PSR B0329+54: Substructure in the scatter-broadened image discovered with RadioAstron on baselines up to 330,000 km
| Autor: | Popov, M. V., Bartel, N., Gwinn, C. R., Johnson, M. D., Andrianov, A., Fadeev, E., Joshi, B. C., Kardashev, N. S., Karuppusamy, R., Kovalev, Y. Y., Kramer, M., Rudnitskiy, A., Shishov, V. I., Smirnova, T. V., Soglasnov, V. A., Zensus, J. A. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stw2353 |
| Popis: | We have resolved the scatter-broadened image of PSR B0329+54 and detected substructure within it. These results are not influenced by any extended structure of a source but instead are directly attributed to the interstellar medium. We obtained these results at 324 MHz with the ground-space interferometer RadioAstron which included the space radio telescope (SRT), ground-based Westerbork Synthesis Radio Telescope and 64-m Kalyazin Radio Telescope on baseline projections up to 330,000 km in 2013 November 22 and 2014 January 1 to 2. At short 15,000 to 35,000 km ground-space baseline projections the visibility amplitude decreases with baseline length providing a direct measurement of the size of the scattering disk of 4.8$\pm$0.8 mas. At longer baselines no visibility detections from the scattering disk would be expected. However, significant detections were obtained with visibility amplitudes of 3 to 5% of the maximum scattered around a mean and approximately constant up to 330,000 km. These visibilities reflect substructure from scattering in the interstellar medium and offer a new probe of ionized interstellar material. The size of the diffraction spot near Earth is 17,000$\pm$3,000 km. With the assumption of turbulent irregularities in the plasma of the interstellar medium, we estimate that the effective scattering screen is located 0.6$\pm$0.1 of the distance from Earth toward the pulsar. Comment: 9 pages, 4 figures, 2 tables; accepted by MNRAS |
| Databáze: | arXiv |
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