标题： 结合ROSAT和ASCA观测的椭圆星系中的ISM与密集星团中的热气体的比较 显示英文标题

标题： A Comparison of the ISM in Ellipticals to the Hot Gas in a Dense Group from Combined ROSAT and ASCA Observations

摘要： 我们分析了NGC4649、NGC5044和NGC5846的弥散X射线发射，结合了来自两个X射线天文台ROSAT和ASCA的数据。使用ASCA，我们进行了详细的X射线发射分析，该分析充分考虑了ASCA点扩散函数，并且还包括一个三维源模型。这三个源在其中心均表现出冷却流。从Si、S和Fe的推导丰度来看，我们认为NGC5044（一个密集的星系群）在早期星系风阶段能够保留大量的气体。NGC5846（正常的椭圆星系）中的Fe丰度对应于约0.2倍Tammann率的Ia型超新星爆发率，而NGC4649（正常椭圆星系，在室女星系团中）中的低Fe质量可能是环境效应的结果。 显示英文摘要

摘要： We analyze diffuse X-ray emission from NGC4649, NGC5044 and NGC5846, combining data from two X-ray observatories, ROSAT and ASCA. With ASCA, we perform a detailed analysis of the X-ray emission which properly accounts for the ASCA PSF and also include a 3-dimensional source model. All three sources exhibit cooling flows in their centers. From the derived abundances of Si, S and Fe, we conclude that NGC5044 (a dense group of galaxies) was able to retain significant amounts of gas during an early galaxy wind phase. Fe abundance in NGC5846 (normal E galaxy) corresponds to current SNIa rate of ~0.2 of Tammann rate, while low Fe mass in NGC4649 (normal E in the Virgo cluster) could be an environmental effect.