Skymaps of observables of three-dimensional magnetohydrodynamic astrosphere models
Skymaps of observables of three-dimensional magnetohydrodynamic astrosphere models
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DOI：
10.1051/0004-6361/201937017
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发表时间：
2020-02-11
影响因子：
6.5
通讯作者：
Weis, K.
中科院分区：
文献类型：
--
作者：
Baalmann, L. R.;Scherer, K.;Weis, K.
语境。天体的三维模型最近引起了人们的兴趣。然而，由于观测的二维性质，这些模型和观测之间的比较并非微不足道。通过将选定的天体三维模型的物理值投影到以虚拟全天观察者为中心的球体表面，这些模型可以与不同可观测值中的观测数据进行比较：柱密度、轫致辐射通量、旋转测量、H α通量以及同步加速器或回旋加速器通量。方法。通过将天体模型旋转和移动到所需的位置和方向，然后通过修改后的视线积分计算球体上给定斑块的值来计算投影。考虑了通过相关视线连接到贴片的所有模型单元对所选可观测值的贡献。结果。当模型产生弓激波时，在每个可观测的投影中都可以看到由外星鞘产生的独特抛物线结构，其确切形状取决于视线和恒星运动的方向。在所有四个检查的天体模型中，只有仙王座 lambda 的通量高于当前观测阈值。这是由于仙王座 lambda 模型的强烈恒星风和星际流入所致。
Context. Three-dimensional models of astrospheres have recently become of interest. However, comparisons between these models and observations are non-trivial because of the two-dimensional nature of observations.Aims. By projecting selected physical values of three-dimensional models of astrospheres onto the surface of a sphere that is centred on a virtual all-sky observer, these models can be compared to observational data in different observables: the column density, bremsstrahlung flux, rotation measure, H alpha flux, and synchrotron or cyclotron flux.Methods. Projections were calculated by rotating and moving the astrosphere model to the desired position and orientation and by then computing the value of a given patch on the sphere by a modified line-of-sight integration. Contributions to the selected observable made by all model cells that are connected to the patch by the line of sight in question were taken into account.Results. When the model produces a bow shock, a distinct parabolic structure produced by the outer astrosheath can be seen in every observable of the projection, the exact shape depending on the orientations of the line of sight and the stellar motion. Of all four examined astrosphere models, only that of lambda Cephei shows fluxes that are higher than current observational thresholds. This is due to the strong stellar wind and interstellar inflow of the lambda Cephei model.