MilkyWayBarSormani2022

class cogsworth.sfh.MilkyWayBarSormani2022(potential, kappa=0.7, present_day_bar_angle=<Quantity 28. deg>, pattern_speed=<Quantity 40. km / (kpc s)>, x_max=<Quantity 20. kpc>, y_max=<Quantity 20. kpc>, z_max=<Quantity 20. kpc>, Fm=-1, gradient=<Quantity -0.075 1 / kpc>, Rnow=<Quantity 8.7 kpc>, gamma=0.3, zsun=0.0142, galaxy_age=<Quantity 8. Gyr>, **kwargs)

Bases: StarFormationHistory

A star formation history for the Milky Way bar, based on Sormani+2022.

Positions and velocities use the agama Density sampler, and metallicities use the Frankel+2018 gradient relation.

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

Parameters:

potentialPotentialBase

A potential to use for sampling velocities

kappafloat, optional

Kappa parameter for the axisymmetric Jeans equations, by default 0.7

present_day_bar_angleQuantity [angle], optional

Present-day angle of the bar major axis with respect to the Galactocentric x-axis (Sun-GC line), by default 28*u.deg

pattern_speedQuantity [angle/time], optional

Pattern speed of the bar, by default 40*u.km/u.s/u.kpc

x_maxQuantity [length], optional

Maximum x coordinate (bar major axis), by default 20*u.kpc

y_maxQuantity [length], optional

Maximum y coordinate (bar intermediate axis), by default 20*u.kpc

z_maxQuantity [length], optional

Maximum z coordinate (bar minor axis), by default 20*u.kpc

Fmfloat, optional

Metallicity at the Galactic centre at lookback time galaxy_age, by default -1

gradientQuantity [1/length], optional

Radial metallicity gradient, by default -0.075/u.kpc

RnowQuantity [length], optional

Radius at which the present-day metallicity is solar, by default 8.7*u.kpc

gammafloat, optional

Time exponent for chemical enrichment, by default 0.3

zsunfloat, optional

Solar metallicity, by default 0.0142

galaxy_ageQuantity [time], optional

Maximum lookback time, by default 12*u.Gyr

Methods Summary

draw_lookback_times(size)	Use inverse CDF sampling to draw lookback times from SB15 model, only between 0 and galaxy_age
get_metallicity()	Compute metallicities using the Frankel+2018 relation.
sample(size)	Sample from the bar density using Agama's Density sampler

Methods Documentation

draw_lookback_times(size)

Use inverse CDF sampling to draw lookback times from SB15 model, only between 0 and galaxy_age

Parameters:

sizeint

Number of lookback times to draw

Returns:

tauQuantity [time]

Random lookback times

get_metallicity()

Compute metallicities using the Frankel+2018 relation.

Returns:

ZQuantity [dimensionless]

Metallicities

sample(size)

Sample from the bar density using Agama’s Density sampler

Parameters:

sizeint

Number of samples to return