远红外亮类星体的研究进展

远红外亮类星体是极亮红外星系中具有I型活动星系核光谱特征的天体,光学光谱研究表明它们在光学波段的辐射主要由中心活动星系核主导,其中心超大质量黑洞的质量为107~108M☉,且有超爱丁顿吸积率.与光学选类星体相比,远红外亮类星体在远红外波段存在明显的辐射超出,这可能是由其核区周围~1 kpc尺度内的星暴活动(恒星形成率约为几百M☉yr-1)加热尘埃造成.对分子气体进行观测发现远红外亮类星体的宿主星系中存在约109~1010M☉的分子气体,这些分子气体可以为黑洞和核球的增长提供"原料".几乎所有远红外亮类星体都处于富气星系并合的晚期,是极亮红外星系向光学选类星体演化的过渡天体.

Research progress on low-redshift IR QSOs

Infrared ultra-luminous quasi-stellar objects（IR QSOs）are ultra-luminous infrared galaxies（ULIRGs） with type Ⅰ active galactic nucleus（AGN）spectral characteristics in the optical.The optical spectra show that in IR QSOs AGN activities are responsible for the optical emission.IR QSOs have supermassive black holes with 107-108 M☉ and super Eddington acctetion rate.Compared with classical optically selected QSOs,IR QSOs show evident far-IR emission excess.This may arise from dust heated by starburst（the star formation rate is about hundreds of M☉per year） within 1 kpc scale around the nucleus.CO molecular gas observations reveal there is large gas reservoirs of a few times 109-1010 M☉ in the host galaxies of IR QSOs,which can provide the fuel to sustain the growth of black hole and galactic bulge.Almost all the IR QSOs are in the later period of galaxies merging and they are the transition objects from starburst dominated ULIRGs to classical QSOs.