The magnetic field topology and chemical abundance distributions of the Ap star HD 32633
Previous observations of the Ap star HD 32633 indicated that its magnetic field was unusually complex in nature and could not be characterized by a simple dipolar structure. Here we derive magnetic field maps and chemical abundance distributions for this star using full Stokes vector (Stokes IQUV) h...
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Uppsala universitet, Institutionen för fysik och astronomi
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ftuppsalauniv:oai:DiVA.org:uu-267668 2023-05-15T18:50:48+02:00 The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 Silvester, James Kochukhov, Oleg Wade, G. A. 2015 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267668 https://doi.org/10.1093/mnras/stv1775 eng eng Uppsala universitet, Institutionen för fysik och astronomi Uppsala universitet, Observationell astrofysik Royal Mil Coll Canada, Dept Phys, Kingston, ON K7K 7B4, Canada. Monthly notices of the Royal Astronomical Society, 0035-8711, 2015, 453:2, s. 2163-2176 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267668 doi:10.1093/mnras/stv1775 ISI:000363486000082 info:eu-repo/semantics/openAccess stars: chemically peculiar stars: individual: HD 32633 stars: magnetic field Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi Article in journal info:eu-repo/semantics/article text 2015 ftuppsalauniv https://doi.org/10.1093/mnras/stv1775 2023-02-23T21:49:01Z Previous observations of the Ap star HD 32633 indicated that its magnetic field was unusually complex in nature and could not be characterized by a simple dipolar structure. Here we derive magnetic field maps and chemical abundance distributions for this star using full Stokes vector (Stokes IQUV) high-resolution observations obtained with the ESPaDOnS and Narval spectropolarimeters. Our maps, produced using the INVERS 10 magnetic Doppler imaging (MDI) code, show that HD 32633 has a strong magnetic field which features two large regions of opposite polarity but deviates significantly from a pure dipole field. We use a spherical harmonic expansion to characterize the magnetic field and find that the harmonic energy is predominately in the l = 1 and 2 poloidal modes with a small toroidal component. At the same time, we demonstrate that the observed Stokes parameter profiles of HD 32633 cannot be fully described by either a dipolar or dipolar plus quadrupolar field geometry. We compare the magnetic field topology of HD 32633 with other early-type stars for which MDI analyses have been performed, supporting a trend of increasing field complexity with stellar mass. We then compare the magnetic field topology of HD 32633 with derived chemical abundance maps for the elements Mg, Si, Ti, Cr, Fe, Ni and Nd. We find that the iron-peak elements show similar distributions, but we are unable to find a clear correlation between the location of local chemical enhancements or depletions and the magnetic field structure. Article in Journal/Newspaper narval narval Uppsala University: Publications (DiVA) Monthly Notices of the Royal Astronomical Society 453 2 2163 2176 |
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Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
stars: chemically peculiar stars: individual: HD 32633 stars: magnetic field Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi |
spellingShingle |
stars: chemically peculiar stars: individual: HD 32633 stars: magnetic field Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi Silvester, James Kochukhov, Oleg Wade, G. A. The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 |
topic_facet |
stars: chemically peculiar stars: individual: HD 32633 stars: magnetic field Astronomy Astrophysics and Cosmology Astronomi astrofysik och kosmologi |
description |
Previous observations of the Ap star HD 32633 indicated that its magnetic field was unusually complex in nature and could not be characterized by a simple dipolar structure. Here we derive magnetic field maps and chemical abundance distributions for this star using full Stokes vector (Stokes IQUV) high-resolution observations obtained with the ESPaDOnS and Narval spectropolarimeters. Our maps, produced using the INVERS 10 magnetic Doppler imaging (MDI) code, show that HD 32633 has a strong magnetic field which features two large regions of opposite polarity but deviates significantly from a pure dipole field. We use a spherical harmonic expansion to characterize the magnetic field and find that the harmonic energy is predominately in the l = 1 and 2 poloidal modes with a small toroidal component. At the same time, we demonstrate that the observed Stokes parameter profiles of HD 32633 cannot be fully described by either a dipolar or dipolar plus quadrupolar field geometry. We compare the magnetic field topology of HD 32633 with other early-type stars for which MDI analyses have been performed, supporting a trend of increasing field complexity with stellar mass. We then compare the magnetic field topology of HD 32633 with derived chemical abundance maps for the elements Mg, Si, Ti, Cr, Fe, Ni and Nd. We find that the iron-peak elements show similar distributions, but we are unable to find a clear correlation between the location of local chemical enhancements or depletions and the magnetic field structure. |
format |
Article in Journal/Newspaper |
author |
Silvester, James Kochukhov, Oleg Wade, G. A. |
author_facet |
Silvester, James Kochukhov, Oleg Wade, G. A. |
author_sort |
Silvester, James |
title |
The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 |
title_short |
The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 |
title_full |
The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 |
title_fullStr |
The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 |
title_full_unstemmed |
The magnetic field topology and chemical abundance distributions of the Ap star HD 32633 |
title_sort |
magnetic field topology and chemical abundance distributions of the ap star hd 32633 |
publisher |
Uppsala universitet, Institutionen för fysik och astronomi |
publishDate |
2015 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267668 https://doi.org/10.1093/mnras/stv1775 |
genre |
narval narval |
genre_facet |
narval narval |
op_relation |
Monthly notices of the Royal Astronomical Society, 0035-8711, 2015, 453:2, s. 2163-2176 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267668 doi:10.1093/mnras/stv1775 ISI:000363486000082 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1093/mnras/stv1775 |
container_title |
Monthly Notices of the Royal Astronomical Society |
container_volume |
453 |
container_issue |
2 |
container_start_page |
2163 |
op_container_end_page |
2176 |
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1766244557901529088 |