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标题：Chandra X-ray observations of the HII region G5.89-0.39 and TeV Source HESSJ1800-240B
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作者：G. Rowell ; D. Horns ; Y. Uchiyama 等
期刊名称：PoS - Proceedings of Science
印刷版ISSN：1824-8039
出版年度：2010
卷号：2010
出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The TeV gamma-ray sources in the field of the old age (> 104 yr) supernova remnant (SNR) W28 [2] present a unique opportunity to probe for a new type of multi-TeV particle accelerator, namely, HII regions. One such example is the TeV source HESS J1800−240B which is found towards the highly unusual HII region complex G5.89−0.39. In this context X-rays studies are highly valuable in probing the particle acceleration potential of such HII regions and their subsequent contribution to the gamma-ray emission. Previous high resolution XMM-Newton X-ray observations despite being affected by stray light from a nearby X-ray binary, revealed several sources co-located with the two star forming components of G5.89−0.39, namely G5.89-0.39A, a HII region, as well as G5.89-0.39B, an ultracompact or UCHII region. Here we describe preliminary analysis and results from our Chandra observations towards G5.89−0.39 and HESS J1800−240B (∼80 ks) which are not affected by stray light. With Chandra, we reveal over 200 X-ray sources which appear to cluster somewhat towards G5.89−0.39A and B respectively. This includes possibly extended emission towards a massive O5 or earlier spectral type star (known as Feldt’s star) thought to provide much of the ionisation and energetics in G5.89−0.39B. Some of the X-ray sources exhibit energetics typical of young moderate to high mass stars. Our Chandra observations reveal for the first time the extent of star formation in the two HII components. Ongoing work centres on detailed spectral studies, cross-correlation with stellar catalogues, and the search for extended X-ray emission.