pynrc.obs_hci¶
NIRCam coronagraphic observations
Subclass of the nrc_hci
instrument class used to observe
stars (plus exoplanets and disks) with either a coronagraph or direct
imaging.
The main concept is to generate a science target of the primary source along with a simulated disk structure. Planets are further added to the astronomical scene. A separate reference source is also defined for PSF subtraction, which contains a specified WFE. A variety of methods exist to generate slope images and analyze the PSF-subtracted results via images and contrast curves.
- Parameters
sp_sci (
pysynphot.spectrum
) – A pysynphot spectrum of science target (e.g., central star). Should already be normalized to the apparent flux.sp_ref (
pysynphot.spectrum
or None) – A pysynphot spectrum of reference target. Should already be normalized to the apparent flux.distance (float) – Distance in parsecs to the science target. This is used for flux normalization of the planets and disk.
wfe_ref_drift (float) – WFE drift in nm RMS between the science and reference targets. Expected values are between ~3-10 nm.
wfe_roll_drift (float) – WFE drift in nm RMS between science roll angles. Default=0.
wind_mode (str) – ‘FULL’, ‘STRIPE’, or ‘WINDOW’
xpix (int) – Size of the detector readout along the x-axis. The detector is assumed to be in window mode unless the user explicitly sets wind_mode=’FULL’.
ypix (int) – Size of the detector readout along the y-axis. The detector is assumed to be in window mode unless the user explicitly sets wind_mode=’FULL’.
disk_params (dict) –
- Arguments describing disk model information for a given FITS file:
‘file’ : Path to model file or an HDUList.
‘pixscale’ : Pixel scale for model image (arcsec/pixel).
‘dist’ : Assumed model distance in parsecs.
‘wavelength’ : Wavelength of observation in microns.
‘units’ : String of assumed flux units (ie., MJy/arcsec^2 or muJy/pixel)
‘cen_star’ : True/False. Is a star already placed in the central pixel?
autogen_coeffs (bool) – Automatically generate base PSF coefficients. Equivalent to performing self.gen_psf_coeff(). gen_wfedrift_coeff, and gen_wfemask_coeff. Default: True.
use_ap_info (bool) – For subarray observations, the mask reference points are not actually in the center of the array. Set this to True to shift the sources to actual aperture reference location. Otherwise, default will place in center of array.
sgd_type (str or None) – Small grid dither pattern. Valid types are ‘9circle’, ‘5box’, ‘5diamond’, ‘3bar’, or ‘5bar’. If ‘auto’, then defaults are ‘5diamond’ for round masks, ‘5bar’ for bar masks, and ‘5diamond’ for direct imaging. If None, then no FSM pointings, but there will be a single slew.
fsm_std (float) – One-sigma accuracy per axis of fine steering mirror positions. This provides randomness to each position relative to the nominal central position. Ignored for central position. Values should be in units of mas.
slew_std (float) – One-sigma accuracy per axis of the initial slew. This is applied to all positions and gives a baseline offset relative to the desired mask center. *Values should be in units of mas*
Module Attributes
Use Coronagraphic ND acquisition square? |
|
SIAF aperture name for detector pixel to sky coords transformations |
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Return bandpass throughput |
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Offset position along bar mask (arcsec). |
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Include coronagraphic substrate material? |
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Dictionary housing detector info parameters and keywords. |
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Detector selected for simulated PSF |
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Detectors on which the simulated PSF could lie |
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The pixel position in (X, Y) on the detector, relative to the currently-selected SIAF aperture subarray. |
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Fast readout direction in sci coords |
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Currently selected filter name (e.g. |
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List of available filter names for this instrument |
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Currently selected image plane mask, or None for direct imaging |
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Observation with coronagraphic mask (incl Lyot stop)? |
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Is a Lyot mask in the pupil wheel? |
|
|
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Exposure timings in dictionary |
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Number of wavelengths/PSFs to fit |
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A dictionary capable of storing other arbitrary options, for extensibility. |
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Detector pixel scale, in arcsec/pixel |
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Planet info (if any exists) |
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PSF parameters |
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Filename or fits.HDUList for JWST pupil mask. |
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Currently selected Lyot pupil mask, or None for direct imaging |
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Filename or fits.HDUList for JWST pupil OPD. |
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Perform quicker coeff calculation over limited bandwidth? |
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Coefficient save directory |
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Coefficient file name |
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SCA ID (481, 482, . |
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SIAF Aperture object |
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Give all possible SIAF aperture names |
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Slow readout direction in sci coords |
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Wavelength range to fit |
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Detector well level in units of electrons |
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WFE drift (nm) of ref obs relative to sci obs |
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WFE drift (nm) of Roll2 obs relative to Roll1 obs |