Galaxy Zoo Talk

What does the jargon under "Flags" mean. Where can you find out?

  • suelaine by suelaine

    SDSS J005522.69+302913.8 ( AGZ0005vfr )

    Type RA,dec ObjID
    Decimal Hexagesimal
    GALAXY 13.84456682,30.48717754 00:55:22.69,+30:29:13.83 1237680285993336905

    Move mouse over a column name to get its units.
    mode PRIMARY
    flags DEBLEND_DEGENERATE DEBLENDED_AT_EDGE STATIONARY BAD_MOVING_FIT MOVED BINNED1 SATURATED INTERP COSMIC_RAY NODEBLEND CHILD BLENDED

    Posted

  • Ex103 by Ex103

    suelaine,

    Now granted this isn't my profession, but what your seeing I believe are computerized algorithm notations taken during the processing side of the image...

    They are creating layers - mosaic of sorts with multiple em bands / with a few exposure passes with the telescope and trying to stay consistent with a sort of software processing protocol.

    I unfortunately never found the time to really set down and really read through the SDSS - Sloan Digital Sky Survey processes but JeanTate referred me to a site awhile back ... lets see... I can't remember where this person told me it was.

    Ok my bare with me as I go through my goofy / fuzzy logic process... Using a search engine and "SDSS DR8" I found " http://skyserver.sdss3.org/dr8/en/ " looking under "Data Release" led me to " http://www.sdss3.org/dr8/ " and under "algorithm" led me to " http://www.sdss3.org/dr8/algorithms/ " in there under the second column is the "Summery of flags" you seek.

    Hopes this helps! Take care out there!

    Posted

  • Budgieye by Budgieye moderator

    Such confused algorithms. This is why Galaxy Zoo needs humans. I'm no expert either, so if a scientist reads this, keep the laughter down. Software has no eyes, so it recognizes objects by some algorithms. Software can't identify the bright thing at the left, so it ticks every box that it might be.

    DEBLEND_DEGENERATE It can't decide if galaxy + star is one object or two, but separating them didn't seem to work.

    DEBLENDED_AT_EDGE STATIONARY and it doesn't help that one object is at an edge

    BAD_MOVING_FIT maybe it is an asteroid? it used asteroid algorithm, but didn't fit the data. Probably not an asteroid

    MOVED Software can't identify the bright thing at the left, so it ticks every box that it might be. Blame it on airplanes or satellites.

    BINNED1 might be two objects

    SATURATED thing at left is too bright anyway

    INTERP COSMIC_RAY - when in doubt, call it a cosmic ray hit, and let the human decide if it is or not. This human thinks not.

    NODEBLEND - is the star+galaxy two objects, no, don't treat them as one object, keep them separate

    CHILD Two bright things near each other, the bright one is the parent, the dimmer one is the child

    BLENDED There seems to be two objects in the images, but they are touching so is it one object or two objects? The two objects are different colours, so try to separate it into two objects.

    Posted