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Measurements of stellar magnetic fields using synthetic spectrum fitting

Nielsen, Krister LU and Wahlgren, Glenn LU (2002) In Astronomy & Astrophysics 395(2). p.549-556
Abstract
A sample of Ap and Bp stars have been investigated with respect to theirsurface magnetic field using synthetic spectrum fitting. The advantageof this technique is the simplicity in determining the surface fieldstrength and the possibility to apply it to objects whose spectrum doesnot display resolved Zeeman components. We show the usefulness of themethod by demonstrations on stellar spectra with resolved Zeemancomponents, where the results have been compared with values based onmeasurements of the Zeeman splitting for the magnetically sensitive FeIi lambda 6149 line. The objects <ASTROBJ>HD 192678</ASTROBJ> and<ASTROBJ>HD 165474</ASTROBJ> have been observed over their rotationalperiod to investigate magnetic field... (More)
A sample of Ap and Bp stars have been investigated with respect to theirsurface magnetic field using synthetic spectrum fitting. The advantageof this technique is the simplicity in determining the surface fieldstrength and the possibility to apply it to objects whose spectrum doesnot display resolved Zeeman components. We show the usefulness of themethod by demonstrations on stellar spectra with resolved Zeemancomponents, where the results have been compared with values based onmeasurements of the Zeeman splitting for the magnetically sensitive FeIi lambda 6149 line. The objects <ASTROBJ>HD 192678</ASTROBJ> and<ASTROBJ>HD 165474</ASTROBJ> have been observed over their rotationalperiod to investigate magnetic field variations. The analysis is thenextended to objects where no resolved structure is observed. The rapidlyrotating stars <ASTROBJ>HD 22316</ASTROBJ> and <ASTROBJ>HD10783</ASTROBJ> are used as examples where this method is useful toachieve a value of the surface field. The relative intensification ofthe Fe Ii lambda lambda 6147, 6149 lines is investigated in an attemptto understand its relation to the surface magnetic field strength forthe stars HD 22316 and HD 10783. Based on observations obtained with theNordic Optical Telescope, operated on the island of La Palma jointly byDenmark, Finland, Iceland, Norway, and Sweden, in the SpanishObservatorio del Roque de los Muchachos of the Instituto de Astrofisicade Canarias. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
magnetic fields, line: profiles, stars: chemically peculiar
in
Astronomy & Astrophysics
volume
395
issue
2
pages
549 - 556
publisher
EDP Sciences
external identifiers
  • wos:000179291000024
  • scopus:0036855278
ISSN
0004-6361
DOI
10.1051/0004-6361:20021276
language
English
LU publication?
yes
id
b694fc57-1905-4061-bd8d-6ee906186e96 (old id 130314)
date added to LUP
2007-07-13 14:16:36
date last changed
2017-05-21 04:18:00
@article{b694fc57-1905-4061-bd8d-6ee906186e96,
  abstract     = {A sample of Ap and Bp stars have been investigated with respect to theirsurface magnetic field using synthetic spectrum fitting. The advantageof this technique is the simplicity in determining the surface fieldstrength and the possibility to apply it to objects whose spectrum doesnot display resolved Zeeman components. We show the usefulness of themethod by demonstrations on stellar spectra with resolved Zeemancomponents, where the results have been compared with values based onmeasurements of the Zeeman splitting for the magnetically sensitive FeIi lambda 6149 line. The objects &lt;ASTROBJ&gt;HD 192678&lt;/ASTROBJ&gt; and&lt;ASTROBJ&gt;HD 165474&lt;/ASTROBJ&gt; have been observed over their rotationalperiod to investigate magnetic field variations. The analysis is thenextended to objects where no resolved structure is observed. The rapidlyrotating stars &lt;ASTROBJ&gt;HD 22316&lt;/ASTROBJ&gt; and &lt;ASTROBJ&gt;HD10783&lt;/ASTROBJ&gt; are used as examples where this method is useful toachieve a value of the surface field. The relative intensification ofthe Fe Ii lambda lambda 6147, 6149 lines is investigated in an attemptto understand its relation to the surface magnetic field strength forthe stars HD 22316 and HD 10783. Based on observations obtained with theNordic Optical Telescope, operated on the island of La Palma jointly byDenmark, Finland, Iceland, Norway, and Sweden, in the SpanishObservatorio del Roque de los Muchachos of the Instituto de Astrofisicade Canarias.},
  author       = {Nielsen, Krister and Wahlgren, Glenn},
  issn         = {0004-6361},
  keyword      = {magnetic fields,line: profiles,stars: chemically peculiar},
  language     = {eng},
  number       = {2},
  pages        = {549--556},
  publisher    = {EDP Sciences},
  series       = {Astronomy & Astrophysics},
  title        = {Measurements of stellar magnetic fields using synthetic spectrum fitting},
  url          = {http://dx.doi.org/10.1051/0004-6361:20021276},
  volume       = {395},
  year         = {2002},
}