Galaxy Zoo Talk


  • FemkeLara by FemkeLara

    Why are the colors this strange in the bulge?


  • zoob1172 by zoob1172

    #qso Sy1.0 xray source 306 references pos64


  • vrooje by vrooje admin, scientist in response to FemkeLara's comment.

    Well spotted and good question - it's because, in addition to a bulge, there's emission here from the black hole at the center of the galaxy. It's quite bright in this case, and it's what we call unobscured, which often looks white-blue in SDSS imaging. The slight variation in color is because the black hole is unresolved, so it looks (effectively) like a bright star over the top of the center of the galaxy, and the appearance (shape) of a star varies slightly with wavelength, so sometimes you get these color effects. So that part is an artifact, but the main bright spot is real.


  • BioMiep by BioMiep

    Ahh, is that what those are. Very cool. We were breaking our brains over one of those a while ago. Super odd. Thank you, Scientist! These colors are so different from set to set, it can be confusing to know what you're actually looking at.