Astrophysics (index)about

galaxy cluster

(CL, cluster)
(large group of galaxies gravitationally-bound to the group)

A galaxy cluster (CL) is on the order of hundreds of galaxies bound to the group by gravity. A smaller group of galaxies is known as a galaxy group. Often has an intergalactic medium, i.e., plasma. Typical mass is on the order of 1015 solar masses. It can be part of a supercluster.

Shock waves from matter striking a galaxy cluster's intracluster medium produces X-rays, which are a sign to observers of the presence of a galaxy cluster. X-ray signals can reveal very distant clusters, the furthest currently known (CL J1001+0220) at redshift 2.5.

Example galaxy clusters: Virgo Cluster, Fornax, Hercules, Coma.

The abbreviation CL is often included in designators for galaxy clusters, e.g., for CL J1001+0220.

The term cluster can also refer to stellar clusters such as open clusters, sometimes confusingly called galactic clusters (meaning clusters within a galaxy).

(galaxies,object type)
CLCL J1001+0220galaxy clustergeneral prefix for clusters

Referenced by:
Abell Catalog
Atacama Cosmology Telescope (ACT)
Arecibo General Catalog (AGC)
Alcock-Paczyński effect
astronomical quantities
brightest cluster galaxy (BCG)
Bullet Cluster
cold dark matter (CDM)
Catalog of Galaxies and Clusters of Galaxies (CGCG)
cosmic infrared background (CIB)
cluster radius
CMB lensing
Comet Galaxy
comoving units
Compton scattering
computational astrophysics
cosmic distance ladder
cosmological principle
dark flow
dark matter
dark matter halo
Dark Energy Survey (DES)
diffuse emission
velocity dispersion (σ)
elliptical galaxy
ESO 137-001
field galaxy
galaxy bias
galaxy filament
galaxy group
gas fraction
gravitational instability (GI)
gravitational instability model
gravitational lensing
gravitational redshift
Great Wall
Hydra-Centaurus Supercluster
intracluster medium (ICM)
intergalactic medium (IGM)
intensity mapping
Lambda-CDM model (ΛCDM)
Laniakea Supercluster
large scale structure (LSS)
luminosity function (LF)
Massive Cluster Survey (MACS)
metallicity (Z)
mock catalog
non-Gaussian (NG)
Perseus-Pisces Supercluster
planetary nebula luminosity function (PNLF)
projected separation
radio relics
rare designator prefixes
redshift survey
Scott effect
star formation history (SFH)
South Pole Telescope (SPT)
standard candle
stellar dynamics
supergalactic coordinate system
Sachs-Wolfe effect (SWE)
systemic velocity
Sunyaev-Zel'dovich effect (SZ effect)
3C 295
three dimensional model
21cm experiment
21cm line
Virgo Cluster
Virgo Supercluster
virial theorem
weak lensing
X-ray source (RS)