Astrophysics (index)about

disk galaxy

(galaxy shaped like a flat circle)

Disk galaxy is a term for disk-shaped galaxies (e.g., as opposed to elliptical galaxies), including spiral galaxies, and including galaxies that are generally disk-shaped, even if they have a bulge, e.g., lenticular galaxy.

Some analysis of observation suggests a majority of disk galaxies (including the Milky Way) comprise two overlaid disks of stars: a thick disk (i.e., thick disk stars), and within it, a thin disk (thin disk stars) that also includes gas, and dust. The thin disk stars are apparently younger, the result of more recent star formation.


(galaxy type)
http://en.wikipedia.org/wiki/Disc_galaxy
http://en.wikipedia.org/wiki/Thick_disk
http://en.wikipedia.org/wiki/Thin_disk

Referenced by:
bulge
circumgalactic medium (CGM)
galaxy
galaxy classification
lenticular galaxy (S0)
Milky Way
spiral galaxy
stellar dynamics
surface density (Σ)
Toomre Q parameter (Q)

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