Galaxies appear in groups and clusters. Their mutual gravity spans unimaginable distances to bring them together over cosmic time. As a result, these groups are rich in interactions and varied appearances. We find monstrous galaxies that cannibalize others and we find the largest gravitationally bound structures in the cosmos.

The local group: https://en.wikipedia.org/wiki/Local_Group
M31 in Andromeda: https://en.wikipedia.org/wiki/Andromeda_Galaxy
Hickson Compact Groups: https://en.wikipedia.org/wiki/Hickson_Compact_Group
Virgo Cluster: https://en.wikipedia.org/wiki/Virgo_Cluster
Coma Cluster: https://en.wikipedia.org/wiki/Coma_Cluster
Dark matter: https://en.wikipedia.org/wiki/Dark_matter
Intracluster X-ray gas: https://en.wikipedia.org/wiki/Intracluster_medium
Superclusters: https://en.wikipedia.org/wiki/Supercluster
The Virgo Supercluster: https://en.wikipedia.org/wiki/Virgo_Supercluster
The Laniakea Supercluster: https://en.wikipedia.org/wiki/Laniakea_Supercluster
Voids: https://en.wikipedia.org/wiki/Void_(astronomy)
Filaments: https://en.wikipedia.org/wiki/Galaxy_filament
The Sloan /"Great Wall/": https://en.wikipedia.org/wiki/Sloan_Great_Wall
Redshift survey: https://en.wikipedia.org/wiki/Redshift_survey

00:00 Presentation
12:30 a.m. The local group
2:35 p.m. APOD: May 10, 2009, M31 and M32
2:51 Galaxy groups and clusters
4:25 p.m. Hickson compact groups
5:04 Virgo Cluster
6:30 p.m. Rich galaxy clusters
7:27 a.m. Coma cluster
7:47 a.m. Abell 02352
8:40 a.m. Abell 03496: Hercules' cluster
9:00 a.m. Dark matter dominates! Most of the mass of all galaxy clusters is in the form of duck matter. This
12:32 X-ray emitting gas overwhelms stars
3:00 p.m. Superclusters: the largest known structures
16:28 The Virgo Supercluster
5:38 p.m. The Laniakea supercluster
19:32 The Universe on a very large scale
20:18 Voids, filaments and walls
11:56 p.m. The Sloan /"Great Wall/" found in the seas Digital Sky Survey, a large-scale survey of Palesia. It is a sheet of
26:32 Galaxy Redshift 20F survey
29:51 Cosmography of the local universe

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