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Paper: LMC Cepheids in the MACHO Database: Constraints on the Star Formation Rate and on Stellar Models
Volume: 135, A Half Century of Stellar Pulsation Interpretations: a Tribute to Arthur N. Cox
Page: 24
Authors: Bersier, D.; Alcock, C.; Allsman, R. A.; Alves, D.; Axelrod, T. S.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Freeman, K. C.; Griest, K.; Guern, J.; Marshall, S. L.; Minniti, D.; Lehner, M. J.; Peterson, B. A.; Pratt, M. R.; Quinn, P. J.; Rodgers, A. W.; Sutherland, W.; Welch, D. L.; Tomaney, A.; Vandehei, T.
Abstract: Cepheids are young intermediate-mass stars. They are thus tracers of recent star formation history in a galaxy. In this work, we use the Cepheid period distribution obtained with the MACHO experiment in the LMC and completed with Payne-Gaposchkin's work to determine the recent star formation history of the LMC (the total sample represents more than 1600 stars). A theoretical period distribution is determined by combining stellar evolutionary tracks and pulsation models. While a constant star formation rate does not fit the data, it is possible to reproduce the main characteristics of the period distribution by invoking an enhancement of star formation with a peak between 80 Myr and 100 Myr. However there is a large number of short period Cepheids that cannot be accounted for by current models. Several possibilities will be discussed in order to explain the origin of these stars.
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