0520050

Several years ago a new class of type I X-ray bursters was discovered. This sources were detected only during an X-ray burst and no persistent emission around the burst (burst-only sources). On the present moment more then ten sources can be related to this class of objects (that exceed 15% from all known bursters).We propose a set from 2 observations any of 14 known sources (or/and from unknown source(s) from which it will be detected an X-ray burst and which do not show clear detectable persistent emission) in a bursting state. Duration of each observation is ~200ks one just after a detecting the first X-ray burst from a source with any X-ray mission (INTEGRAL SWIFT RXTE...) and one 30-40 days after the first observation. A bursting state of a such source could means that the source stays in a high state (with flux $>10^{34-35}$ ergs/s in soft energy band 1-8 keV). But then the flux from this system in a low state could be below $10^{33}$ ergs/s. It means that it is very difficult to detect such source in the low state even using high sensitive telescopes. The main goal of the proposal to determine possible hard X-ray counterpart of such source during a high state and to study its spectral and temporal evolution (during transition to low state).We also have submitted proposal on the follow-up observations of X-ray bursters with weak persistent emission in a high state on CHANDRA mission and planing organize simultaneous observations on other wavelength. [truncated! Please see actual data for full text]

几年前，一类新型I型X射线暴源（type I X-ray bursters）被发现。这些源仅在X射线暴期间被探测到，在暴发生前后无持续辐射（即仅暴源，burst-only sources）。目前，已有十余个源可归入此类天体（占所有已知暴源的15%以上）。我们提议对14个已知源中的每个源（或/及未知源——即从中探测到X射线暴且无明显可探测持续辐射的源）在爆发状态下进行两组观测。每组观测时长约为200千秒：一组在任何X射线任务（INTEGRAL、SWIFT、RXTE……）探测到该源的首次X射线暴后立即进行，另一组在首次观测后30-40天进行。此类源的爆发状态可能意味着其处于高态（软能段1-8 keV的流量>10^34-35尔格每秒）。但该系统在低态时的流量可能低于10^33尔格每秒，这意味着即使使用高灵敏度望远镜也难以在低态探测到此类源。本提案的主要目标是确定此类源在高态时可能存在的硬X射线对应体，并研究其能谱和时间演化（包括向低态的过渡过程）。我们还已向钱德拉任务（CHANDRA mission）提交了关于高态下具有弱持续辐射的X射线暴源后续观测的提案，并计划组织其他波长的同步观测。[内容截断！请查阅实际数据获取全文]