Astr 3- Hw 10

If galaxy A is 10 times farther away than galaxy B, then galaxy A is receding— galaxy B.

•  

  10 times slower than

•  

  10 times faster than

•  

  100 times slower than

•  

  100 times faster than

The cosmic microwave background emission was produced from gas that was at a temperature of —when the universe was —of age.

•  

  3000 K; 370,000 years

• 3000K; 10^-6 seconds

•  

  2.74 K; 20 minutes

•  

  3 K; 300,000 years

The geometry of the universe is now known to be — curvature.

•  

  negative (saddle)

•  

  positive (sphere)

•  

  flat (Euclidean)

What percentage of the universe consists of ordinary baryonic matter in visible sources such as galaxies, stars, & gas?

•  100%

•  32%

•  27%

•  5%

Which of the following is NOT observational evidence in favor of the Big Bang?

•  The Hubble law.

•  The tendency of galaxies to cluster.

•  That the composition of the universe is 30% helium by mass, and nearly all the rest is hydrogen.

•  The cosmic microwave background radiation.

Which of the following standard candle methods revealed the acceleration of the universe?

•  

  radar ranging

•  

  luminosities of core-collapse supernovae, SN Type II

•  

   

  luminosities of white dwarf supernovae, SN Type Ia

•  

  spectroscopic parallax determinations from main sequence stars

If the universe is isotropic, that means

•  

  there is a distribution of galaxies of different masses

•  

  galaxies are distributed uniformly in redshift

•  

   

  the distribution of galaxies is the same in all directions.

•  

  galaxies all have the same mass.

In its earliest phase, the universe was dominated by

• baryons

• matter

•  dark energy

•  radiation

At the current time, the evolution of the universe is dominated by 

• baryons

•  dark energy

• radiation

• matter

Approximately what percentage of the mass of a rich galaxy cluster is dark matter?

•  100%

•  less than 5%

•  less than 10%

•  more than 90%