Methanol 7_2-8_1a^+ Emission and Some Maser Series in Orion Kl
Author: Zeng, Q.
Source: Astrophysics and Space Science, Volume 243, Number 2, 1 February 1996 , pp. 361-369(9)
Abstract:Methanol 7_2 -8_1 A^+ is mapped for the first time in Orion KL. Analysing the observed data and solving the statistical equilibrium and radiative transfer equations, it is concluded that line series of J_2 -(J+1)_1 A^+ (J=7,8,9) is in quasi-thermal emission rather than the masers in Orion KL. The maser spots of methanol J_2 -J_1 E(J=6,7) and 8_0 -7_1 A^+ are distributed in the northeast part of the contour plot of 7_2 -8_1 A^+. The physical conditions of the regions of maser series J_0 -(J-1)_1 A^+ (J=7,8,9) are discussed. Also from the calculation results another maser series J_1 -(J-1)_2 A^- (J=10,11,12) that might coexist with maser series J_2 -J_1 E, is found. The sizes of the 2-dimension Gaussian fit plots of methanol 7_2 -8_1 A^+ and HCOOCH_3 10(0,10)-9(0,9)A are almost the same, and the main parts overlap each other.
Document Type: Regular Paper
Affiliations: Purple Mountain Observatory, Nanjing 210008, P.R. China
Publication date: February 1, 1996