Galaxy Zoo Talk

Colors in UKIDSS

  • planetaryscience by planetaryscience

    I've been looking at UKIDSS images, studying their colors. I have looked at what things are certain things in real color and what are artifacts, and here are a few thing I have drawn with this as the central data information:

    The light that we receive from the UKIDSS images are the stars in it, with the blue-indigo ones being those. As they get brighter, it indicates more dense ones, and as it gets a lighter tone (to light blue even) it indicates hotter areas.

    The orange and red images indicate radiation emission, particularly from microwaves. As they get brighter, it indicates strong microwaves as this little galaxy here shows, and as it gets redder (As opposed to orange) they get further from far Infrared to microwaves. You can easily tell if a galaxy has a high microwave emission based on its color.

    ~planetaryscience

    post comments and remarks below, please!

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  • pitchaxis by pitchaxis

    Great information...Thanks!

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  • planetaryscience by planetaryscience

    You're welcome. 😄

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  • Alpha_Aurigae by Alpha_Aurigae

    Ah, thanks 😃

    So the couple of UKIDSS images with possible nuclear rings can indeed be genuine nuclear rings.

    EDIT - They aren't .

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  • c_cld by c_cld

    AGZ0006ezz

    #Mrk 1239

    Here the active galactic nucleus (AGN) in Mrk 1239 shows an infrared excess that can be attributed to blackbody emission from hot dust at a temperature ~1200 K (Rodríguez-Ardila & Mazzalay 2006).

    No ring but diffraction spikes and airy disks as in HST image Instrument: NICMOS
    Filter/Grating: POL120L: (~20007.6Angs) or just below K band

    filter POL120L

    see NICMOS POLARIMETRY OF "POLAR-SCATTERED" SEYFERT 1 GALAXIES 😉

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  • mlpeck by mlpeck

    The UKIDSS photometric passbands span the near IR from about 0.83-2.37μ. The official reference for that is Hewett et al. 2006. That's nowhere near the microwave regime (> 1cm. according to Wikipedia).

    The imaging survey that provided the images used by GZ used the YJHK filters, I think. I don't know which ones were actually used to create the false color images we were fed but in any case the pictures are probing the cool star population.

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  • Alpha_Aurigae by Alpha_Aurigae

    Thanks C_cld and mlpeck, this is very educational 😃

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  • c_cld by c_cld in response to mlpeck's comment.

    From blog GZ by Kyle Willett

    Images and artifacts in Galaxy Zoo: UKIDSS

    All of the UKIDSS images you see in Galaxy Zoo are what we call “artificial-color” — we use images captured by the telescope’s infrared detector, and then combine the different infrared wavelengths into a single color image. For our images, we use data from the Y-band filter (1.03 microns) for the red channel, J-band filter (1.25 microns) for green, and K-band (2.20 microns) for the blue channel.

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