786 research outputs found

    Impact of the 3D source geometry on time-delay measurements of lensed type-Ia Supernovae

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    It has recently been proposed that gravitationally lensed type-Ia supernovae can provide microlensing-free time-delay measurements provided that the measurement is taken during the achromatic expansion phase of the explosion and that color light curves are used rather than single-band light curves. If verified, this would provide both precise and accurate time-delay measurements, making lensed type-Ia supernovae a new golden standard for time-delay cosmography. However, the 3D geometry of the expanding shell can introduce an additional bias that has not yet been fully explored. In this work, we present and discuss the impact of this effect on time-delay cosmography with lensed supernovae and find that on average it leads to a bias of a few tenths of a day for individual lensed systems. This is negligible in view of the cosmological time delays predicted for typical lensed type-Ia supernovae but not for the specific case of the recently discovered type-Ia supernova iPTF16geu, whose time delays are expected to be smaller than a day.Comment: 7 pages, 4 figures, published in A&

    COSMOGRAIL XVIII: time delays of the quadruply lensed quasar WFI2033-4723

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    We present new measurements of the time delays of WFI2033-4723. The data sets used in this work include 14 years of data taken at the 1.2m Leonhard Euler Swiss telescope, 13 years of data from the SMARTS 1.3m telescope at Las Campanas Observatory and a single year of high-cadence and high-precision monitoring at the MPIA 2.2m telescope. The time delays measured from these different data sets, all taken in the R-band, are in good agreement with each other and with previous measurements from the literature. Combining all the time-delay estimates from our data sets results in Dt_AB = 36.2-0.8+0.7 days (2.1% precision), Dt_AC = -23.3-1.4+1.2 days (5.6%) and Dt_BC = -59.4-1.3+1.3 days (2.2%). In addition, the close image pair A1-A2 of the lensed quasars can be resolved in the MPIA 2.2m data. We measure a time delay consistent with zero in this pair of images. We also explore the prior distributions of microlensing time-delay potentially affecting the cosmological time-delay measurements of WFI2033-4723. There is however no strong indication in our measurements that microlensing time delay is neither present nor absent. This work is part of a H0LiCOW series focusing on measuring the Hubble constant from WFI2033-4723.Comment: Submitted to Astronomy and Astrophysic

    Faith in the Republic: A Frances Lewis Law Center Conversation

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    This is a spontaneous conversation discussing Hauserwas’ singular political theology in response to Levinson and Tushnet’s constitutional jurisprudence. It developed into a highly interesting debate concerning constitutional faith. This conversation was recorded at Washington and Lee’s Law Center on December 11, 1987

    Faith in the Republic: A Frances Lewis Law Center Conversation

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    This is a spontaneous conversation discussing Hauserwas’ singular political theology in response to Levinson and Tushnet’s constitutional jurisprudence. It developed into a highly interesting debate concerning constitutional faith. This conversation was recorded at Washington and Lee’s Law Center on December 11, 1987

    J1721+8842: a gravitationally lensed binary quasar with a proximate damped Lyman-α absorber

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    High-redshift binary quasars provide key insights into mergers and quasar activity, and are useful tools for probing the spatial kinematics and chemistry of galaxies along the line of sight. However, only three sub-10-kpc binaries have been confirmed above z = 1. Gravitational lensing would provide a way to easily resolve such binaries, study them in higher resolution, and provide more sightlines, though the required alignment with a massive foreground galaxy is rare. Through image deconvolution of StanCam Nordic Optical Telescope (NOT) monitoring data, we reveal two further point sources in the known, z ≈ 2.38, quadruply lensed quasar (quad) J1721+8842. An ALFOSC/NOT long-slit spectrum shows that the brighter of these two sources is a quasar with z = 2.369 ± 0.007 based on the C III] line, while the C III] redshift of the quad is z = 2.364 ± 0.003. Lens modelling using point-source positions rules out a single source model, favouring an isothermal lens mass profile with two quasar sources separated by ∼6.0 kpc (0.73″) in projection. Given the resolving ability from lensing and current lensed quasar statistics, this discovery suggests a large population of undiscovered, unlensed sub-10-kpc binaries. We also analyse spectra of two images of the quad, showing narrow Lyα emission within the trough of a proximate damped Lyman-α absorber (PDLA). An apparent mismatch between the continuum and narrow line flux ratios provides a new potential tool for simultaneously studying microlensing and the quasar host galaxy. Signs of the PDLA are also seen in the second source, but a deeper spectrum is still required to confirm this. Thanks to the multiple lines of sight from lensing and two quasar sources, this system offers simultaneous subparsec- and kiloparsec-scale probes of a PDLA. The reduced 2D spectra are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/657/A113</A

    The Big Three Perfectionism Scale: A new measure of perfectionism

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    This article introduces a new measure of dispositional perfectionism: the Big Three Perfectionism Scale (BTPS). The BTPS assesses three higher-order global factors (rigid perfectionism, self-critical perfectionism, narcissistic perfectionism) via 10 lower-order perfectionism facets (self-oriented perfectionism, self-worth contingencies, concern over mistakes, doubts about actions, self-criticism, socially prescribed perfectionism, other-oriented perfectionism, hypercriticism, grandiosity, entitlement). The present investigation examined the structure of the BTPS using exploratory factor analysis in Study 1 (288 undergraduates), and confirmatory factor analyses in Study 2 (352 community adults) and Study 3 (290 undergraduates). Additionally, in Study 3 the relationships among the BTPS, other measures of perfectionism, and the five-factor model of personality were investigated. Overall, findings provide first evidence for the reliability and validity of the BTPS as a multidimensional measure of perfectionism

    Una combinación nueva en Erica (Ericaceae).

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    [EN] A new nomenclatural status and combination is proposed for Erica cinerea var. numidica. New data about the morphology, chorology and ecology of this taxon are given.[ES] Una combinación nueva en Erica (Ericaceae).- Se propone un nuevo estatus y combinación nomenclatural para Erica cinerea var. numidica. Se aportan nuevos datos sobre la morfología, corología y ecología de este taxón.This work has been supported by “Ajuts a grups de recerca consolidats: 2005SGR00344 and 2009SGR0439, Generalitat de Catalunya” and "Proyectos Intramurales de Incorporación del CSIC: 2009930I161".Peer reviewe

    Ernst Freund as Precursor of the Rational Study of Corporate Law

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    Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe

    The complementary roles of dynamic contrast-enhanced MRI and 18F-fluorodeoxyglucose PET/CT for imaging of carotid atherosclerosis

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    Inflammation and neovascularization in vulnerable atherosclerotic plaques are key features for severe clinical events. Dynamic contrast-enhanced (DCE) MRI and FDG PET are two noninvasive imaging techniques capable of quantifying plaque neovascularization and inflammatory infiltrate, respectively. However, their mutual role in defining plaque vulnerability and their possible overlap has not been thoroughly investigated. We studied the relationship between DCE-MRI and [supersript 18]F-FDG PET data from the carotid arteries of 40 subjects with coronary heart disease (CHD) or CHD risk equivalent, as a substudy of the dal-PLAQUE trial (NCT00655473)
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