Adaptive binning of X-ray data with weighted Voronoi tessellations

We present a technique to adaptively bin sparse data using weighted Voronoi tessellations (WVTs). WVT binning is a generalization of the Voronoi binning algorithm by Cappellari & Copin, developed for integral field spectroscopy. WVT binning is applicable to many types of data and creates unbiase...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society 2006-05, Vol.368 (2), p.497-510
Main Authors: Diehl, Steven, Statler, Thomas S.
Format: Article
Language:English
Subjects:
Algorithms
Astronomy
Data analysis
Earth, ocean, space
Exact sciences and technology
galaxies: clusters: general
ISM: general
methods: data analysis
Spectrum analysis
Stars & galaxies
supernova remnants
techniques: image processing
X-ray astronomy
X-rays: galaxies
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a technique to adaptively bin sparse data using weighted Voronoi tessellations (WVTs). WVT binning is a generalization of the Voronoi binning algorithm by Cappellari & Copin, developed for integral field spectroscopy. WVT binning is applicable to many types of data and creates unbiased binning structures with compact bins that do not lead the eye. We apply the algorithm to simulated data, as well as several X-ray data sets, to create adaptively binned intensity images, hardness ratio maps and temperature maps with constant signal-to-noise ratio per bin. We also illustrate the separation of diffuse gas emission from contributions of unresolved point sources in elliptical galaxies. We compare the performance of WVT binning with other adaptive binning and adaptive smoothing techniques. We find that the csmooth tool in ciao versions 1.1-3.1 creates serious artefacts and advise against its use to interpret diffuse X-ray emission.
ISSN:0035-8711
1365-2966
DOI:10.1111/j.1365-2966.2006.10125.x