A jellyfish galaxy is a type of
galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...
found in
galaxy cluster
A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-l ...
s. They are characterised by
ram pressure
Ram pressure is a pressure exerted on a body moving through a fluid medium, caused by relative bulk motion of the fluid rather than random thermal motion. It causes a drag force to be exerted on the body. Ram pressure is given in tensor form as
...
stripping of gas from the affected galaxy by the
intracluster medium
In astronomy, the intracluster medium (ICM) is the superheated plasma that permeates a galaxy cluster. The gas consists mainly of ionized hydrogen and helium and accounts for most of the baryonic material in galaxy clusters. The ICM is heated to t ...
, triggering
starbursts along a tail of gas.
Jellyfish galaxies have been seen in a number of galaxy clusters including
Abell 2125 (
redshift
In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...
z=0.20; ACO 2125 C153);
(z=0.23; G234144−260358);
Abell 2744
Abell 2744, nicknamed Pandora's Cluster, is a giant galaxy cluster resulting from the simultaneous pile-up of at least four separate, smaller galaxy clusters that took place over a span of 350 million years, and is located approximately 4 billion ...
(z=0.31; ACO 2744 Central Jellyfish;
HLS001427–30234/ACO 2744 F0083;
[ ).
]
Gallery
Example of a jellyfish galaxy JO204.jpg, Jellyfish galaxy JO204 taken by ESO
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based ast ...
's MUSE instrument.
Of bent time and jellyfish SDSS J1110+6459.jpg, Jellyfish galaxy in SDSS J1110+6459, visible next to the cluster and apparently dripping bright blue material.
References
{{Galaxy
Galaxies