TY - JOUR
T1 - Constraining the thermally pulsing asymptotic giant branch phase with resolved stellar populations in the Small Magellanic Cloud
AU - Pastorelli, Giada
AU - Marigo, Paola
AU - Girardi, Léo
AU - Chen, Yang
AU - Rubele, Stefano
AU - Trabucchi, Michele
AU - Aringer, Bernhard
AU - Bladh, Sara
AU - Bressan, Alessandro
AU - Montalbán, Josefina
AU - Boyer, Martha L.
AU - Dalcanton, Julianne J.
AU - Eriksson, Kjell
AU - Groenewegen, Martin A.T.
AU - Höfner, Susanne
AU - Lebzelter, Thomas
AU - Nanni, Ambra
AU - Rosenfield, Philip
AU - Wood, Peter R.
AU - Cioni, Maria Rosa L.
N1 - Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
PY - 2019/3/13
Y1 - 2019/3/13
N2 - The thermally pulsing asymptotic giant branch (TP-AGB) experienced by low- and intermediate-mass stars is one of the most uncertain phases of stellar evolution and the models need to be calibrated with the aid of observations. To this purpose, we couple high-quality observations of resolved stars in the Small Magellanic Cloud (SMC) with detailed stellar population synthesis simulations computed with the TRILEGAL code. The strength of our approach relies on the detailed spatially resolved star formation history of the SMC, derived from the deep near-infrared photometry of the VISTA survey of the Magellanic Clouds, as well as on the capability to quickly and accurately explore a wide variety of parameters and effects with the COLIBRI code for the TP-AGB evolution. Adopting a well-characterized set of observations - star counts and luminosity functions - we set up a calibration cycle along which we iteratively change a few key parameters of the TP-AGB models until we eventually reach a good fit to the observations. Our work leads to identify two best-fitting models that mainly differ in the efficiencies of the third dredge-up and mass-loss in TP-AGB stars with initial masses larger than about 3 M☉. On the basis of these calibrated models, we provide a full characterization of the TP-AGB stellar population in the SMC in terms of stellar parameters (initial masses, C/O ratios, carbon excess, mass-loss rates). Extensive tables of isochrones including these improved models are publicly available.
AB - The thermally pulsing asymptotic giant branch (TP-AGB) experienced by low- and intermediate-mass stars is one of the most uncertain phases of stellar evolution and the models need to be calibrated with the aid of observations. To this purpose, we couple high-quality observations of resolved stars in the Small Magellanic Cloud (SMC) with detailed stellar population synthesis simulations computed with the TRILEGAL code. The strength of our approach relies on the detailed spatially resolved star formation history of the SMC, derived from the deep near-infrared photometry of the VISTA survey of the Magellanic Clouds, as well as on the capability to quickly and accurately explore a wide variety of parameters and effects with the COLIBRI code for the TP-AGB evolution. Adopting a well-characterized set of observations - star counts and luminosity functions - we set up a calibration cycle along which we iteratively change a few key parameters of the TP-AGB models until we eventually reach a good fit to the observations. Our work leads to identify two best-fitting models that mainly differ in the efficiencies of the third dredge-up and mass-loss in TP-AGB stars with initial masses larger than about 3 M☉. On the basis of these calibrated models, we provide a full characterization of the TP-AGB stellar population in the SMC in terms of stellar parameters (initial masses, C/O ratios, carbon excess, mass-loss rates). Extensive tables of isochrones including these improved models are publicly available.
KW - Magellanic Clouds
KW - Stars: AGB and post-AGB
KW - Stars: carbon
KW - Stars: evolution
KW - Stars: mass-loss
UR - http://www.scopus.com/inward/record.url?scp=85067055759&partnerID=8YFLogxK
U2 - 10.1093/mnras/stz725
DO - 10.1093/mnras/stz725
M3 - Article
SN - 0035-8711
VL - 485
SP - 5666
EP - 5692
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -