Short Definition
Galaxy
cluster is astronomical structure that consist of dark matter, hot
plasma and galaxies. They are the biggest bound by gravity formations
that we know of.
Detailed
Definition
Galaxy
clusters are the biggest structures bound by gravity. They consist in
85% of dark matter that is connecting the whole structure together.
We can detect dark matter only by observing how its gravitation
affects objects around it and what influence it has on light passing
near it. The amount of gravity produced in clusters by dark matter is
a cause for effect called “gravitational lensing”. That effect
bends the light magnifying it and making the cluster into a big
natural telescope. Without it, we wouldn’t be able to observe some
of the smaller, further galaxies.
Most of the visible
matter in galaxy clusters is in form of hot plasma called the
intracluster medium (ICM). Due to the high gravitational potential
energy of material the shock sends gas into really high temperatures
that can raise up to 10s of millions grad Celsius. That temperature
later causes the emission of X-Rays.
The smallest part
of galaxy clusters are galaxies, they are around 2% of a total mass
of the structure. Yet the biggest known to us galaxies are formed in
clusters.
Etymology
Galaxy
(Noun.), originated from Ancient Greek word galaxías, that means
“Milky Way”. At first used only to describe Milky Way Galaxy,
later on it changed its meaning to more general.
Cluster
(Noun.), derived from Proto-Germanic *klas-, *klus-, meaning “to
clump, lump together”.
Sample Sentence(s)
Galaxy
clusters can consist of thousands of galaxies.
Translations of Terms/Concepts into Partner
Languages
French: amas
de galaxies
German: Galaxienhaufen
Italian: mmasso
di galassie
Polish: gromada
galaktyk
Swedish: galaxhop
Links to Videos/Articles:
Max
Planck Institute for Extraterrestrial Physics (n.d.), Clusters and
Group of Galaxies, Retrieved from
https://www.mpe.mpg.de/2040034/clusters_and_groups_of_galaxies
Center
for Astrophysics Harvard & Smithsonian (n.d.), Galaxy Clusters,
Retrieved from
https://www.cfa.harvard.edu/research/topic/galaxy-clusters
Online
Etymology Dictionary (n.d.), galaxy (n.), Retrieved from
https://www.etymonline.com/word/galaxy#etymonline_v_1225
Online
Etymology Dictionary (n.d.), cluster (n.), Retrieved from
https://www.etymonline.com/word/cluster#etymonline_v_13860
European Space Agency (2007,
Juli), The Bullet Cluster, Retrieved from
https://www.esa.int/ESA_Multimedia/Images/2007/07/The_Bullet_Cluster2#.ZFmq1Dq136A.link
