Scintillation-induced variability in radio absorption spectra against extragalactic sources
Spectral features absorbed against some radio quasars exhibit ~50 mJy variations, with the lines varying both relative to the continuum and, when several lines are present, even relative to one another. We point out that such variability can be expected as a consequence of refractive scintillation c...
| Main Author: | |
|---|---|
| Format: | Journal Article |
| Published: |
EDP Sciences
2005
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.11937/40033 |
| _version_ | 1848755756085542912 |
|---|---|
| author | Macquart, Jean-pierre |
| author_facet | Macquart, Jean-pierre |
| author_sort | Macquart, Jean-pierre |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Spectral features absorbed against some radio quasars exhibit ~50 mJy variations, with the lines varying both relative to the continuum and, when several lines are present, even relative to one another. We point out that such variability can be expected as a consequence of refractive scintillation caused by the interstellar medium of our Galaxy. Scintillation can cause independent variations between closely-spaced spectral lines, and can even alter the line profile. The background source need not he compact to exhibit spectral variability. The variability can he used to infer the parsec to sub-parsec scale structure of the intervening absorbing material. We discuss the importance of scintillation relative to other possible origins of spectral variability. The present theory is applied to account for the variations observed in the HI-absorbed quasar PKS I 127-145. |
| first_indexed | 2025-11-14T09:01:21Z |
| format | Journal Article |
| id | curtin-20.500.11937-40033 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:01:21Z |
| publishDate | 2005 |
| publisher | EDP Sciences |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-400332017-09-13T15:53:17Z Scintillation-induced variability in radio absorption spectra against extragalactic sources Macquart, Jean-pierre Interstellar matter Variability Galaxy structure Continuum scattering Galaxies Absorption spectra radio lines Line shape high angular resolution Extragalactic source Quasars Radio spectrum Spectral features absorbed against some radio quasars exhibit ~50 mJy variations, with the lines varying both relative to the continuum and, when several lines are present, even relative to one another. We point out that such variability can be expected as a consequence of refractive scintillation caused by the interstellar medium of our Galaxy. Scintillation can cause independent variations between closely-spaced spectral lines, and can even alter the line profile. The background source need not he compact to exhibit spectral variability. The variability can he used to infer the parsec to sub-parsec scale structure of the intervening absorbing material. We discuss the importance of scintillation relative to other possible origins of spectral variability. The present theory is applied to account for the variations observed in the HI-absorbed quasar PKS I 127-145. 2005 Journal Article http://hdl.handle.net/20.500.11937/40033 10.1051/0004-6361:20034425 EDP Sciences fulltext |
| spellingShingle | Interstellar matter Variability Galaxy structure Continuum scattering Galaxies Absorption spectra radio lines Line shape high angular resolution Extragalactic source Quasars Radio spectrum Macquart, Jean-pierre Scintillation-induced variability in radio absorption spectra against extragalactic sources |
| title | Scintillation-induced variability in radio absorption spectra against extragalactic sources |
| title_full | Scintillation-induced variability in radio absorption spectra against extragalactic sources |
| title_fullStr | Scintillation-induced variability in radio absorption spectra against extragalactic sources |
| title_full_unstemmed | Scintillation-induced variability in radio absorption spectra against extragalactic sources |
| title_short | Scintillation-induced variability in radio absorption spectra against extragalactic sources |
| title_sort | scintillation-induced variability in radio absorption spectra against extragalactic sources |
| topic | Interstellar matter Variability Galaxy structure Continuum scattering Galaxies Absorption spectra radio lines Line shape high angular resolution Extragalactic source Quasars Radio spectrum |
| url | http://hdl.handle.net/20.500.11937/40033 |