Suppose We Observe a Source of X- Rays That Varies

question 146

Multiple Choice

Suppose we observe a source of X- rays that varies substantially in brightness over a period of a few days. What can we conclude?

• A)The X- ray source must have a strong, rapidly varying magnetic field.
• B)We must be seeing the rapid orbit of two stars in a binary system.
• C)The X- ray source must be a quasar.
• D)The X- ray source must contain a black hole with an accretion disk.
• E)The X- ray source can be no more than a few light- days in diameter.

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Definitions:

Zerk Fittings

Grease fittings installed on mechanical systems to allow for easy application of lubricant with a grease gun.

Control Arm Bushing

A component of the control arm in a vehicle's suspension system, made of rubber or polyurethane, designed to cushion the impact and reduce friction between the moving parts for smoother operation and handling.

Sway Bar Link

A component of a vehicle's suspension system that connects the sway bar to the suspension to help reduce body roll during turns.

Ball Joint

A pivot point for the steering system, allowing the wheels to move up and down while steering left or right.