Hezaveh uses image size with a pixel size of 0.04" (seconds of arc). This seems to be a reasonable choice to follow.
Proposed Selection Algorithm¶
This is based on a sketch by Ben David March 2026.
Choose the Einstein radius uniformly at random, so that .
where , i.e. converted to angular units.
Choose the source position inside or around the critical curve, For example, choose the polar coordinates
so that for some constant , e.g. .
chosen uniformly at random
Choose the orientation of the elliptical lens uniformly at random from a half-circle.
Choose the orientation of the elliptical source uniformly at random from a half-circle.
CHoose the ellipticity of the lens uniformly at random, so that .
Source parameters - sersic profile
size:
sersic index
luminosity , exponentially distributed with (see below)
Cluster lenses¶
For cluster lenses, each constituent lens is placed in the same way as the source, relative to the origin, in polar co-ordinates .
select random distance , where is the Einstein radius of the constituent lens
select random angle
Proposal from Oda¶
| Parameter | Hezaveh (arcsec) | CosmoSim (512x512) |
|---|---|---|
| (resiprocal) | ||
| Lens Ellipticity | (resiprocal) | |
| Source Size | ||
| Source Position () | not specified | |
| not specified | 50 | |
| Lens rotation () | not specified | |
| Source rotation () | not specified | |
Sersisk indeks (n_sersic) | N/A | |
| Luminosity | N/A | [1] |
The exponential distribution used for luminsoty returns
where
is exponentially distributed, that is with a probability
density function
for positive .
This is scaled to within the given range.
Luminosity is exponentially distributed with .