esorex fors_align_sky [OPTIONS] FILE.sof


This recipe is used to align the wavelength solution based on the arc lamp exposure on a set of sky lines observed on a scientific exposure.

The input rectified frames are produced by the recipe fors_extract_slits.

An input catalog of sky lines can be specified, otherwise an internal one is used.

This recipe should be applied to multi-slit MOS/MXU data: for LSS or long-slit like data (MOS/MXU with all slits at the same offset) use recipe fors_align_sky_lss instead. Please refer to the FORS Pipeline User\'s Manual for more details.

In the table below the MXU acronym can be alternatively read as MOS, and SCI as STD.

Input files:

  DO category:               Type:       Explanation:         Required:
  or RECTIFIED_SKY_SCI_MXU   Calib       Frame with sky lines    Y
  SPATIAL_MAP_MXU            Calib       Spatial coordinate map  Y
  CURV_COEFF_MXU             Calib       Spectral curvature      Y
  SLIT_LOCATION_MXU          Calib       Slit location on CCD    Y
  DISP_COEFF_MXU             Calib       Dispersion solution     Y
  MASTER_SKYLINECAT          Calib       Catalog of sky lines    .
  GRISM_TABLE                Calib       Grism table             .

Output files:

  DO category:               Data type:  Explanation:
  SKY_SHIFTS_SLIT_SCI_MXU    FITS table  Observed sky lines offsets
  WAVELENGTH_MAP_SCI_MXU     FITS image  Wavelength mapped on CCD
  DISP_COEFF_SCI_MXU         FITS image  Upgraded dispersion solution


--dispersion <float>

Expected spectral dispersion (Angstrom/pixel) (float; default: 0.0). The full name of this option for the EsoRex configuration file is fors.fors_align_sky.dispersion [default = 0.0].

--startwavelength <float>

Start wavelength in spectral extraction (float; default: 0.0). The full name of this option for the EsoRex configuration file is fors.fors_align_sky.startwavelength [default = 0.0].

--endwavelength <float>

End wavelength in spectral extraction (float; default: 0.0). The full name of this option for the EsoRex configuration file is fors.fors_align_sky.endwavelength [default = 0.0].

--skyalign <long>

Polynomial order for sky lines alignment (long; default: 0). The full name of this option for the EsoRex configuration file is fors.fors_align_sky.skyalign [default = 0].

--wcolumn <str>

Name of sky line catalog table column with wavelengths (str; default: \'WLEN\'). The full name of this option for the EsoRex configuration file is fors.fors_align_sky.wcolumn [default = WLEN].

Note that it is possible to create a configuration file containing these options, along with suitable default values. Please refer to the details provided by the 'esorex --help' command.

RELATED TO fors_align_sky…

The full documentation for the fors pipeline can be downloaded as a PDF file using the following URL:


An overview over the existing ESO pipelines can be found on the web page

Basic documentation about the EsoRex program can be found at the esorex (1) man page.

It is possible to call the pipelines from python using the python-cpl package. See for further information.

The other recipes of the fors pipeline are fors_wave_calib_lss(7), fors_img_sky_flat(7), fors_resample(7), fors_config(7), fors_extract_objects(7), fors_calib(7), fors_wave_calib(7), fors_detect_objects(7), fors_pmos_science(7), fors_extract_slits(7), test_hough(7), fors_img_screen_flat(7), fors_extract(7), fors_remove_bias(7), fors_subtract_sky(7), fors_normalise_flat(7), montecarlo(7), fors_photometry(7), fors_zeropoint(7), fors_dark(7), fors_subtract_sky_lss(7), fors_trace_flat(7), fors_flatfield(7), fors_img_science(7), fors_detect_spectra(7), fors_sumflux(7), fors_pmos_extract(7), fors_align_sky_lss(7), fors_bias(7), fors_pmos_calib(7), fors_spec_mflat(7), fors_science(7)


fors_align_sky 5.0.0


Carlo Izzo <[email protected]>


Please report any problems to [email protected] Alternatively, you may send a report to the ESO User Support Department <[email protected]>.


This file is currently part of the FORS Instrument Pipeline Copyright (C) 2002-2010 European Southern Observatory

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