NIRISS¶

class webbpsf.NIRISS(auto_pupil=True)[source]¶

Bases: JWInstrument

A class modeling the optics of the Near-IR Imager and Slit Spectrograph: (formerly TFI)

Relevant attributes include image_mask, and pupil_mask.

Imaging:

WebbPSF models the direct imaging and nonredundant aperture masking modes of NIRISS in the usual manner.

Note that long wavelength filters (>2.5 microns) have a pupil which includes the pupil alignment reference. If auto_pupil is set, the pupil will be toggled between CLEAR and CLEARP automatically depending on filter.

Spectroscopy:

Added in version 0.3 is partial support for the single-object slitless spectroscopy (“SOSS”) mode using the GR700XD cross-dispersed grating. Currently this includes the clipping of the pupil due to the undersized grating and its mounting hardware, and the cylindrical lens that partially defocuses the light in one direction.

Warning

Prototype implementation - Not yet fully tested or verified.

Note that WebbPSF does not model the spectral dispersion in any of NIRISS’ slitless spectroscopy modes. For wide-field slitless spectroscopy, this can best be simulated by using webbpsf output PSFs as input to the aXe spectroscopy code. Contact Van Dixon at STScI for further information. For SOSS mode, contact Loic Albert at Universite de Montreal.

The other two slitless spectroscopy grisms use the regular pupil and do not require any special support in WebbPSF.

Attributes Summary

`LONG_WAVELENGTH_MAX`
`LONG_WAVELENGTH_MIN`
`SHORT_WAVELENGTH_MAX`
`SHORT_WAVELENGTH_MIN`
`filter`	Currently selected filter name (e.g. F200W).

Attributes Documentation

LONG_WAVELENGTH_MAX = 5.299999999999999e-06¶

LONG_WAVELENGTH_MIN = 2.35e-06¶

SHORT_WAVELENGTH_MAX = 2.35e-06¶

SHORT_WAVELENGTH_MIN = 6e-07¶

filter¶: Currently selected filter name (e.g. F200W)