Basics Flashcards
1
Q
How much of the mass of a galaxy comes from stars?
A
10-20%
2
Q
How much large a portion of the energy content of the Universe is baryonic matter?
A
4%
3
Q
How much large a portion of the energy content of the Universe is dark matter?
A
25%
4
Q
How old an concept is a galaxy
A
About 100 years
5
Q
Reyleigh-Jeans limit
A
hv/kT «_space;1
6
Q
The huge luminosity of quasars results from the accretion discs of central supermassive black holes, which can convert around ___ % of the mass of an object into energy, compared to just 0.7% for the p–p chain nuclear fusion process that dominates the energy production in Sun-like stars.
A
15
