fors_subtract_sky7

Usage

Overview

This recipe is used to subtract the sky emission from unrebinned slit spectra. This is obtained by robust fitting (i.e., excluding the signal from possible point-like objects in slit) of the emission along the CCD columns within each spectrum). This method doesn´t work if extended objects are in slit (it really destroys the object spectra), and is not applicable to LSS data. The input scientific frames are produced by the recipes fors_remove_bias and fors_flatfield.

This recipe cannot be applied to LSS or long-slit like data (MOS/MXU with all slits at the same offset). No automatic recipe is available for this.

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:
SCIENCE_UNBIAS_MXU
or SCIENCE_UNFLAT_MXU
or STANDARD_UNBIAS_MXU
or STANDARD_UNFLAT_MXU Calib Frame with sky lines Y
CURV_COEFF_MXU Calib Spectral curvature Y
SLIT_LOCATION_MXU Calib Slit location on CCD Y
GRISM_TABLE Calib Grism table .

Output files:

DO category: Data type: Explanation:
UNMAPPED_SCI_MXU
or UNMAPPED_STD_MXU FITS image Sky subtracted scientific frame
UNMAPPED_SKY_SCI_MXU
or UNMAPPED_SKY_STD_MXU FITS image Subtracted sky frame

Options

--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_subtract_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_subtract_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_subtract_sky.endwavelength [default = 0.0].

--cosmics <bool>

Eliminate cosmic rays hits (bool; default: False). The full name of this option for the EsoRex configuration file is fors.fors_subtract_sky.cosmics [default = False].

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.

Version

fors_subtract_sky 5.5.6