The fors_subtract_sky recipe =============================================================== .. data:: fors_subtract_sky Synopsis -------- Subtract sky from scientific spectra Description ----------- 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 Constructor ----------- .. method:: cpl.Recipe("fors_subtract_sky") :noindex: Create an object for the recipe fors_subtract_sky. :: import cpl fors_subtract_sky = cpl.Recipe("fors_subtract_sky") Parameters ---------- .. py:attribute:: fors_subtract_sky.param.dispersion Expected spectral dispersion (Angstrom/pixel) (float; default: 0.0) [default=0.0]. .. py:attribute:: fors_subtract_sky.param.startwavelength Start wavelength in spectral extraction (float; default: 0.0) [default=0.0]. .. py:attribute:: fors_subtract_sky.param.endwavelength End wavelength in spectral extraction (float; default: 0.0) [default=0.0]. .. py:attribute:: fors_subtract_sky.param.cosmics Eliminate cosmic rays hits (bool; default: False) [default=False]. The following code snippet shows the default settings for the available parameters. :: import cpl fors_subtract_sky = cpl.Recipe("fors_subtract_sky") fors_subtract_sky.param.dispersion = 0.0 fors_subtract_sky.param.startwavelength = 0.0 fors_subtract_sky.param.endwavelength = 0.0 fors_subtract_sky.param.cosmics = False You may also set or overwrite some or all parameters by the recipe parameter `param`, as shown in the following example: :: import cpl fors_subtract_sky = cpl.Recipe("fors_subtract_sky") [...] res = fors_subtract_sky( ..., param = {"dispersion":0.0, "startwavelength":0.0}) .. seealso:: `cpl.Recipe `_ for more information about the recipe object. Bug reports ----------- Please report any problems to `Carlo Izzo `_. Alternatively, you may send a report to the `ESO User Support Department `_. Copyright --------- This file is currently part of the FORS Instrument Pipeline Copyright (C) 2002-2010 European Southern Observatory This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA .. codeauthor:: Carlo Izzo