The list below includes:

INFALL: a code for calculating the mean initial
and final density profiles around a virialized dark matter halo.

GEMINI: a toolkit for analytical models of two-point correlations and
inhomogeneous structure formation.

FASTELL: a code to calculate lensing by an elliptical galaxy model.

Q0957+561: the full covariance matrix from VLBI fitting of the lensed
jets.

Infall is a code for calculating the mean initial and final density profiles around a virialized dark matter halo. The initial profile is derived from the statistics of the initial Gaussian random field, accounting for the problem of peaks within peaks using the extended Press-Schechter model. Spherical collapse then yields the typical density and velocity profiles of the gas and dark matter that surrounds the final, virialized halo. In additional to the mean profile, ±1-σ profiles are calculated and can be used as an estimate of the scatter. The code was developed by Rennan Barkana, 2002/3.

The paper [*MNRAS* 347, 59 (2004)],
entitled " A model for infall around virialized halos",
is available on the astro-ph archive,
**
here**.

The code in C cosistes of three files:

**Infall.c** (main program)

**InfallSub.c** (functions and subroutines)

**Infall.h** (header file)

Compile, e.g., with: gcc -O Infall.c -o Infall.out -lm

Here are six example input command files and the resulting
output data files (Each file takes a couple seconds to run). These
consider a 10^{10} solar mass halo
that virializes at redshift 2. WMAP 5-year cosmological parameters
are assumed.

Infall.out < Infall1.in >
Infall1.out (mean initial profile)

Infall.out < Infall2.in >
Infall2.out (-1-σ initial profile)

Infall.out < Infall3.in >
Infall3.out (+1-σ initial profile)

Infall.out < Infall4.in >
Infall4.out (mean final profile)

Infall.out < Infall5.in >
Infall5.out (-1-σ final profile)

Infall.out < Infall6.in >
Infall6.out (+1-σ final profile)

Here are two example figures that use these data files.

Supermongo input: InfallEx1.mon,
resulting EPS figure: InfallEx1.eps. This figure
is in the style of Figure 3 in Barkana (2004) (but it includes only
some of the curves, and the cosmological parameters are slightly different).
The same data files can be used to create figures in the style of
Figures 1 and 2 from Barkana (2004).

Supermongo input: InfallEx2.mon,
resulting EPS figure: InfallEx2.eps. This figure
is in the style of Figure 4 in Barkana (2004) (but it includes only
one curve, from the middle panel, and the
cosmological parameters are slightly different).

Gemini is a toolkit for analytical models of two-point correlations and inhomogeneous structure formation. It extends standard Press-Schechter theory to inhomogeneous situations, allowing a realistic, analytical calculation of halo correlations and bias. The code was developed by Evan Scannapieco and Rennan Barkana, 2000 - 2001.

The paper [*ApJ* 571, 585 (2002)],
entitled "An Analytical Approach to Inhomogeneous Structure Formation",
is available on the astro-ph archive,
**
here**.

The code in C is available
**here**.

FASTELL is a code to calculate quickly and accurately the lensing deflection and magnification matrix for the SPEMD lens galaxy model. The SPEMD consists of a softened power-law radial distribution with elliptical isodensity contours. The code was developed by Rennan Barkana, Fall 1997 - 1998.

The paper [*ApJ* 502, 531 (1998)],
entitled "Fast calculation of
a family of elliptical mass gravitational lens models",
is available on the astro-ph archive,
**
here**. (417 kbytes)

The same paper but with color figures is available (in postscript)
**here**. (417 kbytes)

The code in Fortran is available
**here**. (163 kbytes)

We give here the covariance matrix from VLBI fitting by Barkana et al. (1999) of the Garrett et al. (1994) data of Q0957+561.

The paper [*ApJ* 520, 479 (1999)],
entitled "A reassessment of the data and models of the gravitational
lens Q0957+561",
is available on the astro-ph archive,
**
here**. (417 kbytes)

In the paper we increased our parameter error estimates from
the following by an additional factor of the square root
of the reduced chisq, where the reduced chisq = 2.1933586480011
for 59 parameters fit to a total of 21040 visibility amplitudes
and phases.

In the following, we give a complete covariance matrix for
74 parameters (of which 59 are independent). The order is:
34 A component parameters (corresponding to the top half of
Table 1 in the paper. Thus there is a Flux, x-comp, y-comp,
Maj. Axis, Axis Ratio, and Pos. Ang. for each of six components,
except that the position of component #1 is set to 0,0 .), 34 B
component parameters (as in the bottom half of Table 1 in the
paper), and six magnification parameters (as in Table 2): M1 at
A5, M2 at A5, phi_1, phi_2, M1 at A1, M2 at A1.

Click **here** for a file with
the 74 parameters and their one-sigma errors.

Click **here** for a file with
the normalized Covariance Matrix (Order is A_[ij], with j=i to 74 for
each of i=1 to 74. Number of entrees is 2775, in 925 lines of
3 numbers each).