SkyDisk

class gammapy.image.models.SkyDisk(lon_0, lat_0, r_0, frame='galactic')[source]

Bases: gammapy.image.models.SkySpatialModel

Constant radial disk model.

\[\begin{split}\phi(lon, lat) = \frac{1}{2 \pi (1 - \cos{r_0}) } \cdot \begin{cases} 1 & \text{for } \theta \leq r_0 \\ 0 & \text{for } \theta > r_0 \end{cases}\end{split}\]

where \(\theta\) is the sky separation

Parameters:
lon_0 : Longitude

\(lon_0\)

lat_0 : Latitude

\(lat_0\)

r_0 : Angle

\(r_0\)

frame : {“galactic”, “icrs”}

Coordinate frame of lon_0 and lat_0.

Attributes Summary

evaluation_radius Returns the effective radius of the sky region where the model evaluates to non-zero.
frame
lat_0
lon_0
parameters Parameters (Parameters)
position Spatial model center position
r_0

Methods Summary

__call__(lon, lat) Call evaluate method
copy() A deep copy.
evaluate(lon, lat, lon_0, lat_0, r_0) Evaluate the model (static function).

Attributes Documentation

evaluation_radius

Returns the effective radius of the sky region where the model evaluates to non-zero. For a Disk source, we fix it to \(r_0\).

Returns:
radius : Angle

Radius in angular units

frame
lat_0
lon_0
parameters

Parameters (Parameters)

position

Spatial model center position

r_0

Methods Documentation

__call__(lon, lat)

Call evaluate method

copy()

A deep copy.

static evaluate(lon, lat, lon_0, lat_0, r_0)[source]

Evaluate the model (static function).