Radio Galaxy Zoo Talk

SkyView Image: ARG00011sy

  • zutopian by zutopian

    enter image description here

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  • zutopian by zutopian

    Here is the SDSS Skyserver Image.:

    enter image description here

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  • zutopian by zutopian

    Which galaxy is associated with the radio source ?
    It isn't the bright object, because it has a star spectrum.
    I guess, that it is the elliptical.

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  • 42jkb by 42jkb scientist, admin in response to zutopian's comment.

    This is hard to say without any follow-up observations. Higher resolution would provide the necessary information to determine which galaxy the radio belonged to.

    However, WATs indicate clusters/groups so I wouldn't be surprised if the star spectrum source was misidentified. My first thought would be the elliptical galaxy but I would need to rule out the "star".

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  • zutopian by zutopian

    However, WATs indicate clusters/groups so I wouldn't be surprised if the star spectrum source was misidentified. My first thought would be the elliptical galaxy but I would need to rule out the "star".

    Thanks for your reply! Sorry, but I didn't understand, what your statement " I wouldn't be surprised if the star spectrum source was misidentified." means.
    Could the star actually be a Quasar, though its spectrum class is star ?
    What does "possible misidentification of star spectrum source" mean ? Doesn't the star spectrum possibly belong to the object?

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  • planetaryscience by planetaryscience

    I would say it's most likely the elliptical for several reasons:

    First that the star spectrum does not seem to have any spectral qualities similar to that of a quasar. It lacks the CIV, Mg, and OIV spikes characteristic of a quasar. Plus the redshift indicates nothing even outside of our own galaxy.

    And you would assume that if it was an overlapped quasar that it might show minor characteristics of that, but it doesn't.

    I'm not an expert on this, but also typically well-defined radio lobes like this come from a fairly large, nearby source. Which the star/quasar isn't.

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  • 42jkb by 42jkb scientist, admin in response to zutopian's comment.

    I believe that when the SDSS has classified the objects many have found that some QSOs have been incorrectly identified to be Stars in the SDSS database. So if you see a star with a radio signature, chances are it has been misidentified in SDSS and is actually a QSO.

    However, looking at the image again this may just be a star to the left of the central galaxy in the SDSS image.

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  • zutopian by zutopian

    So some objects have the spectral class QSO, though they are actually Stars.
    Well, I think, that the discussed object, which is classified as star is indeed a star.: The classification of the spectrum looks right.
    Here is a case, where the QSO is behind a star.:
    http://radiotalk.galaxyzoo.org/#/boards/BRG0000002/discussions/DRG00006q8

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  • zutopian by zutopian

    I found out, that there are stars, which are radio sources according to following paper.:

    A Sample of Candidate Radio Stars in FIRST and SDSS

    (...) The selection criteria are positional coincidence within $1\arcsec$, radio and optical point source morphology, and an
    SDSS spectrum classified as stellar.
    (...)
    We conclude that, while the present wide-area radio surveys are not sensitive enough to provide homogeneous samples of the extremely rare radio stars, upcoming surveys which exploit the great sensitivity of current and planned telescopes do have sufficient sensitivity and will allow the properties of this class of object to be investigated in detail.

    Amy E. Kimball, Gillian R. Knapp, Zeljko Ivezic, Andrew A. West, John J. Bochanski, Richard M. Plotkin, Michael S. Gordon
    (Submitted on 16 Jun 2009 (v1), last revised 18 Jun 2009 (this version, v3))
    http://arxiv.org/abs/0906.3030

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  • zutopian by zutopian

    I don't think, that ARG00011sy might be associated with a radio star, because it isn't a radio compact source.
    Here is a Radio Zoo image, which is one of the radio star candidates in that paper.:
    http://radiotalk.galaxyzoo.org/#/subjects/ARG0002y28

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  • HAndernach by HAndernach scientist, translator

    yes, there are radio stars, but they are extremely rare, and their radio emission never has a WAT shape;
    so here we must have another extremely rare case where the WAT originates in the E galaxy, but the star is accidentally
    superposed on the eastern jet, even such that it appears to be at the symmetry center of the WAT!

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