Efficient multi-Gaussian expansion of galaxies

被引:407
作者
Cappellari, M [1 ]
机构
[1] Leiden Observ, NL-2300 RA Leiden, Netherlands
关键词
stellar dynamics; techniques : image processing; galaxies : kinematics and dynamics; galaxies : photometry; galaxies : structure;
D O I
10.1046/j.1365-8711.2002.05412.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We describe a simple, efficient, robust and fully automatic algorithm for the determination of a multi-Gaussian expansion (MGE) fit to galaxy images, to be used as a parametrization for the galaxy stellar surface brightness. In most cases the least-squares 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 multiple-resolution images (e.g. Hubble Space Telescope (HST ) and ground-based images). It works orders of magnitude faster and is more accurate than currently available methods. An alternative, more computing-intensive, fully linear algorithm that is guaranteed to converge to the smallest chi(2) solution is also discussed. Examples of MGE fits are presented for objects with HST or ground-based photometry, including galaxies with significant isophote twist.
引用
收藏
页码:400 / 410
页数:11
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