SpheroidalDwarf#

class cogsworth.sfh.SpheroidalDwarf(J_0_star, alpha, eta, fixed_Z, tau_min, galaxy_age, mass=None, **kwargs)[source]#

Bases: DistributionFunctionBasedSFH

An action-based model for dwarf spheroidal galaxies and globular clusters Pascale+2019.

Parameters are the same as DistributionFunctionBasedSFH and StarFormationHistory but additionally with the following:

Parameters:
J_0_starfloat

The action scale that naturally defines the length- and velocity-scale

alphafloat

A non-negative, dimensionless parameter that mainly regulates the model’s density profile

etafloat

A non-negative, dimensionless parameter that mainly controls the radial or tangential bias of the model velocity distribution; models sharing the parameters $(alpha, eta)$ are homologous.

fixed_Zfloat

Fixed metallicity for all stars in the dwarf galaxy

tau_minQuantity [time]

Minimum lookback time for star formation, by default 10 Gyr

galaxy_ageQuantity [time]

Maximum lookback time for star formation, by default 12 Gyr

massfloat, optional

Total mass of the galactic potential. If not given, a potential must be provided. If given, this will be used to create a NFW potential with scale radius 1 kpc and concentration 1. By default None.

Methods Summary

draw_lookback_times(size)

Uniform sampling of lookback times between tau_min and tau_max

get_metallicity()

Fixed metallicity for all stars in the dwarf galaxy

Methods Documentation

draw_lookback_times(size)[source]#

Uniform sampling of lookback times between tau_min and tau_max

Parameters:
sizeint

How many times to draw

componentstr

Which component of the Milky Way

Returns:
tauQuantity [time]

Random lookback times

get_metallicity()[source]#

Fixed metallicity for all stars in the dwarf galaxy

Returns:
ZQuantity [dimensionless]

Metallicities