muse_skyflat(7) Combine several separate (twilight) sky flat-fields into one master skyflat, and compute the integrated flux within the given wavelength range of the IFU.

SYNOPSIS

esorex muse_skyflat [OPTIONS] FILE.sof

DESCRIPTION

Processing trims the raw data and records the overscan statistics, subtracts the bias (taking account of the overscan, if --overscan is not &none&), and optionally, the dark from each raw input image, converts them from adu to count, and combines the exposures using input parameters. Bad pixels are then interpolated from surrounding good ones before computing the integrated flux in all slices by summing the pixel values of all within the boundaries given by the trace table and the --lambdamin and --lambdamax parameters. The integrated flux value is then later used as estimate for the relative throughput of each IFU, to scale values to a common flux level. Since twilight sky flat-fields will have an illumination similar to that of science exposures, they should preferably be used as input to this recipe. Normal lamp flat-fields can be used, if twilight sky flats are not available. The output image is not further used by the pipeline, only the FITS header with the integrated flux is propagated to the science data.

OPTIONS

--nifu <long>
IFU to handle. If set to 0, all IFUs are processed serially. If set to -1, all IFUs are processed in parallel. (long; default: 0). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.nifu [default = 0].
--overscan <str>
If this is "none", stop when detecting discrepant overscan levels (see ovscsigma), for "offset" it assumes that the mean overscan level represents the real offset in the bias levels of the exposures involved, and adjusts the data accordingly; for "vpoly", a polynomial is fit to the vertical overscan and subtracted from the whole quadrant. (str; default: 'vpoly'). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.overscan [default = vpoly].
--ovscreject <str>
This influences how values are rejected when computing overscan statistics. Either no rejection at all ("none"), rejection using the DCR algorithm ("dcr"), or rejection using an iterative constant fit ("fit"). (str; default: 'dcr'). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.ovscreject [default = dcr].
--ovscsigma <float>
If the deviation of mean overscan levels between a raw input image and the reference image is higher than |ovscsigma x stdev|, stop the processing. If overscan="vpoly", this is used as sigma rejection level for the iterative polynomial fit. Has no effect for overscan="offset". (float; default: 3.0). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.ovscsigma [default = 3.0].
--ovscignore <long>
The number of pixels of the overscan adjacent to the data region of the CCD that are ignored when computing statistics or fits. (long; default: 3). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.ovscignore [default = 3].
--combine <str>
Type of combination to use (str; default: 'sigclip'). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.combine [default = sigclip].
--nlow <long>
Number of minimum pixels to reject with minmax (long; default: 1). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.nlow [default = 1].
--nhigh <long>
Number of maximum pixels to reject with minmax (long; default: 1). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.nhigh [default = 1].
--nkeep <long>
Number of pixels to keep with minmax (long; default: 1). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.nkeep [default = 1].
--lsigma <float>
Low sigma for pixel rejection with sigclip (float; default: 3.0). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.lsigma [default = 3.0].
--hsigma <float>
High sigma for pixel rejection with sigclip (float; default: 3.0). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.hsigma [default = 3.0].
--scale <bool>
Scale the individual images to a common exposure time before combining them. (bool; default: False). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.scale [default = False].
--lambdamin <float>
Minimum wavelength to use for flux integration. (float; default: 4800.0). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.lambdamin [default = 4800.0].
--lambdamax <float>
Maximum wavelength to use for flux integration. (float; default: 9300.0). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.lambdamax [default = 9300.0].
--normalize <bool>
Normalize the master skyflat to the flux integrated over the given wavelength range. (bool; default: True). The full name of this option for the EsoRex configuration file is muse.muse_skyflat.normalize [default = True].

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

muse_skyflat 0.18.5

AUTHOR

Peter Weilbacher <[email protected]>

BUG REPORTS

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

LICENSE

This file is part of the MUSE Instrument Pipeline Copyright (C) 2005, 2014 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 02111-1307 USA