The vmifustandard recipe

vmifustandard

Synopsis

Extract a standard star spectrum.

Description

This recipe extracts IFU standard star fiber spectra using the input extraction mask, after aligning it to the brightest fiber spectra detected on the input exposure. The extracted spectra are then resampled at a constant wavelength step, after aligning the input wavelength calibration to the positions of a set of identified sky lines. The extracted spectra are finally corrected for the relative differences in transmission from fiber to fiber, and summed together.

Input files

DO category:            Type:       Explanation:           Required:
IFU_STANDARD            Raw         Standard star spectra     Y
MASTER_BIAS             Calib       Master bias               Y
IFU_TRACE               Calib       Extraction mask           Y
IFU_IDS                 Calib       Wavelength calibration    Y
IFU_TRANSMISSION        Calib       Transmission correction   Y
EXTINCT_TABLE           Calib       Atmospheric extinction    Y
STD_FLUX_TABLE          Calib       Standard star fluxes      Y
CCD_TABLE               Calib       Bad pixel table           .

Output files

DO category:            Data type:  Explanation:
IFU_STANDARD_REDUCED    FITS image  Reduced standard star spectra
IFU_FOV                 FITS image  Reconstructed field-of-view image
IFU_STANDARD_EXTRACTED  FITS table  Total standard star spectrum
IFU_SCIENCE_SKY         FITS table  Total sky spectrum
IFU_SPECPHOT_TABLE      FITS table  Efficiency and response curves

The extraction mask, the wavelength calibration, and the relative transmission table, are those generated by the recipe vmifucalib. A CCD table must be specified only if a bad pixel cleaning is requested.

The spectra extracted from the fibers on the standard star are added and compared to the catalog fluxes of the same star, to obtain the efficiency curve and the response curve to use for flux calibration.

The procedure is the same as the one applied in the case of MOS data, by recipe vmmosstandard.

Constructor

cpl.Recipe("vmifustandard")

Create an object for the recipe vmifustandard.

import cpl
vmifustandard = cpl.Recipe("vmifustandard")

Parameters

vmifustandard.param.BiasMethod

Bias removal method. (str; default: ‘Zmaster’) [default=”Zmaster”].

vmifustandard.param.CleanBadPixel

Bad pixel correction on master flat field. (bool; default: False) [default=False].

vmifustandard.param.UseSkylines

Use sky lines to refine the wavelength calibration (bool; default: True) [default=True].

vmifustandard.param.ResponseOrder

Order of the polynomial used to smooth the instrument response curve. (int; default: 5) [default=5].

vmifustandard.param.ReduceAnyFrame

Reduce any frame. (bool; default: False) [default=False].

vmifustandard.param.ComputeQC

Compute QC1 parameters (bool; default: True) [default=True].

The following code snippet shows the default settings for the available parameters.

import cpl
vmifustandard = cpl.Recipe("vmifustandard")

vmifustandard.param.BiasMethod = "Zmaster"
vmifustandard.param.CleanBadPixel = False
vmifustandard.param.UseSkylines = True
vmifustandard.param.ResponseOrder = 5
vmifustandard.param.ReduceAnyFrame = False
vmifustandard.param.ComputeQC = True

You may also set or overwrite some or all parameters by the recipe parameter param, as shown in the following example:

import cpl
vmifustandard = cpl.Recipe("vmifustandard")
[...]
res = vmifustandard( ..., param = {"BiasMethod":"Zmaster", "CleanBadPixel":False})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

Please report any problems to ESO VIMOS Pipeline Team. Alternatively, you may send a report to the ESO User Support Department.