摘要
近期, Sloan数字巡天(Sloan Digital Sky Survey, SDSS)对一个天区成功进行了反响映射观测,目的在于检验已被广泛应用的R-L关系. R为宽线区的响应权重半径, L为5100?A处的单色光度.在第1年的数据中获得了两方面结果:(1)高吸积率AGN(Active Galactic Nucleus)具有远远短于R-L关系的时间延迟,证实了丽江2.4 m望远镜反响映射观测结果;(2)一些较低吸积率的AGN也具有很短的时间延迟.较低吸积率AGN的时间延迟变短是由于黑洞反向吸积过程导致.这个结果从观测上证实了Wang等人2014年的理论预言.反向吸积黑洞的发现具有重要意义,这表明类星体中黑洞的宇宙学演化是通过随机吸积而进行的.
Recently, Sloan Digital Sky Survey successfully carried out reverberation mapping campaign for a sky area, aiming to test the R-L relation that has been widely used. R is the responsivity weighted radius of the broad line region, and L is the optical luminosity at 5100 ?A. They obtained two results from the first year of data:(1) The time lags of AGNs(Active Galactic Nuclei) with high accretion rate are much shorter than that estimated from the R-L relation, confirmed the reverberation mapping observation results of Lijiang 2.4 meter telescope.(2) Some AGNs with low accretion rate also have much shorter time lags. The time lags of the AGNs with low accretion rate are shortened because they have retrograde spins. The observation result agrees with the prediction in Wang et al. 2014. The discovery of black holes with retrograde accretion has important implications. That indicates accretion events onto black holes are inherently random and episodic.
引文
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