X-Ray Morphology Due to Charge-exchange Emissions Used to Study the Global Structure around Mars
X-Ray Morphology Due to Charge-exchange Emissions Used to Study the Global Structure around Mars
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电荷交换发射产生的 X 射线形态用于研究火星周围的全球结构
DOI：
10.3847/1538-4357/acac7e
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发表时间：
2022-12
影响因子：
4.9
通讯作者：
Zhao G.
中科院分区：
文献类型：
--
作者：
Liang G.Y.;Sun T.R.;Lu H.Y.;Zhu X.L.;Wu Y.;Li S.B.;Wei H.G.;Yuan D.W.;Zhong J.Y.;Cui W.;Ma X.W.;Zhao G.
太阳风离子与太阳系中性物质碰撞产生的软X射线辐射已经在行星周围被探测到，并被提议作为太阳风与火星外圈相互作用的远程探测器。采用多流体三维磁流体力学模型计算了太阳风粒子的全球分布。利用球对称的外层H、H2、He、O和CO2密度分布和一个包括电荷交换和质子中性激发过程的复杂的混合模型，研究了Ovii的低三重线比G=i+fr(0.77±0.58)和火星周围的总X射线光度。我们进一步计算了在较宽的离子丰度和速度范围内，不同中性物的发射因子α值。我们的结果与以前的报道吻合得很好。太阳风离子电荷阶段的演化表明，在相互作用区，电荷交换引起的有序复合可以忽略不计。这只出现在海拔400公里以下。在中性密度高于1011 cm−3的情况下，碰撞猝灭效应很容易解释这种低的盘G比。然而，在火星的外圈，猝灭的贡献很小，只出现在400公里以下。与H_2和N_2的电荷交换仍然是这种低G比的最可能的原因。不同中性粒子碰撞中的X射线发射率图各不相同。与所有中立子的碰撞产生了明显的弓形激波，这与之前的报道一致。由此得到的X射线总光度为6.55 mW，与XMM-牛顿观测的12.8±1.4 mW相比，符合得更好。
Soft X-ray emissions induced by solar wind ions that collide with neutral material in the solar system have been detected around planets, and were proposed as a remote probe for solar wind interaction with the Martian exosphere. A multi-fluid three-dimensional magnetohydrodynamic model is adopted to derive the global distributions of solar wind particles. Spherically symmetric exospheric H, H2, He, O, and CO2 density profiles and a sophisticated hybrid model that includes charge-exchange and proton–neutral excitation processes are used to study the low triplet line ratio G=i+fr (0.77 ± 0.58) of O vii and the total X-ray luminosity around Mars. We further calculate the emission factor α-value with different neutrals over wide ion-abundance and velocity ranges. Our results are in good agreement with those of previous reports. The evolution of the charge stage of solar wind ions shows that sequential recombination due to charge-exchange can be negligible in the interaction region. This only appears below an altitude of 400 km. The anonymous low disk G-ratio can be easily explained by the collisional quenching effect at neutral densities higher than 1011 cm−3. However, the quenching contribution is small in Mars’ exosphere and only appears below 400 km. Charge-exchange with H2 and N2 is still the most likely reason for this low G-ratio. X-ray emissivity maps in collisions with different neutrals differ from each other. A clear bow shock arising from the collision with all the neutrals is in accordance with previous reports. The resulting total X-ray luminosity of 6.55 MW shows better agreement with the XMM-Newton observation of 12.8 ± 1.4 MW than that of previous predictions.
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DOI：
10.1007/springerreference_30900
发表时间：
2019-05
期刊：
Destined for the Stars
影响因子：
--
作者：
Robert L. Marcialis
通讯作者：
Robert L. Marcialis
DOI：
10.3847/1538-4357/ac6876
发表时间：
2022-05
期刊：
The Astrophysical Journal
影响因子：
--
作者：
R. Zhang;D. Seely;V. Andrianarijaona;I. Draganic;C. Havener
通讯作者：
R. Zhang;D. Seely;V. Andrianarijaona;I. Draganic;C. Havener
影响因子：
3.2
作者：
V. Krasnopolsky
通讯作者：
V. Krasnopolsky
DOI：
10.3847/1538-4357/aa7752
发表时间：
2017-07
期刊：
The Astrophysical Journal
影响因子：
--
作者：
P. D. Mullen;R. Cumbee;D. Lyons;L. Gu;J. Kaastra;R. Shelton;P. Stancil
通讯作者：
P. D. Mullen;R. Cumbee;D. Lyons;L. Gu;J. Kaastra;R. Shelton;P. Stancil
影响因子：
6.5
作者：
D. Koutroumpa;R. Lallement;V. Kharchenko;A. Dalgarno;R. Pepino;V. Izmodenov;E. Quémerais
通讯作者：
D. Koutroumpa;R. Lallement;V. Kharchenko;A. Dalgarno;R. Pepino;V. Izmodenov;E. Quémerais