1. The Aarhus red giants challenge: I. Stellar structures in the red giant branch phase
- Author
-
Maurizio Salaris, V. Silva Aguirre, Santi Cassisi, Anwesh Mazumdar, Dennis Stello, George C. Angelou, Andrea Miglio, R. M. Ouazzani, Federico Spada, Earl P. Bellinger, Diego Bossini, Tiara Battich, M. M. Miller Bertolami, Jakob Rørsted Mosumgaard, Richard H. D. Townsend, K. B. Nielsen, Adriano Pietrinferni, Chen Jiang, S. Deheuvels, Saskia Hekker, A. Weiss, Jørgen Christensen-Dalsgaard, Aldo Serenelli, T. Constantino, Patrick Eggenberger, Yveline Lebreton, Kavli Institute for Theoretical Physics [Santa Barbara] (KITP), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Stellar Astrophysics Centre [Aarhus] (SAC), Aarhus University [Aarhus], Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), School of Physics [UNSW Sydney] (UNSW), University of New South Wales [Sydney] (UNSW), Max Planck Institute for Astrophysics, Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare [Pisa] (INFN), Istituto Nazionale di Fisica Nucleare (INFN), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Collurania Astronomical Observatory, Istituto Nazionale di Astrofisica (INAF), University of Wisconsin-Madison, INAF - Osservatorio Astronomico di Padova (OAPD), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), School of Physics and Astronomy, University of Birmingham [Birmingham], Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Astrophysical Research Institute [Liverpool], Liverpool John Moore University (ljmu), Danish National Research Foundation, European Commission, Villum Fonden, Independent Research Fund Denmark, Ministerio de Ciencia e Innovación (España), Generalitat de Catalunya, Australian Research Council, National Science Foundation (US), Fundação para a Ciência e a Tecnologia (Portugal), Department of Atomic Energy (India), University of California [Santa Barbara] (UCSB), University of California-University of California, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université de Genève (UNIGE), Department of Physics and Astronomy [Aarhus], Sydney Institute for Astronomy (SIfA), The University of Sydney, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, DNK, Silva Aguirre V., Christensen-Dalsgaard J., Cassisi S., Miller Bertolami M., Serenelli A., Stello D., Weiss A., Angelou G., Jiang C., Lebreton Y., Spada F., Bellinger E.P., Deheuvels S., Ouazzani R.M., Pietrinferni A., Mosumgaard J.R., Townsend R.H.D., Battich T., Bossini D., Constantino T., Eggenberger P., Hekker S., Mazumdar A., Miglio A., Nielsen K.B., and Salaris M.
- Subjects
Stellar mass ,FOS: Physical sciences ,evolution [Stars] ,Context (language use) ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,7. Clean energy ,01 natural sciences ,Asteroseismology ,Luminosity ,purl.org/becyt/ford/1 [https] ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Stellar structure ,010303 astronomy & astrophysics ,Stellar evolution ,Solar and Stellar Astrophysics (astro-ph.SR) ,QC ,Astrophysics::Galaxy Astrophysics ,ComputingMilieux_MISCELLANEOUS ,QB ,Physics ,010308 nuclear & particles physics ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,interiors [Stars] ,Astronomy and Astrophysics ,purl.org/becyt/ford/1.3 [https] ,Red-giant branch ,Stars ,Stars: evolution ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,[SDU]Sciences of the Universe [physics] ,Stars: interiors ,Astrophysics::Earth and Planetary Astrophysics - Abstract
[Context] With the advent of space-based asteroseismology, determining accurate properties of red-giant stars using their observed oscillations has become the focus of many investigations due to their implications in a variety of fields in astrophysics. Stellar models are fundamental in predicting quantities such as stellar age, and their reliability critically depends on the numerical implementation of the physics at play in this evolutionary phase., [Aims] We introduce the Aarhus red giants challenge, a series of detailed comparisons between widely used stellar evolution and oscillation codes that aim to establish the minimum level of uncertainties in properties of red giants arising solely from numerical implementations. We present the first set of results focusing on stellar evolution tracks and structures in the red-giant-branch (RGB) phase., [Methods] Using nine state-of-the-art stellar evolution codes, we defined a set of input physics and physical constants for our calculations and calibrated the convective efficiency to a specific point on the main sequence. We produced evolutionary tracks and stellar structure models at a fixed radius along the red-giant branch for masses of 1.0 M⊙, 1.5 M⊙, 2.0 M⊙, and 2.5 M⊙, and compared the predicted stellar properties., [Results] Once models have been calibrated on the main sequence, we find a residual spread in the predicted effective temperatures across all codes of ∼20 K at solar radius and ∼30–40 K in the RGB regardless of the considered stellar mass. The predicted ages show variations of 2–5% (increasing with stellar mass), which we attribute to differences in the numerical implementation of energy generation. The luminosity of the RGB-bump shows a spread of about 10% for the considered codes, which translates into magnitude differences of ∼0.1 mag in the optical V-band. We also compare the predicted [C/N] abundance ratio and find a spread of 0.1 dex or more for all considered masses., [Conclusions] Our comparisons show that differences at the level of a few percent still remain in evolutionary calculations of red giants branch stars despite the use of the same input physics. These are mostly due to differences in the energy generation routines and interpolation across opacities, and they call for further investigation on these matters in the context of using properties of red giants as benchmarks for astrophysical studies., Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement No. DNRF106). The research was supported by the ASTERISK project (ASTERoseismic Investigations with SONG and Kepler) funded by the European Research Council (Grant agreement No. 267864). VSA acknowledges support from VILLUM FONDEN (research grant 10118) and the Independent Research Fund Denmark (Research grant 7027-00096B). AS is partially supported by grant ESP2017-82674-R (MICINN) and 2017-SGR-1131 (Generalitat Catalunya). DS acknowledges support from the Australian Research Council. Part of this research was supported by the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no 338251 (StellarAges). RHDT acknowledges support from National Science Foundation grants ACI-1663696 and AST-1716436. This work was supported by FCT/MCTES through national funds and by FEDER – Fundo Europeu de Desenvolvimento Regional through COMPETE2020 – Programa Operacional Competitividade e Internacionalização by these grants: UID/FIS/04434/2019; PTDC/FIS-AST/30389/2017 and POCI-01-0145-FEDER-030389. DB is supported in the form of work contract funded by national funds through Fundação para a Ciência e Tecnologia (FCT). AM acknowledges the support of the Govt. Of India, Department of Atomic Energy, under Project No. 12-R&D-TFR-6.04-0600. We would like to thank Bill Paxton for assistance with the MESA solar calibration and for accommodating requested changes to the code along the way.
- Published
- 2020
- Full Text
- View/download PDF