by Dfraser44

Is this a black hole ?

Posted January 9, 2014 9:49 AM

by JeanTate in response to Dfraser44's comment.

The bright (white) elliptical-shaped thing in the IR image is, in fact, the source of the radio emission; it's the 'core' (the other radio stuff is a pair of jets and maybe a lobe, offstage right).

The core is the nucleus of a big elliptical galaxy, called SDSS J143526.23+275335.5 (as cosmic luck would have it, there's a Milky Way star almost 'on top' of it!). There is an SDSS spectrum of it (the nucleus), which shows no sign of it being an AGN; the spectrum enables us to say that its redshift is 0.176, which is relatively small for the core/jet/lobes radio sources in RGZ. However, despite a lack of an AGN signature in the optical spectrum, the nucleus of the galaxy is active, meaning that it contains a super-massive black hole (note that black holes - all black holes - are far, far, far, far, far too small to be 'seen' directly).

SDSS eye candy:

Hope this helps (and don't you just love RGZ!)

Posted January 9, 2014 11:38 AM