Studies on the Relativistic Sunyaev-Zeldovich Effect for Clusters of Galaxies

1.星系团中多重散射对Sunyaev-Zeldovich效应的影响我们利用Fokker-Planck展开方法和Boltzmann碰撞项的数值积分，研究了星系团中多重散射对相对论Sunyaev-Zeldovich效应的影响。我们发现，对于普通星系团，多重散射效应远小于单次散射贡献的1%。这一结果支持了本研究者及其合作者在以前的计算中使用的单散射近似的有效性。随着这项工作的开展，相对论性Sunyaev-Zeldovich效应的研究进入了精密科学阶段。此外，本研究结果对统计物理领域的研究具有重要的参考价值。2.极热星系团的Sunyaev-Zeldovich效应最近发现了温度超过25 keV的星系团。因此，对极热星系团进行Sunyaev-Zeldovich效应的计算是非常重要的。本研究者与合作者对1 keV < T < 50 keV的温度范围进行了详细的数值计算，给出了详细的数值表和精确的解析拟合公式。这项工作将是非常有价值的未来Sunyaev-Zeldovich效应观测星系团。这项工作已发表在天文学和天体物理学。

1.Multiple-Scattering Effects on the Sunyaev-Zeldovich Effect for Clusters of GalaxiesWe have studied the multiple-scattering effects on the relativistic Sunyaev-Zeldovich effect for clusters of galaxies by using the Fokker-Planck expansion method as well as the numerical integration of the Boltzmann collision term. We have found that the multiple-scattering effect is much less than 1% of the single-scattering contribution for ordinary galaxy clusters. This result gives a support to the validity of the single-scattering approximations that have been used in the previous calculations of the present investigator and his collaborators. With this work, the studies of the relativistic Sunyaev-Zeldovich effect have entered the stage of precision science. Furthermore, the present finding gives great values to the present investigation as an investigation in the field of statistical physics. This work has been published in Monthly Notices of Royal Astronomical Society.2.Sunyaev-Zeldovich Effect for Extremely Hot Clusters of GalaxiesVery recently galaxy clusters with the temperature in excess of 25 keV have been discovered. Therefore, it is very important to carry out the calculation of the Sunyaev-Zeldovich effect for extremely hot clusters of galaxies. The present investigator together with his collaborator has carried out a detailed numerical calculation for the temperature range 1 keV < T < 50 keV, and has presented a detailed numerical table and an accurate analytic fitting formula. This work will be of great value for the forthcoming Sunyaev-Zeldovich effect observations of galaxy clusters. This work has been published in Astronomy and Astrophysics.