Estimating the magnetic field strength from magnetograms

Bibcode
2015A&A...577A.125A
DOI
10.1051/0004-6361/201423859
Asensio Ramos, A.; Martínez González, M. J.; Manso Sainz, R.
Bibliographical reference

Astronomy and Astrophysics, Volume 577, id.A125, 8 pp.

Advertised on:
5
2015
Journal
Astronomy and Astrophysics
Number of authors
3
IAC number of authors
3
Citations
2
Refereed citations
2
Description
A properly calibrated longitudinal magnetograph is an instrument that measures circular polarization and gives an estimation of the magnetic flux density in each observed resolution element. This usually constitutes a lower bound of the field strength in the resolution element, given that it can be made arbitrarily large as long as it occupies a proportionally smaller area of the resolution element and/or becomes more transversal to the observer while still produce the same magnetic signal. However, we know that arbitrarily stronger fields are less likely - hG fields are more probable than kG fields, with fields above several kG virtually absent - and we may even have partial information about their angular distribution. Based on a set of sensible considerations, we derive simple formulae based on a Bayesian analysis to give an improved estimation of the magnetic field strength for magnetographs.
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Magnetic fields are at the base of star formation and stellar structure and evolution. When stars are born, magnetic fields brake the rotation during the collapse of the mollecular cloud. In the end of the life of a star, magnetic fields can play a key role in the form of the strong winds that lead to the last stages of stellar evolution. During

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In progress
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In progress
Type
Refereed
Magnetic fields
Methods
Solar Physics (FS)

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