The kmos_wave_cal recipe

kmos_wave_cal

Synopsis

Create a wavelength calibration frame

Description

This recipe creates the wavelength calibration frame needed for all three detectors. It must be called after the kmo_flat recipe, which generates the two spatial calibration frames needed in this recipe. As input a lamp-on frame, a lamp-off frame, the spatial calibration frames and the list with the reference arclines are required.

An additional output frame is the resampled image of the reconstructed arc frame. All slitlets of all IFUs are aligned one next to the other. This frame serves for quality control. One can immediately see if the calibration was successful.

The lists of reference arclines are supposed to contain the lines for both available calibration arc-lamps, i.e. Argon and Neon. The list is supposed to be a F2L KMOS FITS file with three columns:

  1. Reference wavelength
  2. Relative strength
  3. String either containing “Ar” or “Ne”

The recipe extracts, based on the header keywords, either the applying argon and/or neon emission lines. Below are the plots of the emission lines for both argon and neon. The marked lines are the ones used for wavelength calibration.

Furthermore frames can be provided for several rotator angles. In this case the resulting calibration frames for each detector are repeatedly saved as extension for every angle.

Input files

DO category       Type   Explanation                    Required #Frames
-----------       -----  -----------                    -------- -------
ARC_ON            RAW    Arclamp-on exposure                Y        >=1
ARC_OFF           RAW    Arclamp-off exposure               Y          1
XCAL              F2D    x calibration frame                Y          1
YCAL              F2D    y calibration frame                Y          1
ARC_LIST          F2L    List of arclines                   Y          1
FLAT_EDGE         F2L    Fitted edge parameters             Y          1
REF_LINES         F2L    Reference line table               Y          1
WAVE_BAND         F2L    Table with start-/end-wavelengths  Y          1

Output files

DO category       Type   Explanation
-----------       -----  -----------
LCAL              F2D    Wavelength calibration frame
                         (3 Extensions)
DET_IMG_WAVE      F2D    reconstructed arclamp-on exposure
                         (4 extensions: 3 detector images +
                         the arclines list table)

Constructor

cpl.Recipe("kmos_wave_cal")

Create an object for the recipe kmos_wave_cal.

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

Parameters

kmos_wave_cal.param.order

The fitting polynomial order used for the wavelength solution. By default, 4 for IZ band, 5 for HK, 6 for the others (int; default: 0) [default=0].

kmos_wave_cal.param.suppress_extension

Suppress arbitrary filename extension (bool; default: False) [default=False].

kmos_wave_cal.param.lines_estimation

Trigger lines estimation method (bool; default: False) [default=False].

kmos_wave_cal.param.b_samples

The number of samples in wavelength for the reconstructed cube (int; default: 2048) [default=2048].

kmos_wave_cal.param.det

Only reduce the specified detector (int; default: 0) [default=0].

kmos_wave_cal.param.angle

Only reduce the specified angle (float; default: 370.0) [default=370.0].

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

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

kmos_wave_cal.param.order = 0
kmos_wave_cal.param.suppress_extension = False
kmos_wave_cal.param.lines_estimation = False
kmos_wave_cal.param.b_samples = 2048
kmos_wave_cal.param.det = 0
kmos_wave_cal.param.angle = 370.0

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

import cpl
kmos_wave_cal = cpl.Recipe("kmos_wave_cal")
[...]
res = kmos_wave_cal( ..., param = {"order":0, "suppress_extension":False})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

Please report any problems to Alex Agudo Berbel, Yves Jung. Alternatively, you may send a report to the ESO User Support Department.