Some of the Interstellar Gas in Our Galaxy Has Been

question 12

Multiple Choice

Some of the interstellar gas in our Galaxy has been heated to millions of degrees, a temperature that surprised astronomers when it was first discovered. How do we now think that gas between stars gets that hot?

• A) any gas close to a star will naturally get that hot
• B) very powerful shock waves from exploding stars heat the gas they come into contact with
• C) gas gets to be this hot when hydrogen atoms flip their spin and give off 21-cm radiation
• D) such gas is heated by the radiation given off by complex molecules in clouds
• E) astronomers have no idea how gas gets this hot; this is an unsolved mystery in astronomy

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Definitions:

Location

A specific position or point in physical or virtual space.

Z-statistic

A type of standard score that indicates how many standard deviations an element is from the mean, used in significance testing.

Significance Level

A threshold for determining whether a p-value indicates a statistically significant result, usually set at 0.05 (5%).

Nonparametric Tests

Statistical tests that do not assume a specific distribution for the data, making them suitable for analyzing ordinal data or when the assumptions for parametric tests are not met.