Radio Galaxy Zoo Talk

ARG0002uaw, doublelobe, SDRAGN candidate?

  • ChrisMolloy by ChrisMolloy

    Here's ARG0002uaw which appears to be a #doublelobe.

    enter image description here

    The contour overlay image in this post was created from sources, and using methods, described in this RGZ Talk
    thread.
    First in red.

    A possible host for this emission appears to be SDSS J160845.75+123534.9, which has a z_ph=0.211 ± 0.0461. This galaxy has a radio reference in NED, and an ALLWISE reference, ALLWISE J160845.77+123534.5. This object is aligned slightly NW of the S lobe, almost making this emission a #slip-strike #doublelobe. And interestingly, this galaxy appears #disk like in morphology.

    SDSS J160845.75+123534.9

    enter image description here

    If SDSS J160845.75+123534.9 is the host of the emission, and it does appear to be centred on an ir source looking at the ARG image left, then this object could possibly be an #SDRAGN candidate. It has a fracDev_g, _r, of 0.942, and 0.972; and an expAB_g of 0.303 and expAB_r of 0.319 respectively. For c, the inverse concentration index, it has a figure of 0.440 for the g band and 0.392 for the r band. It's hard to discern the morphology of this galaxy and whether it is an #SDRAGN candidate based on the above parameters, and the fact that it appears visually quite distant, is not face on, and possibly #disturbed or interacting with another object. Others may wish to comment on this.

    There is a radio reference in NED for SDSS J160845.54+123548.6, which has a z_ph=0.341 ± 0.1806. This galaxy has an ALLWISE reference, ALLWISE J160845.55+123548.2. This object is more aligned with the N lobe, S of the centre.

    SDSS J160845.54+123548.6

    enter image description here

    And finally, there is another radio reference in NED for SDSS J160846.35+123543.7, which has a z_ph=0.444 ± 0.1177. This object also has an ALLWISE reference, ALLWISE J160846.28+123543.7, and is slightly NE of the centre of the lobes.

    SDSS J160846.35+123543.7

    enter image description here

    As always, comments, suggestions, welcome.

    Posted

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

    I have come across plenty of "slipstrike" doubles, sources where the axes ("ridgelines") of the lobes do not intersect near the host, and which are not bent; this source is mildly slipstrikey 😉

    I have also classified a lot of sources as "asymm" (asymmetric), because the lobes have very different radio brightness, the obvious host is not at all near the centerpoint between the lobes, etc.

    This source seems to lack an IR (WISE) or SDSS source near where you'd expect one to be, if the lobes were regular; that motivates a hunt for a host somewhere else.

    I think any of the optical sources you mention could be the host, and the host may be something else entirely, such as a galaxy which is not an SDSS PO (photometric object), because it's too faint.

    Without higher resolution (radio) data, also much deeper, I don't think anything certain can be said about the host of this double.

    Posted