5 research outputs found

    FSR584 - a new globular cluster in the Galaxy?

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    We investigate the nature of the recently catalogued star cluster candidate FSR584, which is projected in the direction of the molecular cloud W3 and may be the nearest globular cluster to the Sun. 2MASS CMDs, the stellar radial density profile, and proper motions are employed to derive fundamental and structural parameters. The CMD morphology and the radial density profile show that FSR584 is an old star cluster. With proper motions, the properties of FSR584 are consistent with a metal-poor globular cluster with a well-defined turnoff and evidence of a blue horizontal-branch. FSR584 might be a Palomar-like halo globular cluster that is moving towards the Galactic plane. The distance from the Sun is approx 1.4kpc, and it is located at approx 1kpc outside the Solar circle. The radial density profile is characterized by a core radius of rc=0.3+/-0.1 pc. However, we cannot exclude the possibility of an old open cluster. Near-infrared photometry coupled to proper motions support the scenario where FSR584 is a new globular cluster in the Galaxy. The absorption is A_V=9.2+/-0.6$, which makes it a limiting object in the optical and explains why it has so far been overlookedComment: Astronomy and Astrophysics, accepted. 6 pages and 6 figure

    Pricing k-th-to-default Swaps under Default Contagion: The Matrix-Analytic Approach

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    We study a model for default contagion in intensity-based credit risk and its consequences for pricing portfolio credit derivatives. The model is specified through default intensities which are assumed to be constant between defaults, but which can jump at the times of defaults. The model is translated into a Markov jump process which represents the default status in the credit portfolio. This makes it possible to use matrix-analytic methods to derive computationally tractable closed-form expressions for single-name credit default swap spreads and kth-to-default swap spreads. We ”semicalibrate” the model for portfolios (of up to 15 obligors) against market CDS spreads and compute the corresponding kth-to-default spreads. In a numerical study based on a synthetic portfolio of 15 telecom bonds we study a number of questions: how spreads depend on the amount of default interaction; how the values of the underlying market CDS-prices used for calibration influence kth-th-to default spreads; how a portfolio with inhomogeneous recovery rates compares with a portfolio which satisfies the standard assumption of identical recovery rates; and, finally, how well kth-th-to default spreads in a nonsymmetric portfolio can be approximated by spreads in a symmetric portfolio
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