Collaborative Research: New Frontiers in Reverberation Mapping

在类星体发现后的50年里，一幅关于这些神秘物体的图景出现了，其中类星体是位于大型星系中心的超大质量黑洞。黑洞的质量可能是太阳的数百万到数十亿倍。正如这幅图所暗示的那样，类星体现象与被称为“活动星系核”的物体是同一种现象。所有类星体的特征都是巨大的亮度，以至于类星体经常比其宿主星系中数十亿颗恒星发出的光都要亮。黑洞的存在吸引了各个科学水平的人。对活动星系核以及我们自己星系核的研究已经提供了强有力的证据，证明超大质量黑洞确实存在，而且它们是类星体现象的核心引擎。该项目旨在继续估算物体样本中超大质量黑洞的质量，并将其扩展到比以前研究过的亮度更高的物体上，通过结合密集的观测计划和开发新的分析技术。这个合作项目将建立活跃星系和类星体的“混响映射”技术。混响映射是一种技术，通过观察活动物体的发射谱线的反应，来观察它如何对连续源的强度变化做出反应，连续源电离并激发周围的发射谱线气体。在过去的几十年里，这项技术一直被用于测量活动星系核中所谓的宽线区域的大小和结构。在过去的五年里，这项技术已被应用于高节奏的观测，以提供对活动天体中心吸积黑洞质量的最佳约束。该项目将通过三个阶段的努力进一步推进该技术：(1)分析来自NGC 5548的高节奏光学/紫外线监测活动的数据，该活动将代表有史以来最密集的混响映射程序；(2)在利克天文台执行为期一年的混响测绘活动，以探测宽线区域结构，其亮度比其他最近的专门监测项目探测的亮度高一个数量级；(3)最新混响映射数据建模软件的发展。这些项目的结合将使人们有可能比以往更详细地剖析宽线区域的结构和动力学特性，从而对类星体黑洞质量尺度的局部校准进行关键的新测试。

In the fifty years since the discovery of quasars, a picture of these enigmatic objects has emerged wherein quasars are supermassive black holes residing at the centers of large galaxies. The black hole may have a mass of millions to billions times that of the sun. As this picture implies, the quasar phenomenon is one and the same as that of the objects referred to as "active galactic nuclei." All are characterized by enormous luminosity such that the quasar frequently outshines the light from all of the billions of stars in its host galaxy. The existence of black holes has captivated people of all levels of scientific sophistication. The study of active galactic nuclei as well as the nucleus of our own galaxy has produced strong evidence that, indeed, supermassive black holes do exist and that they are the engines at the heart of the quasar phenomenon. This project aims to continue the estimate of the mass of the supermassive black holes in a sample of objects and extend it to objects of higher luminosity than those previously studied via a combination of an intense observational program as well as development of new analysis techniques.This collaborative project will establish the state of the art in "reverberation mapping" of active galaxies and quasars. Reverberation mapping is a technique where one looks at the reaction of the emission line spectrum of the active object to see how it responds to a change in the intensity of the continuum source that ionizes and excites the surrounding line-emitting gas. It is a technique that has been employed over the last few decades to measure the size and structure of the so-called broad line region in active galactic nuclei, and, in the past five years, the technique has been applied to high-cadence observations to provide the best constraints on the mass of the accreting black hole at the heart of the active object. This project will further advance the technique via a three-phase effort: (1) analysis of data from a high-cadence optical/ultraviolet monitoring campaign for NGC 5548 that will represent the single most intensive reverberation mapping program ever attempted; (2) execution of a one year duration reverberation mapping campaign at Lick Observatory to probe broad-line region structure at luminosities an order of magnitude higher than the luminosities probed by other recent dedicated monitoring programs; and (3) new development of state-of-the-art software for modeling reverberation mapping data. The combination of these projects will make it possible to dissect the structural and dynamical properties of the broad-line region in greater detail than ever before, enabling critical new tests of the local calibration for the quasar black hole mass scale.