According to the Theory of Self-Propagating Star Formation, the Spiral

question 38

Multiple Choice

According to the theory of self-propagating star formation, the spiral arms of flocculent spiral galaxies are broad and poorly designed because

• A) the spiral arms in these galaxies are strongly influenced by the black hole at the center of the galaxy.
• B) the density wave has been disrupted by the bar across the center of the galaxy.
• C) dust lanes occur in broad bands rather than in the narrow bands found in grand-design spirals.
• D) the spiral arm segments are defined only by the relatively short-lived O- and B-type stars.