Descripción del código fortran

Subroutine that computes and assign Gaia errors to observables (Versión, October 2012)

Errors are computed following Gaia Science Performance web page

Universitat de Barcelona

Contact: Merce Romero-Gomez (, Josep Manel Carrasco (

Input external tables:

  • geometrical factors ('gfactor-Oct2012.dat')
  • Radial Velocity coefficients ('TableVr-Oct2012.dat')

Input files for the definition of constants:
  • const_math.h : mathematical constants
  • const_ast.h : astronomical constants

Additional functions:
  • gaussdev.f : gasdev, ran2

Input parameters from the star:
  • Equatorial helicocentric coordinates (units: radians)
  • Equatorial proper motions (units: mas/yr)
  • Parallax (units: mas)
  • Radial velocity (units: km/s)
  • V apparent magnitude
  • Observed (V-I) colour index (affected by extinction)
  • Atmospheric parameters for the star (Teff, logg, [Fe/H], Av)

Output values:
  • Actual parameters of the star (input values, not affected by errors)
  • Parameters of the star as observed by Gaia (affected by errors): astrometry, Vr, photometry and atmospheric parameters
  • Gaia errors assigned to each parameter:
  • The code offers two options depending of the type of errors you want to apply (see website):
    • jflag=1, errors computed from mean geometrical factors (see website)
    • jflag=-1,errors computed considering the scanning law of the satellite (the geometrical factors are then computed from the ecliptic latitude and the number transits)

Topic revision: r4 - 2013-01-18 - FrancescaFigueras
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2024 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback