标题： 对硬态和休眠状态黑洞X射线双星的深度射电调查 显示英文标题

标题： A deep radio survey of hard state and quiescent black hole X-ray binaries

摘要： 我们对一批处于硬态和休眠态的黑洞X射线双星进行了深入的射电调查，以确定是否有任何系统足够明亮，可以使用高灵敏度的甚长基线干涉测量（VLBI）阵列进行天体测量后续观测。 其中一个硬态系统Swift J1753.5-0127，在0.5 mJy/beam的水平上被检测到。 所有十一个休眠系统均未被检测到。 在三个预测休眠态射电亮度最高的情况下（GRO J0422+32、XTE J1118+480和GRO J1655-40），利用了扩展甚大望远镜的新能力，将噪声水平降低到2.6微Jy/beam。 这三个源均未被检测到，对应的3-sigma上限分别为8.3、7.8和14.2微Jy/beam。 这些观测代表了目前对黑洞X射线双星休眠态射电辐射最严格的限制。 源的距离、观测时的休眠态X射线光度以及射电和X射线光度之间经验相关性的幂律指数的不确定性，使得无法确定这三个源是否在射电波段的光度明显低于预期。 因此，尚不清楚该相关性是否适用于所有黑洞X射线双星，直到休眠状态。 显示英文摘要

摘要： We have conducted a deep radio survey of a sample of black hole X-ray binaries in the hard and quiescent states, to determine whether any systems were sufficiently bright for astrometric follow-up with high-sensitivity very long baseline interferometric (VLBI) arrays. The one hard-state system, Swift J1753.5-0127, was detected at a level of 0.5 mJy/beam. All eleven quiescent systems were not detected. In the three cases with the highest predicted quiescent radio brightnesses (GRO J0422+32, XTE J1118+480, and GRO J1655-40), the new capabilities of the Expanded Very Large Array were used to reach noise levels as low as 2.6 microJy/beam. None of the three sources were detected, to 3-sigma upper limits of 8.3, 7.8, and 14.2 microJy/beam, respectively. These observations represent the most stringent constraints to date on quiescent radio emission from black hole X-ray binaries. The uncertainties in the source distances, quiescent X-ray luminosities at the times of the observations, and in the power-law index of the empirical correlation between radio and X-ray luminosities, make it impossible to determine whether these three sources are significantly less luminous in the radio band than expected. Thus it is not clear whether that correlation holds all the way down to quiescence for all black hole X-ray binaries.