Void galaxies are galaxies

Galaxy

A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...

 which exist in cosmological voids

Void (astronomy)

In astronomy, voids are the empty spaces between filaments, the largest-scale structures in the Universe, that contain very few, or no, galaxies. They were first discovered in 1978 during a pioneering study by Stephen Gregory and Laird A. Thompson at the Kitt Peak National Observatory...

. Few galaxies exist in voids; most galaxies exist in sheets, walls and filaments

Galaxy filament

In physical cosmology, galaxy filaments, also called supercluster complexes or great walls, are, so far, the largest known cosmic structures in the universe. They are massive, thread-like structures with a typical length of 50 to 80 megaparsecs h-1 that form the boundaries between large voids in...

 that surround voids and supervoids. Many of the void galaxies are connected through void filaments, lightweight versions of the regular galaxy filaments that surround voids, to each other. These filaments are often straighter than their regular counterparts due to the lack of influence by surrounding filaments. These filaments can even be rich enough to form poor groups of galaxies

Galaxy cluster

A galaxy cluster is a compact cluster of galaxies. Basic difference between a galaxy group and a galaxy cluster is that there are many more galaxies in a cluster than in a group. Also, galaxies in a cluster are more compact and have higher velocity dispersion. One of the key features of cluster is...

. The void galaxies themselves are thought to represent pristine examples of galactic evolution, having few neighbours, and likely to have formed from pure intergalactic gas.

List of void galaxies

Galaxy	Void	Filament	Notes	Comments
PC 1357+4641	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Emission-line Galaxy
IRAS 14288+5255	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			AGN Active galactic nucleus An active galactic nucleus is a compact region at the centre of a galaxy that has a much higher than normal luminosity over at least some portion, and possibly all, of the electromagnetic spectrum. Such excess emission has been observed in the radio, infrared, optical, ultra-violet, X-ray and...  X-ray source Astrophysical X-ray source Astrophysical X-ray sources are astronomical objects with physical properties which result in the emission of X-rays.There are a number of types of astrophysical objects which emit X-rays, from galaxy clusters, through black holes in active galactic nuclei to galactic objects such as supernova...
G 1432+5302	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Starburst galaxy Starburst galaxy A starburst galaxy is a galaxy in the process of an exceptionally high rate of star formation, compared to the usual star formation rate seen in most galaxies. Galaxies are often observed to have a burst of star formation after a collision or close encounter between two galaxies...
G 1458+4944	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			LINER galaxy
G 1507+4554	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Starburst galaxy Starburst galaxy A starburst galaxy is a galaxy in the process of an exceptionally high rate of star formation, compared to the usual star formation rate seen in most galaxies. Galaxies are often observed to have a burst of star formation after a collision or close encounter between two galaxies...
G 1510+4727A & G 1510+4727B	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Interacting galaxy pair
BHI 1514+3819	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...
FSS 1515+3823	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...
G 1517+3949	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Starburst galaxy Starburst galaxy A starburst galaxy is a galaxy in the process of an exceptionally high rate of star formation, compared to the usual star formation rate seen in most galaxies. Galaxies are often observed to have a burst of star formation after a collision or close encounter between two galaxies...
G 1517+3956A & G 1517+3956B	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Interacting galaxy pair
IRAS 15195+5050	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			AGN Active galactic nucleus An active galactic nucleus is a compact region at the centre of a galaxy that has a much higher than normal luminosity over at least some portion, and possibly all, of the electromagnetic spectrum. Such excess emission has been observed in the radio, infrared, optical, ultra-violet, X-ray and...  X-ray source Astrophysical X-ray source Astrophysical X-ray sources are astronomical objects with physical properties which result in the emission of X-rays.There are a number of types of astrophysical objects which emit X-rays, from galaxy clusters, through black holes in active galactic nuclei to galactic objects such as supernova...
Markarian 845	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Seyfert 1 Seyfert galaxy Seyfert galaxies are a class of galaxies with nuclei that produce spectral line emission from highly ionized gas, named after Carl Keenan Seyfert, the astronomer who first identified the class in 1943...  (X-ray source Astrophysical X-ray source Astrophysical X-ray sources are astronomical objects with physical properties which result in the emission of X-rays.There are a number of types of astrophysical objects which emit X-rays, from galaxy clusters, through black holes in active galactic nuclei to galactic objects such as supernova... )
CG 547	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Emission-line Galaxy
CG 637	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Emission-line Galaxy
CG 922	Bootes Void Boötes void The Boötes void or the Great Void is a huge and approximately spherically shaped region of space, containing very few galaxies. It is located in the vicinity of the constellation Boötes, hence its name...			Emission-line Galaxy