Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn
In a previous paper we presented an updated magnetic field map for the chemically peculiar star Alpha 2 CVn using ESPaDOnS and Narval time-resolved high-resolution Stokes $IQUV$ spectra. In this paper we focus on mapping various chemical element distributions on the surface of Alpha 2 CVn. With the...
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ftdatacite:10.48550/arxiv.1407.7695 2023-05-15T18:50:52+02:00 Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn Silvester, James Kochukhov, Oleg Wade, Gregg A 2014 https://dx.doi.org/10.48550/arxiv.1407.7695 https://arxiv.org/abs/1407.7695 unknown arXiv https://dx.doi.org/10.1093/mnras/stu1531 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences article-journal Article ScholarlyArticle Text 2014 ftdatacite https://doi.org/10.48550/arxiv.1407.7695 https://doi.org/10.1093/mnras/stu1531 2022-04-01T12:50:35Z In a previous paper we presented an updated magnetic field map for the chemically peculiar star Alpha 2 CVn using ESPaDOnS and Narval time-resolved high-resolution Stokes $IQUV$ spectra. In this paper we focus on mapping various chemical element distributions on the surface of Alpha 2 CVn. With the new magnetic field map and new chemical abundance distributions we can investigate the interplay between the chemical abundance structures and the magnetic field topology on the surface of Alpha 2 CVn. Previous attempts at chemical abundance mapping of Alpha 2 CVn relied on lower resolution data. With our high resolution (R=65,000) dataset we present nine chemical abundance maps for the elements O, Si, Cl, Ti, Cr, Fe, Pr, Nd and Eu. We also derive an updated magnetic field map from Fe and Cr lines in Stokes $IQUV$ and O and Cl in Stokes $IV$. These new maps are inferred from line profiles in Stokes $IV$ using the magnetic Doppler imaging code Invers10. We examine these new chemical maps and investigate correlations with the magnetic topology of Alpha 2 CVn. We show that chemical abundance distributions vary between elements, with two distinct groups of elements; one accumulates close to the negative part of the radial field, whilst the other group shows higher abundances located where the radial magnetic field is on the order of 2 kG regardless of the polarity of the radial field component. We compare our results with previous works which have mapped chemical abundance structures of Ap stars. With the exception of Cr and Fe, we find no clear trend between what we reconstruct and other mapping results. We also find a lack of agreement with theoretical predictions. This suggests that there is a gap in our theoretical understanding of the formation of horizontal chemical abundance structures and the connection to the magnetic field in Ap stars. : 14 Pages, 8 Figures, Accepted in MNRAS Text narval narval DataCite Metadata Store (German National Library of Science and Technology) |
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Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences |
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Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences Silvester, James Kochukhov, Oleg Wade, Gregg A Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn |
topic_facet |
Solar and Stellar Astrophysics astro-ph.SR FOS Physical sciences |
description |
In a previous paper we presented an updated magnetic field map for the chemically peculiar star Alpha 2 CVn using ESPaDOnS and Narval time-resolved high-resolution Stokes $IQUV$ spectra. In this paper we focus on mapping various chemical element distributions on the surface of Alpha 2 CVn. With the new magnetic field map and new chemical abundance distributions we can investigate the interplay between the chemical abundance structures and the magnetic field topology on the surface of Alpha 2 CVn. Previous attempts at chemical abundance mapping of Alpha 2 CVn relied on lower resolution data. With our high resolution (R=65,000) dataset we present nine chemical abundance maps for the elements O, Si, Cl, Ti, Cr, Fe, Pr, Nd and Eu. We also derive an updated magnetic field map from Fe and Cr lines in Stokes $IQUV$ and O and Cl in Stokes $IV$. These new maps are inferred from line profiles in Stokes $IV$ using the magnetic Doppler imaging code Invers10. We examine these new chemical maps and investigate correlations with the magnetic topology of Alpha 2 CVn. We show that chemical abundance distributions vary between elements, with two distinct groups of elements; one accumulates close to the negative part of the radial field, whilst the other group shows higher abundances located where the radial magnetic field is on the order of 2 kG regardless of the polarity of the radial field component. We compare our results with previous works which have mapped chemical abundance structures of Ap stars. With the exception of Cr and Fe, we find no clear trend between what we reconstruct and other mapping results. We also find a lack of agreement with theoretical predictions. This suggests that there is a gap in our theoretical understanding of the formation of horizontal chemical abundance structures and the connection to the magnetic field in Ap stars. : 14 Pages, 8 Figures, Accepted in MNRAS |
format |
Text |
author |
Silvester, James Kochukhov, Oleg Wade, Gregg A |
author_facet |
Silvester, James Kochukhov, Oleg Wade, Gregg A |
author_sort |
Silvester, James |
title |
Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn |
title_short |
Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn |
title_full |
Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn |
title_fullStr |
Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn |
title_full_unstemmed |
Stokes $IQUV$ magnetic Doppler imaging of Ap stars - III. Next generation chemical abundance mapping of Alpha 2 CVn |
title_sort |
stokes $iquv$ magnetic doppler imaging of ap stars - iii. next generation chemical abundance mapping of alpha 2 cvn |
publisher |
arXiv |
publishDate |
2014 |
url |
https://dx.doi.org/10.48550/arxiv.1407.7695 https://arxiv.org/abs/1407.7695 |
genre |
narval narval |
genre_facet |
narval narval |
op_relation |
https://dx.doi.org/10.1093/mnras/stu1531 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1407.7695 https://doi.org/10.1093/mnras/stu1531 |
_version_ |
1766244624726228992 |