The expected distribution of Cepheids within the instability strip directly reflects upon the predicted Period-Luminosity (PL) relation; however from a theoretical point of view this distribution is affected by the uncertaintes on several model inputs. We evaluated the effects on the theoretical PL relation of current uncertainties on the chemical abundances of Cepheids in the Large Magellanic Cloud (LMC) on the basis of new and updated sets of evolutionary and pulsational models. As a result, we found that current uncertainties on the LMC chemical composition affect significantly the loop extension and also reflect in the predicted topology of the instability strip; however their influence on the predicted pulsational parameters is negligible.
Theoretical uncertainties on classical Cepheid pulsational quantities.
VALLE, GIADA;DEGL'INNOCENTI, SCILLA;PRADA MORONI, PIER GIORGIO
2010-01-01
Abstract
The expected distribution of Cepheids within the instability strip directly reflects upon the predicted Period-Luminosity (PL) relation; however from a theoretical point of view this distribution is affected by the uncertaintes on several model inputs. We evaluated the effects on the theoretical PL relation of current uncertainties on the chemical abundances of Cepheids in the Large Magellanic Cloud (LMC) on the basis of new and updated sets of evolutionary and pulsational models. As a result, we found that current uncertainties on the LMC chemical composition affect significantly the loop extension and also reflect in the predicted topology of the instability strip; however their influence on the predicted pulsational parameters is negligible.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.