摘要
射电星系根据射电形态可以分为FRⅠ和FRⅡ两类,而根据其光学光谱特征可以分为低激发和高激发射电星系。它们在观测上表现出不同,其原因并不清楚,部分原因是喷流与周围介质的相互作用导致的,也可能是因为FR Ⅰ和FR Ⅱ的中央引擎吸积模式不同导致的。为了检验这些源是否存在尘埃环,用CLOUDY程序模拟3C 288射电源的光致电离模型,发现理论得到的电离光度远大于实际观测到的光学核光度,这说明在3C 288中确实存在遮挡效应。为了进一步检验这个结论,又根据尘埃消光来验证高喷流射电功率星系中的遮挡效应是尘埃环造成的。
Radio galaxies are classified as FR Ⅰ or FR Ⅱ sources according to their radio morphology, but separated into high excitation galaxies（HEG） and low excitation galaxies（LEG） according to their spectroscopic properties. So far the origin of FR Ⅰ/FR Ⅱ classilication is not clear. There are different interpretations for the FR dichotomy, such as, the interaction of the jet with the ambient medium or the intrinsic nuclei properties of accretion.Cao and Rawlings（2004） analyzed the optical and radio properties of a sample of 3CR FR Ⅰ radio galaxies and found that the jet power for more than one-third of the sources in the sample is greater than the maximal jet power extraced from a rapid spinning black hole with ADAF accretion disk. They argued that a significant fraction, at least for the high-jet-power sources, of 3CR FRⅠ radio galaxies have standard thin discs, but their optical core and broad line regions can be hidden by torus. In order to examine the existence of torus in the high-jet power sources, we carry out photoionization model calculations for the radio galaxy 3C 288 using CLOUDY. We find that the theoretical ionizing luminosity is more than the observed optical core luminosity, as well as the [O III] luminosity. We conclude that there is indeed obscuring torus in 3C 288.
出处
《天文学进展》
CSCD
北大核心
2017年第1期119-126,共8页
Progress In Astronomy
基金
国家自然科学基金(11233006)
