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.
Voids typically have a diameter of 11 to 150 Mpc; particularly large voids, defined by the absence of rich superclusters, are sometimes called 'supervoids'. Voids located in high-density environments are smaller than voids situated in low-density spaces of the universe. (3)
A 1994 census ("''The structure of the Universe traced by rich clusters of galaxies.''", see References) lists a total of 27 supervoids with a distance of up to 740 Mpc; a selection is given below:

#	Name	Distance (Mpc)	Diameter (Mpc)
1		188	124
5		182	130
9	Southern Local Supervoid	135	158
18		168	144
19		168	152
20	Boötes void	304	110
21		201	163
24	Northern Local Supervoid	86	146

The Eridanus Supervoid, reported on 24 August 2007 by the NRAO from Very Large Array Sky Survey data, is much larger than these, being about 300 Mpc in diameter and 1800–3000 Mpc distant. It also corresponds to a cold spot in the cosmic microwave background. ^[1]

Contents

External links

References

External links

★ Universe family tree: Void

★ a few animated views of voids and their distribution from Hume Feldman with Sergei Shandarin, Dept. Physics and Astronomy, University of Kansas, Lawrence, KS, USA.

References

1. NRAO: "Astronomers Find Enormous Hole in the Universe". NRAO website, retrieved 24 August 2007.

:'General references'
:
★ U. Lindner, J. Einasto, M. Einasto, W. Freudling, K. Fricke, E. Tago: ''The structure of supervoids. I. Void hierarchy in the Northern Local Supervoid.'', Astron. Astrophys., v.301, p.329 (1995)
:
★ M. Einasto, J. Einasto, E. Tago, G. B. Dalton, H Andernach: ''The structure of the Universe traced by rich clusters of galaxies.'', Mon. Not. R. Astron. Soc. 269, 301 (1994)
:
★ 3 Information on Voids