trunc(r/|r_t|) rho(r) = C ------------------------------------, inner eta (outer-inner)/eta x * (x + 1) with trunc(x) = sech(x) if r_t > 0 2 = ------------------ if r_t < 0 sech(x) +1/sech(x) and 2 2 x = sqrt(r + r_c)/r_s Default parameters will construct a Dehnen & McLaughlin (2005) model. parameters out=file The initial conditions are written in NEMO snapshot format to file. If file=-, output is made to stdout. Default: required. nbody=num The initial conditions will contain num body masses, positions, and velocities. Default: required. inner=val The inner logarithmic slope (parameter inner above) is set to val. Default: 7/9. outer=val The outer logarithmic slope (parameter outer above) is set to val. Notein order for the total mass to be finite (required), the outer slope must either be larger than 3 or the truncation radius (see r_t below) must be finite (or both). Default: 31/9. eta=val The parameter eta, controlling the transitions in power-law slopes, is set to val. Default: 4/9. mass=val The total mass of the model is set to val; used to determine the constant C. Default: 1. r_s=val The scale radius of the halo model is set to val. Default: 1. r_2=val If given, r_s is ignored and the scale radius set to r_s = val * ( [2-inner]/[outer-2] )^[1/eta] such that for zero core radius and infinite truncation radius the negative logarithmic density slope equals 2 at radius equal val. No Default. r_c=val The core radius of the model set to val. Default: 0. r_t=val The truncation radius of the model is set to val. For val>0 the truncation factor is sech(r/val>0), while for val<0 it is 2/(sech(r/|val>0|)+1/sech(r/|val>0|)). Both have the same asymptotic exponential decay, but the latter affects the density less at radii smaller than the truncation radius. Note if val=0, the truncation radius is set to infinity. Default: 0. seed=num We will use num as seed for the (pseudo-) random number generator. If num=0, a unique new seed is created from the current value of the time, otherwise, the seed actually provided is used. Default: 0. q_ran=t|f If true, we use quasi-random rather than pseudo-random numbers for drawing position and angles in velocity space. Pseudo-random numbers are still used in the rejection-method to draw the total velocity from the DF. Default: f. eps=val If given, all individual softening lengths are set to val. No Default. f_pos=val The fraction of bodies with positive sense of rotation about the z-axis is set to val. Default: 0.5. giveF=t|f If true, the phase-space densities of the model are written with the snapshot in the auxiliary (’aux’) data fields. Default: f. giveP=t|f If true, the total gravitational potential (internal plus external) at each body position are written with the snapshot in the ’pot’ data fields. Default: f. giveA=t|f If true, the total gravitational acceleration (internal plus external) at each body position are written with the snapshot in the ’acc’ data fields. Default: f. accname=name If given, the potential name is taken as external potential (in addition to the potential generated by the density model sampled) and taken into account when computing the equilibrium. No Default. accpars=vals If accname is given, the parameters vals are provided as parameters for the external potential. No Default. accfile=file If accname is given, the file name is provided as data file for the external potential. No Default. see alsomkdehnen(1falcON), mkplum(1falcON), mkking(1falcON) McMillan & Dehnen, 2007, MNRAS, 378, 541 files falcON/doc/user_guide.pdf User Guide for falcON falcON/doc/mkgalaxy_user_guide.pdf User Guide for mkhalo
Walter Dehnen walter.dehnen@astro.le.ac.uk update history of this man page 17-Sep-2007 WD first version of manual 02-Nov-2007 WD added giveP and giveA