Extreme abundance ratios in the polluted atmosphere of the cool white dwarf NLTT 19868
dc.contributor.author | Kawka, Adela | |
dc.contributor.author | Vennes, S. | |
dc.date.accessioned | 2018-12-13T09:11:46Z | |
dc.date.available | 2018-12-13T09:11:46Z | |
dc.date.created | 2018-12-12T02:46:40Z | |
dc.date.issued | 2016 | |
dc.identifier.citation | Kawka, A. and Vennes, S. 2016. Extreme abundance ratios in the polluted atmosphere of the cool white dwarf NLTT 19868. Monthly Notices of the Royal Astronomical Society. 458 (1): pp. 325-331. | |
dc.identifier.uri | http://hdl.handle.net/20.500.11937/71932 | |
dc.identifier.doi | 10.1093/mnras/stw383 | |
dc.description.abstract |
We present an analysis of intermediate-dispersion spectra and photometric data of the newly identified cool, polluted white dwarf NLTT 19868. The spectra obtained with X-shooter on the Very Large Telescope-Melipal show strong lines of calcium, and several lines of magnesium, aluminium and iron. We use these spectra and the optical-to-near-infrared spectral energy distribution to constrain the atmospheric parameters of NLTT 19868. Our analysis shows that NLTT 19868 is iron poor with respect to aluminium and calcium. A comparison with other cool, polluted white dwarfs shows that the Fe to Ca abundance ratio (Fe/Ca) varies by up to approximately two orders of magnitudes over a narrow temperature range with NLTT 19868 at one extremum in the Fe/Ca ratio and, in contrast, NLTT 888 at the other extremum. The sample shows evidence of extreme diversity in the composition of the accreted material: in the case of NLTT 888, the inferred composition of the accreted matter is akin to iron-rich planetary core composition, while in the case of NLTT 19868 it is close to mantle composition depleted by subsequent chemical separation at the bottom of the convection zone. | |
dc.publisher | Oxford University Press | |
dc.title | Extreme abundance ratios in the polluted atmosphere of the cool white dwarf NLTT 19868 | |
dc.type | Journal Article | |
dcterms.source.volume | 458 | |
dcterms.source.number | 1 | |
dcterms.source.startPage | 325 | |
dcterms.source.endPage | 331 | |
dcterms.source.issn | 0035-8711 | |
dcterms.source.title | Monthly Notices of the Royal Astronomical Society | |
curtin.note |
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. | |
curtin.department | Curtin Institute of Radio Astronomy (Physics) | |
curtin.accessStatus | Open access |