ValleeSpiral#

class gammapy.astro.population.ValleeSpiral[source]#

Bases: gammapy.astro.population.spatial.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).