Radio Galaxy Zoo Talk

ARG000207w - Red galaxies with green lobes

  • Chris188 by Chris188

    Hello!

    I have found 2 interesting objects in the FIRSTJ165803.8+252105 (ARG000207w) field, red galaxies with green lobes.

    SDSS J165759.89+252002.5 galaxy zph 0.424
    SDSS J165805.01+252200.9 galaxy zph 0.292

    Real or unreal objects?

    Posted

  • Chris188 by Chris188

    SDSS J165759.89+252002.5

    SDSS J165805.01+252200.9

    Posted

  • JeanTate by JeanTate

    Sadly, these are optical (SDSS) artifacts. 😦

    If you open an SDSS Explore window/tab in your browser, recenter on the more northern weirdo object (SDSS J165807.48+252125.9), then click Chart (top left), and finally the SDSS Masks button (bottom left), you should get something like this:

    enter image description here

    The regions masked (automatically?) will have "bad photometry", meaning that objects in these regions are very likely to be affected by one or more artifacts. Also, in the object Explore webpage, you'll see a whole lot of "flags":

    MAYBE_CR PSF_FLUX_INTERP DEBLENDED_AT_EDGE INTERP_CENTER SATUR_CENTER BAD_MOVING_FIT BINNED1 DEBLENDED_AS_PSF SUBTRACTED NOTCHECKED SATURATED INTERP COSMIC_RAY NODEBLEND PEAKCENTER CHILD BLENDED

    These are generated automatically by the photometric pipeline and require some effort to unpack; in this case I think all they tell you is that "stuff happened", and that the data are not reliable.

    Hope this helps, and happy hunting! 😃

    Posted

  • Chris188 by Chris188 in response to JeanTate's comment.

    Very thanks!
    I will checking the SDSS images.

    Posted

  • Chris188 by Chris188 in response to JeanTate's comment.

    I checked the masks. Yes, the SDSS J165807.48+252125.9 is artifact and seen on SDSS r-band (skyview).
    The SDSS J165759.89+252002.5 galaxy zph 0.424 and SDSS J165805.01+252200.9 galaxy zph 0.292 are real objects without masks.
    Interesting pairs, green and red objects are very close.

    Posted