VikhlininDensityProfile#

class profiles.density.VikhlininDensityProfile(**kwargs)[source]#

Vikhlinin Density Profile.

This profile is used to model the density of galaxy clusters, incorporating a truncation at large radii and additional flexibility for inner slopes [1].

\[\rho(r) = \rho_0 \left(\frac{r}{r_c}\right)^{-0.5 \alpha} \left(1 + \left(\frac{r}{r_c}\right)^2\right)^{-1.5 \beta + 0.25 \alpha} \left(1 + \left(\frac{r}{r_s}\right)^{\gamma}\right)^{-0.5 \epsilon / \gamma}\]

where:

  • \(\rho_0\) is the central density.

  • \(r_c\) is the core radius.

  • \(r_s\) is the truncation radius.

  • \(\alpha, \beta, \gamma, \epsilon\) control the slope and truncation behavior.

Parameters
Parameters for VikhlininDensityProfile#

Name

Symbol

Description

rho_0

\(\rho_0\)

Central density

r_c

\(r_c\)

Core radius

r_s

\(r_s\)

Truncation radius

alpha

\(\alpha\)

Controls the innermost slope

beta

\(\beta\)

Governs the outer slope

epsilon

\(\epsilon\)

Steepens the outer decline

gamma

\(\gamma\)

Exponent in the truncation factor

Expressions
Expressions for VikhlininDensityProfile#

Name

Symbol

Notes

ellipsoidal_psi

\(\psi(r) = 2\int_{0}^{r}\!\xi\,\rho(\xi)\,d\xi\)

Inherited from base

References

Example

>>> import matplotlib.pyplot as plt
>>> from pisces.profiles.density import (
...     VikhlininDensityProfile,
... )
>>> r = np.linspace(0.1, 10, 100)
>>> profile = VikhlininDensityProfile(
...     rho_0=1.0,
...     r_c=1.0,
...     r_s=5.0,
...     alpha=1.0,
...     beta=1.0,
...     epsilon=1.0,
...     gamma=3.0,
... )
>>> rho = profile(r)
>>> _ = plt.loglog(
...     r, rho, "k-", label="Vikhlinin Profile"
... )
>>> _ = plt.xlabel("Radius (r)")
>>> _ = plt.ylabel("Density (rho)")
>>> _ = plt.legend()
>>> plt.show()

(Source code, png, hires.png, pdf)

../_images/profiles-density-VikhlininDensityProfile-1.png

Methods

__init__(**kwargs)

Initialize a profile instance with specific parameter values.

compute_circular_velocity(r[, units, G])

Compute the circular velocity at radius \(r\).

compute_cosmological_overdensity_profile(z, R)

Compute the spherical overdensity profile relative to the critical density at redshift \(z\).

compute_cosmological_overdensity_radius(z, ...)

Find the radius enclosing a target overdensity relative to the critical density at redshift \(z\).

compute_deflection_angle(R[, mode, units, ...])

Compute the gravitational lensing deflection angle at projected radius \(R\).

compute_einstein_radius(z_lens, z_source[, ...])

Compute the Einstein ring angular radius \(\\theta_E\) for a perfectly aligned source-lens system.

compute_enclosed_mass(r[, units])

Numerically compute the enclosed mass \(M(r)\) within radius \(r\).

compute_escape_velocity(r[, units, G])

Compute the escape velocity at radius \(r\).

compute_fractional_mass_radius(rmin, rmax[, ...])

Find the radius enclosing a given fraction of the total mass.

compute_gravitational_field(r[, units, G])

Numerically compute the gravitational field \(g(r)\) at radius \(r\).

compute_gravitational_potential(r[, units, G])

Numerically compute the gravitational potential \(\Phi(r)\).

compute_lensing_convergence(R, z_lens, z_source)

Compute the lensing convergence \(\kappa(R)\) at projected radius \(R\).

compute_surface_density(R[, units])

Numerically compute the projected surface density at radius R from the origin.

compute_total_mass([units])

Numerically compute the total mass of the profile by integrating to infinity.

from_dict(data)

Reconstruct a profile instance from a dictionary.

from_hdf5(h5obj[, name])

Reconstruct a profile from HDF5 attributes.

from_json(filepath)

Reconstruct a profile from a JSON file.

from_yaml(filepath)

Reconstruct a profile from a YAML file.

get_derived_profile(profile_name, **kwargs)

Access and instantiate a derived profile by name.

get_expression_latex([substitute])

Return the LaTeX representation of the profile's symbolic expression.

get_output_units(*argu)

Determine the output units of the operation given some set of input units.

get_parameters_latex()

Return a LaTeX table of the profile parameters.

lambdify_expression(expression)

Convert a symbolic expression into a callable function.

list_derived_profiles()

List all available derived profiles for this instance.

substitute_expression(expression)

Replace symbolic parameters with numerical values in an expression.

to_dict()

Serialize this profile to a minimal dictionary representation.

to_hdf5(h5obj[, name])

Store profile metadata into an HDF5 object as attributes.

to_json(filepath, **kwargs)

Serialize the profile to a JSON file.

to_yaml(filepath, **kwargs)

Serialize the profile to a YAML file.

Attributes

derived_profile_classes

Get the available derived profile classes for this instance.

parameter_symbols

Get the symbolic representations of the coordinate system parameters.

parameters

The parameters of this coordinate system.

variable_symbols

The symbols representing each of the coordinate axes in this coordinate system.

variables

The axes names present in this coordinate system.