标题： 寻找遥远的X射线星系团 显示英文标题

标题： A search for distant X-ray galaxy clusters

摘要： 我们报告了在ROSAT PSPC定点观测档案中寻找偶然发现的遥远X射线星系团的进展。 我们工作的初始目标是测量到4 x 10^-14 erg cm^-2 s^-1的X射线光度函数，并以此检验在中等红移处的星系团演化主张。 我们拥有45个在100个最深南天场中的扩展源的R波段图像和光谱数据。 初步分析表明，我们覆盖了从附近星系团到可能的遥远星系团的距离范围，z\simeq 1.0。 显示英文摘要

摘要： We report on the progress of our search for serendipitous distant X-ray galaxy clusters in the ROSAT PSPC pointed observations archive. The initial aim of our work is to measure the X-ray luminosity function of clusters down to 4 x 10^-14 erg cm^-2 s^-1 and so test the claims of cluster evolution at moderate redshifts. We have R band images and spectroscopy for 45 extended sources detected in 50 of the 100 deepest southern fields. A preliminary analysis suggests we cover a range of distances, from nearby clusters to possible distant clusters, z \simeq 1.0.