A New Pumping Mechanism for A Series of Class II Methanol Masers in the J 0 - J -1 E Transitions |
| |
Authors: | Hanping Liu Jin Sun Weihai Fang |
| |
Affiliation: | (1) Department of Physics, Beijing Normal University, China;(2) Department of Astronomy, Beijing Normal University, China;(3) Chinese Academy of science-Peking University Joint Beijing Astrophysics Center, China;(4) Department of Chemistry, Beijing Normal University, China |
| |
Abstract: | A new pumping mechanism – methanol masers without population inversion is presented in this paper. It can be used to explain the formation of a series of J 0 → J -1 E methanol masers, while the 21 → 30 A + methanol masers are regarded as a driving coherent micrwave field. In the new mechanism, the intensities of J 0 - J -1 E methanol masers are increased with the decreasing transition frequencies (or with rotational number J, approximately). These results agree with Slysh et al. (1995) and Slysh et al. (1999) J ≤ 5 observations for G3345.01+1.79 and W48, in which both J 0 → J -1 E and 21 → 30 A + methanol masers are detected coincidentally. Other astronomical conditions, such as magnetic field, 21 → 30 A + coherent radition, incoherent pumping rate by thermal radition and so on are also discussed. The new mechanism can operate as a complement to other ordinary maser pumping mechanisms for some class II methonal maser sources. This revised version was published online in July 2006 with corrections to the Cover Date. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|