Other
Scientific paper
May 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997acasn..38..129l&link_type=abstract
Acta Astronomica Sinica, vol. 38, p. 129
Other
Interstellar Masers, Methyl Alcohol, H Ii Regions, Stimulated Emission, Coherent Radiation, Population Inversion, Microwave Frequencies
Scientific paper
We have observed that the 6.7GHz and 12.2GHz methanol masers of class II sources are associated with each other and coexist near the ultra-compact HII regions. Therefore, we suggest a new excitation mechanism: methanol masers without population inversion. Let us suppose that there is a three-level system and that the upper level is pumped by weak incoherent radiation. The upper level consists of two sublevels, b and c, which are strongly driven by a coherent microwave field. Thus, the microwave field will cause the Rabi oscillation between levels b and c. As a result, based on the quantum interference effect, the spontaneous emission from upper level to lower levels will be restrained, but the stimulated emission between the same levels is not affected much. So there will still be net coherent radiation amplification even though there is no population inversion. Then the maser emission between upper and lower levels appears. This mechanism can be applied to interpret the formation of the intense 6.7GHz methanol maser, while the 12.2GHz methanol maser is regarded as the coherent microwave field mentioned above. In this paper we demonstrate that the new mechanism is compatible with astronomical conditions and does not contradict other mechanisms.
Liu Han-Ping
Sun Jin
No associations
LandOfFree
The excitation mechanism of 6.7GHz interstellar methanol masers does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The excitation mechanism of 6.7GHz interstellar methanol masers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The excitation mechanism of 6.7GHz interstellar methanol masers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-832070