Radio Galaxy Zoo Talk

WISE: IR sources everywhere ! (aka confusion)

  • DocR by DocR scientist

    One of the challenges we face with the use of WISE is that these images show sources almost everywhere you look. This is a major problem for the faintest IR sources, because the chance of a radio source overlapping with a faint source is very high, even if there is no real association. In addition, once the image reaches such faint levels, many of the IR "sources " are not even individual objects, but blends of objects that you could see individually if you had higher resolution. This means that the IR identifications we make with bright IR sources are safe, but the faint ones are highly questionable.

    Users should not worry about this during classification; this will get sorted out when we do the next stage of scientific analysis. For a technical description of the confusion levels in WISE, see http://iopscience.iop.org/0004-637X/735/2/112/pdf (not for the faint of heart) .

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  • ivywong by ivywong scientist, admin

    Thanks heaps @DocR for this post. The WISE images are challenging and confusing.

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  • DocR by DocR scientist

    Here is an example of the problem. Source ARG0002rbg http://umn.edu/~larry/RGZ/ARG0002rbg.jpg . On the left is the red filter image from the Sloan Digital Sky Survey. Middle is FIRST image. Right is WISE. WISE blends two objects together as seen in SDSS. The likely identification is the fainter SDSS source to the bottom right, inside the radio contours.

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  • ivywong by ivywong scientist, admin

    Hi @DocR and everyone else, if you'd like to know how you can get larger FIRST images or see what the fields look like in SDSS or DSS, check out this link:
    http://radiotalk.galaxyzoo.org/#/boards/BRG0000001/discussions/DRG00001ou

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