Radio Galaxy Zoo Talk

ARG0001k68 - host is a strong gravitational lens (blue arc)? Are there any confirmed radio lenses?

  • JeanTate by JeanTate

    On March 29 2014 1:25 PM, WizardHowl wrote this, in a comment on ARG0001k68:

    #doublelobe host has arc of three blue objects on one side, reminiscent of lens but nothing opposite, SDSS J152207.70+325113.3 Z_ph~.68-.83

    Here's SDSS J152207.70+325113.3 (DR10 image):

    enter image description here

    I posted this in the GZ forum's Possible strong gravitational lenses thread, here. Budgieye, a super-zooite member of the Space Warps Science Team, replied:

    I looked through my SpaceWarps collection, and didn't see it. http://talk.spacewarps.org/#/collections/CSWS00004f

    It looks similar to others, doesn't it?

    Super-zooite zutopian also replied:

    It looks similar to lens candidates in following paper, but curiously isn't listed.:

    Lensing clusters of galaxies in the SDSS-III
    Z. L. Wen, J. L. Han, Y. Y. Jiang
    (Submitted on 2 Aug 2011 (v1), last revised 6 Sep 2011 (this version, v2))
    http://arxiv.org/abs/1108.0494

    If it is a lens, how much of the radio emission might be from the (far) background galaxy, and how much from the lens itself? Do radio lenses have the same sort of potential, science-wise, as optical (and IR/x-ray) ones do?

    Is this object on any of the science team's radars?

    Posted

  • zutopian by zutopian

    There is following new paper on arxiv.:

    3C 220.3: a radio galaxy lensing a submillimeter galaxy

    Herschel Space Observatory photometry and extensive multiwavelength followup have revealed that the powerful radio galaxy 3C 220.3 at z=0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z=2.221. At an observed wavelength of 1mm, the SMG is lensed into three distinct images. In the observed near infrared, these images are connected by an arc of 1.8" radius forming an Einstein half-ring centered near the radio galaxy. In visible light, only the arc is apparent. 3C 220.3 is the only known instance of strong galaxy-scale lensing by a powerful radio galaxy not located in a galaxy cluster and therefore it offers the potential to probe the dark matter content of the radio galaxy host. (...)

    Martin Haas, Christian Leipski, Peter Barthel, Belinda J. Wilkes, Simona Vegetti, R. Shane Bussmann, S. P. Willner, Christian Westhues, Matthew L. N. Ashby, Rolf Chini, David L. Clements, Christopher D. Fassnacht, Assaf Horesh, Ulrich Klaas, Leon V. E. Koopmans, Joanna Kuraszkiewicz, David J. Lagattuta, Klaus Meisenheimer, Daniel Stern, Dominika Wylezalek
    (Submitted on 11 Jun 2014)
    http://arxiv.org/abs/1406.2872

    Posted

  • zutopian by zutopian

    There is a new post in the GZ forum.: Capella05, who is one of the moderators of Spacewarps Talk, did following comment.:

    While it does look exciting 😃 A word of caution - as mentioned by WizardHowl - there is no apparent counter image on the right. That alone would be a deal breaker. While it is possible that it could be hidden / embedded within the galaxy itself, I can find no sign of it. There are a few colour distortions on the right, but nothing that lends itself to be anything but noise. I will see if I can a second opinion.
    To echo Budgie, the shape does look quite familiar (that is good!), but I have seen more convincing candidates that did not turn out to be lenses.

    http://www.galaxyzooforum.org/index.php?topic=6927.7125

    Posted

  • zutopian by zutopian

    In DR10 the photometric redshifts are as follows.:

    KD-tree method:
    the arc: 0.098
    galaxy: 0.826

    RF-method::
    the arc: 0.126
    galaxy: 0.685

    Posted

  • ivywong by ivywong scientist, admin

    There are radio gravitational lenses around. Not as many as in the optical though. It seems that the radio emission usually come from the foreground object and not the source that is being lensed. Check out this fairly relevant paper by Boyce et al (2006) http://adsabs.harvard.edu/abs/2006ApJ...640...62B

    It would be most interesting if we can spot a few of these in RGZ. As always, keep up the good work!

    Posted

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

    I did a post concerning the photometric redshifts also in the GZ forum and Jean replied as follows.:

    The photoz's (z_ph) are interesting, but I'm not sure they're terribly informative. (...)
    In any case, both methods quote errors, which are just as important as the central values: for the red blob, they're 0.826 ± 0.0598 and 0.685 ± 0.1266; for SDSS J152207.91+325114.0 (the center of the 'arc'), 0.098 ± 0.0908 and 0.126 ± 0.0689.
    (...) Ergo, in at least one well-established case, the z_ph of the lensed object is wildly wrong.

    http://www.galaxyzooforum.org/index.php?topic=6927.7125

    I replied to her post in the GZ forum.

    Posted