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{Meyer:2021:mnras/stab1456,
author = {Meyer, A and van, Dyk D and Kashyap, VL and Campos, LF and Jones, DE and Siemiginowska, A and Zezas, A},
doi = {mnras/stab1456},
journal = {Monthly Notices of the Royal Astronomical Society},
pages = {6160--6180},
title = {eBASCS: disentangling overlapping astronomical sources II, usingspatial, spectral, and temporal information},
url = {http://dx.doi.org/10.1093/mnras/stab1456},
volume = {506},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The analysis of individual X-ray sources that appear in a crowded field can easily be compromised by the misallocation of recorded events to their originating sources. Even with a small number of sources, which none the less have overlapping point spread functions, the allocation of events to sources is a complex task that is subject to uncertainty. We develop a Bayesian method designed to sift high-energy photon events from multiple sources with overlapping point spread functions, leveraging the differences in their spatial, spectral, and temporal signatures. The method probabilistically assigns each event to a given source. Such a disentanglement allows more detailed spectral or temporal analysis to focus on the individual component in isolation, free of contamination from other sources or the background. We are also able to compute source parameters of interest like their locations, relative brightness, and background contamination, while accounting for the uncertainty in event assignments. Simulation studies that include event arrival time information demonstrate that the temporal component improves event disambiguation beyond using only spatial and spectral information. The proposed methods correctly allocate up to 65 per cent more events than the corresponding algorithms that ignore event arrival time information. We apply our methods to two stellar X-ray binaries, UV Cet and HBC 515 A, observed with Chandra. We demonstrate that our methods are capable of removing the contamination due to a strong flare on UV Cet B in its companion ≈40× weaker during that event, and that evidence for spectral variability at times-scales of a few ks can be determined in HBC 515 Aa and HBC 515 Ab.
AU  - Meyer,A
AU  - van,Dyk D
AU  - Kashyap,VL
AU  - Campos,LF
AU  - Jones,DE
AU  - Siemiginowska,A
AU  - Zezas,A
DO  - mnras/stab1456
EP  - 6180
PY  - 2021///
SN  - 0035-8711
SP  - 6160
TI  - eBASCS: disentangling overlapping astronomical sources II, usingspatial, spectral, and temporal information
T2  - Monthly Notices of the Royal Astronomical Society
UR  - http://dx.doi.org/10.1093/mnras/stab1456
UR  - http://arxiv.org/abs/2105.08606v1
UR  - http://hdl.handle.net/10044/1/89272
VL  - 506
ER  -
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