Radio Galaxy Zoo Talk

gravitational lens candidate

  • WizardHowl by WizardHowl

    source at right has blue lens arc at 5 o'clock position in SDSS image, host SDSS J131803.93+453101.1 Z_sp=0.186 is radio emission extended in this direction also? (I don't see the contours after classifying to check but the radio outline is extended)

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

    Looks to me like two independent sources:

    • a faint-ish #doublelobe in the center, with SDSS J131808.09+453057.0 (z_ph ~0.66) as the possible host (same location as the bright IR source in the middle
    • SDSS J131803.93+453101.1 as the host of the extended, somewhat bent #core on the right (as you note)

    The fairly local elliptical is the BCG of a cluster, and it quite bright in the IR (obviously); it's also known as 2MASX J13180395+4531009. Here's the SDSS image of this BCG, zoomed in somewhat:

    enter image description here

    The spectrum doesn't seem to have a second redshift system, which is what you might expect if the blue arc is a lensed background galaxy, but it's likely little of the light from the blue arc entered the fiber (so you may not see anything in the spectrum anyway).

    I've posted this over in the GZ forum's Possible strong gravitational lenses thread (here); let's see what the SW expert ordinary zooites have to say about it! 😃

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

    I've found another lensing candidate, although I'm not too sure about whether the pair of blue objects on either side of this galaxy are too far from it to have been lensed. I would rather highlight something like this and be wrong, though, than let it slip...
    http://radiotalk.galaxyzoo.org/#/subjects/ARG0001lhj

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  • WizardHowl by WizardHowl

    Amidst this bhgroup flagged by antikodon it looks like there could be almost a complete lens ring around SDSS J103221.63+315300.6 (Z_sp=0.338) but there is a second elliptical galaxy(?) right next to the would-be host that might be obscuring the rest. The feature is faint enough that colour is hard to distinguish but it looks noticeably blue-er than the yellow elliptical galaxy it surrounds and it also seems a believable size for a ring. Also, this is clearly not a disk galaxy and would be unlikely to have a ring feature of its own; although depending on its interaction (if any) with the neighbouring galaxy (if that is what it is, SDSS J103221.48+315258.1 no Z, classed as a star) it might have been disrupted, although the symmetry would be unusual.

    http://radiotalk.galaxyzoo.org/#/subjects/ARG0001m7o

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  • WizardHowl by WizardHowl

    Possible gravitational lens in

    http://radiotalk.galaxyzoo.org/#/subjects/ARG0001k7n

    The blue candidate lens arc is large and wide - it is being lensed by a tight group of galaxies not a single one. The brightest galaxy in this group is a compact radio source and has Z_sp=0.418 (SDSS J143956.51+325024.5).

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

    It looks pretty good, eh? 😃 Though perhaps not curved enough?

    enter image description here

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