Astronomy current events question: black hole SDSS J010013.02+280225.8

Astronomy 210L, spring semester 2015
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Davide Castelvecchi, "Young Black Hole Had Monstrous Growth Spurt," (February 25, 2015)
http://www.nature.com/news/young-black-hole-had-monstrous-growth-spurt-1.16989

The mass of the supermassive, early formation black hole SDSS J010013.02+280225.8 was estimated by analyzing:
(A) spacetime expansion.
(B) x-ray emissions.
(C) infalling gas velocities.
(D) its intrinsic brightness.
(E) gravitational lensing.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 10 students
(B) : 5 students
(C) : 21 students
(D) : 11 students
(E) : 8 students