The ACS LCID Project: RR Lyrae stars as tracers of old population gradients in the isolated dwarf spheroidal galaxy Tucana - AstrophysicsReportar como inadecuado




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Abstract: We present a study of the radial distribution of RR Lyrae variables, whichpresent a range of photometric and pulsational properties, in the dwarfspheroidal galaxy Tucana. We find that the fainter RR Lyrae stars, having ashorter period, are more centrally concentrated than the more luminous, longerperiod RR Lyrae variables. Through comparison with the predictions oftheoretical models of stellar evolution and stellar pulsation, we interpret thefainter RR Lyrae stars as a more metal-rich subsample. In addition, we showthat they must be older than about 10 Gyr. Therefore, the metallicity gradientmust have appeared very early on in the history of this galaxy.



Autor: Edouard J. Bernard, Carme Gallart, Matteo Monelli, Antonio Aparicio, Santi Cassisi, Evan D. Skillman, Peter B. Stetson, Andrew A.

Fuente: https://arxiv.org/







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