We present two new catalogues of superclusters of galaxies out to a redshit of z = 0.15, based on the Abell/ACO cluster redshift compilation maintained by one of us (HA). The first of these catalogues, the all-sky Main SuperCluster Catalogue (MSCC), is based on only the rich (A-) Abell clusters, and the second one, the Southern SuperCluster Catalogue (SSCC), covers declinations delta < -17 deg and includes the supplementary Abell S-clusters. A tunable Friends-of-Friends (FoF) algorithm was used to account for the cluster density decreasing with redshift and for different selection functions in distinct areas of the sky. We present the full list of Abell clusters used, together with their redshifts and supercluster memberships and including the isolated clusters. The SSCC contains about twice the number of superclusters than MSCC for delta < -17 deg, which we found to be due to: (1) new superclusters formed by A-clusters in their cores and surrounded by S-clusters (50%), (2) new superclusters formed by S-clusters only (40%), (3) redistribution of member clusters by fragmentation of rich (multiplicity m > 15) superclusters (8%), and (4) new superclusters formed by the connection of A-clusters through bridges of S-clusters (2%). Power-law fits to the cumulative supercluster multiplicity function yield slopes of alpha = -2.0 and alpha = -1.9 for MSCC and SSCC respectively. This power-law behavior is in agreement with the findings for other observational samples of superclusters, but not with that of catalogues based on cosmological simulations.
The evolution of dwarf galaxies in the Coma supercluster
利用SDSS DR 7在500平方度区域的分光光度数据，研究后发座超星系团（z=0.023）中矮星系（~M*+2<M_z<M*+4）的演化。我们发现，在后发座超星系团中，红矮星主要集中在后发座和阿贝尔1367星系团的致密核心，以及嵌入连接它们的灯丝中的星系群中。然而，在后发座星系团和Abell 1367星系团的陷落区发现了后星爆（k+A）矮星，偶尔也在沿暗条嵌入的星系群中发现，这表明深势阱附近普遍存在的强速度场可能与导致矮星系后星爆阶段的机制密切相关。此外，后发座星系团中一些k+A矮星的蓝色，在其维里半径内发现，这表明这些星系中的恒星形成在过去的500 Myr中非常迅速地熄灭了。超星系团中60%以上的红矮星系的H_δ吸收角为0-3角，这表明在这些星系中有一个不可忽略的部分发生了一个主要的恒星形成事件，在最后一个Gyr内结束，使它们能够移动到红色序列。后发座超星系团中的蓝矮星系在EW（H_α）-EW（H_δ）平面上呈双峰分布，其中一个星系团在H_α中有很高的发射，在H_δ中也有一些发射。在EW（H_α）-EW（H_δ）平面上，蓝矮星和红矮星的一个子群重合，在H_δ上表现出吸收，在H_α上表现出相对较低的发射。我们认为，后者人口的很大一部分是被动矮星系的祖先，大量发现在低红移丰富的集群，如后发座的核心。
The Cosmic Large-Scale Structure in X-rays (CLASSIX) Cluster Survey III: The Perseus-Pisces supercluster and the Southern Great Wall as traced by X-ray luminous galaxy clusters
LoVoCCS. III. Third Generation Pipeline & The Hercules Supercluster
Brown University（布朗大学）；University of California, Davis（加州大学戴维斯分校）；NSF-DOE Vera C. Rubin Observatory / SLAC National Accelerator Laboratory（美国国家科学基金会-能源部薇拉·C·鲁宾天文台/斯坦福直线加速器中心）；Kavli Institute for Particle Astrophysics and Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；University of California Merced（加州大学默塞德分校）；National Research Institute of Astronomy and Geophysics（国家天文地球物理研究所）；Cairo University（开罗大学）；Michigan State University（密歇根州立大学）
