The width of an emission line is usually determined by how fast the light-emitting gas clouds are moving – in this case, how fast they’re orbiting around a supermassive black hole. Measure the width of the [S II] line pair in Angstroms by first measuring the wavelength of the right edge with your cursor, then the left edge, then subtracting. (Your instructor can show you this technique.) Then use this equation,
v = (width in Angstroms) x (300000 km/sec) / (6730 Angstroms)
to figure out how fast the gas clouds are moving in units of kilometers per second. Then convert that speed into miles per hour. Is that faster or slower than a jet aircraft?
(d) Repeat steps 2(a), 2(b), and 2(c) for the object named “3C 244.1” which is even more redshifted than 3C 236.