Magnetochronology of solar-type star dynamos. (arXiv:2401.14460v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Noraz_Q/0/1/0/all/0/1">Quentin Noraz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brun_A/0/1/0/all/0/1">Allan Sacha Brun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Strugarek_A/0/1/0/all/0/1">Antoine Strugarek</a>
Aims. In this study, we analyse magnetic field properties of a set of 15
global magnetohydrodynamics simulations of solar-type star dynamos conducted
using the ASH code. Our objective is to enhance our understanding of these
properties by comparing theoretical results to current observations, aiming
finally to provide fresh insights into the field. Methods. We analyse
rotational and magnetic properties as a function of various stellar parameters
(mass, age, rotation rate) in a Sun in time approach in our extended set of 3D
MHD simulations. To facilitate direct comparisons with stellar magnetism
observations using various Zeeman-effect techniques, we decompose numerical
data into vectorial spherical harmonics. Results. The comparison of the trends
we found in our simulations set reveals a promising overall agreement with the
observational context of stellar magnetism, enabling us to suggest a plausible
scenario for the magneto-rotational evolution of solar-type stars. In
particular, we find that the magnetic field may reach a minimum in amplitude at
a transition value in Rossby number near unity. This may have important
consequences on the long term evolution of solar-type stars, by impacting the
relation between stellar age, rotation and magnetism. This supports the need
for future observational campaigns, especially for stars in the high Rossby
number regime.
Aims. In this study, we analyse magnetic field properties of a set of 15
global magnetohydrodynamics simulations of solar-type star dynamos conducted
using the ASH code. Our objective is to enhance our understanding of these
properties by comparing theoretical results to current observations, aiming
finally to provide fresh insights into the field. Methods. We analyse
rotational and magnetic properties as a function of various stellar parameters
(mass, age, rotation rate) in a Sun in time approach in our extended set of 3D
MHD simulations. To facilitate direct comparisons with stellar magnetism
observations using various Zeeman-effect techniques, we decompose numerical
data into vectorial spherical harmonics. Results. The comparison of the trends
we found in our simulations set reveals a promising overall agreement with the
observational context of stellar magnetism, enabling us to suggest a plausible
scenario for the magneto-rotational evolution of solar-type stars. In
particular, we find that the magnetic field may reach a minimum in amplitude at
a transition value in Rossby number near unity. This may have important
consequences on the long term evolution of solar-type stars, by impacting the
relation between stellar age, rotation and magnetism. This supports the need
for future observational campaigns, especially for stars in the high Rossby
number regime.
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