Radio Galaxy Zoo Talk

Invisible object?

  • DaveNicko by DaveNicko

    There doesn't seem to be anything associated with the radio image. But there does seem to be an infrared response either side of it. Is it correct to place the infrared marker in the middle (as I have done) or mark each infrared source (as I believe I should have done).



  • planetaryscience by planetaryscience

    If there is no obvious object, do not put one and say there is no source. However, you should usually choose the one it appears thickest at or is pointing towards. In this case, it appears to be the left object.


  • ElisabethB by ElisabethB

    Not too sure about that. I'd go for no infrared in this one


  • enno.middelberg by enno.middelberg scientist, translator in response to DaveNicko's comment.

    Placing the IR marker inbetween would actually not be a good choice in this case. I'd say that here neither of the two is the correct IR counterpart: radio emission (produced by electrons in magnetic fields) can be very elongated and can extend beyond the IR part of the galaxy, which is produced by stars. Take a look at this composite image of a nearby radio galaxy, Centaurus A: It is much larger in the radio than in the optical or IR.

    I have never seen it the other way around and would be very skeptical that it can happen.