calwebb_tso3: Stage 3 Time-Series Observation(TSO) Processing

Class:

jwst.pipeline.Tso3Pipeline

Alias:

calwebb_tso3

The stage 3 TSO pipeline is to be applied to associations of calibrated TSO exposures (e.g. NIRCam TS imaging, NIRCam TS grism, NIRISS SOSS, NIRSpec BrightObj, MIRI LRS Slitless) and is used to produce calibrated time-series photometry or spectra of the source object.

The steps applied by the calwebb_tso3 pipeline for Imaging and Spectroscopic TSO exposures are shown below:

calwebb_tso3

Imaging

Spectroscopy

outlier_detection

tso_photometry

extract_1d

white_light

The logic that decides whether to apply the imaging or spectroscopy steps is based on the EXP_TYPE and TSOVISIT keyword values of the input data. Imaging steps are applied if either of the following is true:

  • EXP_TYPE = ‘NRC_TSIMAGE’

  • EXP_TYPE = ‘MIR_IMAGE’ and TSOVISIT = True

The spectroscopy steps will be applied in all other cases.

Inputs

3D calibrated images

Data model:

CubeModel

File suffix:

_calints

The input to calwebb_tso3 is in the form of an ASN file that lists multiple exposures or exposure segments of a science target. The individual inputs should be in the form of 3D calibrated (“_calints”) products from either calwebb_image2 or calwebb_spec2 processing. These products contain 3D stacks of per-integration images. Each pipeline step will loop over all of the integrations in each input.

Many TSO exposures may contain a sufficiently large number of integrations (NINTS) so as to make their individual exposure products too large (in terms of file size on disk) to be able to handle conveniently. In these cases, the uncalibrated raw data for a given exposure are split into multiple “segmented” products, each of which is identified with a segment number (see segmented products). The calwebb_tso3 input ASN file includes all “_calints” exposure segments. The outlier_detection step will process a single segment at a time, creating one output “_crfints” product per segment. The remaining calwebb_tso3 steps, will process each segment and concatenate the results into a single output product, containing the results for all exposures and segments listed in the ASN.

Outputs

3D CR-flagged images

Data model:

CubeModel

File suffix:

_crfints

If the outlier_detection step is applied, a new version of each input calibrated product is created, which contains a DQ array that has been updated to flag pixels detected as outliers. This updated product is known as a CR-flagged product and is saved as a “_crfints” product type.

Imaging photometry

Data model:

N/A

File suffix:

_phot

For imaging TS observations, the tso_photometry step produces a source catalog containing photometry results from all of the “_crfints” products, organized as a function of integration time stamps. This file is saved in ASCII “ecsv” format, with a product type of “_phot.” The file naming is source-based, using the output product name specified in the ASN file, e.g. “jw93065-a3001_t1_nircam_f150w-wlp8_phot.ecsv.”

1D extracted spectral data

Data model:

MultiSpecModel

File suffix:

_x1dints

For spectroscopic TS observations, the extract_1d step is applied to all “_crfints” products, to create a single “_x1dints” product that contains 1D extracted spectral data for all integrations contained in the input exposures. The file name is source-based, using the output product name specified in the ASN file, e.g. “jw87600-a3001_t001_niriss_clear-gr700xd_x1dints.fits.”

Spectroscopic white-light photometry

Data model:

N/A

File suffix:

_whtlt

For spectroscopic TS observations, the white_light step is applied to all of the 1D extracted spectral data in the “_x1dints” product, to produce an ASCII catalog in ecsv format containing the wavelength-integrated white-light photometry of the source. The catalog lists the integrated white-light flux as a function of time, based on the integration time stamps. The file name is source-based, using the output product name specified in the ASN file, e.g. “jw87600-a3001_t001_niriss_clear-gr700xd_whtlt.ecsv.”