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| Main Authors: | , , , , , , |
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| Format: | Preprint |
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2024
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2403.13500 |
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| _version_ | 1866909216435863552 |
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| author | Ranchod, S. Mao, S. A. Deane, R. Sridhar, S. S. Damas-Segovia, A. Livingston, J. D. Ma, Y. K. |
| author_facet | Ranchod, S. Mao, S. A. Deane, R. Sridhar, S. S. Damas-Segovia, A. Livingston, J. D. Ma, Y. K. |
| contents | The S-band Polarisation All Sky Survey (SPASS/ATCA) rotation measure (RM) catalogue is the largest broadband RM catalogue to date, increasing the RM density in the sparse southern sky. Through analysis of this catalogue, we report a latitude dependency of the Faraday complexity of polarised sources in this catalogue within 10$^\circ$ of the Galactic plane towards the inner Galaxy. In this study, we aim to investigate this trend with follow-up observations using the Australia Telescope Compact Array (ATCA). We observe 95 polarised sources from the SPASS/ATCA RM catalogue at 1.1 - 3.1 GHz with ATCA's 6 km configuration. We present Stokes QU fitting results and a comparative analysis with the SPASS/ATCA catalogue. We find an overall decrease in complexity in these sources with the higher angular resolution observations, with a complexity fraction of 42\%, establishing that the majority of the complexity in the SPASS/ATCA sample is due to the mixing-in of diffuse Galactic emission at scales $θ> 2.8'$. Furthermore, we find a correlation between our observed small-scale complexity $θ< 2.8'$ and the Galactic spiral arms, which we interpret to be due to Galactic turbulence or small-scale polarised emission. These results emphasise the importance of considering the maximum angular scale to which the observations are sensitive in the classification of Faraday complexity; the effect of which can be more carefully investigated with SKA-precursor and pathfinder arrays (e.g. MeerKAT and ASKAP). |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2403_13500 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | The Galactic latitude dependency of Faraday complexity in the S-PASS/ATCA RM catalogue Ranchod, S. Mao, S. A. Deane, R. Sridhar, S. S. Damas-Segovia, A. Livingston, J. D. Ma, Y. K. Astrophysics of Galaxies The S-band Polarisation All Sky Survey (SPASS/ATCA) rotation measure (RM) catalogue is the largest broadband RM catalogue to date, increasing the RM density in the sparse southern sky. Through analysis of this catalogue, we report a latitude dependency of the Faraday complexity of polarised sources in this catalogue within 10$^\circ$ of the Galactic plane towards the inner Galaxy. In this study, we aim to investigate this trend with follow-up observations using the Australia Telescope Compact Array (ATCA). We observe 95 polarised sources from the SPASS/ATCA RM catalogue at 1.1 - 3.1 GHz with ATCA's 6 km configuration. We present Stokes QU fitting results and a comparative analysis with the SPASS/ATCA catalogue. We find an overall decrease in complexity in these sources with the higher angular resolution observations, with a complexity fraction of 42\%, establishing that the majority of the complexity in the SPASS/ATCA sample is due to the mixing-in of diffuse Galactic emission at scales $θ> 2.8'$. Furthermore, we find a correlation between our observed small-scale complexity $θ< 2.8'$ and the Galactic spiral arms, which we interpret to be due to Galactic turbulence or small-scale polarised emission. These results emphasise the importance of considering the maximum angular scale to which the observations are sensitive in the classification of Faraday complexity; the effect of which can be more carefully investigated with SKA-precursor and pathfinder arrays (e.g. MeerKAT and ASKAP). |
| title | The Galactic latitude dependency of Faraday complexity in the S-PASS/ATCA RM catalogue |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2403.13500 |