Protogalactic - definition of protogalactic by The Free Dictionary
protogalaxy (redirected from protogalactic)
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n. pl. pro·to·gal·ax·ies
A cloud of gas, primarily hydrogen, that is forming a galaxy or has sufficient mass to eventually form a galaxy.
, pl -axies
(Astronomy) a cloud of gas in the early stages of its evolution into a galaxy
References in periodicals archive
Perhaps massive galaxies could develop quickly within deep gravitational wells holding several protogalactic
fragments at one time.
Astronomers originally thought that the Milky Way's halo was the first component to congeal out of the protogalactic
chaos, when flurries of small gaseous and stellar blobs were rapidly merging into larger structures that would ultimately form the galaxy.
Proposed determinants of a galaxy's Hubble type include the galaxy's total mass; the mass of its bulge; its angular momentum; the angular momentum of its dark-matter halo; the collapse rate of the protogalactic
gas cloud that formed the galaxy; and the protogalaxy's "cooling time.