A fresh perspective on the 3D dynamics of Tycho's supernova remnant: Ejecta asymmetries in X-ray band
A fresh perspective on the 3D dynamics of Tycho's supernova remnant: Ejecta asymmetries in X-ray band
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第谷超新星遗迹 3D 动力学的全新视角：X 射线带中的喷射物不对称性
DOI：
10.1051/0004-6361/202346954
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
J. Ballet
中科院分区：
文献类型：
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作者：
L. Godinaud;F. Acero;A. Decourchelle;J. Ballet
在Ia型超新星SN1572型爆炸450年后，第谷超新星残骸的动力学可以为我们理解爆炸机制以及残骸与星际介质的相互作用提供关键。为了探索不对称性和信噪比的演变，我们使用新的方法跟踪抛射动力学，这些方法应用于钱德拉太空望远镜档案中可用的深部X射线观测。对于视线速度测量VZ，我们利用聚焦在1.6-2.1keV波段明亮的硅线上的多普勒效应。使用组元分离工具通用形态组元分析(GMCA)，我们成功地解开了红移和蓝移的硅发射。这使我们能够重建具有2‘’分辨率的信噪比总覆盖率和视线速度的代理的硅线峰值能量的地图。对于天空Vxy平面内的自行，我们发展了一种新的方法，称为泊松光流，用于测量2003年至2009年观测之间的2D特征的位移。结果是覆盖整个SNR的1700个速度矢量场。这些详尽的三维速度测量揭示了SNR的复杂和斑驳的动力学。在大尺度上，观测到了北方以蓝移为主，南方以红移为主的不对称性。自行矢量场Vxy突出了SNR的东部和西部之间的不同动态。东部速度场更多地受到外部不均匀和东南抛射结的干扰。特别是，在东北部观察到了一种减速，这可能是由于与其他波长中看到的更高密度的相互作用所致。矢量场也被用来回溯爆炸的中心，然后将其与潜在的恒星前身与最新的Gaia DR3的距离进行比较，只有恒星B和E可能是候选恒星。
450 years after the explosion of the Type Ia SN1572, the dynamics of the Tycho supernova remnant can give us keys to understand the explosion mechanism and the interaction of the remnant with the interstellar medium. To probe the asymmetries and the evolution of the SNR, we track the ejecta dynamics using new methods applied to the deep X-ray observations available in the Chandra space telescope archive. For the line of sight velocity measurement Vz, we use the Doppler effect focused on the bright Si line in the 1.6-2.1 keV band. Using the component separation tool General Morphological Component Analysis (GMCA), we successfully disentangle the red and blueshifted Si ejecta emission. This allows us to reconstruct a map of the peak energy of the Si line with a total coverage of the SNR at a 2'' resolution and a proxy of the velocity in the line of sight. For the proper motions in the plane of the sky Vxy, we develop a new method, named Poisson Optical Flow, to measure the displacement of 2D features between the observations of 2003 and 2009. The result is a field of 1700 velocity vectors covering the entire SNR. These exhaustive 3D velocity measurements reveal the complex and patchy dynamics of the SNR. At the large-scale, an asymmetry with the North being dominantly blueshifted and the South redshifted is observed. The proper motion vector field Vxy highlights different dynamics between the East and the West parts of the SNR. The eastern velocity field is more disturbed by external inhomogeneities and the South-East ejecta knot. In particular, a slow-down is observed in the North-East which could be due to the interaction with higher densities as seen in other wavelengths. The vector field is also used to backtrace the center of the explosion which is then compared with potential stellar progenitors distances from the latest Gaia DR3, leaving only stars B and E as possible candidates.