Server: Moscow
Version: 0.4.4
(2011-09-28)

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Extract Stellar

This request must have the following format

   begin request
   extract stellar
   [long format]
   [short format]
   <wavelength 1>,<wavelength 2>
   <detection-limit>,<microturbulence>
   <Teff>,<logg>
   [chemical composition]
   ......................
   end request
where <wavelength 1>,<wavelength 2> are again the limits of the spectral interval in Angstroem. Effective temperature <Teff> and gravity <logg> are used to select a solar abundant model atmosphere for estimating the central depth of spectral lines; <detection-limit> contains the user's lower limit to the central depth, ignoring line blending and expressed as a fraction of the continuum (broadening mechanisms not affecting the equivalent width such as stellar rotation or instrumental broadening are not accounted for). Thus, <detection-limit> of 0.05 rejects all the lines with central depths less than 5% of the continuum. VALD has the latest models computed by R.L. Kurucz (Kurucz CDROM 13, June 23, 1993 edition) covering a temperature range from 3500K to 50000K and log g from 0.0 to 5.0. The chemical composition is set as a log10 of the ratio of atomic number density to the total number of atoms. The default values are solar. The abundance value must be separated from the element name with a column (for example, Fe:-4.7). Several values can be set on the same line, separated with commas. The request mail can contain as many lines as needed to set the chemical composition.

Example

   begin request          #  Start of the request
   extract stellar        #  Request type
   5700.,5703.            #  Specify wavelength range in Angstroems,
   0.05, 2.               #  Look for lines reaching more than 0.05
                          #  central depth and use microturbulence
                          #  of 2 km/s
   8000, 4.5              #  Teff and log g
   Sr: -4.67, Cr: -3.37,  #  Setup specific chemical composition
   Eu: -5.53               
   end request            #  End of the request
The return mail will contain the following table reqextstar.txt

Note that for this request type the output table includes also the microturbulence (Vmic) in km/s and the estimated central line depth relative to continuum. We also provide the name of model atmosphere file in the format '<Teff>g<10*logg>.<source>' and the abundances of the first 99 elements. The abundances of three elements have been substituted from the request data. However the model atmosphere used is not affected by the change in composition.