4.6 Article

Magnetic fields in M dwarfs from the CARMENES survey

Journal

ASTRONOMY & ASTROPHYSICS
Volume 626, Issue -, Pages -

Publisher

EDP SCIENCES S A
DOI: 10.1051/0004-6361/201935315

Keywords

stars: low-mass; stars: magnetic field; stars: rotation; stars: atmospheres

Funding

  1. German Max-Planck-Gesellschaft (MPG)
  2. Spanish Consejo Superior de Investigaciones Cientificas (CSIC)
  3. European Union [FEDER/ERF FICTS-2011-02]
  4. Max-Planck-Institut fur Astronomie
  5. Instituto de Astrofisica de Andalucia
  6. Landessternwarte Konigstuhl
  7. Institut de Ciencies de l'Espai
  8. Insitut fur Astrophysik Gottingen
  9. Universidad Complutense de Madrid
  10. Thuringer Landessternwarte Tautenburg
  11. Instituto de Astrofisica de Canarias
  12. Hamburger Sternwarte
  13. Centro de Astrobiologia
  14. Centro Astronomico Hispano-Aleman
  15. Spanish Ministry of Economy
  16. German Science Foundation
  17. DFG Research Unit FOR2544 Blue Planets around Red Stars
  18. Klaus Tschira Stiftung
  19. state of Baden-Wurttemberg
  20. state of Niedersachsen
  21. Junta de Andalucia
  22. Israel Science Foundation [848/16]
  23. STFC [ST/P000592/1] Funding Source: UKRI

Ask authors/readers for more resources

Context. M dwarfs are known to generate the strongest magnetic fields among main-sequence stars with convective envelopes, but we are still lacking a consistent picture of the link between the magnetic fields and underlying dynamo mechanisms, rotation, and activity. Aims. In this work we aim to measure magnetic fields from the high-resolution near-infrared spectra taken with the CARMENES radial-velocity planet survey in a sample of 29 active M dwarfs and compare our results against stellar parameters. Methods. We used the state-of-the-art radiative transfer code to measure total magnetic flux densities from the Zeeman broadening of spectral lines and filling factors. Results. We detect strong kG magnetic fields in all our targets. In 16 stars the magnetic fields were measured for the first time. Our measurements are consistent with the magnetic field saturation in stars with rotation periods P < 4 d. The analysis of the magnetic filling factors reveal two different patterns of either very smooth distribution or a more patchy one, which can be connected to the dynamo state of the stars and/or stellar mass. Conclusions. Our measurements extend the list of M dwarfs with strong surface magnetic fields. They also allow us to better constrain the interplay between the magnetic energy, stellar rotation, and underlying dynamo action. The high spectral resolution and observations at near-infrared wavelengths are the beneficial capabilities of the CARMENES instrument that allow us to address important questions about the stellar magnetism.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.6
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available