Review of Cheshire Cat lens models

There are different prefixes to my lens models, They indicate different assumptions I made during lens making process.

All models with prefixes v1 to v4 are toy models and should not be considered. I use them to train myself to familiarise with glafic operation.

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All models with prefix v5 follows the logic laid out in my thesis.

Preliminary lens model (label: pre_model) :

setup: 1 nfw, all free; 2 Jaffe, fixed positions, pa, e but not mass; 6 images from 3 sources, follow Bayliss.

result: NFW, 4.7e13 mass, -0.6, -0.8 ; Jaffe mass 243, 385;

Robust: No delensing-relensing, used as pre-determination of critical curve.

Single halo spec-z(ii) model ( label: v5_fiducial_run1)

setup: 1 nfw, all free; 2 Jaffe, fixed positions, pa, e but not mass; 13 images from 3 sources.

result : NFW 5.9e+13, 0.1, 0.4; Jaffe mass 407,232;

Robust: delens-relens as expected.

Single halo specz and photo-z (final) model ( label: v5_fiducial_run3)

setup: 1 nfw, all free; 2 Jaffe, fixed positions, pa, e but not mass; 22 images from 6 sources initial redshifts from photo-z, allow range of redshifts.

result : NFW 6.5e+13, -0.8, 0.3; Jaffe mass 419,464;

Robust: delens-relens poor result in source E and G

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Double halo pre model (not in thesis) ( label: v5_2nfw)

setup: 13 images from 3 sources

Double halo model (label : v5_2nfw_run2)

setup: 2 nfw, all free; 2 Jaffe, fixed positions, pa, e but not mass; 22 images from 6 sources.

result : NFW 5.3e+13, -3.3, -1.2; NFW 4.9e+13, 3.9, 1.4; Jaffe mass, 255,236;

Robust: delens-relens good result.

variants : power law and sersic models available.

group halos displaced inward wrt BCGs

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All models with prefixes v7 and v8 :

seperate BCGs into jaffe or sersic (represent light) and nfw (halo), where nfw all free parameters.

Label: V7_run1

setup: 2 nfw (group), all free; 2 sersic, fixed positions, pa, e but not mass; 2 nfw(BCGs) all free; 22 images from 6 sources.

result : NFW 4.2e+13, -2.7, -1.4; NFW 3.7e+13, 3.9, 1.2; sersic 5e+11 and 5e+11; nfw 3.7e+12, -4.3, -1; nfw 2.13e+13, 4.5, 1.6;

Robust: delens-relens good result.

variants : power law and sersic models available.

Label: v7_run2

setup same as run 1; add C12,C13 & C15,C18 pairs of counterimages.

result : NFW 6e+13, -2.5, -1.6; NFW 3.4e+13, 4, 1.6; sersic 3e+11 and 2.8e+11; nfw 4.4e+12, -4.3, -1; nfw 4.9e+13, 4.5, 1.6;

Robust: delens-relens good result. consistent with previous robust models. relens of G2 image longer than expected. see https://www.jackyastronomy.org/post/cheshire-cat-7-components-model

model (label:v7_run3)

setup: same as v7_run2 ; add nose as an aforeground object into gal file

Similar lens parameter

robust : good delens-relens result inc image G (as shown in figure below)

model v7_run3b

all same as v7_run3; minor changes :corrected some PA of some member galaxies.

result and robust remain similar as previous model.

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models with prefix v8: I fixed the redshifts of system E at z=2.2 (originally 2.28 with sigma 0.1) due to Jones et al 2013 spectroscopic measurement.

as discussed here:

https://www.jackyastronomy.org/post/cheshire-cat-lens-model-with-source-e-spec-z-2-2

2 halo model v8_run1

satisfactory delens-relens, no big changes to lens parameters. (use sersic to represent light)

variants: jaffe model also available

Exported this model (excluding group halo nfws) as input of WSLAP

also has a single halo model version for this. (label : v8_run2)

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This is the current review on glafic models.

Not much can be further done using glafic as we previously discussed.

WSLAP+ issue:

8 by 8 grid: not enough resolution to resolve the displacement between group halo and BCGs.

16 by 16 grid : model blow up due to insufficient constraints. especially outside the einstein ring as there is virtually no constraint.

What can be done:

tailor made grid: like 10 by 10; source code has to be changed. contact chema

dynamical grid: too many grids assigned to near BCGs, so we currently suffer from insufficient lensing constraints near BCGs. we need to find some way to force the program to reduce number of grid assigned near BCGs.