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).