hmfast.tracers.GalaxyTracer
- class hmfast.tracers.GalaxyTracer(profile=None, dndz=None)[source]
Bases:
TracerGalaxy counts tracer.
- Attributes:
- profileGalaxyHODProfile
Halo occupation distribution profile used to model galaxy number counts.
- dndztuple of jnp.ndarray
Normalized galaxy redshift distribution stored as \((z, dN/dz)\).
Methods
kernel(cosmology, z)Compute the galaxy kernel \(W_g(\chi)\) at redshift \(z\).
update([profile, dndz])Return a new GalaxyTracer instance with updated attributes using PyTree logic.
- update(profile=None, dndz=None)[source]
Return a new GalaxyTracer instance with updated attributes using PyTree logic.
- Parameters:
- profileGalaxyHODProfile, optional
New HOD profile to use for the tracer. If None, the profile is unchanged.
- dndzarray_like, optional
New redshift distribution (z, dN/dz). If None, the distribution is unchanged.
- Returns:
- GalaxyTracer
New tracer instance with updated attributes.
- kernel(cosmology, z)[source]
Compute the galaxy kernel \(W_g(\chi)\) at redshift \(z\).
The kernel is given by:
\[W_g(\chi) = \frac{H(z)}{c} \frac{dN}{dz}\]where \(dN/dz\) is the normalized redshift distribution of galaxies.
- Parameters:
- cosmologyCosmology
Cosmology object with required methods and parameters.
- zfloat or array_like
Redshift(s) at which to compute the kernel.
- Returns:
- W_garray_like
Galaxy kernel evaluated at redshift(s) \(z\).