The vmmoscombine recipe¶
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vmmoscombine
¶
Synopsis¶
Combine reduced MOS observations from different OBs.
Description¶
This recipe is used to sum the contributes from a sequence of 2D-extracted spectral frames generated by the recipes vmmosobsstare, vmmosobsjitter, and vmmoscombine itself. The only restriction is that all frames must be obtained with the same mask. Sky subtraction, fringing correction, flat fielding, etc., are not applied, since they had been applied in the previous reduction of each input dataset.
Each input image is corrected to airmass zero before the stacking, and for this reason an atmospheric extinction table must always be specified. Optionally a correction for the instrument response can also be applied.
Input files¶
DO category: Type: Explanation: Required:
MOS_SCIENCE_EXTRACTED Product Combined slit spectra Y
GRISM_TABLE Calib Grism table Y
EXTINCT_TABLE Calib Atmospheric extinction Y
MOS_SPECPHOT_TABLE Calib Response curve .
Output files¶
DO category: Data type: Explanation:
MOS_SCIENCE_REDUCED FITS image Extracted objects spectra
MOS_SCIENCE_FLUX_REDUCED FITS image Flux calibrated objects spectra
MOS_SCIENCE_EXTRACTED FITS image Combined slit spectra
OBJECT_TABLE FITS table Objects spectra identification
WINDOW_TABLE FITS table Objects positions in slit
The positions of the extracted slit spectra and of the detected objects that they may contain are listed in the window table.
If a spectro-photometric table (produced by the recipe vmmosstandard) is specified and a flux calibration is requested, then a MOS_SCIENCE_FLUX_REDUCED image is also created. This image is identical to the MOS_SCIENCE_REDUCED, but the spectra it contains are flux calibrated, and expressed in units of erg/cm/cm/s/Angstrom.
For more details, please refer to the VIMOS Pipeline User’s Guide.
Constructor¶
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cpl.
Recipe
("vmmoscombine") Create an object for the recipe vmmoscombine.
import cpl
vmmoscombine = cpl.Recipe("vmmoscombine")
Parameters¶
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vmmoscombine.param.
StackMethod
¶ Frames combination method (str; default: ‘Average’) [default=”Average”].
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vmmoscombine.param.
KSigmaLow
¶ Low threshold for K-sigma clipping method. (float; default: 5.0) [default=5.0].
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vmmoscombine.param.
KSigmaHigh
¶ High threshold for K-sigma clipping method. (float; default: 5.0) [default=5.0].
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vmmoscombine.param.
MinRejection
¶ Number of lowest rejected values for rejection method. (int; default: 1) [default=1].
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vmmoscombine.param.
MaxRejection
¶ Number of highest rejected values for rejection method. (int; default: 1) [default=1].
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vmmoscombine.param.
DetectionLevel
¶ Object detection level in units of sigma. (float; default: 2.0) [default=2.0].
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vmmoscombine.param.
WatershedLevels
¶ Number of levels in the watershed method in object detection. (int; default: 32) [default=32].
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vmmoscombine.param.
WatershedFraction
¶ Flux fraction to use in watershed. (float; default: 0.01) [default=0.01].
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vmmoscombine.param.
MinObjectSize
¶ Minimal size for an object candidate to be considered an object. (int; default: 2) [default=2].
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vmmoscombine.param.
MaxObjectSize
¶ Maximal size for an object candidate for not trying deblend into sub- objects. (int; default: 7) [default=7].
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vmmoscombine.param.
CalibrateFlux
¶ Extracted spectra are flux calibrated. (bool; default: False) [default=False].
The following code snippet shows the default settings for the available parameters.
import cpl
vmmoscombine = cpl.Recipe("vmmoscombine")
vmmoscombine.param.StackMethod = "Average"
vmmoscombine.param.KSigmaLow = 5.0
vmmoscombine.param.KSigmaHigh = 5.0
vmmoscombine.param.MinRejection = 1
vmmoscombine.param.MaxRejection = 1
vmmoscombine.param.DetectionLevel = 2.0
vmmoscombine.param.WatershedLevels = 32
vmmoscombine.param.WatershedFraction = 0.01
vmmoscombine.param.MinObjectSize = 2
vmmoscombine.param.MaxObjectSize = 7
vmmoscombine.param.CalibrateFlux = False
You may also set or overwrite some or all parameters by the recipe parameter param, as shown in the following example:
import cpl
vmmoscombine = cpl.Recipe("vmmoscombine")
[...]
res = vmmoscombine( ..., param = {"StackMethod":"Average", "KSigmaLow":5.0})
See also
cpl.Recipe for more information about the recipe object.
Bug reports¶
Please report any problems to ESO VIMOS Pipeline Team and VIMOS Consortium. Alternatively, you may send a report to the ESO User Support Department.
Copyright¶
This file is part of the VIMOS Instrument Pipeline Copyright (C) 2002-2005 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
Code author: ESO VIMOS Pipeline Team and VIMOS Consortium <usd-help@eso.org>