天体H_2O脉泽的时变

The Time Variation of Celestial H_2O Maser

本文评述了天体H_2O脉泽的时变。内容包括(1)星际H_2O脉泽的时变:(ⅰ)星际H_2O脉泽的时变与星际H_2O脉泽的生成区域的物理化学特性有密切关系。(ⅱ)星际H_2O脉泽的时变分为典型的三类:独立型、相关型和互补型。(ⅲ)星际H_2O脉泽时变的时标可以分为短时标和长时标两种。特别是星际H_2O脉泽的短时标时变可以提供一种研究脉泽抽运机制的方法;(2)恒星H_2O脉泽的时变:(ⅰ)恒星H_2O脉泽一般处在恒星拱星包层中,离恒星中心大约为10倍恒星半径处。(ⅱ)恒星H_2O脉泽时变可分为两类;一类恒星H_2O脉泽谱征流量有明显的周期性。另一类,其恒星是一颗半规则变星;它的恒星H_2O脉泽谱征流量通常有两个峰。这两个峰的相对强度往往会发生变化,并且在通常情况下不是独立变化。(ⅲ)恒星H_2O脉泽时变机制的理论主要有两种:第一种是由于恒星的近红外抽运机制所引起的。第二种是包层中气体分子的碰撞抽运机制所引起的。

The time variations of both interstellar H2O maser and stellar H2O maser are reviewed in this paper.For time variations of interstellar H2O maser, they are related to physical and chemical characterics of its forming regions and divided into three types: independent-type, relative-type as well as complement each other-type. The time scales of the time variation of the interstellar maser are divided into two kinds.- short and long, and, especially, the former may provide a way to study maser pumping mechanism.In general, stellar H2O maser is in stellar circumstellar envelope, which is about 10 stellar radii far from the stellar centre. The time variations of stellar H2O maser are divided into two kirtds: 1. spectra flu.x of stellar H2O maser contains the obvious periodicity, 2. its star is a semiregular variable and the spectra flux of the stellar H2O maser contains two peaks, which relative intensity often changes indepently. The theories of the time variation mechanism of the stellar H2O contain the stellar near-infrared pumping mechanism and collisional pumping mechanism of gas molecules in envelope