The non-thermal emission from the colliding-wind binary Apep
| Autor: | S. del Palacio, P. Benaglia, M. De Becker, V. Bosch-Ramon, G. E. Romero |
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| Přispěvatelé: | Ministerio de Ciencia e Innovación (España), Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
non-thermal [Radiation mechanisms] Radiation Radiation mechanisms: non-thermal Astrophysics::High Energy Astrophysical Phenomena Relativistic processes FOS: Physical sciences Relativity (Physics) Astronomy and Astrophysics Outflows Astrophysics::Cosmology and Extragalactic Astrophysics Relativitat (Física) Stars Stars: winds Radiació Estels Space and Planetary Science massive [Stars] Computer Science::Programming Languages Stars: massive winds [Stars] Astrophysics - High Energy Astrophysical Phenomena Astrophysics::Galaxy Astrophysics |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Dipòsit Digital de la UB Universidad de Barcelona |
| Popis: | The recently discovered massive binary system Apep is the most powerful synchrotron emitter among the known Galactic colliding-wind binaries. This makes this particular system of great interest to investigate stellar winds and the non-thermal processes associated with their shocks. This source was detected at various radio bands, and in addition the wind-collision region was resolved by means of very-long baseline interferometric observations. We use a non-thermal emission model for colliding-wind binaries to derive physical properties of this system. The observed morphology in the resolved maps allows us to estimate the system projection angle on the sky to be $\psi \approx 85^\circ$. The observed radio flux densities also allow us to characterise both the intrinsic synchrotron spectrum of the source and its modifications due to free--free absorption in the stellar winds at low frequencies; from this we derive mass-loss rates of the stars of $\dot{M}_\mathrm{WN} \approx 4\times10^{-5}$ $\mathrm{M}_\odot$ yr$^{-1}$ and $\dot{M}_\mathrm{WC} \approx 2.9\times10^{-5}$ $\mathrm{M}_\odot$ yr$^{-1}$. Finally, the broadband spectral energy distribution is calculated for different combinations of the remaining free parameters, namely the intensity of the magnetic field and the injected power in non-thermal particles. We show that the degeneracy of these two parameters can be solved with observations in the high-energy domain, most likely in the hard X-rays but also possibly in $\gamma$-rays under favourable conditions. Comment: 10 pages, 5 figures, 2 tables. This version has been accepted for publication in PASA after improvements and updates in the discussion of the results |
| Databáze: | OpenAIRE |
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