The kmos_std_star recipe

kmos_std_star

Synopsis

Create the telluric correction frame.

Description

This recipe creates a telluric frame and a PSF frames.

Since there cannot be 1 std star per IFU in one exposure, we use several exposures in order to have at least one standard star and one sky in each IFU. The frames are organised following this logic: 1. For each IFU the first standard star in the list of frames is

taken. All subsequent standard star exposures for this IFU are ignored
  1. A closest in time sky exposure is uѕed
  2. IFUs not containing a standard star and a sky will be empty in the result

NOISE_SPEC contains the shot noise [sqrt(counts*gain)/gain] If the exposures have been taken with KMOS_spec_cal_stdstarscipatt, an additional noise component is added: All existing sky exposures for an IFU are subtracted pairwise, spectra are extracted and the std deviation is computed

Input files

DO                      KMOS
category                Type  Explanation                Required #Frames
--------                ----- -----------                -------- -------
STD                     RAW   Std. star & sky exposures      Y     >=1
XCAL                    F2D   x calibration frame            Y      1
YCAL                    F2D   y calibration frame            Y      1
LCAL                    F2D   Wavelength calib. frame        Y      1
MASTER_FLAT             F2D   Master flat frame              Y      1
WAVE_BAND               F2L   Table with start-/end-wl       Y      1
ILLUM_CORR              F2I   Illumination correction        N     0,1
SOLAR_SPEC              F1S   Solar spectrum                 N     0,1
                              (only for G stars)
ATMOS_MODEL             F1S   Model atmospheric transmisson  N     0,1
                              (only for OBAF stars in K band)
SPEC_TYPE_LOOKUP        F2L   LUT  eff. stellar temperature  N     0,1

Output files

DO                      KMOS
category                Type   Explanation
--------                -----  -----------
TELLURIC                F1I    The normalised telluric spectrum
                               (including errors)
STAR_SPEC               F1I    The extracted star spectrum
                               (including errors)
STD_IMAGE               F2I    The standard star PSF images
STD_MASK                F2I    The mask used to extract the star spec
NOISE_SPEC              F1I    The extracted noise spectrum

Constructor

cpl.Recipe("kmos_std_star")

Create an object for the recipe kmos_std_star.

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

Parameters

kmos_std_star.param.startype

The spectral type of the star (O, B, A, F, G) e.g. G4V (str; default: ‘’) [default=”“].

kmos_std_star.param.imethod

Method to use for interpolation. [“NN” (nearest neighbour), “lwNN” (linear weighted nearest neighbor), “swNN” (square weighted nearest neighbor), “MS” (Modified Shepard’s method), “CS” (Cubic spline)] (str; default: ‘CS’) [default=”CS”].

kmos_std_star.param.fmethod

Fitting method (gauss, moffat, profile (str; default: ‘gauss’) [default=”gauss”].

kmos_std_star.param.neighborhoodRange

Defines the range to search for neighbors in pixels (float; default: 1.001) [default=1.001].

kmos_std_star.param.magnitude

Star magnitude (2 values in HK, eg. 12.1,13.2) (str; default: ‘’) [default=”“].

kmos_std_star.param.flux

TRUE: Apply flux conservation. FALSE: otherwise (bool; default: True) [default=True].

kmos_std_star.param.save_cubes

Flag to save reconstructed cubes (bool; default: False) [default=False].

kmos_std_star.param.no_noise

Skip the noise computation on sky exposures (bool; default: False) [default=False].

kmos_std_star.param.xcal_interpolation

Flag to Interpolate xcal between rotator angles (bool; default: True) [default=True].

kmos_std_star.param.suppress_extension

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

kmos_std_star.param.b_samples

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

kmos_std_star.param.mask_method

Method used : mask, integrated or optimal (str; default: ‘optimal’) [default=”optimal”].

kmos_std_star.param.centre

The centre of the circular mask (pixel) (str; default: ‘7.5,7.5’) [default=”7.5,7.5”].

kmos_std_star.param.radius

The radius of the circular mask (pixel) (float; default: 3.0) [default=3.0].

kmos_std_star.param.cmethod

Apply “average”, “median”, “sum”, “min_max.” or “ksigma”. (str; default: ‘ksigma’) [default=”ksigma”].

kmos_std_star.param.cpos_rej

The positive rejection threshold for kappa-sigma-clipping (sigma). (float; default: 3.0) [default=3.0].

kmos_std_star.param.cneg_rej

The negative rejection threshold for kappa-sigma-clipping (sigma). (float; default: 3.0) [default=3.0].

kmos_std_star.param.citer

The number of iterations for kappa-sigma-clipping. (int; default: 3) [default=3].

kmos_std_star.param.cmax

The number of maximum pixel values to clip with min/max-clipping. (int; default: 1) [default=1].

kmos_std_star.param.cmin

The number of minimum pixel values to clip with min/max-clipping. (int; default: 1) [default=1].

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

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

kmos_std_star.param.startype = ""
kmos_std_star.param.imethod = "CS"
kmos_std_star.param.fmethod = "gauss"
kmos_std_star.param.neighborhoodRange = 1.001
kmos_std_star.param.magnitude = ""
kmos_std_star.param.flux = True
kmos_std_star.param.save_cubes = False
kmos_std_star.param.no_noise = False
kmos_std_star.param.xcal_interpolation = True
kmos_std_star.param.suppress_extension = False
kmos_std_star.param.b_samples = 2048
kmos_std_star.param.mask_method = "optimal"
kmos_std_star.param.centre = "7.5,7.5"
kmos_std_star.param.radius = 3.0
kmos_std_star.param.cmethod = "ksigma"
kmos_std_star.param.cpos_rej = 3.0
kmos_std_star.param.cneg_rej = 3.0
kmos_std_star.param.citer = 3
kmos_std_star.param.cmax = 1
kmos_std_star.param.cmin = 1

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

import cpl
kmos_std_star = cpl.Recipe("kmos_std_star")
[...]
res = kmos_std_star( ..., param = {"startype":"", "imethod":"CS"})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

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