探讨了脉泽(Maser:Microwave amplification by stimulated emission of radiation)的产生机理,根据它产生区域和形成机制的不同,对脉泽进行了分类.给出了如何利用观测资料来确定脉泽寄主星系的距离和中央黑洞质量的方法,并以经典盘脉泽源NGC4258为例进行了计算,得到星系距离D=7.2±0.5Mpc和中央黑洞质量M=(3.9±0.3)×10^7Mn.
The producing principle of maser was discussed (Maser: Microwave amplification by stimulated emission of radiation). According to the different producing regions and mechanisms, masers were classified into the different types, and the method was put forward to calculate the distance of maser host galaxy and the mass of the central black hole, using the available observed data of the disk maser source. For the archetypal disk maser source NGC4258, the distance of maser host galaxy D = 7.2 ±0.5 Mpc, and the mass of the central black hole M = (3.9 ± 0.3) ×10^7M were obtained.