ValleeSpiral

class gammapy.astro.population.ValleeSpiral[source]

Bases: gammapy.astro.population.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
thetaarray_like

Angle (deg)

spiralarm_indexint

Spiral arm index

Returns
radiusarray_like

Radius (kpc)

theta(radius, spiralarm_index)

Angle for a given radius.

Parameters
radiusarray_like

Radius (kpc)

spiralarm_indexint

Spiral arm index

Returns
thetaarray_like

Angle (deg)

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

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

Parameters
thetaarray_like

Angle (deg)

radiusarray_like

Radius (kpc)

spiralarm_indexint

Spiral arm index

Returns
x, yarray_like

Position (x, y)