Pulsar observations of extreme scattering events
Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage of a "diverging plasma lens" across the line of sig...
| Main Authors: | , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
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Institute of Physics Publishing
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/36200 |
| _version_ | 1848754702846525440 |
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| author | Coles, W. Kerr, M. Shannon, Ryan Hobbs, G. Manchester, R. You, X. Bailes, M. Bhat, N. Burke-Spolaor, S. Dai, S. Keith, M. Levin, Y. Oslowski, S. Ravi, V. Reardon, D. Toomey, L. Straten, W. Wang, J. Wen, L. Zhu, X. |
| author_facet | Coles, W. Kerr, M. Shannon, Ryan Hobbs, G. Manchester, R. You, X. Bailes, M. Bhat, N. Burke-Spolaor, S. Dai, S. Keith, M. Levin, Y. Oslowski, S. Ravi, V. Reardon, D. Toomey, L. Straten, W. Wang, J. Wen, L. Zhu, X. |
| author_sort | Coles, W. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage of a "diverging plasma lens" across the line of sight (LOS). Modeling the refraction of such a lens indicates that the structure size must be of the order of AU and the electron density of the order of 10s of cm−3. Similar structures have been observed in measurements of pulsar intensity scintillation and group delay. Here we report observations of two ESEs, showing increases in both intensity scintillation and dispersion made with the Parkes Pulsar Timing Array. These allow us to make more complete models of the ESE, including an estimate of the "outer-scale" of the turbulence in the plasma lens. These observations clearly show that the ESE structure is fully turbulent on an AU scale. They provide some support for the idea that the structures are extended along the LOS, such as would be the case for a scattering shell. The dispersion measurements also show a variety of AU scale structures that would not be called ESEs, yet involve electron density variations typical of ESEs and likely have the same origin. |
| first_indexed | 2025-11-14T08:44:37Z |
| format | Journal Article |
| id | curtin-20.500.11937-36200 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:44:37Z |
| publishDate | 2015 |
| publisher | Institute of Physics Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-362002023-02-22T06:24:17Z Pulsar observations of extreme scattering events Coles, W. Kerr, M. Shannon, Ryan Hobbs, G. Manchester, R. You, X. Bailes, M. Bhat, N. Burke-Spolaor, S. Dai, S. Keith, M. Levin, Y. Oslowski, S. Ravi, V. Reardon, D. Toomey, L. Straten, W. Wang, J. Wen, L. Zhu, X. Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage of a "diverging plasma lens" across the line of sight (LOS). Modeling the refraction of such a lens indicates that the structure size must be of the order of AU and the electron density of the order of 10s of cm−3. Similar structures have been observed in measurements of pulsar intensity scintillation and group delay. Here we report observations of two ESEs, showing increases in both intensity scintillation and dispersion made with the Parkes Pulsar Timing Array. These allow us to make more complete models of the ESE, including an estimate of the "outer-scale" of the turbulence in the plasma lens. These observations clearly show that the ESE structure is fully turbulent on an AU scale. They provide some support for the idea that the structures are extended along the LOS, such as would be the case for a scattering shell. The dispersion measurements also show a variety of AU scale structures that would not be called ESEs, yet involve electron density variations typical of ESEs and likely have the same origin. 2015 Journal Article http://hdl.handle.net/20.500.11937/36200 10.1088/0004-637X/808/2/113 Institute of Physics Publishing unknown |
| spellingShingle | Coles, W. Kerr, M. Shannon, Ryan Hobbs, G. Manchester, R. You, X. Bailes, M. Bhat, N. Burke-Spolaor, S. Dai, S. Keith, M. Levin, Y. Oslowski, S. Ravi, V. Reardon, D. Toomey, L. Straten, W. Wang, J. Wen, L. Zhu, X. Pulsar observations of extreme scattering events |
| title | Pulsar observations of extreme scattering events |
| title_full | Pulsar observations of extreme scattering events |
| title_fullStr | Pulsar observations of extreme scattering events |
| title_full_unstemmed | Pulsar observations of extreme scattering events |
| title_short | Pulsar observations of extreme scattering events |
| title_sort | pulsar observations of extreme scattering events |
| url | http://hdl.handle.net/20.500.11937/36200 |