Quality Control and
Data Processing

Raw CALIB data types

Calibration data are taken for two purposes:

• to calibrate SCIENCE data
• to measure and control the instrumental status

MUSE calibration data are mostly taken as daytime calibrations. Twilight flat-field exposures, standard stars and astrometry fields are taken as part of the calibration plan during the night. Find information about the MUSE data format, spectral format and the detector here. The following calibration data are taken as part of the MUSE calibration plan. The data types are identified by the DPR.TYPE and DPR.TECH keyword in the FITS headers. For details on the data, and in particular, on each extension see the MUSE reference frames web page.

frame	DPR.CATG	DPR.TYPE	DPR.TECH	purpose	N*
BIAS	CALIB	BIAS	IFU	detector status, bias level	11
DARK	CALIB	DARK	IFU	dark current	5
FLAT	CALIB	FLAT,LAMP	IFU	tracing of slices; flat flux level	11
ARC LAMPs	CALIB	WAVE	IFU	wavelength calibration	15, the input frames come as multiple of 3 for Ne, Xe, and HgCd arc lamps each
SKY FLAT	CALIB	FLAT,SKY	IFU	illumination correction	>=3
Spectrophotometric STD	CALIB	STD	IFU	absolute flux calibration, telluric correction	1
ASTROMETRY	CALIB	ASTROMETRY	IFU	astrometric correction	1
GEOMETRY	CALIB	WAVE,MASK	IFU	geometry correction	80

*N: typical number taken per night and setting

The ARC LAMP exposures are taken separately for each spectral lamp: Ne, Xe and HgCd. Thus, the number of input frames is always multiple of 3. The different lamp exposures can be distinguished by the shutter status keyword having True (T) rather than False (F) value:

• Ne: INS.SHUT3.ST=T
• Xe: INS.STUT4.ST=T
• HgCd: INS.SHUT5.ST=T

The GEOMETRY and ASTROMETRY observations are taken about monthly to monitor status of the instrument. They have to be processed together and the pipeline requires special hardware and software setup. Thus, the products exist as "static calibrations" and are renewed whenever it is necessary.

Raw frame(s)	recipe	description	product(s)
BIAS	muse_bias	creates a master bias from a set of input raw frames	MASTER_BIAS
DARK	muse_dark	creates a master dark from a set of input raw frames	MASTER_DARK
LAMP_FLAT	muse_flat	creates a master lamp flat and trace table from a set of input frames	MASTER_FLAT, TRACE_TABLE
ARC	muse_wavecal	obtains the wavelength calibration solution from an input arc-lamp frames	WAVECAL_TABLE
STD	muse_standard	determines instrumental response	STD_RESPONSE, STD_TELLURIC, DATACUBE_STD
SKY_FLAT	muse_twilight	creates a master twilight flat from a set of input frames	TWILIGHT_CUBE

STD_RESPONSE - change between pipeline v.1 and v.2

The shape of STD_RESPONSE changed with transition from pipeline v.1 to v.2 (2017-05-01 in QC system). The v.2 response contains the correction for the flat field, while the v.1 one does not. The flat field correction is indicated by the ESO_DRS_FFCORR keyword, which allows the pipeline to distiguish between different formats and handle them accordingly. Thus, the pipeline is backwards compatible.

Naming scheme

After production and certification, the calibration products are archived. They are named with a scheme including type, creation date and relevant setting parameters. For the detailed description of the product names go here. The master calibrations are available for archive users through the calSelector service.

The processing of MUSE calibration frames requires a cascaded scheme where the mutual dependencies of products and raw frames are respected. The proper sequence of all these production steps is called the calibration cascade. It is described here.

Within that cascade, all products are checked with respect to their quality and their relationship in time. This means e.g. that a dispersion solution is not only generated using an arbitrary quality-checked localization solution, but that specific solution is chosen which is closest in time.

All products created by QC Garching follow the calibration cascade. On the other hand, Paranal-processed science data use standard solutions created by QC Garching and possibly several months old.

Static calibration tables (the ones not being regularly processed from raw calibration data) come as FITS tables and are available through the calSelector archive service. Some of them come with different versions indicated by unique date, e.g.140101, of creation, as they are being updated with time.

Table name	PRO.CATG	Purpose
MU_GASR_dateA_astrom_cat.fits	ASTROMETRY_REFERENCE	catalog of astrometric standards
MU_GASW_dateA_astrom_wcs_wfm.fits	ASTROMETRY_WCS	catalog of the WCS positions of the astrometric standards
MU_GBPT_dateA_badpix_table.fits	BADPIX_TABLE	table of bad pixels
MU_GEOT_dateA_geometry_table_wfm.fits	GEOMETRY_TABLE	geometry table
MU_GEXT_dateA_extinct_table.fits	EXTINCT_TABLE	extinction table
MU_GFIL_140101A_filter_list.fits	FILTER_LIST	list of filters
MU_GLNC_140101A_line_cat.fits	LINE_CATALOG	line catalog
MU_GSDR_dateA_std_response_wfm-e.fits	STD_RESPONSE	response curve for the WFM-E mode
MU_GSDR_dateA_std_response_wfm-n.fits	STD_RESPONSE	response curve for the WFM-N mode
MU_GSDR_dateA_std_response_nfm-ao-n.fits	STD_RESPONSE	response curve for the NFM mode
MU_GSFT_140101A_stdflux_table.fits	STD_FLUX_TABLE	flux table for the standard stars
MU_GSKL_140101A_sky_lines.fits	SKY_LINES	catalog of the sky lines
MU_GVIM_140906A_vignetting_mask.fits	VIGNETTING_MASK	vignetting mask, OBSOLETE, NOT used for the data since 2018-01-01
MU_GLSP_dateA_lsf_profile_slow_wfm-e.fits	LSF_PROFILE	LSF profile for the WFM-E mode
MU_GLSP_dateA_lsf_profile_slow_wfm-n.fits	LSF_PROFILE	LSF profile for the WFM-N mode
MU_GLST_140501A_lsf_table.fits	LSF_TABLE	LSF table, OBSOLETE, NOT used with current pipeline version
MU_GLSC_141014A_lsf_cube_slow_wfm-e.fits	LSF_CUBE	LSF cube for WFM-E mode, OBSOLETE, NOT used with current pipeline version
MU_GLSC_141014A_lsf_cube_slow_wfm-n.fits	LSF_CUBE	LSF cube for WFM-N mode, OBSOLETE, NOT used with current pipeline version