标题： 利用红移的共轭卫星OH谱线探测基本常数的演化 显示英文标题

标题： Probing fundamental constant evolution with redshifted conjugate-satellite OH lines

摘要： 我们报告了使用韦斯特博合成射电望远镜和阿雷西博望远镜对PKS1413+135的红移伴星OH-18厘米谱线（$z \sim 0.247$）的观测结果。 这些谱线的“共轭”性质（一条谱线处于发射状态，另一条处于吸收状态，但形状相同）表明它们起源于相同的气体。 伴星OH-18厘米谱线频率对精细结构常数 $\alpha$、质子-电子质量比 $\mu = m_p/m_e$和质子旋磁比 $g_p$的依赖关系也不同。 因此，可以通过比较共轭系统的伴星红移来探测 $\alpha$、$\mu$和$g_p$的变化，且系统误差较少。 当该技术应用于近距共轭伴星系统Cen.A时，得到了预期的零结果。 对于$z \sim 0.247$系统指向 PKS1413+135 的情况，我们结合两台望远镜的结果发现，$[\Delta G/G] = (-1.18 \pm 0.46) \times 10^{-5}$（加权平均值），其中$G = g_p [\mu \alpha^2]^{1.85}$；这是较小的$\alpha$、$\mu$和/或$g_p$值的试探性证据（显著性为$2.6 \sigma$，即 99.1% 的置信度），对应红移 z ~ 0.247，即回溯时间约为 2.9 亿年。 如果我们假设主要变化出现在$\alpha$中，则这意味着$[\Delta \alpha /\alpha ] = (-3.1 \pm 1.2) \times 10^{-6}$。我们没有发现任何证据表明观测到的偏差可能是由系统效应引起的，无论是由于观测方法或分析程序，还是分子云中的局部条件。 显示英文摘要

摘要： We report Westerbork Synthesis Radio Telescope and Arecibo Telescope observations of the redshifted satellite OH-18cm lines at $z \sim 0.247$ towards PKS1413+135. The "conjugate" nature of these lines, with one line in emission and the other in absorption, but with the same shape, implies that the lines arise in the same gas. The satellite OH-18cm line frequencies also have different dependences on the fine structure constant $\alpha$, the proton-electron mass ratio $\mu = m_p/m_e$, and the proton gyromagnetic ratio $g_p$. Comparisons between the satellite line redshifts in conjugate systems can hence be used to probe changes in $\alpha$, $\mu$, and $g_p$, with few systematic effects. The technique yields the expected null result when applied to Cen.A, a nearby conjugate satellite system. For the $z \sim 0.247$ system towards PKS1413+135, we find, on combining results from the two telescopes, that $[\Delta G/G] = (-1.18 \pm 0.46) \times 10^{-5}$ (weighted mean), where $G = g_p [\mu \alpha^2]^{1.85}$; this is tentative evidence (with $2.6 \sigma$ significance, or at 99.1% confidence) for a smaller value of $\alpha$, $\mu$, and/or $g_p$ at z~0.247, i.e. at a lookback time of ~2.9 Gyrs. If we assume that the dominant change is in $\alpha$, this implies $[\Delta \alpha /\alpha ] = (-3.1 \pm 1.2) \times 10^{-6}$. We find no evidence that the observed offset might be produced by systematic effects, either due to observational or analysis procedures, or local conditions in the molecular cloud.