# potfile¶

Under this identifier are defined the default parameters for all the galaxy scale mass components that account for perturbations to the cluster potential by the galaxies. By default, the mass distribution model for the galaxies is PIEMD.

filein -- type -- mag0 -- zlens -- sigma -- core -- corekpc -- cut -- cutkpc -- slope -- vdslope

### filein *int* *filename*¶

If **int** = 1 or 3 the galaxy catalog format is (id xc yc a b θ mag lum).

If **int** = 3, xc and yc are given in degrees in the equatorial coordinates.

If **int** = 1, xc and yc are given in arcseconds relative to the reference point given in the runmode section.

Note that the keyword *#REFERENCE* in the header of the catalog overrides this behavior in all cases.

If *int* = 2, the galaxy catalog format is (ftype xc yc ε θ rcore(kpc) rcut(kpc) σ(km/s) z).

The ellipticity ε parameter is linked to a and b by : ε = (a ^{2} − b ^{2})/(a ^{2} + b ^{2}) . The ellipticity ε of the galaxies is then computed again according to their potential type (type).

### type *int*¶

All the galaxies have the same mass profile set by **int**. Default value is 81, i.e. PIEMD potential.

In the current version, the last column in the catalog (Luminosity) is not used. The dynamical parameters (rcore,rcut,σ) of the potfile galaxies are scaled with the scaling relations described below.

### mag0 *float*¶

float is the m* parameter of the reference galaxy for the scaling relations below. It can be in absolute or in relative magnitudes according to the magnitude you give in your potfile. m* default value is 17 mag.

### zlens *float*¶

All the galaxies with no specified redshift (Catalog format 3) have the same redshift **float**. This is used to compute the diameter angular distance.

### sigma *int* *float1* *float2*¶

*float1* is σ* in km/s. The velocity dispersion of the galaxies is given by $\sigma = \sigma^*\ \left( \frac{L}{L^*} \right)^{\frac{1}{\rm vdslope}}$

In the inverse 3 bayesian optimisation method, *int* can be either 1 or 3 for the uniform or Gaussian prior respectively.

If *int* = 1, *float1* and *float2* are the min and max limits respectively.

If *int* = 3, *float1* and *float2* are the mean and stddev parameters of the Gaussian pdf.

In the inverse 2 optimisation mode (deprecated), *int* sets the number of bins for the potfile optimisation in the range (min,max) = (*float1*, *float2*).

### core *float*¶

*float* is rc* in arc seconds. It is used to compute the core radius of the galaxies using the scaling relation $r_c= r_c^*\ \left( \frac{L}{L^*} \right)^{\frac{1}{2}}$.

### corekpc *float*¶

*float* is rc in kpc. It is used to compute the core radius in kpc of the galaxies. The cosmological parameters defined in the cosmologie Section are used to convert from kpc to arc seconds. core parameter defined in arc second takes precedence over corekpc.

### cut *int* *float1* *float2*¶

**float1** is rcut* in arc seconds. The cut radius in arc seconds of a galaxy is $\r_{\rm cut}$ = $r_{\rm cut}^*\ \left( \frac{L}{L^*} \right)^{\frac{2}{\rm slope}}$.

**int** and **float2** are used for the potfile optimisation. (see sigma keyword and inverse section).

### cutkpc *int* *float1* *float2*¶

**float1** is rcut* in kpc and is used to compute the cut radius of the galaxies in kpc. The cosmological parameters defined in the cosmologie section are then used to convert from kpc to arc seconds. Arguments *int*, *float1* and *float2* work in the same way as for the cut parameter. cut parameter defined in arc second takes precedence over cutkpc.

### slope *int* *float1* *float2*¶

*float1* is the slope value used in the cut radius computation. *int* and *float2* are used in the potfile optimisation. Slope default value is 4, i.e. a constant M/L ratio. To reproduce the fundamental plane, you need to set slope to 2.5.

### vdslope *int* *float1* *float2*¶

*float1* is the velocity dispersion slope value used in the σ computation (see sigma parameter). *int* and *float2* are used in the potfile optimisation. vdslope default value is 4.