The Tully-Fisher Method for Measuring the Distance to Galaxies Relies

question 33

Multiple Choice

The Tully-Fisher method for measuring the distance to galaxies relies on the observed relationship between the luminosity of a spiral galaxy and

• A) its rotational velocity (as determined from the width of the 21-cm line)
• B) its number of high-energy sources (as determined from the total gamma-ray emission)
• C) the size of its supernova remnants (as determined from radio maps)
• D) the number of globular clusters (as determined from high-resolution images)
• E) the number of companion galaxies found directly around it
• Section 26.5: The Expanding Universe