تقرير
Evidence for a toroidal magnetic field in the core of 3C 84
| العنوان: | Evidence for a toroidal magnetic field in the core of 3C 84 |
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| المؤلفون: | Paraschos, G. F., Debbrecht, L. C., Kramer, J. A., Traianou, E., Liodakis, I., Krichbaum, T. P., Kim, J. -Y., Janssen, M., Nair, D. G., Savolainen, T., Ros, E., Bach, U., Hodgson, J. A., Lisakov, M., MacDonald, N. R., Zensus, J. A. |
| المصدر: | A&A 686, L5 (2024) |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies |
| الوصف: | The spatial scales of relativistic radio jets, probed by relativistic magneto-hydrodynamic jet launching simulations (RMHDs) and by most very-long-baseline interferometry (VLBI) observations differ by an order of magnitude. Bridging the gap between these RMHD simulations and VLBI observations requires selecting nearby active galactic nuclei (AGN), the parsec-scale region of which can be resolved. 3C 84 is a nearby bright AGN fulfilling the necessary requirements: it is launching a powerful, relativistic jet powered by a central supermassive black hole, while also being very bright. Using 22 GHz global VLBI measurements of 3C 84 we aim to study its sub-parsec region in both total intensity and linear polarisation, to explore the properties of this jet, with a linear resolution of $\sim0.1$ parsec. We test different simulation setups by altering the bulk Lorentz factor $\Gamma$ of the jet, as well as the magnetic field configuration (toroidal, poloidal, helical). We confirm the persistence of a limb brightened structure, which reaches deep into the sub-parsec region. The corresponding electric vector position angles (EVPAs) follow the bulk jet flow inside but tend to be orthogonal to it near the edges. Our state-of-the-art RMHD simulations show that this geometry is consistent with a spine-sheath model, associated with a mildly relativistic flow and a toroidal magnetic field configuration. Comment: 10 pages, 8 figures, accepted for publication in Astronomy and Astrophysics |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/202450218 |
| URL الوصول: | http://arxiv.org/abs/2405.00097 |
| رقم الأكسشن: | edsarx.2405.00097 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/202450218 |
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