Light curve temporal model

This model parametrises a LightCurve time model.

The gammapy internal lightcurve model format is a RegionNDMap with time, and optionally energy axes. The times are defined wrt to a reference time.

For serialisation, a table and a map format are supported. A table format is a Table with the reference_time` serialised as a dictionary in the table meta. Only maps without an energy axis can be serialised to this format.

In map format, a RegionNDMap is serialised, with the reference_time in the SKYMAP_BANDS HDU.

from astropy.time import Time
from gammapy.modeling.models import (
    LightCurveTemplateTemporalModel,
    Models,
    PowerLawSpectralModel,
    SkyModel,
)

time_range = [Time("59100", format="mjd"), Time("59365", format="mjd")]
path = "$GAMMAPY_DATA/tests/models/light_curve/lightcrv_PKSB1222+216.fits"
light_curve_model = LightCurveTemplateTemporalModel.read(path)
light_curve_model.plot(time_range)

YAML representation

Here is an example YAML file using the model:

model = SkyModel(
    spectral_model=PowerLawSpectralModel(),
    temporal_model=light_curve_model,
    name="light_curve_model",
)
models = Models([model])

print(models.to_yaml())

components:
-   name: light_curve_model
    type: SkyModel
    spectral:
        type: PowerLawSpectralModel
        parameters:
        -   name: index
            value: 2.0
        -   name: amplitude
            value: 1.0e-12
            unit: cm-2 s-1 TeV-1
        -   name: reference
            value: 1.0
            unit: TeV
    temporal:
        type: LightCurveTemplateTemporalModel
        parameters:
        -   name: t_ref
            value: 59000.49919925926
            unit: d
        scale: utc
        filename: /home/runner/work/gammapy-docs/gammapy-docs/gammapy-datasets/1.2/tests/models/light_curve/lightcrv_PKSB1222+216.fits
        format: table
        unit: ''
metadata:
    creator: Gammapy 1.2
    date: '2024-02-29T10:22:01.322554'
    origin: null