Clumpfinder (PHEW)#

The block named &CLUMPFIND_PARAMS contains the parameters related to the built-in RAMSES clump finder (PHEW). The parameters are described only briefly, for more backround information read the PHEW paper.

Variable name, syntax, default value	Fortran type	Description
`ivar_clump=1`	`integer`	Control which density field is used for clump finding (1: gas density, 0: particle density)
`density_threshold=-1.d0`	`float`	Density threshold for the clump finder (code units)
`rho_clfind=-1.d0`	`float`	Density threshold for the clump finder (g/cc). Not recommended - use `density_threshold` instead.
`n_clfind=-1.d0`	`float`	Density threshold for the clump finder (H/cc). Not recommended -use `density_threshold` instead.
`relevance_threshold=2.d0`	`float`	Relevance (peak-to-saddle ratio) threshold for a clump to be considered real (instead of noise).
`saddle_threshold=-1.d0`	`float`	Saddle density threshold for sub-structure merging (code units). A negative value turns sub-structure merging off (PHEW will only merge noise).
`mass_threshold=0.d0`	`float`	When set to a value > 0, the properties of those clumps/haloes with `mass > mass_threshold * particle_mass` are written to disk. `particle_mass` is the smallest strictly positive particle mass in the simulation. Setting this parameter does NOT affect the merging of noise/clumps.
`age_cut_clfind=0.d0`	`float`	When set to a value > 0, only the stars with an age lower than `age_cut_clfind` are used by the clump finder. Stellar and DM particles are used otherwise.