تقرير
Localization of the X-ray Source in the Globular Cluster G1 with Chandra
| العنوان: | Localization of the X-ray Source in the Globular Cluster G1 with Chandra |
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| المؤلفون: | Kong, A. K. H., Heinke, C. O., Di Stefano, R., Cohn, H. N., Lugger, P. M., Barmby, P., Lewin, W. H. G., Primini, F. A. |
| سنة النشر: | 2009 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | We report the most accurate X-ray position of the X-ray source in the giant globular cluster G1 in M31 by using the Chandra X-ray Observatory, Hubble Space Telescope (HST), and Canada-France-Hawaii Telescope (CFHT). G1 is clearly detected with Chandra and by cross-registering with HST and CFHT images, we derive a 1-sigma error radius of 0.15 arcsec, significantly smaller than the previous measurement by XMM-Newton. We conclude that the X-ray emission of G1 is likely to come from within the core radius of the cluster. We have considered a number of possibilities for the origin of the X-ray emission but can rule all but two scenarios out: it could be due to either accretion onto a central intermediate-mass black hole (IMBH), or an ordinary low-mass X-ray binary (LMXB). Based on the X-ray luminosity and the Bondi accretion rate, an IMBH accreting from the cluster gas seems unlikely and we suggest that the X-rays are due to accretion from a companion. Alternatively, the probability that a 1.5 solar masses cluster LMXB lies within the 95 per cent X-ray error circle is about 0.7. Therefore we cannot rule out a single LMXB as the origin of the X-ray emission. While we cannot distinguish between different models with current observations, future high-resolution and high-sensitivity radio imaging observations will reveal whether there is an IMBH at the centre of G1. Comment: 5 pages, 1 figure, accepted for publication in MNRAS |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1111/j.1745-3933.2010.00910.x |
| URL الوصول: | http://arxiv.org/abs/0910.3944 |
| رقم الأكسشن: | edsarx.0910.3944 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1111/j.1745-3933.2010.00910.x |
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