A Rotation Curve Is a Plot of the Rotational Velocity

question 80

Multiple Choice

A rotation curve is a plot of the rotational velocity of a galaxy as a function of the distance away from the galactic center. Predictions for rotation curves for spiral galaxies suggest that the curve should decline beyond the galactic bulge. Actual measurements, however, show that the rotation curve is flat beyond the bulge. What does this deviation from prediction state about spiral galaxies, including the Milky Way?

• A) Spiral galaxies are not rotating as rapidly as previously believed.
• B) The spiral arms move together as a rigid object.
• C) There is a great deal of unseen mass surrounding the visible galaxy.
• D) The centers of spiral galaxies contain supermassive black holes.

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Definitions:

Secondary Sex Characteristics

Physical traits that emerge during puberty which are not directly involved in reproduction, such as breast development in females and facial hair in males.

Gender Identity

Our sense of being male, female, or some combination of the two.

Androgyny

The combination of masculine and feminine characteristics into an ambiguous form, often related to gender identity, behavior, and fashion.

Father Absence

A situation where a father is physically or emotionally unavailable to their child, which can impact the child's development and psychological health.