How Do Astronomers Most Directly Measure the Amount of Dark

question 55

Multiple Choice

How do astronomers most directly measure the amount of dark matter in elliptical galaxies?

• A) through their rotation curves
• B) through their velocity dispersion
• C) through their radii
• D) through their reddening

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Definitions:

Mortality Rate

The measure of the number of deaths in a particular population, scaled to the size of that population, per unit of time.

Bulimia

An eating disorder characterized by episodes of binge eating followed by behaviors such as vomiting to prevent weight gain.

Dopamine Levels

Concentrations of dopamine, a neurotransmitter in the brain that influences mood, motivation, and reward, among other functions.

Sweets

While not a psychological term, sweets refer to food items that are high in sugar content, and their consumption can affect mood and behavior due to their impact on blood sugar levels and brain chemistry.