Long-term variability of the Be/X-ray binary A0535+26 — III. Photometry
Long-term variability of the Be/X-ray binary A0535+26 — III. Photometry
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Be/X 射线二元 A0535+26 的长期变化 — III.
DOI：
10.1046/j.1365-8711.1999.02112.x
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发表时间：
1999
影响因子：
4.8
通讯作者：
M. Coe
中科院分区：
文献类型：
--
作者：
J. Clark;V. M. Lyuty;G. Zaitseva;V. Larionov;L. Larionova;M. Finger;A. Tarasov;P. Roche;M. Coe
介绍了近十年来对Be/ x射线双星系统HDE 245770/A0535+26的紫外波段光度观测。结果表明，所有波长的发射都是相关的，不同波段的变化之间不存在可分辨的时滞。这表明系统内只有一个源在发射。我们发现，光学连续体可以被理解为围绕主星的星周圆盘中物质的光学薄的自由和束缚自由发射。我们发现，在观测过程中，星盘的辐射测量变化了约40倍。如果这被解释为原液的质量损失率的变化，则对应于一个系数为：1 ~ 6的变化。
UBV-band photometric observations of the Be/X-ray binary system HDE 245770/A0535+26 over the last decade are presented. It is shown that the emission at all wavelengths is correlated, and that no resolvable time-lag exists between variations in differing wavebands. This is suggestive of emission from only one source within the system. It is found that the optical continuum can be understood as optically thin free--free and bound--free emission from material in the circumstellar disc around the primary Oe star. We find a change in the emission measure of the disc by a factor of ∼ 40 over the course of the observations. If this is interpreted as a variation in the mass-loss rate from the primary, it corresponds to a change by a factor of␣∼ 6.
Period searches on the optical light curve reveal no evidence for modulation of the circumstellar envelope at the orbital period; therefore it seems unlikely that the mass-loss rate from the primary is affected by the neutron star at periastron. No positive correlation exists␣between the optical and X-ray light curves; such a result appears to exclude models for the X-ray behaviour in which accretion is directly fed from the dense circumstellar wind of the primary. It is likely that X-ray outbursts are instead triggered by discrete mass ejection events from the primary.