تقرير
A 420 day X-ray/optical modulation and extended X-ray dips in the short-period transient Swift J1753.5-0127
| العنوان: | A 420 day X-ray/optical modulation and extended X-ray dips in the short-period transient Swift J1753.5-0127 |
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| المؤلفون: | Shaw, A. W., Charles, P. A., Bird, A. J., Cornelisse, R., Casares, J., Lewis, F., Muñoz-Darias, T., Russell, D. M., Zurita, C. |
| سنة النشر: | 2013 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | We have discovered a \sim420d modulation, with associated X-ray dips, in RXTE-ASM/MAXI/Swift-BAT archival light-curves of the short-period (3.2h) black-hole X-ray transient, Swift J1753.5-0127. This modulation only appeared at the end of a gradual rebrightening, approximately 3 years after the initial X-ray outburst in mid-2005. The same periodicity is present in both the 2-20 keV and 15-50 keV bands, but with a \sim0.1 phase offset (\sim40d). Contemporaneous photometry in the optical and near-IR reveals a weaker modulation, but consistent with the X-ray period. There are two substantial X-ray dips (very strong in the 15-50 keV band, weaker at lower energies) that are separated by an interval equal to the X-ray period. This likely indicates two physically separated emitting regions for the hard X-ray and lower energy emission. We interpret this periodicity as a property of the accretion disc, most likely a long-term precession, where the disc edge structure and X-ray irradiation is responsible for the hard X-ray dips and modulation, although we discuss other possible explanations, including Lense-Thirring precession in the inner disc region and spectral state variations. Such precession indicates a very high mass ratio LMXB, which even for a \sim10M_sun BH requires a brown dwarf donor (\sim0.02M_sun), making Swift J1753.5-0127 a possible analogue of millisecond X-ray pulsars.We compare the properties of Swift J1753.5-0127 with other recently discovered short-period transients, which are now forming a separate population of high latitude BH transients located in the galactic halo. Comment: 6 pages, 4 figures, 1 table, accepted for publication in MNRAS |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stt763 |
| URL الوصول: | http://arxiv.org/abs/1303.6308 |
| رقم الأكسشن: | edsarx.1303.6308 |
| قاعدة البيانات: | arXiv |
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