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.

The Potential Function for Double Square-Well Model and Its Application to Calculation of the Second Virial Coefficient

In the present paper,the mechanism of molecular aggregation and the character of potential function for square-well model have been investigated with the principle of molecular thermodynamics,leading to the potential function for double square-well(DSW) model,In addition,the equation of second virial coefficient for DSW model is derived from the statistical mechanics method.The above equation obtained has been verified by tests and the test results are excellent.It is concluded that this equation can well represent the behaviour of fluid molecules.