Collaborative Research: The HET Echo Mapping Project

AST-0086683Edward L.罗宾逊这是一个合作研究项目与威廉F。Welsh at San Diego州立大学（AST 0086692）。该项目将利用9米霍比-埃伯利望远镜，以良好的时间取样获得类星体宽线区域的高信噪比光谱，分析整个运动学光谱剖面随时间的变化。这些将被用来测试宽线发射区的不同运动学类星体模型（流入与流出）。潜伏在许多大质量星系中心的是超大质量黑洞（BH）。如果附近有物质，黑洞将捕获并吸积这些物质，释放出大量的能量，这将表现为星系核的亮度增加。拥有这种吸积BH的星系被称为有一个“活动核”（AGN）。吸积是一个固有的不稳定过程。靠近黑洞的吸积区称为宽线区（BLR）。BLR是发光的，因为它被非常接近BH产生的硬（UV和X射线）连续通量光电离。因为这种电离辐射是可变的，所以BLR也是可变的。因此，来自BLR的发射谱线“回声”了连续通量的变化。利用这些“回波”，可以绘制出BH附近微弧秒尺度的结构。要做到这一点，需要一个非常长的时间基线的良好采样的观察变化的最大似然比。这需要数周或数月的数据。“HET回波测绘计划”是一个新的研究项目，其目标是：（1）绘制BLR气体的大小，几何形状和流量。(2)使用BLR的几何学和运动学直接估计中心BH的质量。(3)绘制活动星系核，其黑洞质量是先前测量的10到100倍。(4)测量任何吸积风的参数和BLR的时间变化。该项目的资金由美国国家科学基金会的河外天文宇宙学计划（AST/EXC）提供。

AST-0086683Edward L. RobinsonThis is a collaborative research project with William F. Welsh at San Diego State University (AST0086692). This project will use the 9m Hobby-Eberly Telescope (HET) to obtain high signal-to-noise spectra of QSO broad line regions, with good time sampling, to analyze changes in the full kinematic spectral profiles as a function of time. These will be used to test different kinematic QSO models ( inflow vs. outflow) for the broad line emission regions.Lurking at the center of many massive galaxies are supermassive Black Holes (BH). If there is material nearby, the BH will trap and accrete this matter releasing a huge amount of energy which will show up as increased luminosity of the galaxy nucleus. Galaxies which possess such an accreting BH are said to have an "active Nucleus" (AGN). Accretion is an inherently unstable process. The accretion region close to the BH is called the Broad Line Region (BLR). The BLR is luminous because it is photoionized by the hard (UV and x-ray) continuum flux produced very close to the BH. Because this ionizing radiation is variable, so is the BLR. Thus the emission lines from the BLR "echo" the variations in the continuum flux. Using these "echoes" structures near the BH with microarcsecond scales can be mapped. To do this one needs a very long time baseline of well-sampled observations of the variations in the BLR. This requires data over weeks or months. The "HET Echo Mapping Project" is a new research project which aims to: (1) Map the size, geometry, and flow of the BLR gas. (2) Make direct estimates of the mass of the central BH using the geometry and kinematics of the BLR. (3) map AGN with BH of 10 to 100 times the mass of those previously measured. (4) Measure the parameters of any accretion wind and the temporal changes in the BLR. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***