Multiple Choice
Absorption lines produced by the interstellar medium indicate that some components of the interstellar medium are cold and of a very low density because
A) the lines are blue shifted.
B) the lines are red shifted.
C) the lines are extremely broad.
D) the lines are extremely narrow.
E) the lines are much darker than the stellar lines.
Correct Answer:

Verified
Correct Answer:
Verified
Q9: Stars are born in<br>A)reflection nebulae.<br>B)dense molecular clouds.<br>C)HII
Q12: The extinction of starlight due to the
Q13: Molecular clouds can be observed<br>A) using infrared
Q14: Coronal gas radiates energy at<br>A) gamma-ray wavelengths.<br>B)
Q15: The intercloud medium has the highest density
Q17: _ is(are)believed to be produced by supernova
Q18: The air inside two balloons has the
Q19: Reflection nebulae look blue because they are
Q20: The _ is the component of the
Q21: _ are small dark nebulae less than