An updated MILES stellar library and stellar population models (Research Note)

© ESO 2011. We would like to thank H. Kuntschner and M. Cappellari for reporting some of the questions addressed in this research note. We also thank the referee for very constructive comments. We are grateful to F. Valdes for his assistance clarifying the spectral resolution of the Indo-US library, and C. Allende Prieto for useful discussions. J.F.B. and P. S. B. acknowledge support from the Ramón y Cajal Program financed by the Spanish Ministry of Science and Innovation. P. S. B. also acknowledges an E.R.C. grant within the 6th European Community Framework Programme. This research has been supported by the Spanish Ministry of Science and Innovation (MICINN) under grants AYA2009-10368, AYA2010-21322-C03-02 and AYA2010-21322-C03-03. This paper is based on observations obtained at the Isaac Newton Telescope, operated by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.
We present a number of improvements to the MILES library and stellar population models. We correct some small errors in the radial velocities of the stars, measure the spectral resolution of the library and models more accurately, and give a better absolute flux calibration of the models. Methods. We use cross-correlation techniques to correct the radial velocities of the offset stars and the penalised pixel-fitting method, together with different sets of stellar templates, to re-assess the spectral resolution of the MILES stellar library and models. We have also re-calibrated the zero-point flux level of the models using a new calibration scheme. Results. The end result is an even more homogeneously calibrated stellar library than the originally released one, with a measured spectral resolution of similar to 2.5 angstrom, almost constant with wavelength, for both the MILES stellar library and models. Furthermore, the new absolute flux calibration for the spectra excellently agrees with predictions based on independent photometric libraries. Conclusions. This improved version of the MILES library and models (version 9.1) is available at the project's website (http://miles.iac.es).
Spanish Ministry of Science and Innovation
E.R.C. within European Community
Spanish Ministry of Science and Innovation (MICINN)
Depto. de Física de la Tierra y Astrofísica
Fac. de Ciencias Físicas
TRUE
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