Radio Galaxy Zoo Talk

Comparing RGZ FIRST and NVSS. How to judge what is worth flagging up?

  • Tobend by Tobend

    In RGZ this object looks like a #compact, everything else appearing to be #artefact. However NVSS gives the appearance of it having tails to the North in a v formation. Is there any way to judge if these are real, noise, artefacts from the interferometer or separate, poorly resolved sources? If they are real how is it possible to tell if they are connected to the central source? Looking at the FIRST image more bright sources can be seen, with associated plume like structures in NVSS and the same question applies to these. I appreciate the answer may not be straightforward but any guidance would be appreciated. Finally do the SCIENTISTS want these flagged up, at least in cases such as this where the NVSS image seems to have good contrast? Thanks for any replies.


  • 42jkb by 42jkb scientist, admin

    Hi Tobend, Thanks for the great question!

    For the image on RGZ: The radio source in the centre of the image does look #compact. Since this is the only object in the radio image with contour lines on it, the rest of the radio data is noise.

    NVSS image: I wouldn't worry about the v-shape in the NVSS image. I would say that this is noise in the NVSS image.

    FIRST image: Looking at the FIRST image, I would say that this compact source is a source in itself. A good check is to look at other surrounding sources and if they "point" towards the central source, then they made be connected. If this occurs, this is a good source to follow-up and use the hashtag #giant.

    Another good thing to flag is any radio source that appears "weird". Does the source look like a "w", "u", "v"? Is the source not symmetric? What about the infrared image? Is there many clustered together near the radio source? This could be a #bhgroup (black hole group) or cluster. Really, flag what ever you find interesting and we will follow up.

    Let us know if you need more information or if I wasn't clear enough.

    Hope you are enjoying RGZ!