
 MAMECLOT: MAke ME a CLuster Or Two

 Construct initial conditions of 1 (or 2) cluster(s) for N-body simulations 

 A 2 cluster system with orbit in the x-y plane is made if the mass ratio q>0 
 Five equilibrium models are available, a cut-off radius can be provided
 The velocities can be isotropic or radially anisotropic (a la Osipkov-Merritt)
 Optional angular momentum by aligning the angular momentum vectors along z
 System is scaled to N-body units with G = M = -4E = 1 (Heggie & Mathieu 1986)
 In the case of a two-body system E = mu*e_orb + E_1 + E_2 (mu = reduced mass) 
 The 2-body orbit is computed from input q, e_hat and l_hat (and eta if q<1):
        e_hat = e_orb/0.5<sigma^2> 
        l_hat = l_orb/<r_vir*sigma>
        eta => defines the relative radii: r2/r1 = q^eta, for example:
               eta=[-0.33/0/0.33/0.5] for equal [t_rh/r_h/rho_h/Sigma_h]

 Mass, pos[3], vel[3] are written to standard output
 System diagnostics are written to the standard error

 Usage: mameclot [OPTIONS] 

 Options: 
          -N Total number of stars [10000]
          -m Cluster model [3]
             0: Dehnen (1993): gamma=0            =>     core, -4 halo
             1: Hernquist (1990)                  =>  -1 cusp, -4 halo
             2: Jaffe (1983)                      =>  -2 cusp, -4 halo
             3: Henon (1959) "Isochrone" sphere   =>     core, -4 halo
             4: Plummer (1911)                    =>     core, -5 halo
          -q Mass ratio of the two clusters (q=m2/m1) [0] 
             0: Make 1 cluster
             0<q<=1: Make 2 clusters
          -e eta: Relative cluster sizes: r2/r1 = q^eta [0.333] 
          -i IMF [0] 
             0: Single mass cluster
             1: Kroupa (2001) between 0.1 Msun and 100 Msun
          -l Angular momentum in z-direction, -, + or x [0] 
              0: xx (both none)
              1: ++ (both positive)
              2: +x 
              3: +- 
              4: x+ 
              5: x- 
             -1: -- (both negative)
             -2: -x 
             -3: -+ 
          -f Fraction of maximum rotational energy [1] 
          -a Osipkov-Merritt anisotropy radius in units of r_0 [999] 
          -c Cut-off radius in units of r_h [20] 
          -r Physical scale in pc [1] 
          -d Distance between 2 clusters in N-body units [20] 
          -E Dimensionless orbital energy of two-cluster system [0] 
          -L Dimensionless orbital angular momentum two-cluster system [4]
             <0 : forces a circular orbit
          -s Random seed [0=from clock] 

 Example 1: Isochrone sphere with a Kroupa mass function and Osipkov-Merrit 
            anisotropy radius equal to half-mass radius:
            (./mameclot -m 3 -a 3.06 -i 1 > snap.tab)2> diag.txt

 Example 2: Two Hernquist models with isotropic velocity distribution on a 
            circular orbit and a mass ratio of 1/3:
            (./mameclot -m 1 -q 0.333 -L -1 > snap.tab)2> diag.txt

