ASTO Final Exam

Question 1

What type of light we use to see the center of the Milky Way?

Answer 1

X-ray, Infrared, and radio waves are the best to look into the milky way.

Question 2

What can you see when viewing X-ray?

Answer 2

Only the more extreme objects.(white dwarfs, neutron stars, and stellar-mass black holes)

Question 3

What is a globular cluster?

Answer 3

clusters that
form so many stars that they are
gravitationally bound even after the
gas is depleted.

Question 4

What’s bound to happen to the satellite galaxy orbiting the Milky way.

Answer 4

They get ripped apart by tidal forces.

Question 5

How are large galaxies formed.

Answer 5

They are formed through Galaxy mergers.

Question 6

What does a elliptical galaxy look like?

Answer 6

Elliptical galaxies are galaxies that have no
disk and appear as spheroids or overloids. With little gas.

Question 7

With the hubble constant what is the milky way.

Answer 7

The milky way is a SBa or a SBb (spiral barr)

Question 8

What makes an irregular galaxy?

Answer 8

Galaxy merging causes these weird galaxies.

Question 9

What piece of evidence show we have dark matter.

Answer 9

Bullet clusters

Question 10

What does mass to light ratio measure.

Answer 10

how much more a
galaxy weighs than the amount of light it
produces.

Question 11

What is dark matter mass to light ratio?

Answer 11

0

Question 12

What type of galaxy has the old stars.

Answer 12

elliptical

Question 13

What type of galaxy has the highest mass?

Answer 13

Spiral galaxies

Question 14

What galaxy has the biggest diameter?

Answer 14

Spiral galaxies

Question 15

How do we measure distant galaxies?

Answer 15

By calculating its red shift.

Question 16

What spectrum is used to measure the redshift?

Answer 16

Redshifts are determined by
looking at common absorption
lines in the spectrum.

Question 17

Z=v/c What are these

Answer 17

Z = redshift
c= speed of light
v= radial velocity

Question 18

Why are galaxies moving
away from us?

Answer 18

Because the universe is expanding.

Question 19

What percentage of the universe is Dark matter?

Answer 19

27%

Question 20

What percentage of the universe is ordinary matter?

Answer 20

5%

Question 21

What percentage of the universe is Dark energy?

Answer 21

68%

Question 22

What percentage of the universe is stars?

Answer 22

<1%

Question 23

What was the cause of the universe.

Answer 23

The big bang

Question 24

What does dark energy do to the universe?

Answer 24

Makes the universe expand faster.

Question 25

What is the Hubble constant today?

Answer 25

68 km/s/Mpc

Question 26

What is the thought of dark energy?

Answer 26

The best guess is that dark energy is has a constant density in the Universe over time.

Question 27

What will happen to the universe if matter dominates?

Answer 27

the universe will collapse.

Question 28

What will happen to the universe if dark matter dominates?

Answer 28

The universe will expand infinitely fast.

Question 29

At the beginning of the universe why weren't photons and electrons formed.

Answer 29

because the temperature was to hot.

Question 30

What allowed photons and electrons to form?

Answer 30

As the universe expands it cooled. within a few second they were able to form.

Question 31

What happens to a free neutron?

Answer 31

Because it is unstable it decays into a proton.

Question 32

What happened to electrons as the universe cooled?

Answer 32

The moment the Universe cooled enough for electrons to join protons and form atoms, all the trapped light escaped.

Question 33

What is the CMB?

Answer 33

Cosmic Microwave Background

Question 34

What is inflation?

Answer 34

that the Universe started small and then expanded very fast.

Question 35

What is a peak in the universe?

Answer 35

These are over dense areas that get smaller and more dense.

Question 36

What are voids in the universe?

Answer 36

These are areas that expand and get even less dense.

Question 37

What is the Dark age of the universe?

Answer 37

The period between the CMB light and the first star is called the Dark Age of the Universe and cannot be observed.

Question 38

What is the Reionization era.

Answer 38

matter was ionized before recombination.

Question 39

What is Photoevaporation?

Answer 39

where light adds enough heat or momentum to cause atoms to escape a gravity well of a galaxy.

Question 40

What happens to a galaxy after photoevaporation.

Answer 40

Galaxies fail to form stars for a long time, if ever.

Question 41

what is the cosmic noon.

Answer 41

this was the peak of star formation in the universe.

Question 42

What is the cosmic dawn.

Answer 42

This is the start of star formation at the start of reionization.

Question 43

What makes most of the Milky ways mass.

Answer 43

Dark matter halo

Question 44

What is the largest local cluster?

Answer 44

The Virgo cluster

Question 45

Super cluster

Answer 45

The Virgo supercluster

Question 46

An even larger super cluster?

Answer 46

The Laniakea that contains four superclusters.

Question 47

What is the single point in the Laniakea Supercluster are all attracted to?

Answer 47

The great Attractor/