make_theta_squared_table#

gammapy.makers.utils.make_theta_squared_table(observations, theta_squared_axis, position, position_off=None)[source]#

Make theta squared distribution in the same FoV for a list of Observation objects.

The ON theta2 profile is computed from a given distribution, on_position. By default, the OFF theta2 profile is extracted from a mirror position radially symmetric in the FOV to pos_on.

The ON and OFF regions are assumed to be of the same size, so the normalisation factor between both region alpha = 1.

Parameters
observations: `~gammapy.data.Observations`

List of observations.

theta_squared_axisMapAxis

Axis of edges of the theta2 bin used to compute the distribution.

positionSkyCoord

Position from which the on theta^2 distribution is computed.

position_offastropy.coordinates.SkyCoord

Position from which the OFF theta^2 distribution is computed. Default is reflected position w.r.t. to the pointing position.

Returns
tableTable

Table containing the on counts, the off counts, acceptance, off acceptance and alpha for each theta squared bin.