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1. Why are there older, Population II stars in the halo and not in the plane of

ID: 1484112 • Letter: 1

Question

1.

Why are there older, Population II stars in the halo and not in the plane of the Milky Way?

Pop II stars are only stars that have been stolen from other, older galaxies

Very old Pop III stars gradually evolve to appear like Pop II stars

Pop II stars are the left-over stars that formed before gas settled into the plane

Pop II stars migrate from the plane to the halo over time

Pop II stars only form in globular clusters, which are found primarily in the halo

2.

What is required, in a galaxy, to have active, ongoing star formation?

The presence of cool gas in the galaxy

A flat rotation curve

A supermassive black hole at the center of the galaxy

Old stars which have gone supernova

The presence of substantial amounts of Dark Matter

3.

What is the cosmological interpretation of the redshift observed of distant galaxies?

That redshift is a measure of how much times has sped up since the light was emitted

That redshift is an indication of how much space itself has expanded since the light was emitted

That redshift is a Doppler shift because the object is moving rapidly through space

That redshift is proportional to the recession velocity of a galaxy

That redshift means that dark matter causes the wavelength of light to be stretched with time

4.

What is the evidence that the Universe is expanding?

We can see distant galaxies dissolve, pulled apart by the expansion of space

All of these responses indicate an expanding Universe

We can see the discs of galaxies getting bigger in more recent times

We see the edge of the Universe moving away from us

We observe galaxies moving away from us, and more distant galaxies receding faster

5.

What is the evidence that not only is the Universe expanding, but it is accelerating?

The ‘space’ of the Universe was smaller in the past than today

More distant galaxies have a greater cosmological redshift the farther they are from Earth

The Universe is larger than the ‘cosmic horizon’ at any point in the Universe

We observe flat rotation curves for distant galaxies, but not for nearby galaxies

Studies of Type Ia supernovae indicate an expansion rate that was smaller in the past than now

6.

Scorpius, where will it be in about a month?

Aquarius

Capricorn

Sagittarius

Scorpius

Libra

Pop II stars are only stars that have been stolen from other, older galaxies

Very old Pop III stars gradually evolve to appear like Pop II stars

Pop II stars are the left-over stars that formed before gas settled into the plane

Pop II stars migrate from the plane to the halo over time

Pop II stars only form in globular clusters, which are found primarily in the halo

2.

What is required, in a galaxy, to have active, ongoing star formation?

The presence of cool gas in the galaxy

A flat rotation curve

A supermassive black hole at the center of the galaxy

Old stars which have gone supernova

The presence of substantial amounts of Dark Matter

3.

What is the cosmological interpretation of the redshift observed of distant galaxies?

That redshift is a measure of how much times has sped up since the light was emitted

That redshift is an indication of how much space itself has expanded since the light was emitted

That redshift is a Doppler shift because the object is moving rapidly through space

That redshift is proportional to the recession velocity of a galaxy

That redshift means that dark matter causes the wavelength of light to be stretched with time

4.

What is the evidence that the Universe is expanding?

We can see distant galaxies dissolve, pulled apart by the expansion of space

All of these responses indicate an expanding Universe

We can see the discs of galaxies getting bigger in more recent times

We see the edge of the Universe moving away from us

We observe galaxies moving away from us, and more distant galaxies receding faster

5.

What is the evidence that not only is the Universe expanding, but it is accelerating?

The ‘space’ of the Universe was smaller in the past than today

More distant galaxies have a greater cosmological redshift the farther they are from Earth

The Universe is larger than the ‘cosmic horizon’ at any point in the Universe

We observe flat rotation curves for distant galaxies, but not for nearby galaxies

Studies of Type Ia supernovae indicate an expansion rate that was smaller in the past than now

6.

Scorpius, where will it be in about a month?

Aquarius

Capricorn

Sagittarius

Scorpius

Libra

Explanation / Answer

1)

1)Pop II stars only form in globular clusters, which are found primarily in the halo

2)The presence of cool gas in the galaxy

3)That redshift is a Doppler shift because the object is moving rapidly through space

4)We observe galaxies moving away from us, and more distant galaxies receding faster

5)The Universe is larger than the ‘cosmic horizon’ at any point in the Universe