Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/28519

Title: Forward Asteroseismic Modeling of Stars with a Convective Core from Gravity-mode Oscillations: Parameter Estimation and Stellar Model Selection
Authors: Aerts, Conny
Molenberghs, Geert
Michielsen, Melissa
Pedersen, M. G.
Bjorklund, R.
Johnston, C.
Mombarg, J. S. G.
Bowman, D. M.
Buysschaert, B.
Papics, P., I
Sekaran, S.
Sundqvist, J. O.
Tkachenko, A.
Truyaert, K.
Van Reeth, T.
Vermeyen, E.
Issue Date: 2018
Abstract: We propose a methodological framework to perform forward asteroseismic modeling of stars with a convective core, based on gravity-mode oscillations. These probe the near-core region in the deep stellar interior. The modeling relies on a set of observed high-precision oscillation frequencies of low-degree coherent gravity modes with long lifetimes and their observational uncertainties. Identification of the mode degree and azimuthal order is assumed to be achieved from rotational splitting and/or from period spacing patterns. This paper has two major outcomes. The first is a comprehensive list and discussion of the major uncertainties of theoretically predicted gravity-mode oscillation frequencies based on linear pulsation theory, caused by fixing choices of the input physics for evolutionary models. Guided by a hierarchy among these uncertainties of theoretical frequencies, we subsequently provide a global methodological scheme to achieve forward asteroseismic modeling. We properly take into account correlations among the free parameters included in stellar models. Aside from the stellar mass, metallicity, and age, the major parameters to be estimated are the near-core rotation rate, the amount of convective core overshooting, and the level of chemical mixing in the radiative zones. This modeling scheme allows for maximum likelihood estimation of the stellar parameters for fixed input physics of the equilibrium models, followed by stellar model selection considering various choices of the input physics. Our approach uses the Mahalanobis distance instead of the often-used chi(2) statistic and includes heteroscedasticity. It provides estimation of the unknown variance of the theoretically predicted oscillation frequencies.
Notes: [Aerts, C.; Michielsen, M.; Pedersen, M. G.; Bjorklund, R.; Johnston, C.; Mombarg, J. S. G.; Bowman, D. M.; Buysschaert, B.; Papics, P., I; Sekaran, S.; Sundqvist, J. O.] Katholieke Univ Leuven, Inst Astron, Celestijnenlaan 200D, B-3001 Leuven, Belgium. [Aerts, C.] Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands. [Aerts, C.; Molenberghs, G.] Univ Calif Santa Barbara, Kavli Inst Theoret Phys, Santa Barbara, CA 93106 USA. [Molenberghs, G.] Univ Hasselt, I BioStat, Martelarenlaan 42, B-3500 Hasselt, Belgium. [Molenberghs, G.] Katholieke Univ Leuven, I BioStat, Kapucijnenvoer 35, B-3000 Leuven, Belgium. [Buysschaert, B.] UPMC Univ Paris 06, Univ Paris Diderot, Sorbonne Univ, LESIA,Observ Paris,PSL Res Univ,CNRS,Sorbonne Par, 5 Pl Jules Janssen, F-92195 Meudon, France.
URI: http://hdl.handle.net/1942/28519
DOI: 10.3847/1538-4365/aaccfb
ISI #: 000439371200002
ISSN: 0067-0049
Category: A1
Type: Journal Contribution
Appears in Collections: Research publications

Files in This Item:

Description SizeFormat
Published version2.33 MBAdobe PDF

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.