Galaxy Zoo Talk

Spiral-QSO merger? OR Star-galaxy overlap?

  • zutopian by zutopian

    The bright blue object looks like a star. If it is not a star, but a QSO, then it is a #merger, because that arm of the #spiral is #disturbed.

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  • StereoSpace by StereoSpace

    I'm very skeptical that QSO is at the same distance as the galaxy because its brightness is greater than the galaxy. It's more likely a coincidental alignment of a foreground star.

    I do agree that arm is disturbed though. I think more likely candidates are the two cloud puffs also visible in the image, which may be dwarf galaxies, one SE and very close and the other NE and some distance away. Most likely is the one to the SE (Occams razor). Just my humble opinion. 😃

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  • ElisabethB by ElisabethB moderator

    Foreground star for me too.

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  • zutopian by zutopian in response to StereoSpace's comment.

    StereoSpace
    I'm very skeptical that QSO is at the same distance as the galaxy because its brightness is greater than the galaxy. It's more likely a coincidental alignment of a foreground star.
    I do agree that arm is disturbed though. I think more likely candidates are the two cloud puffs also visible in the image, which may be dwarf galaxies, one SE and very close and the other NE and some distance away. Most likely is the one to the SE (Occams razor). Just my humble opinion. 😃

    Thank you for your comment.
    There are bright QSOs, which are at the same distance as a galaxy, and even more distant ones. On that image, I don't see another object, which might interact with that spiral. Since in this case there are no redshifts available in SDSS/NED, one can not be sure, if it is a QSO or a star.

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  • ElisabethB by ElisabethB moderator

    You are right, without redshift we cannot be 100% sure. But if you look at the star on the left, they both look very much alike. My bet would still be a foreground star.

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  • zutopian by zutopian

    In SDSS, that object doesn't look as bright as on the GZ image.:

    http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237680316063023174

    Note: Image rotated

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  • JeanTate by JeanTate

    The SDSS photometric pipeline classifies this as a star, in all five bands (click on "PhotoObj", scroll down to "probPSF_x", where x=(u,g,r,i,z)). The colors are also consistent with a foreground star; are they inconsistent with those of a quasar? I don't know, if only because QSOs can spring many surprises.

    As Els says, without a spectrum, one can't say for sure, either way.

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  • trevor_allen_faller by trevor_allen_faller

    blue blob at end of spiral is a star confirmed with skyserver

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  • trevor_allen_faller by trevor_allen_faller

    just a footnote the galaxy does not appear on skyserver as an object with any science done

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