Issue |
A&A
Volume 686, June 2024
|
|
---|---|---|
Article Number | A189 | |
Number of page(s) | 5 | |
Section | Numerical methods and codes | |
DOI | https://doi.org/10.1051/0004-6361/202449459 | |
Published online | 12 June 2024 |
Statistical relations between spectropolarimetric observables and the polar strength of the stellar dipolar magnetic field
Department of Physics and Astronomy, Uppsala University,
Box 516,
75120
Uppsala,
Sweden
e-mail: oleg.kochukhov@physics.uu.se
Received:
2
February
2024
Accepted:
13
April
2024
Global magnetic fields of early-type stars are commonly characterised by the mean longitudinal magnetic field 〈Bz〉 and the mean field modulus 〈B〉, derived from the circular polarisation and intensity spectra, respectively. Observational studies often report a root mean square (rms) of 〈Bz〉 and an average value of 〈B〉. In this work, I used numerical simulations to establish statistical relationships between these cumulative magnetic observables and the polar strength, Bd, of a dipolar magnetic field. I show that in the limit of many measurements randomly distributed in rotational phase, 〈Bz〉rms = 0.179−0.043+0.031 Bd and 〈B〉avg = 0.691−0.023+0.020 Bd. The same values can be recovered with only three measurements, provided that the observations are distributed uniformly in the rotational phase. These conversion factors are suitable for ensemble analyses of large stellar samples, where each target is covered by a small number of magnetic measurements.
Key words: techniques: polarimetric / stars: early-type / stars: magnetic field
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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