Space Warps Talk

ASW0003r61 Modelled

  • jon273 by jon273

    Ok, you'll have to forgive me here - I've only just really started modelling in earnest.

    I've had a go at modelling ASW0003r61 - it's not a definitely lens candidate but it looked simple so i thought I'd give it a go.

    Model is here: http://mite.physik.uzh.ch/data/002481

    Screenshot of my points is here: ASW0003r61

    Does this look anything like it should? I've tried to line up the brighter and dimmer points of the arc.

    I suppose this possible lens is so simple then it can definitely be modelled - meaning that the actual process of modelling tells us nothing about whether it's a real lens or not?

    Posted

  • psaha by psaha scientist

    The model looks very plausible. The location of the saddle point at 10 o'clock is something we can only guess at (at this resolution) but if that point moves a little, it probably won't change the model too much.

    Looking at the mass map, we can see it's elongated in the upper-left to lower-right direction. But the galaxy looks pretty round. This implies (assuming the system is a lens and the model is on the right track) a dark halo elongated in that way. Now what could be elongating a halo? Well, if there are big galaxies nearby that would do it. And indeed there are other galaxies to the upper left. So your model is doing well: it made a prediction that we'd see a perturbing galaxy to the upper left or lower right, which turned out correct.

    Posted