ValleeSpiral

class gammapy.astro.population.ValleeSpiral

Bases: LogSpiral

Milky way spiral arm model from Vallee (2008).

Reference: https://ui.adsabs.harvard.edu/abs/2008AJ….135.1301V

Attributes Summary

bar_radius
m
p
r_0
r_sun
spiralarms
theta_0

Methods Summary

radius(theta, spiralarm_index)	Radius for a given angle.
theta(radius, spiralarm_index)	Angle for a given radius.
xy_position([theta, radius, spiralarm_index])	Compute (x, y) position for a given angle or radius.

Attributes Documentation

bar_radius = <Quantity 3. kpc>

m = 4

p = <Quantity 12.8 deg>

r_0 = <Quantity 2.1 kpc>

r_sun = <Quantity 7.6 kpc>

spiralarms = array(['Norma', 'Perseus', 'Carina Sagittarius', 'Crux Scutum'],       dtype='<U18')

theta_0 = <Quantity -20. deg>

Methods Documentation

radius(theta, spiralarm_index)

Radius for a given angle.

Parameters:

thetaQuantity

Angle (deg).

spiralarm_indexint

Spiral arm index.

Returns:

radiusndarray

Radius (kpc).

theta(radius, spiralarm_index)

Angle for a given radius.

Parameters:

radiusQuantity

Radius (kpc).

spiralarm_indexint

Spiral arm index.

Returns:

thetandarray

Angle (deg).

xy_position(theta=None, radius=None, spiralarm_index=0)

Compute (x, y) position for a given angle or radius.

Parameters:

thetaQuantity, optional

Angle (deg). Default is None.

radiusQuantity, optional

Radius (kpc). Default is None.

spiralarm_indexint, optional

Spiral arm index. Default is 0.

Returns:

x, yndarray

Position (x, y).