6,219 research outputs found

    Library of medium-resolution fiber optic echelle spectra of F, G, K, and M field dwarfs to giants stars

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    We present a library of Penn State Fiber Optic Echelle (FOE) observations of a sample of field stars with spectral types F to M and luminosity classes V to I. The spectral coverage is from 3800 AA to 10000 AA with nominal a resolving power 12000. These spectra include many of the spectral lines most widely used as optical and near-infrared indicators of chromospheric activity such as the Balmer lines (H_alpha, H_beta), Ca II H & K, Mg I b triplet, Na I D_{1} and D_{2}, He I D_{3}, and Ca II IRT lines. There are also a large number of photospheric lines, which can also be affected by chromospheric activity, and temperature sensitive photospheric features such as TiO bands. The spectra have been compiled with the goal of providing a set of standards observed at medium resolution. We have extensively used such data for the study of active chromosphere stars by applying a spectral subtraction technique. However, the data set presented here can also be utilized in a wide variety of ways ranging from radial velocity templates to study of variable stars and stellar population synthesis. This library can also be used for spectral classification purposes and determination of atmospheric parameters (T_eff, log{g}, [Fe/H]). A digital version of all the fully reduced spectra is available via ftp and the World Wide Web (WWW) in FITS format.Comment: Latex file with 17 pages, 4 figures. Full postscript (text and figures) available at http://www.ucm.es/info/Astrof/fgkmsl/FOEfgkmsl.html To be published in ApJ

    Borderland Identity

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    Library of high-resolution UES echelle spectra of F, G, K and M field dwarf stars

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    We present a library of Utrecht echelle spectrograph (UES) observations of a sample of F, G, K and M field dwarf stars covering the spectral range from 4800 AA to 10600 AA with a resolution of 55000. These spectra include some of the spectral lines most widely used as optical and near-infrared indicators of chromospheric activity such as H_beta, Mg I b triplet, Na I D_1, D_2, He I D_3, H_alpha, and Ca II IRT lines, as well as a large number of photospheric lines which can also be affected by chromospheric activity. The spectra have been compiled with the aim of providing a set of standards observed at high-resolution to be used in the application of the spectral subtraction technique to obtain the active-chromosphere contribution to these lines in chromospherically active single and binary stars. This library can also be used for spectral classification purposes. A digital version with all the spectra is available via ftp and the World Wide Web (WWW) in both ASCII and FITS formats.Comment: Latex file with 5 figures using l-aa.sty and psfig.sty. Full postscript (text and figures) available at http://www.ucm.es/OTROS/Astrof/fgkmsl/UESfgkmsl.html Accepted for publication in: Astronomy and Astrophysics Supplement

    Argentina's default and the lack of dire consequences

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    We analyze the 2001 Argentine default on its foreign debt and its consequences in terms of the existing literature on sovereign debt default. It is our purpose to evaluate this experience and to see to what extent the Argentine case requires a re-thinking on the nature and consequences of defaults. We show that the Argentine case contradicts many of their standard predictions, in particular its posterior lack of access to international credit, restriction to international trade and negative economic growth. Moreover, it corroborates the historical fact that many defaulters “get away with it.
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