On rapid interstellar scintillation of quasars: PKS 1257-326 revisited
The line of sight towards the compact, radio loud quasar PKS 1257-326 passesthrough a patch of scattering plasma in the local Galactic ISM that causes large and rapid,intra-hour variations in the received flux density at centimetre wavelengths. This rapid interstellarscintillation (SS) has been occu...
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| Format: | Conference Paper |
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Cambridge University Press
2012
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| Online Access: | http://hdl.handle.net/20.500.11937/7455 |
| _version_ | 1848745373252714496 |
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| author | Bignall, Hayley Hodgson, J. |
| author2 | RE Griffin |
| author_facet | RE Griffin Bignall, Hayley Hodgson, J. |
| author_sort | Bignall, Hayley |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The line of sight towards the compact, radio loud quasar PKS 1257-326 passesthrough a patch of scattering plasma in the local Galactic ISM that causes large and rapid,intra-hour variations in the received flux density at centimetre wavelengths. This rapid interstellarscintillation (SS) has been occurring for at least 15 years, implying that the scattering“screen” is at least 100 AU in physical extent. Through observations of the ISS we have measuredmicroarcsecond-scale “core shifts” in PKS 1257-326, corresponding to changing opacityduring an intrinsic outburst. Recent analysis of VLA data of a sample of 128 quasars found 6sources scintillating with a characteristic time-scale of < 2 hours, suggesting that nearby scatteringscreens in the ISM may have a covering fraction of a few percent. That is an importantconsideration for proposed surveys of the transient and variable radio sky |
| first_indexed | 2025-11-14T06:16:19Z |
| format | Conference Paper |
| id | curtin-20.500.11937-7455 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:16:19Z |
| publishDate | 2012 |
| publisher | Cambridge University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-74552023-02-02T07:57:36Z On rapid interstellar scintillation of quasars: PKS 1257-326 revisited Bignall, Hayley Hodgson, J. RE Griffin RJ Hanisch RL Seaman quasars structure individual high angular resolution techniques ISM The line of sight towards the compact, radio loud quasar PKS 1257-326 passesthrough a patch of scattering plasma in the local Galactic ISM that causes large and rapid,intra-hour variations in the received flux density at centimetre wavelengths. This rapid interstellarscintillation (SS) has been occurring for at least 15 years, implying that the scattering“screen” is at least 100 AU in physical extent. Through observations of the ISS we have measuredmicroarcsecond-scale “core shifts” in PKS 1257-326, corresponding to changing opacityduring an intrinsic outburst. Recent analysis of VLA data of a sample of 128 quasars found 6sources scintillating with a characteristic time-scale of < 2 hours, suggesting that nearby scatteringscreens in the ISM may have a covering fraction of a few percent. That is an importantconsideration for proposed surveys of the transient and variable radio sky 2012 Conference Paper http://hdl.handle.net/20.500.11937/7455 10.1017/S1743921312000439 Cambridge University Press fulltext |
| spellingShingle | quasars structure individual high angular resolution techniques ISM Bignall, Hayley Hodgson, J. On rapid interstellar scintillation of quasars: PKS 1257-326 revisited |
| title | On rapid interstellar scintillation of quasars: PKS 1257-326 revisited |
| title_full | On rapid interstellar scintillation of quasars: PKS 1257-326 revisited |
| title_fullStr | On rapid interstellar scintillation of quasars: PKS 1257-326 revisited |
| title_full_unstemmed | On rapid interstellar scintillation of quasars: PKS 1257-326 revisited |
| title_short | On rapid interstellar scintillation of quasars: PKS 1257-326 revisited |
| title_sort | on rapid interstellar scintillation of quasars: pks 1257-326 revisited |
| topic | quasars structure individual high angular resolution techniques ISM |
| url | http://hdl.handle.net/20.500.11937/7455 |