Imperial College London
Portrait Picture

Professor David van Dyk

Faculty of Natural Sciences, Department of Mathematics

Chair in Statistics
 
 
 
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Contact

 

+44 (0)20 7594 8574d.van-dyk Website

 
 
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Assistant

 

Mr David Whittaker +44 (0)20 7594 8481

 
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Location

 

539Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Stein:2015:1/66,
author = {Stein, NM and van, Dyk DA and Kashyap, VL and Siemiginowska, A},
doi = {1/66},
journal = {Astrophysical Journal},
title = {Detecting Unspecified Structure in Low-Count Images},
url = {http://dx.doi.org/10.1088/0004-637X/813/1/66},
volume = {813},
year = {2015}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Unexpected structure in images of astronomical sources often presents itself uponvisual inspection of the image, but such apparent structure may either correspond totrue features in the source or be due to noise in the data. This paper presents amethod for testing whether inferred structure in an image with Poisson noise represents asignificant departure from a baseline (null) model of the image. To infer image structure,we conduct a Bayesian analysis of a full model that uses a multiscale component toallow flexible departures from the posited null model. As a test statistic, we use atail probability of the posterior distribution under the full model. This choice of teststatistic allows us to estimate a computationally efficient upper bound on a p-valuethat enables us to draw strong conclusions even when there are limited computationalresources that can be devoted to simulations under the null model. We demonstratethe statistical performance of our method on simulated images. Applying our methodto an X-ray image of the quasar 0730+257, we find significant evidence against the nullmodel of a single point source and uniform background, lending support to the claim ofan X-ray jet.
AU  - Stein,NM
AU  - van,Dyk DA
AU  - Kashyap,VL
AU  - Siemiginowska,A
DO  - 1/66
PY  - 2015///
SN  - 1538-4357
TI  - Detecting Unspecified Structure in Low-Count Images
T2  - Astrophysical Journal
UR  - http://dx.doi.org/10.1088/0004-637X/813/1/66
UR  - http://hdl.handle.net/10044/1/29644
VL  - 813
ER  -
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