Statistical Characterization of Complex Structures in H I Maps
N. Ghazzali, G. Joncas, S. Jean;
ApJ, 1999, 511, 242
ABSTRACT:Our study aims at the characterization of H I gas cloud images for classification purposes using their brightness temperature distribution.
The
morphology and velocity structure of the gas cloud is not taken into account in this
first study.
The analysis is based on spatial contiguity at a chosen radial
velocity value.
It is assumed that the form brightness temperature
distribution of each cloud is dependent on the physical process that created it.
We
wish to identify the existing relations between different clouds as a first
step toward understanding the evolutionary and physical processes that
form them.
Our study starts with an exploratory analysis based on
principal components analysis and on cluster analysis.
Because the inherent
signal in each image is noise, the characterization is then studied by using a
method of density estimation by deconvolution.
The clustering of the images
is done by considering single linkage and complete linkage criteria of
cluster aggregation.
KEYWORDS: ism: clouds, ism: structure, methods: statistical, radio lines: ism
CODE: ghazzali99