How Do We Determine the Amount of Dark Matter in Elliptical

question 71

Multiple Choice

How do we determine the amount of dark matter in elliptical galaxies?

• A)We measure how fast the galaxy rotates as a whole.
• B)We measure the broadening of the galaxy's absorption lines to infer the speeds of stars at different distances from the galactic center.
• C)We count the number of stars in the galaxy. Combining this with the galaxy's volume, we can calculate the galaxy's density.
• D)We measure the orbital velocities of star- forming gas clouds in the outer portion of the galaxy.
• E)We search for dark lanes of dust and black holes within the galaxy.

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Definitions:

Aqueous Fluid

The clear, watery fluid found between the lens and the cornea of the eye, serving to maintain intraocular pressure and provide nutrition to the eye’s avascular tissues.

Cornea

The transparent covering of an eye.

Photoreceptors

Specialized cells found in the retina of the eye that are sensitive to light, allowing for the perception of vision.

Self-Concept

Domain-specific self-evaluations.