Radio Galaxy Zoo Talk

lobed emission from disk-like? QSO

  • WizardHowl by WizardHowl

    The asymmetric but clearly lobed radio emission here originates in SDSS J121659.93+323106.0 (there are no other candidates and this object is bright enough to obscure them in both IR and optical if there were). This is a very unusual galaxy: not only does it appear as if it is a face-on disk, it has a spectrum of a QSO, with extremely strong and wide emission lines. It is very close for a QSO, having a spectroscopic redshift of 0.125. Ordinarily the host galaxies of QSOs are too faint to be seen, so that would make this an interesting object by itself, regardless of any radio emission. I'm not sure how much of the spectrum will be from the AGN and how much from the disk/surrounding galaxy but should not exclude the possibility that this could very well be a spherical host galaxy rather than a disk. The colours do not seem to resemble the red+dead ellipticals and at this redshift that would be obvious but I suspect that ultimately the determination of the host galaxy type can only be done spectroscopically. I note the inaccuracy of the photometric redshift estimates, which suggests unusual colours, however.

    Posted

  • JeanTate by JeanTate in response to WizardHowl's comment.

    SDSS J121659.93+323106.0's SDSS spectrum (low-res PNG):

    enter image description here

    NED gives two references:

    • Stern&Laor 2012, "Type 1 AGN at low z - II. The relative strength of narrow lines and the nature of intermediate type AGN"
    • Smith+ 2010, "A Search for Binary Active Galactic Nuclei: Double-peaked [O III] AGNs in
      the Sloan Digital Sky Survey"

    With a nucleus this bright, it's hard to judge the morphology by eye, and simple profile fitting, color, and inverse concentration ratio tests become inconclusive too; pity it isn't highly-inclined. A detailed GALFIT point source+Sérsic profile fit would be helpful ...

    In the meantime, how about a FIRST contour overlap?

    enter image description here

    And the host itself ...

    enter image description here

    Boilerplate: SDSS image per http://skyservice.pha.jhu.edu/DR10/ImgCutout/getjpeg.aspx, FIRST (red) contours derived from the FITS file produced using SkyView with Python code described in this RGZ Talk thread. Image center is the galaxy SDSS J121659.93+323106.0, near the center of the ARG image (ARG0001kwr; J2000.0). "z_sp" is an SDSS spectroscopic redshift of the galaxy in the center.

    Posted