κ Velorum: another variable interstellar sightline?
Crawford, Ian and Howarth, I.D. and Ryder, S.D. and Stathakis, R.A. (2000) κ Velorum: another variable interstellar sightline? Monthly Notices of the Royal Astronomical Society 319 (2), L1-L6. ISSN 0035-8711.
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Abstract
We present ultra-high-resolution (R = 900 000) observations of interstellar Na I and K I absorption lines towards κ Vel (HD 81188) which show clear evidence for temporal variation between 1994 and 2000. Specifically, the column densities of K0 and Na0 in the main velocity component have increased by 40 and 16 per cent, respectively, over this period. Earlier work had suggested that this component actually consists of two unresolved sub-components; this result is confirmed here, and the overall line profile is found to be consistent with only one of these sub-components having increased in strength since 1994. We argue that this variation is consistent with the line of sight gradually probing a cold, dense interstellar filament of the kind recently proposed by Heiles to explain other observations of small-scale structure in the interstellar medium.
Metadata
Item Type: | Article |
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School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
Depositing User: | Sarah Hall |
Date Deposited: | 13 Aug 2019 11:13 |
Last Modified: | 02 Aug 2023 17:53 |
URI: | https://eprints.bbk.ac.uk/id/eprint/28533 |
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