Radio Galaxy Zoo Talk

Sources, source catalogs, overlapping 'classify' fields, etc

  • JeanTate by JeanTate

    I've noticed that there are often more than one radio source (or complex of sources) in the field we are offered up to classify.

    My guess is that the one in the center is what the GZR software selected, and that the others are 'bonuses'.

    Since the post-classify images started displaying both radio (and contour) and IR, it also gives a source name; FIRST is very common (and also (RA, Dec) coordinates, albeit with ridiculously few significant digits).

    Is FIRST the (only) source catalog?

    If there's another FIRST object in a classify field - well away from the center - how likely is it that this will also be offered for us to classify (at random, of course), this time centered?

    Posted

  • ivywong by ivywong scientist, admin

    Most of them do come from FIRST but you will see a few from ATLAS.

    As for the non-centered objects, don't worry they will come up again. The frames are centered on each of the radio source centres. This way, if part of the jet gets cut off because it is off the frame, we will see it again and then we can eventually merge all the information together. Sometimes the jets are just so large that we will not be able to view it all in one frame but if we made the maps bigger, the visibility of the individual galaxies become a problem.

    Does this help?

    Posted

  • DocR by DocR scientist

    Additional comment: the presence of the other sources in the field are no so much "bonuses" - we'd much rather they were isolated off on their own so we could classify them cleanly. So these other sources are actually a source of confusion, because we don't know a priori whether they are associated with the central source or independent. That's actually a good part of the motivation behind RGZ -- we need human eyes to help resolve this confusion.

    Posted

  • JeanTate by JeanTate in response to ivywong's comment.

    Yes it does, thanks.

    @DocR: that's partly why I put quote marks around 'bonus'!

    For the majority of cases, I expect that you'll be able to merge the classification info from separate fields (containing the same radio source) fairly easily; however, I also expect you'll have some which will prove quite a challenge.

    Related question: do you plan to 'zoom out' for sources which may be over-edge, and present them again, for zooites to classify? That would seem to me to be a pretty neat way to get (semi-) independent confirmation that such sources are, in fact, jets/lobes separated by several arcmins of empty space ...

    Posted

  • JeanTate by JeanTate in response to JeanTate's comment.

    Bump ...

    Related question: do you plan to 'zoom out' for sources which may be over-edge, and present them again, for zooites to classify?

    Posted