Wikipedia:Reference desk/Archives/Science/2019 April 1

= April 1 =

Remoteness in space
Is it fair to say a quasar is more distant than a remote galaxy?  ~^\\\.rT G '{~ 12:52, 1 April 2019 (UTC)
 * Quasars, by definition, are luminous active galactic nuclei, so no. By definition, they are inside galaxies, and therefore are not more remote than galaxies. --OuroborosCobra (talk) 13:22, 1 April 2019 (UTC)


 * Danke,  ~^\\\.rT G '{~ 14:02, 1 April 2019 (UTC)
 * But of course, a particular quasar might be more (or less) distant than a particular galaxy. This might be very relevant when the two are close together (i.e. separated by a small angle) in the sky. {The poster formerly known as 87.81.230.195} 90.200.138.194 (talk) 15:01, 1 April 2019 (UTC)
 * Is it? I mean, a particular tree might be more distant than another particular tree, even if they are on near the same line of sight. There's nothing intrinsic about the more distant tree that defined it as such. --OuroborosCobra (talk) 17:48, 1 April 2019 (UTC)
 * It could be: for example, one might want to observe how the spectrum of a more distant quasar is modified by passing throught the fringes of the less distant galaxy (which can tell you things about the latter). Or one might want to know whether the quasar's host galaxy could be in the same galaxy cluster as the other galaxy. {The poster formerly known as 87.81.230.195} 90.200.138.194 (talk) 10:11, 2 April 2019 (UTC)
 * The original question has a point, in that quasar article says their numbers peaked 10 billion years ago, as they are typically an early step in galaxy formation. Nearby galaxies are more likely to be past that.  (You could make philosophical arguments to turn the answer either way, but they're pretty obvious) Wnt (talk) 13:29, 4 April 2019 (UTC)