lightcurvelynx.obstable.roman_obstable

Attributes

`ROMAN_PIXEL_SCALE`	The pixel scale for Roman in arcseconds per pixel.
`hltds_pass_map`

Classes

`RomanPoissonFluxNoiseModel`	A subclass of PoissonFluxNoiseModel for Roman survey data.
`RomanObsTable`	A subclass for Roman exposure table.

Module Contents

ROMAN_PIXEL_SCALE = 0.11[source]: The pixel scale for Roman in arcseconds per pixel. https://roman-docs.stsci.edu/roman-instruments-home/wfi-imaging-mode-user-guide/introduction-to-the-wfi/wfi-quick-reference

hltds_pass_map[source]

class RomanPoissonFluxNoiseModel[source]

Bases: lightcurvelynx.noise_models.base_noise_models.PoissonFluxNoiseModel

A subclass of PoissonFluxNoiseModel for Roman survey data.

compute_flux_error(bandflux, obs_table, indices)[source]

Compute the flux error for the given bandflux and observation parameters.

Parameters:

bandflux (array_like of float) – Source bandflux in nJy.
obs_table (ObsTable) – Table containing the observation parameters needed to compute the noise.
indices (array_like of int) – Indices of the observations in the ObsTable for which to compute the noise.

Returns:

flux_err – The standard deviation of the bandflux measurement error (in nJy)

Return type:

array_like

class RomanObsTable(table, colmap=None, ma_table_path=None, saturation_mags=None, **kwargs)[source]

Bases: lightcurvelynx.obstable.obs_table.ObsTable

A subclass for Roman exposure table.

Parameters:

table (dict or pandas.core.frame.DataFrame) – The table with all the observation information.
colmap (dict) – A mapping of standard column names to a list of possible names in the input table. Each value in the dictionary can be a string or a list of strings. Defaults to the Roman APT column names, stored in _default_colnames.
ma_table_path (str or pathlib.Path, optional) – The path to the Roman MultiAccum table CSV file. If not provided, a default table included with LightCurveLynx will be used.
saturation_mags (dict, optional) – A dictionary mapping filter names to their saturation thresholds in magnitudes. The filters provided must match those in the table. If not provided, saturation effects will not be applied.
**kwargs (dict) –
Additional keyword arguments to pass to the ObsTable constructor. This includes overrides for survey parameters such as:
- dark_current : The dark current for the camera in electrons per second per pixel.
- gain: The CCD gain (in e-/ADU).
- pixel_scale: The pixel scale for the camera in arcseconds per pixel.
- radius: The angular radius of the observations (in degrees).
- read_noise: The standard deviation of the count of readout electrons per pixel.

apt_table[source]

ma_table = None[source]

zp_table[source]

psf_table[source]

thermal_table[source]

zodiacal_table[source]

pass_map[source]

update_time()[source]: Update the time column assignment.

infer_component_start_time(field_time_offset=None, after_component_delay_time=None)[source]

Infer the start time of each survey commponent for Roman HLTDS.

Parameters:

field_time_offset (tuple or ndarray) – The time offset for the north and south field.
after_component_delay_time (dict) – The delay time after each survey component.

readnoise_func(exptime)[source]

Readout noise function for Roman.

References

Eq. 9 of Rose et al 2025 - https://ui.adsabs.harvard.edu/abs/2025ApJ…988…65R/abstract

Parameters:: exptime (float or npt.ArrayLike) – Exposure time in seconds.
Returns:: sigma_read – Readout noise.
Return type:: float or npt.ArrayLike

calculate_skynoise(exptime, zodi_scale, zodi_countrate_min, thermal_countrate)[source]

Calculate sky noise.

References

Eq. 10 of Rose et al 2025 - https://ui.adsabs.harvard.edu/abs/2025ApJ…988…65R/abstract

Parameters:

exptime (float or npt.ArrayLike) – Exposure time.
zodi_scale (float or npt.ArrayLike) – Zodiacal light scale. The zodiacal light amount is zodi_scale * zodi_countrate_min
zodi_countrate_min (float or npt.ArrayLike) – Minimum zodiacal count rate (e-/s/pixel).
thermal_countrate (float or npt.ArrayLike) – Thermal count rate (e-/s/pixel).

Returns:

sky_variance – Total sky variance (e-^2/pixel).

Return type:

float or npt.ArrayLike