Multicolor Active Galactic Nuclei Monitoring

由于宇宙膨胀和星系演化的影响是混合的，很难区分，用基于远距离星系的光学-红外观测的经典方法很难确定宇宙学参数。我们提出了一种测量遥远星系光度距离的新方法，该方法独立于并克服了星系演化的影响。提出的方法如下：首先，测量活动星系核(AGN)从光学变率到红外变率的滞后(尘埃混响法)。然后，由于发光的活动星系核具有较大的尘埃环面，因此具有较大的滞后，因此可以根据测量的滞后来估计UV/光学绝对星等。最后，通过比较活动星系核的绝对星等和视等星等，就可以测量出活动星系核的光度距离。为了建立和应用该方法，我们在毛伊岛的Haleakala天文台准备了一台专门监测活动星系核的2米望远镜，并从2000财年开始进行观测。在前期观测中，NGC4151和附近的一些活动星系核的光学变率和红外变率之间的滞后比以往任何时候都要准确，因此我们提出的方法是有前景的。我们将启动对大量活动星系核的频繁监测，并将持续几年，并将建立最大的活动星系核光学和红外变率数据库。利用星系的最新观测结果构建了一个新的星系演化模型，并利用新模型估计的演化效应，用经典方法(m-z、theta-z、计数)确定了宇宙学参数。我们论证了在SDF中发现的极红天体是由尘埃包裹形成的椭圆星系，并与理论上的星系形成过程进行了比较。

It is difficult to determine the cosmological parameters by the classical methods based on the optical-infrared observation of distant galaxies, because the effect of the cosmic expansion and the galaxy evolution is mixed and difficult to distinguish. We proposed a new method to measure the luminosity distance of remote galaxies, which is independent of and overcomes the galaxy evolution effect. The proposed method is as follows:At first, a lag from the optical variability to the infrared variability of an active galactic nucleous (AGN) is measured (the dust reverberation method). Then, the UV/optical absolute magnitude can be estimated from the measured lag because a luminous AGN have a large dust torus and therefore have a large lag. At last comparing the absolute and apparant magnitude of the AGN, we can measure the luminosity distance. In order to establish and apply the method, we prepared a 2 m telescope dedicated to monitoring AGNs at the Haleakala observatories at Maui island, and started the observation from fiscal 2000. The lags between the optical variability and infrared variability of NGC 4151 and some other nearby AGNs was measured accurately than ever from the pilot observation, therefore the method we proposed can be concluded promising. We are going to start the frequent monitor of lots of AGNs to be continued several years, and will construct the largest optical and infrared variability database of AGNs.1. A new galaxy evolution model was constructed with the recent observational results of galaxies, and determine the cosmological parameters using the classical methods (m-z, theta-z, number count) concerning with the evolution effect estimated by the new model.2. We argued that the extremely red objects found in SDF is dust enshrouded forming elliptical galaxies, and compared the observation with the theoretical galaxy formation processes.