ESPRESSO: Thorium-Argon wavelength-calibration frames
|
HC PLOTS |
Resolving power |
|
Dispersion solution |
|
Number and flux of ThAR lines |
|
QC1 database (advanced users):
browse |
plot
|
QC1 database (advanced users):
browse |
plot
|
Three different calibration sources can be used in order to wavelength
calibrate ESPRESSO observations: a Fabry-Perot (FP) cavity, ThAr arc lamps, and a
laser-frequency comb (LFC). The Fabry-Perot provides more than 60000 lines
which are evenly distributed over the entire wavelength range of ESPRESSO.
These give a very accurate relative calibration; the absolute wavelength scale has
to be determined with ThAr exposures. The LFC on the other hand gives very
accurate relative and absolute calibration. It covers, however, not the
complete wavelength range of ESPRESSO.
A complete wavelength calibration sequence consists of:
- an exposure with FP in fibre A and fibre B
- an exposure with ThAr in fibre A and FP in fibre B
- an exposure with FP in fibre A and ThAr in fibre B
- an exposure with LFC in fibre A and FP in fibre B
- an exposure with FP in fibre A and LFC in fibre B
|
Wavelength calibration. Example raw frame for the blue detector with ThAr in fibre A and FP in fibre B.
|
Resolving power
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.ORDERS.RESOL.MEDIAN | espresso_wave_thar_a..fiba_resol_med | median resolving power of used lines for fibre A | HC | | [docuSys coming] |
QC.ORDERS.RESOL.MEDIAN | espresso_wave_thar_b..fibb_resol_med | median resolving power of used lines for fibre B | HC | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The median resolving power R is trended separately for fibres A and B
and for the five different combinations of resolving power and binning:
HR with 1x1 and 2x1 binning, UHR with 1x1 binning, and MR with 4x2 and 8x4
binning.
Scoring&thresholds Resolving power
Scoring and thresholds have been set for R using data
acquired during commissioning.
History
No particular events.
Algorithm Resolving power
The pipeline calculates the resolving power from ThAr lines. The QC parameter is the median of the
values of the individual lines.
Dispersion solution
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
none | espresso_wave_thar_a..fiba_disp_avg | average RMS of the dispersion solution for fibre A | CAL | | [docuSys coming] |
none | espresso_wave_thar_a..fiba_disp_rms | RMS of the average RMS of the dispersion solution for fibre A | CAL | | [docuSys coming] |
none | espresso_wave_thar_b..fibb_disp_avg | average RMS of the dispersion solution for fibre B | CAL | | [docuSys coming] |
none | espresso_wave_thar_b..fibb_disp_rms | RMS of the average RMS of the dispersion solution for fibre B | CAL | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The pipeline calculates the RMS of the dispersion solution for each order. For
trending, the average of these values and the RMS of the individual values are
used. These are
trended separately for fibres A and B
and for the five different combinations of resolving power and binning:
HR with 1x1 and 2x1 binning, UHR with 1x1 binning, and MR with 4x2 and 8x4
binning.
Scoring&thresholds Dispersion solution
The first and last orders on each chip have typically the highest values for the
dispersion RMS. Scoring thresholds have been set for the RMS of the values per order
so that a degradation of the dispersion solution for the first or last orders is flagged.
Scoring of the average has been introduced so that the issues that occured in November 2020
with a new FP source, which was noisier, are flagged. Upper limits are set so that
the good wavelength calibrations from March 2020 and earlier would score green.
History
No particular events.
Algorithm Dispersion solution
Pipeline calculated values per order.
Number of ThAr lines
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.THAR.LINES.NB | espresso_wave_thar_a..fiba_thar_lines_tot | total number of valid ThAr lines on fibre A | CAL | | [docuSys coming] |
QC.THAR.LINES.NB | espresso_wave_thar_b..fibb_thar_lines_tot | total number of valid ThAr lines on fibre B | CAL | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The number of ThAr lines is trended separately for fibres A and B
and for the five different combinations of resolving power and binning:
HR with 1x1 and 2x1 binning, UHR with 1x1 binning, and MR with 4x2 and 8x4
binning.
Scoring&thresholds Number of ThAr lines
Scoring and thresholds have been set using data taken in November 2019.
History
Available since pipeline version 1.5.1, installed October 2019.
Algorithm Number of ThAr lines
The QC parameter is the total number of ThAr lines which are used for the wavelength solution.
ThAr flux ratio
QC1_parameters
FITS key |
QC1 database: table, name |
definition |
class* |
HC_plot** |
more docu |
QC.THAR.FLUX.RATIO.MEDIAN | espresso_wave_thar_a..fiba_thar_flux_ratio | median flux ratio of ThAr lines to reference line table | CAL | | [docuSys coming] |
QC.THAR.FLUX.RATIO.MEDIAN | espresso_wave_thar_b..fibb_thar_flux_ratio | median flux ratio of ThAr lines to reference line table | CAL | | [docuSys coming] |
*Class: KPI - instrument performance; HC - instrument health; CAL - calibration quality; ENG - engineering parameter
**There might be more than one. |
Trending
The flux ratio of ThAr lines is trended separately for fibres A and B
and for the five different combinations of resolving power and binning:
HR with 1x1 and 2x1 binning, UHR with 1x1 binning, and MR with 4x2 and 8x4
binning.
Scoring&thresholds ThAr flux ratio
The lower threshold of 0.4 is set after a suggestion from the consortium, the upper threshold
has been set using data taken in November 2019.
History
Available since pipeline version 1.5.9, installed November 2019. Pipeline version 1.5.1
had a bug in the calculation of the QC parameter.
Algorithm ThAr flux ratio
The QC parameter is the median of the flux of the ThAr lines and normalized to a reference line table.
|