IMFIntegrator

class artpop.stars.IMFIntegrator(params, m_min=0.1, m_max=120.0)

Bases: object

A helper class for numerically integrating the IMF.

Parameters

paramsstr or dict

Which IMF to use, if str then must be one of pre-defined: ‘kroupa’, ‘scalo’ or ‘salpeter’. Can also specify broken power law as dict, which must contain either ‘a’ as a Float (describing the slope of a single power law) or ‘a’ (a list with 3 elements describing the slopes of a broken power law) and ‘b’ (a list with 2 elements describing the locations of the breaks).

m_minfloat, optional

Minimum stellar mass.

m_maxfloat, optional

Maximum stellar mass.

Methods Summary

func(m)	Wrapper function to calculate the un-normalized values of of the IMF (i.e.
integrate([m_min, m_max, norm])	"
m_func(m)	Wrapper function to calculate the un-normalized values of the mass times the IMF (i.e.
m_integrate([m_min, m_max, norm])	"
weights(mass_grid[, norm_type, ...])	Calculate the weights of the IMF at grid of stellar masses.

Methods Documentation

func(m)

Wrapper function to calculate the un-normalized values of of the IMF (i.e. dN / dM ) at grid of stellar masses.

Parameters

mass_gridndarray

Stellar mass grid.

Returns

weightsndarray

Values of dN/dM associated with each mass in the input mass_grid.

integrate(m_min=None, m_max=None, norm=False)

” Function to calculate the integral under the IMF.

Parameters

m_minFloat

Lower stellar mass bound of integral.

m_maxFloat

Upper stellar mass bound of integral.

norm:Bool or Float

Whether or not to normalize the inegral, default False. If True will normalize by number of stars. If a Float is given, then will use that value as the normalization.

Returns

weightsFloat

Value of the integral of the IMF between m_min and m_mass.

m_func(m)

Wrapper function to calculate the un-normalized values of the mass times the IMF (i.e. dN / d logM ) at grid of stellar masses.

Parameters

mass_gridndarray

Stellar mass grid.

Returns

weightsndarray

Values dN/d logM associated with each mass in mass_grid.

m_integrate(m_min=None, m_max=None, norm=False)

” Function to calculate the integral under mass times the IMF.

Parameters

m_minFloat

Lower stellar mass bound of integral.

m_maxFloat

Upper stellar mass bound of integral.

norm:Bool or Float

Whether or not to normalize the integral, default False. If True will normalize by the total stellar mass. If a Float is given, then will use that value as the normalization.

Returns

weightsFloat

Value of the integral of mass times the IMF between m_min and m_mass.

weights(mass_grid, norm_type=None, norm_mass_min=None, norm_mass_max=None)

Calculate the weights of the IMF at grid of stellar masses.

Parameters

mass_gridndarray

Stellar mass grid.

norm_typestr, optional

How to normalize the weights: by ‘number’, ‘mass’, or the ‘sum’.

norm_mass_minint or None, optional

Minimum mass to use for normalization. If None, use minimum of mass_grid will be used.

norm_mass_maxint or None, optional

Maximum mass to use for normalization. If None, use maximum of mass_grid will be used.

Returns

weightsndarray

The weights associated with each mass in the input mass_grid.