ORAC Data Reduction Recipes for Michelle

ORAC Data Reduction Recipes for Michelle

We cover all of the most common observing modes when using Michelle. If you plan to use Michelle in a way that isn’t described below and would like a data reduction recipe avaliable for you observing run, or if you don’t see a recipe that fulfills your requirements, please contact your support scientist well in advance of your run.

Observing Modes

Calibration data:

1) Array Tests

ORACDR RecipeRequirementsDescription
ARRAY_TESTSNoneReduce array test data and produce statistics
QUICK_LOOKNoneVery basic reduction, no row extraction

2) Flats and Arcs

ORACDR RecipeRequirementsDescription
REDUCE_DARKDarkReduces a dark frame
REDUCE_FLATFlatReduces and normalises a flatfield
REDUCE_ARCFlat & ArcReduces an arc and produces a 1-d spectrum
QUICK_LOOKNoneVery basic reduction, no row extraction

Observational data:

Imaging:

1) Point Source Imaging

The following recipes are used for imaging point or slightly extended sources. 

ORACDR RecipesRequirementsDescription
NOD_CHOPNoneReduction of ABBA point source imaging
NOD_CHOP_APHOTNoneAs above, but with photometry
NOD_CHOP_FAINTNoneAs above, but for a faint source at the same position on the array as the standard
MOVING_NOD_CHOPNoneAs NOD_CHOP, but or non-sidereal targets
QUICK_LOOKNoneBasic reduction, no coadding

2) Extended Source Imaging

Use the following recipe for scanned imaging of an extended region.

ORACDR RecipeRequirementsDescription
NOD_CHOP_SCANNoneReduction of ABBA imaging at various scan positions

Spectroscopy:

1) Standard Star, Nodding (and Chopping) Along the Slit.

The following recipes will all work given that the requirements are met (e.g., a flat must have been taken at the correct settings for STANDARD_STAR to work) for a bright point source and for nodding along the slit. 

ORACDR RecipeRequirementsDescription
STANDARD_STARFlatReduce star for raitoing and or flux calibration
STANDARD_STAR_NOFLATNoneAs above, but no flat is used
REDUCE_SINGLE_FRAME_ONLYFlatReduces frames but does not create groups
REDUCE_SINGLE_FRAME_ONLY_NOFLATNoneReduces single frames without a flatfield
QUICK_LOOKNoneVery basic reduction, no row extraction

2) Target, Nodding (and Chopping) Along Slit.

These recipes will work for targets that are observed by nodding along the slit. Some require a standard star to have already been observed. 

ORACDR RecipeRequirementsDescription
POINT_SOURCEFlat & reduced standard Full reduction to 1-d spectrum with ratioing
POINT_SOURCE_NOFLATReduced standardAs above, but no flat is used
POINT_SOURCE_NOSTDFlatAs above but no ratioing
POINT_SOURCE_NOFLAT_NOSTDNoneAs above with no flat and no ratioing
REDUCE_SINGLE_FRAME_ONLYFlatReduces frames but does not create groups
REDUCE_SINGLE_FRAME_ONLY_NOFLATNoneAs above but with no flat
QUICK_LOOKNoneVery basic reduction, no row extraction

3) Extended Source,  Nodding to Blank Sky.

The following will work for extended sources that require you to nod to blank sky. They will also work for point sources in crowded fields that also require a nod to blank sky. 

ORACDR RecipeRequirementsDescription
EXTENDED_SOURCEFlat & reduced standardReduces target data, divide spectral image by standard
EXTENDED_SOURCE_NOFLATReduced standardAs above, no flat is used
EXTENDED_SOURCE_NOSTDFlatAs above but no ratioing
EXTENDED_SOURCE_NOFLAT_NOSTDNoneAs above, no flat or ratioing
POINT_SOURCEFlat & reduced standardReduces target data, flat fields and ratios
POINT_SOURCE_NOFLATReduced standardAs above, but no flat is used
POINT_SOURCE_NOSTDFlatAs above, but no ratioing
POINT_SOURCE_NOFLAT_NOSTDNonneAs above with no flat and no ratioing
REDUCE_SINGLE_FRAMES_ONLYFlatReduces frames but does no create groups
REDUCE_SINGLE_FRAMES_ONLY_NOFLATNoneAs above but with no flat
QUICK_LOOKNoneVery basic reduction, no row extraction

Imaging Polarimetry

1) Point Source Imaging Polarimetry

ORACDR RecipeRequirementsDescription
POL_NOD_CHOPNoneBasic reduction of imaging polarimetry data, nod before wave plate is moved
POL_ANGLE_NOD_CHOPNoneBasic reduction of imaging polarimetry data, move wave plate before nodding
QUICK_LOOKNoneVery basic reduction

Spectropolarimetry

1) Point Source and Spectropolarimetry

The following will also work for slightly extended targets as well as point sources. 

ORACDR RecipeRequirementsDescription
SBPOL_POINT_SOURCEFlatSpectropolarimetry reduction with flatfielding
REDUCE_SINGLE_FRAME_ONLYFlatVery basic reduction with no coadding
REDUCE_SINGLE_FRAME_ONLY_NOFLATNoneAs above with no flatfielding
QUICK_LOOKNoneVery basic reduction

Engineering and Miscellaneous Data:

1) End of Night/Emissivity

ORACDR RecipeRequirementsDescription
EMISSIVITYFlatReduces emissivity data, logs results
QUICK_LOOKNoneVery basic reduction

2) Other/miscellaneous

ORACDR RecipeRequirements Description
CHOPCONVNoneWrites out chopped data to individual files
NIGHT_LOGSome dataCreates an observing log
FITSCONVNoneConverts chopped data to fits format