Understanding the fossil magnetic fields of Ap/Bp stars: Conclusions from a volume-limited survey

TL;DR

This study presents a comprehensive, bias-free survey of magnetic fields in intermediate-mass stars within 100 parsecs, revealing new insights into the properties and prevalence of magnetic fields in Ap/Bp stars.

Contribution

It provides the first volume-limited, unbiased dataset of magnetic properties of intermediate-mass stars, improving understanding of magnetic field incidence and characteristics in Ap/Bp stars.

Findings

Approximately 10% of intermediate-mass stars host strong magnetic fields.

Nearly half of the sample had previously uncharacterized or poorly constrained magnetic properties.

The survey results challenge previous biased estimates of magnetic field prevalence.

Abstract

Various observational properties of Ap/Bp stars have been well-established such as the often-cited 10% incidence rate of strong, organized magnetic fields amongst all A- and B-type stars. However, these inferences have generally been drawn fromsurveys biased towards the strongest most easily detectable fields. A volume-limited spectropolarimetric survey of all intermediate-mass stars within 100 pc was initiated in 2007 in order to avoid the biases inherent in previous studies. This workyielded the magnetic properties of a large number of Ap/Bp stars in the sample; however, nearly half of the sample remained either unobserved or had relatively poor constraints on their field strengths and geometries. We have recently completed thissurvey using measurements obtained by ESPaDOnS and NARVAL. We discuss here some of the recent findings of this survey.