Angular momentum transport in stellar interiors constrained by rotational splittings of mixed modes in red giants

By P. Eggenberger, J. Montalbán, A. Miglio. 2012

147 citations recorded by the source corpus.

Context. Recent asteroseismic observations have led to the determination of rotational frequency splittings for � = 1 mixed modes in red giants. Aims. We investigate how these observed splittings can constrain the modelling of the physical processes transporting angular momentum in stellar interiors. Methods. We first compare models including a comprehensive treatment of shellular rotation only, with the rotational splittings observed for the red giant KIC 8366239. We then study how these asteroseismic constraints can give us information about the efficiency of an additional mechanism for the internal transport of angular momentum. This is done by computing rotating models of KIC 8366239 that include a constant viscosity corresponding to this physical process, in addition to the treatment of shellular rotation. Results. We find that models of red giant stars including shellular rotation only predict steep rotation profiles, which are incompatible with the measurements of rotational splittings in the red giant KIC 8366239. Meridional circulation and shear mixing alone are found to produce an insufficient internal coupling so that an additional mechanism for the internal transport of angular momentum is needed during the post-main sequence evolution. We show that the viscosity νadd corresponding to this mechanism is strongly constrained to be νadd = 3 × 10 4 cm 2 s −1 thanks to the observed ratio of the splittings for modes in the wings to those at the centre of the dipole forests. Such a value of viscosity may suggest that the same unknown physical process is at work during the main sequence and the post-main sequence evolution.

Subfields: Astronomy and Astrophysics, Education, Instrumentation

View Paper: https://www.semanticscholar.org/paper/d65e81183b643972221d00ff845f860219461d34

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. Stello
2. D. Huber
3. Aaron Dotter
4. B. Mosser
5. C. Conroy
6. Benjamin D. Johnson
7. B. Paxton
8. Y. Elsworth

In Education

1. B. Paxton
2. Benjamin D. Johnson
3. Matteo Cantiello
4. C. Conroy
5. Jieun Choi
6. Aaron Dotter

In Instrumentation

1. D. Stello
2. B. Mosser
3. D. Huber
4. C. Conroy
5. Benjamin D. Johnson
6. Y. Elsworth
7. S. Hekker
8. Aaron Dotter

Citations in the corpus

• Spin down of the core rotation in red giants (2012, background): “Therefore, a direct measurement of rotation inside red giants would give us an unprecedented opportunity 25 to perform a leap forward on our understanding of angular momentum transport in stellar interiors (e.g. Lagarde et al. 2012; Eggenberger et al. 2012).”
• MESA ISOCHRONES AND STELLAR TRACKS (MIST). I. SOLAR-SCALED MODELS (2016, background): “…and neutron stars (Heger et al. 2005; Suijs et al. 2008) and the angular velocity profiles inferred from asteroseismic observations of red giants (Eggenberger et al. 2012; Cantiello et al. 2014) cannot be reproduced with models that only include rotational mixing from hydrodynamic instabilities…”
• Seismic diagnostics for transport of angular momentum in stars. I. Rotational splittings from the pre-main sequence to the red-giant branch. (2012, result): “Similar conclusions were reached by Eggenberger et al. (2012), which was published during the submission process of the present paper.”
• Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence (2015, unknown): “This has obvious consequences on stellar evolution (Charbonnel et al. 2013), the depletion of light elements such as Lithium (Bouvier 2008; Eggenberger et al. 2012a), and the type of magnetic dynamos that may be instrumental in young solar-type stars (Vidotto et al. 2014a).”
• PLATO as it is: a legacy mission for Galactic archaeology (2017, unknown): “…phase, which enables one to recover information about the internal rotational profile (e.g., see Beck et al. 2012; Deheuvels et al. 2012, 2014; Eggenberger et al. 2012; Mosser et al. 2012), or to infer the inclination of the star’s rotational axis with respect to the line of sight (e.g., see…”
• MODULES FOR EXPERIMENTS IN STELLAR ASTROPHYSICS (MESA): PLANETS, OSCILLATIONS, ROTATION, AND MASSIVE STARS (2013, background): “Models that only include angular momentum transport through rotational instabilities do not produce the core-envelope ratio of angular velocity observed through the splitting of mixed modes in red giant stars (Eggenberger et al. 2012).”
• ANGULAR MOMENTUM TRANSPORT WITHIN EVOLVED LOW-MASS STARS (2014, methodology): “Similar to the case of compact remnants, models solely including angular momentum transport due to rotational mixing and circulations predict rotation rates 2 to 3 orders of magnitude higher than observed (Eggenberger et al. 2012; Marques et al. 2013; Ceillier et al. 2013).”