What Could You Use to Measure the Mass of the Dark

question 3

Multiple Choice

What could you use to measure the mass of the dark matter halo in a spiral galaxy?

• A) Hydrogen emission from H II regions in the spiral disk
• B) The velocities of satellite dwarf galaxies surrounding a spiral galaxy
• C) Absorption lines in the spectra of its globular clusters
• D) all of the above

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A mandatory contribution imposed by governments to fund public programs that provide retirement benefits, disability income, and other social security services.

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Taxes collected from employees and employers to fund the Social Security program, providing retirement, disability, and survivor benefits.