| Issue |
A&A
Volume 677, September 2023
|
|
|---|---|---|
| Article Number | A5 | |
| Number of page(s) | 11 | |
| Section | Interstellar and circumstellar matter | |
| DOI | https://doi.org/10.1051/0004-6361/202345934 | |
| Published online | 24 August 2023 | |
High-resolution simulations of LS 5039★
1
Universität Innsbruck, Institut für Astro- und Teilchenphysik,
Technikerstr. 25,
6020
Innsbruck, Austria
e-mail: ralf.kissmann@uibk.ac.at
2
Universität Innsbruck, Institut für Informatik,
Technikerstr. 21 a,
6020
Innsbruck, Austria
Received:
18
January
2023
Accepted:
9
June
2023
Context. We present an analysis of our high-resolution relativistic hydrodynamics model of the stellar- and pulsar-wind interactions in the LS-5039 system.
Aims. With our high-resolution simulation covering three orbital periods, we analyse the impact of turbulence with a particular focus on short-term and orbit-to-orbit variations.
Methods. Our model uses a relativistic hydrodynamical description of the wind interaction in the LS-5039 system, assuming a pulsar wind-driven scenario. The corresponding system of equations was solved using the finite-volume code CRONOS. We computed the statistical quantities, which are also relevant for particle acceleration in this system, from the results of multiple consecutive timesteps.
Results. In our simulation, we find that the previously observed shock structures related to the wind-collision region (WCR), including the pulsar-wind termination, are dynamically influenced by orbital motion. From our high-resolution simulation, we find high turbulence levels following from instabilities driven at the WCR. These instabilities lead to strong fluctuations of several dynamical quantities, especially around and after apastron. These fluctuations are expected to impact the particle transport and especially the related emission of non-thermal radiation. As an important example, the region for which gamma-ray emission has been found to be boosted due to relativistic beaming (in previous studies) shows strong variations in size both on short and orbital timescales.
Conclusions. Using a large computational domain together with a high spatial resolution allowed us to carry out a detailed study of fluctuations in stellar- and pulsar-wind interactions. The results indicate a possible influence on the non-thermal emission from this system, which will be analysed with dedicated simulations in a forthcoming publication.
Key words: stars: individual: LS 5039 / stars: winds, outflows / hydrodynamics / relativistic processes / gamma rays: stars / methods: numerical
A movie is available at https://www.aanda.org
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.