Gupta, A., Mathur, S., Kingsbury, J. et al. Thermal and chemical properties of the eROSITA bubbles from Suzaku observations. Nat Astron (2023). https://doi.org/10.1038/s41550-023-01963-5
The X-ray bright bubbles at the Galactic Center provide an opportunity to understand the effects of feedback on galaxy evolution. The shells of the eROSITA bubbles show enhanced X-ray emission over the sky background. Previously, these shells were assumed to have a single temperature component and to trace the shock-heated lower-temperature halo gas. Using Suzaku observations, we show that the X-ray emission of the shells is more complex and best described by a two-temperature thermal model: one component close to the Galaxy's virial temperature and the other at super-virial temperatures. Furthermore, we demonstrate that temperatures of the virial and super-virial components are similar in the shells and in the ambient medium, although the emission measures are significantly higher in the shells. This leads us to conclude that the eROSITA bubble shells are X-ray bright because they trace denser gas, not because they are hotter. Given that the pre- and post-shock temperatures are similar and the compression ratio of the shock is high, we rule out that the bubble shells trace adiabatic shocks, in contrast to what was assumed in previous studies. We also observe non-solar Ne/O and Mg/O ratios in the shells, favouring stellar feedback models for the formation of the bubbles and settling a long-standing debate on their origin.
Asymmetric eROSITA bubbles as the evidence of a circumgalactic medium wind
通过同名仪器检测eROSITA气泡。北部的气泡显示出明显的不对称特征，包括向西的扭曲和东部边缘的增强，而南部的气泡则明显较暗。他们的起源有争议。在这里，我们进行了流体动力学模拟表明，不对称的eROSITA气泡有利于动态的，环星系介质风模型，但不利于其他机制，如非轴对称的晕气体或倾斜的核流出。在银河系坐标系中，从东偏北方向吹来的风以大约200 km s $^{-1}$的速度吹过北晕，并有一部分进入南晕。这创造了一个动态的晕圈介质，并重新分配密度和金属量。这自然解释了在形态和表面亮度两方面的不对称气泡。我们的研究结果表明，我们的银河系是吸积低丰度环星系介质从一侧，同时提供外流反馈。
The Double-Episode Jet Genesis of the eROSITA and Fermi Bubbles
Henan Normal University（河南师范大学）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Tianfu Cosmic Ray Research Center（天府宇宙线研究中心）；Guizhou University（贵州大学）；Handan University（邯郸学院）；Nanjing Normal University（南京师范大学）
Nested Fermi and eROSITA bubbles require very similar $\sim10^{56}$ erg collimated Galactic-center outbursts; their asymmetry indicates an eastern density gradient
Ben-Gurion University of the Negev（内盖夫本-古里安大学）；Indian Institute of Astrophysics（印度天体物理研究所）
Southern eROSITA bubble as a forward shock and the low-metallicity CGM. South-east side story
Max Planck Institute for Astrophysics（马克斯·普朗克天体物理学研究所）；Space Research Institute (IKI)（空间研究所）；Rudolf Peierls Centre for Theoretical Physics, Department of Physics, University of Oxford（牛津大学物理系鲁道夫·派尔斯理论物理中心）；Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München（慕尼黑大学物理学院天文台）；Ioffe Institute（约费研究所）；Institute of Astronomy, Russian Academy of Sciences（俄罗斯科学院天文研究所）；NRC ‘Kurchatov Institute’（库尔恰托夫国家研究中心）；Institute of Applied Physics of the Russian Academy of Sciences（俄罗斯科学院应用物理研究所）
Energy Spectra of the Soft X-ray Diffuse Emission in Fourteen Fields Observed with Suzaku
本文介绍了用朱雀观测到的十二个场的软漫射X射线发射，以及以前分析中的另外两个场。所有的星系都有65度< l < 295度的星系角，以避免来自非常明亮的漫射源的贡献，该漫射源从银河系中心延伸至少30度。朱雀星9个观测场的表面亮度在统计上与ROSAT全天巡天（RASS）值一致，在R45波段的差异上限为17 x 10^{-6} c s^{-1} amin^{-2}。Ovii和Oviii的强度彼此之间有很好的相关性，Ovii的发射在约2个光子s^{-1} cm^{-2 str^{-1}（LU）处显示出强度下限。高纬度的Oviii辐射与地面上方过量的Ovii辐射有密切的相关性，（Oviii强度）= 0.5 x [（Ovii强度）-2 LU]，这表明不同视线上的平均温度在约0.2 keV附近有一个狭窄的分布。我们认为Ovii的偏移强度来自太阳层太阳风的电荷交换，可能来自本地的热泡，而多余的Ovii（2-7 LU）是来自银河系更遥远的部分的发射。这个星系辐射的总辐射热光度估计为4 x 10^{39} erg s^{-1}，其特征温度可能与银河系的维里温度有关。
Simulating the Formation of the Young "Fermi Bubbles" in the Circinus Galaxy
Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；University of Chinese Academy of Sciences（中国科学院大学）；Tianfu Cosmic Ray Research Center（天府宇宙线研究中心）；School of Physics, Henan Normal University（河南师范大学物理学院）；Center for Theoretical Physics, Henan Normal University（河南师范大学理论物理中心）；Centre for Astrophysics Research, University of Hertfordshire（赫特福德大学天体物理研究中心）；INAF - Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）
Thermal Structure and Chemical Enrichment of the North and South Polar Spurs: Supersolar N/O and Ne/O in the X-ray Plasma
Columbus State Community College（哥伦布州立社区学院）；The Ohio State University（俄亥俄州立大学）；Center for Cosmology and Astroparticle Physics（宇宙学与高能粒子物理中心）；University of Miami（迈阿密大学）；Kavli Institute for Particle Astrophysics & Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理学与宇宙学研究所）；Instituto de Astronomia, Universidad Nacional Autonoma de Mexico（墨西哥国立自治大学天文学研究所）
The SRG/eROSITA All-Sky Survey: A comprehensive X-ray analysis of the Hydra I galaxy cluster
Universität Bonn（波恩大学）；Università degli studi di Roma ‘Tor Vergata’（罗马托维尔加塔大学）；INFN, Sezione di Roma 2（意大利国家核物理研究所罗马第二分部）；Max-Planck-Institut für Radioastronomie（马克斯·普朗克射电天文研究所）；Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡大学）
Tracing the Energetic Outflows from Galactic Nuclei: Observational Evidence for a Large-Scale Bipolar Radio and X-ray-emitting Bubble-like Structure in M106
