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Table Formats

MIDAS table files are used to store relevant information in tabular form. Four types of tables are considered. The first two, tables order.tbl and line.tbl, are operational tables generated by the user during the session. The other two types of tables are provided by the system to calibrate the data in wavelength and flux.

order.tbl -- Contains echelle orders. This table contains the coefficients aij in relation 7.2 stored as descriptors. The table is created by the command DEFINE/ECHELLE or DEFINE/HOUGH
back.tbl -- Contains information related to the background reference positions. This table is created by the command PREPARE/BACKGROUND which is called by DEFINE/ECHELLE and DEFINE/HOUGH.
line.tbl -- Contains information related to the position of the calibration lines. This table contains the dispersion coefficients for each spectral order, stored as descriptors after the line identification process. It is generated by the command SEARCH/ECHELLE and extended and updated by the command IDENTIFY/ECHELLE.
Line Catalogue
-- Contains the wavelength calibration lines. There are several line catalogues available in instrument related system area, like MID_CASPEC and MID_EFOSC.
Standard Stars
-- Contains the fluxes of standard stars in different units. These tables are copied automatically from the area MID_STANDARD into the user work space with the command SET/ECHELLE FLUXTAB=name


 
Table 7.1: Auxiliary Tables
Table order.tbl
Label Unit Description
ORDER - sequential order number
X PIXEL sample (x-axis) position of the order
Y PIXEL line (y-axis) position of the order
YFIT PIXEL fitted line (y-axis) position of the order
RESIDUAL PIXEL residual ( Y-YFIT)
Table back.tbl
Label Unit Description
ORDER - sequential order number
X PIXEL sample (x-axis) position of the order
YBKG PIXEL line position of the background above the order
BKG DN value of the background
Table line.tbl
Label Unit Description
X PIXEL sample (x-axis) position of the line
Y PIXEL relative order number
PEAK DN estimated line maximum
YNEW PIXEL line (y-axis) position of the line
ORDER - spectral order number
IDENT ANGSTROM manual identification
WAVEC ANGSTROM computed wavelength
RESIDUAL ANGSTROM residual (WAVEC-WAVE)
Line Catalogue
Label Unit Description
WAVE ANGSTROM wavelength
Standard Star Atlas
Label Unit Description
MAGNITUDE - magnitude
WAVE ANGSTROM wavelength
BIN_W ANGSTROM bin width
FLUX_W ERGS/S/CM/CM/ANG flux
 


next up previous contents
Next: MIDAS Commands Up: Implementation Previous: Image Formats
Petra Nass
1999-06-15