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What is the total mass of the galaxy (in billions of solar masses) within a radius of 4 kpc? billions of solar masses (e) What is the mass of dark matter (in billions of solar masses) within a radius of 2 kpc? billions of solar masses (f)

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Final answer:

Without additional data or assumptions regarding the mass distribution model of the galaxy, we can't accurately determine the total mass within a radius of 4 kpc or the dark matter mass within a radius of 2 kpc. The total mass of the Milky Way is about 2 × 10¹² solar masses, with dark matter comprising up to 95%.

Step-by-step explanation:

To estimate the total mass of the galaxy within a radius of 4 kpc (kilo parsecs), and the mass of dark matter within a radius of 2 kpc, we need to use the provided astronomical data. According to the information given, the total mass of the Milky Way galaxy is about 2 × 10¹² solar masses (M☉), with up to 95% of this mass being dark matter.

We must assume that dark matter is uniformly distributed throughout the Milky Way. The mass within a specific volume can be found by calculating the fraction of the total volume that volume represents and then applying that fraction to the total mass.

The radial distribution of mass in a galaxy typically follows certain profiles which require specific models to describe.

Since we are not given a specific mass distribution model or the exact mass within 4 kpc, we can't provide a precise answer without additional data or assumptions.

Similarly, we lack the details to accurately calculate the dark matter mass within a radius of 2 kpc. Such calculations would typically involve complex astrophysical models that go beyond simple volumetric ratios because dark matter distribution is not uniform and is influenced by a galaxy's overall mass distribution and dynamics.

User Gurkan
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3 votes

Final answer:

The total mass of the galaxy within a radius of 4 kpc is about 4 times 10^11 solar masses. The mass of dark matter within a radius of 2 kpc would be approximately 8 times 10^10 solar masses.

Step-by-step explanation:

The total mass of the galaxy within a radius of 4 kpc is about 4 times 10^11 solar masses. This mass includes both the visible (luminous) matter and the dark matter.

Dark matter is estimated to be about 20 times more massive than the visible matter in the galaxy. Therefore, the mass of dark matter within a radius of 2 kpc would be approximately 8 times 10^10 solar masses.

These estimates are based on observations of the motions of globular clusters and small galaxies that orbit the Milky Way.

User Human
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