Using numerical models of bow shocks to investigate the circumstellar medium of massive stars

13th Annual International Astrophysics Conference: Voyager, IBEX, and the Interstellar Medium

物理学;天文学

Van Marle, A.J.^1 ; Decin, L.^1 ; Cox, N.L.J.^1 ; Meliani, Z.^2,3

Institute of Astronomy, KU Leuven, 200d C., Leueven

B-3001, Belgium^1

Observatoire de Paris, 5 place Jules Janssen, Meudon

92195, France^2

APC, Université Paris Diderot, 10 rue Alice Domon et Léonie Duquet, Paris Cedex 13

75205, France^3

关键词: Dust distribution;    Infrared observations;    Interstellar dust;    Interstellar magnetic fields;    Interstellar mediums;    Numerical hydrodynamics;    Physical phenomena;    Supersonic speed;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/577/1/012024/pdf
DOI  :  10.1088/1742-6596/577/1/012024

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

Many massive stars travel through the interstellar medium at supersonic speeds. As a result they form bow shocks at the interface between the stellar wind. We use numerical hydrodynamics to reproduce such bow shocks numerically, creating models that can be compared to observations. In this paper we discuss the influence of two physical phenomena, interstellar magnetic fields and the presence of interstellar dust grains on the observable shape of the bow shocks of massive stars. We find that the interstellar magnetic field, though too weak to restrict the general shape of the bow shock, reduces the size of the instabilities that would otherwise be observed in the bow shock of a red supergiant. The interstellar dust grains, due to their inertia can penetrate deep into the bow shock structure of a main sequence O-supergiant, crossing over from the ISM into the stellar wind. Therefore, the dust distribution may not always reflect the morphology of the gas. This is an important consideration for infrared observations, which are dominated by dust emission. Our models clearly show, that the bow shocks of massive stars are useful diagnostic tools that can used to investigate the properties of both the stellar wind as well as the interstellar medium.