A → galaxy bulge
that is flatter than a → classical bulge.
Such bulges
might be difficult to see in very
inclined galaxies. They may contain sub-structures such as nuclear
→ bars, → spiral arms, or
→ rings. They usually show signs of
→ dust obscuration,
younger → stellar populations,
or ongoing → star formation. These systems seem to
form mostly through disk instabilities (→ disk instability),
such as bars, in a relatively slow,
continuous and smooth process. Essentially, such instabilities induce
a redistribution of → angular momentum
along the galaxy, and, as a
result, mostly gas but also stars are driven to the disk center.
Also called → pseudo-bulge
(Kormendy & Kennicutt, 2004, ARA&A 42, 603;
Fisher & Drory, 2010, ApJ 716, 942).
See also: → -disk; → like;
→ bulge.
