Space Warps Talk

ASW00060lk, ASW0005ms2: SL2SJ140117+571830 modeled

  • c_cld by c_cld

    First tentative for this HST snapshot candidate

    http://mite.physik.uzh.ch/data/004177

    I'll try to improve it as well as you are invited to do!

    Posted

  • c_cld by c_cld

    Exchanging the saddle points:

    http://mite.physik.uzh.ch/data/004191

    and putting pixel radius to11, redshift lens 0.3 and source to 0.8

    http://mite.physik.uzh.ch/data/004192

    Posted

  • ElisabethB by ElisabethB moderator

    First attempt : http://mite.physik.uzh.ch/data/004257 😄

    Posted

  • ElisabethB by ElisabethB moderator

    after some tweaking http://mite.physik.uzh.ch/data/004290

    Posted

  • ElisabethB by ElisabethB moderator

    switching the saddlepoints completely : http://mite.physik.uzh.ch/data/004301

    Posted

  • c_cld by c_cld

    With ASW0005ms2 and putting at 6 the saddle point linked to the mass point

    http://mite.physik.uzh.ch/data/004352

    Looking at the Synthetic Image, I didn't succeed to get an ellipse well tilted. Is it possible?
    The main brighter blobs (seen in GZ forum cutouts ) at 9, 11 , kind of arc between 1:30 and 3, and at 6 show up, but the fainter throughs are not? Is it due to the image stretch process?

    That led me a question to @psaha , @rafael:
    Modeling SpaceWarps images is done on a gri composite presented with Amit's stretch process. When you draw conclusions with a convincing model, are you confident to derive the same with a g-filter cutout or a single band from HLA snapshot processed by a log stretch (or else)?
    It could be of interest to see the results for this lens candidate ASW00060lk, ASW0005ms2, or the other ASW0003dq7 on HLA cutouts.

    Thanks

    Posted

  • ElisabethB by ElisabethB moderator

    tilted ellipse : http://mite.physik.uzh.ch/data/004368

    Posted

  • ElisabethB by ElisabethB moderator

    and another very tilted ellipse : http://mite.physik.uzh.ch/data/004406

    Posted

  • psaha by psaha scientist in response to C_cld's comment.

    SpaghettiLens makes mass models using only the position of point-like features. Once a mass map has been generated, two things can be done.

    1. Put down some trial profile for the source, and generate synthetic arcs from it. So far, SpaghettiLens just uses a `conical' profile for the source, but the size can be adjusted (implicitly) by changing the contrast.
    2. On the basis of the synthetic image, one can revise the model.

    Having a more general source profile is on the ToDo list for SL. The source of source profile would depend on the stretching process. It is also possible to optimize for the source pattern that best fits the observed images. It would be nice to talk about this in more detail in a hangout some time.

    Posted

  • psaha by psaha scientist

    Several interesting ideas in the models here! Some of them feel like just another revision could produce an excellent model, but the system continues to resist.

    What if the background source is a double? Possibly a merging system, but perhaps just a chance alignment. If so, we could be seeing a superposition of two arcs, each with its own saddle points and minima.

    Posted