Galaxies Flashcards
is a massive, stellar
remnants, gas, dust,
and dark matter.
gravitationally bound
system of stars,
Typically contains of
stars.
billions to trillions
Began as
small gas clouds
merging over billions of
years.
Formation:
Galaxies
change shape, size, and
star population over time.
Evolution:
700,000 years after the big
bang,
As a matter of analysis, the
universe was opaque to
radiation since light strongly
interact with matter.
gravity could not clump
matter into stars and galaxies.
Pressure from radiation itself
gravitational
collapse
inhibited
But when elementary
particles recombine, the
universe became transparent,
thus radiation and matter
“decoupled”
This radiation decoupled
from matter, which we now
know as
the Cosmic
Microwave Background
Radiation
At the time before , matter was
in
all directions of outer
space.
CMB decoupled,
distributed uniformly
Disk-shaped
with spiral arms; rich in gas
and dust, ongoing
Spiral Galaxy
Type of Galaxies
Milky Way
Type of Galaxies
Andromeda
Type of Galaxies
M81 and M82
Type of Galaxies
M77
Oval shape, very little
gas and dust, older
stars.
Elliptical Galaxies:
Type of Galaxies
ESO 325-4
Type of Galaxies
M87
No
defined shape, often
formed by gravitational
interactions.
Irregular Galaxies:
Type of Galaxies
Small Magellanic Cloud
Type of Galaxies
IC 4710
