from any pre-existing stars within their host dark matter halos as opposed to deeply embedded within a well-defined galaxy. Properties of the nascent clusters are consistent with observations of some of the faintest and most compact high-redshift sources in \textit{Hubble Space Telescope} lensing fields and are at the edge of what will be detectable as point sources in deep imaging of non-lensed fields with the \textit{James Webb Space Telescope}. By contrast, the star clusters' host galaxies will remain undetectable.Comment: 14 pages, 5 figures, submitted to MNRA

    The anomaly line bundle of the self-dual field theory

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    In this work, we determine explicitly the anomaly line bundle of the abelian self-dual field theory over the space of metrics modulo diffeomorphisms, including its torsion part. Inspired by the work of Belov and Moore, we propose a non-covariant action principle for a pair of Euclidean self-dual fields on a generic oriented Riemannian manifold. The corresponding path integral allows to study the global properties of the partition function over the space of metrics modulo diffeomorphisms. We show that the anomaly bundle for a pair of self-dual fields differs from the determinant bundle of the Dirac operator coupled to chiral spinors by a flat bundle that is not trivial if the underlying manifold has middle-degree cohomology, and whose holonomies are determined explicitly. We briefly sketch the relevance of this result for the computation of the global gravitational anomaly of the self-dual field theory, that will appear in another paper.Comment: 41 pages. v2: A few typos corrected. Version accepted for publication in CM

    A warm Jet in a cold ocean

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    Unprecedented quantities of heat are entering the Pacific sector of the Arctic Ocean through Bering Strait, particularly during summer months. Though some heat is lost to the atmosphere during autumn cooling, a significant fraction of the incoming warm, salty water subducts (dives beneath) below a cooler fresher layer of near-surface water, subsequently extending hundreds of kilometers into the Beaufort Gyre. Upward turbulent mixing of these sub-surface pockets of heat is likely accelerating sea ice melt in the region. This Pacific-origin water brings both heat and unique biogeochemical properties, contributing to a changing Arctic ecosystem. However, our ability to understand or forecast the role of this incoming water mass has been hampered by lack of understanding of the physical processes controlling subduction and evolution of this this warm water. Crucially, the processes seen here occur at small horizontal scales not resolved by regional forecast models or climate simulations; new parameterizations must be developed that accurately represent the physics. Here we present novel high resolution observations showing the detailed process of subduction and initial evolution of warm Pacific-origin water in the southern Beaufort Gyre

    Unreported VOC Emissions from Road Transport Including from Electric Vehicles

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    There are widespread policy assumptions that the phase-out of gasoline and diesel internal combustion engines will over time lead to much reduced emissions of Volatile Organic Compounds (VOCs) from road transport and related fuels. However, the use of real-world emissions measurements from a new mobile air quality monitoring station demonstrated a large underestimation of alcohol-based species in road transport emissions inventories. Scaling of industry sales statistics enabled the discrepancy to be attributed to the use of ancillary solvent products such as screenwash and deicer which are not included in internationally applied vehicle emission methodologies. A fleet average nonfuel nonexhaust VOC emission factor of 58 ± 39 mg veh -1 km -1 was calculated for the missing source, which is greater than the total of all VOCs emitted from vehicle exhausts and their associated evaporative fuel losses. These emissions are independent of the vehicle energy/propulsion system and therefore applicable to all road vehicle types including those with battery-electric powertrains. In contrast to predictions, vehicle VOC emissions may actually increase given a predicted growth in total vehicle kilometers driven in a future electrified fleet and will undergo a complete VOC respeciation due to the source change
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