Efficient multiGaussian expansion of galaxies
Abstract
We describe a simple, efficient, robust and fully automatic algorithm for the determination of a multiGaussian expansion (MGE) fit to galaxy images, to be used as a parametrization for the galaxy stellar surface brightness. In most cases the leastsquares solution found by this method essentially corresponds to the minimax, constant relative error, MGE approximation of the galaxy surface brightness, with the chosen number of Gaussians. The algorithm is well suited to be used with multipleresolution images (e.g. Hubble Space Telescope (HST) and groundbased images). It works orders of magnitude faster and is more accurate than currently available methods. An alternative, more computingintensive, fully linear algorithm that is guaranteed to converge to the smallest χ^{2} solution is also discussed. Examples of MGE fits are presented for objects with HST or groundbased photometry, including galaxies with significant isophote twist.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 June 2002
 DOI:
 10.1046/j.13658711.2002.05412.x
 arXiv:
 arXiv:astroph/0201430
 Bibcode:
 2002MNRAS.333..400C
 Keywords:

 stellar dynamics;
 techniques: image processing;
 galaxies: kinematics and dynamics;
 galaxies: photometry;
 galaxies: structure;
 Astrophysics
 EPrint:
 11 pages, 13 figures, LaTeX, to be published in MNRAS