%0 Journal Article
%T Stellar magnetism: empirical trends with age and rotation
%+ University of St Andrews [Scotland]
%+ Institut de recherche en astrophysique et planétologie (IRAP)
%+ Laboratoire Univers et Particules de Montpellier (LUPM)
%+ Institut de Planétologie et d'Astrophysique de Grenoble (IPAG )
%+ ESO Garching
%+ University of Southern Queensland (USQ)
%+ Institut für Astrophysik [Göttingen]
%+ Univ. Federal do Rio Grande do Norte
%+ Harvard-Smithsonian Center for Astrophysics (CfA)
%A Vidotto, A. A.
%A Gregory, S. G.
%A Jardine, M.
%A Donati, J. -F.
%A Petit, P.
%A Morin, Julien
%A Folsom, C. P.
%A Bouvier, J.
%A Cameron, A. C.
%A Hussain, G.
%A Marsden, S.
%A Waite, I. A.
%A Fares, R.
%A Jeffers, S.
%A Nascimento, J. D. Do
%Z 15 pages, 7 figures.
%< avec comité de lecture
%Z LUPM:14-011
%@ 0035-8711
%J Monthly Notices of the Royal Astronomical Society
%I Oxford University Press (OUP): Policy P - Oxford Open Option A
%V 441
%N 2361
%P arXiv:1404.2733
%8 2014-04-11
%D 2014
%Z 1404.2733
%R 10.1093/mnras/stu728
%K stars: activitystars: evolutionstars: magnetic fieldstars: rotationstars: planetary systems techniques: polarimetric
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]Journal articles
%X We investigate how the observed large-scale surface magnetic fields of low-mass stars (~0.1 -- 2 Msun), reconstructed through Zeeman-Doppler imaging (ZDI), vary with age t, rotation and X-ray emission. Our sample consists of 104 magnetic maps of 73 stars, from accreting pre-main sequence to main-sequence objects (1 Myr < t < 10 Gyr). For non-accreting dwarfs we empirically find that the unsigned average large-scale surface field <|Bv|> is related to age as $t^{-0.655 \pm 0.045}$. This relation has a similar dependence to that identified by Skumanich (1972), used as the basis for gyrochronology. Likewise, our relation could be used as an age-dating method ("magnetochronology"). The trends with rotation we find for the large-scale stellar magnetism are consistent with the trends found from Zeeman broadening measurements (sensitive to large- and small-scale fields). These similarities indicate that the fields recovered from both techniques are coupled to each other, suggesting that small- and large-scale fields could share the same dynamo field generation processes. For the accreting objects, fewer statistically significant relations are found, with one being a correlation between the unsigned magnetic flux and rotation period. We attribute this to a signature of star-disc interaction, rather than being driven by the dynamo.
%G English
%L hal-01770042
%U https://hal.science/hal-01770042
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