A highly sensitive search for magnetic fields in B, A and F stars

被引:141
作者
Shorlin, SLS [1 ]
Wade, GA
Donati, JF
Landstreet, JD
Petit, P
Sigut, TAA
Strasser, S
机构
[1] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada
[2] Royal Mil Coll Canada, Dept Phys, Kingston, ON K7K 7B4, Canada
[3] Observ Midi Pyrenees, F-31400 Toulouse, France
[4] Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada
关键词
line : profiles; polarization; stars : chemically peculiar; stars : magnetic fields; stars : atmospheres;
D O I
10.1051/0004-6361:20021192
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Circular spectropolarimetric observations of 74 stars were obtained in an attempt to detect magnetic fields via the longitudinal Zeeman effect in their spectral lines. The sample observed includes 22 normal B, A and F stars, four emission-line B and A stars, 25 Amstars,10 HgMn stars, two lambda Boo stars and 11 magnetic Ap stars. Using the Least-Squares Deconvolution multi-line analysis approach (Donati et al. 1997), high precision Stokes I and V mean signatures were extracted from each spectrum. We find absolutely no evidence for magnetic fields in the normal, Am and HgMn stars, with upper limits on longitudinal field measurements usually considerably smaller than any previously obtained for these objects. We conclude that if any magnetic fields exist in the photospheres of these stars, these fields are not ordered as in the magnetic Ap stars, nor do they resemble the fields of active late-type stars. We also detect for the first time a field in the A2pSr star HD 108945 and make new precise measurements of longitudinal fields in five previously known magnetic Ap stars, but do not detect fields in five other stars classified as Ap SrCrEu. We also report new results for several binary systems, including a new v sin i for the rapidly rotating secondary of the Am-delta Del SB2 HD 110951.
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页码:637 / 652
页数:16
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