Table 1: Methanol maser transitions - maser class, frequencies, lower state energies, line strengths, and laboratory and astronomical references.

Classa		 Transition, Jk=b Frequency (MHz)c  $E^d_\ell$ (cm-1)  $S\mu^2$ (D2) Laboratory ref.e Astronomical ref.f

I?g		 $1_1\to1_1A^{\mp}$ 834.267(2)h 11.705 1.2129 Radford 1972 Ball et al. (1970)
I?g $3_{1}\to3_{1}A^{\mp}$ 5005.32079(20)h 19.703 00.4693 HD73 Robinson et al. (1973)
II $5_{1}\to6_{0}A^{+}$ 6668.5192(8) 33.876 5.0768 BR95 Menten (1991)
I $9_{-1}\to8_{-2}E$ 9936.202(4) 76.102 2.7769 BR95 Slysh et al. (1993)
II $2_{0}\to3_{-1}E$ 12 178.597(4) 13.556 1.9848 BR95 Batrla et al. (1987)
II $2_{1}\to3_{0}E$ 19 967.3961(2) 18.803 00.9244 M 85 Wilson et al. (1985)
II $9_{2}\to10_{1}A^{+}$ 23 121.0242(5) 98.053 3.1467 M 85 Wilson et al. (1984)
I $3_{2}\to3_{1 }E$ 24 928.707(7) 24.310 2.8073 This work Barrett et al. (1975)
I $4_{2}\to4_{1}E$ 24 933.468(2) 30.764 3.9283 Gaines et al. (1974) Barrett et al. (1971
I $2_{2}\to2_{1}E$ 24 934.382(5) 19.469 1.5948 Gaines et al. (1974) Barrett et al. (1975)
I $5_{2}\to5_{1}E$ 24 959.0789(4) 38.833 5.0264 M 85 Barrett et al. (1971)
I $6_{2}\to6_{1}E$ 25 018.1225(4) 48.514 6.1287 M 85 Barrett et al. (1971)
I $7_{2}\to7_{1}E$ 25 124.8719(4) 59.809 7.2483 M 85 Barrett et al. (1971)
I $8_{2}\to8_{1}E$ 25 294.4165(2) 72.717 8.3910 M 85 Barrett et al. (1971)
I $9_{2}\to9_{1}E$ 25 541.3979(4) 87.239 9.5570 M 85 Menten et al. (1986)
I $10_{2}\to10_{1}E$ 25 878.2661(4) 103.373 10.7398 M 85 Matsakis et al. (1980)
I $12_{2}\to12_{1}E$ 26 847.233(50) 140.478 13.0919 T95 Wilson et al. (1996)
I $13_{2}\to13_{1}E$ 27 472.531(30) 161.449 14.2057 T95 Wilson et al. (1996)
I $14_{2}\to14_{1}E$ 28 169.462(30) 184.032 15.2244 T95 Wilson et al. (1996)
I $15_{2}\to15_{1}E$ 28 905.812(30) 208.226 16.0977 T95 Wilson et al. (1996)
II $8_{2}\to9_{1}A^{-}$ 28 969.942(50) 83.319 3.0236 T95 Wilson et al. 1993
I $16_{2}\to16_{1}E$ 29 636.936(10) 234.031 16.7716 T95 Wilson et al. (1996)
I $17_{2}\to17_{1}E$ 30 308.034(10) 261.445 17.1961 T95 Wilson et al. (1996)
I $4_{-1}\to3_{0}E$ 36 169.265(30) 18.803 2.5184 T95 Morimoto et al. (1985)$^\star$
II $7_{-2}\to8_{-1}E$ 37 703.700(30) 61.930 2.4051 T95 Haschick et al. (1989)
II $6_{2}\to5_{3}A^{+}$ 38 293.268(50) 58.813 00.9488 T95 Haschick et al. (1989)
II $6_{2}\to5_{3}A^{-}$ 38 452.677(50) 58.813 00.9495 T95 Haschick et al. (1989)
I $7_{0}\to6_{1}A^{+}$ 44 069.410(10) 43.694 6.1380 T95 Morimoto et al. (1985)
I $5_{-1}\to4_{0}E$ 84 521.169(10) 25.254 3.0830 This work Batrla & Menten (1988)$^\star$
II $7_{2}\to6_{3}A^{-}$ 86 615.600(5) 68.493 1.3578 This work Sutton et al. (2001)$^\star$
II $7_{2}\to6_{3}A^{+}$ 86 902.949(5) 68.493 1.3596 This work Sutton et al. (2001)$^\star$
I $8_{0}\to7_{1}A^+$ 95 169.463(10) 54.888 7.2211 This work Plambeck & Wright (1988)$^\star$
I $11_{-1}\to10_{-2}E$ 104 300.414(7) 106.779 3.4141 This work Voronkov et al. (2004)$^\star$
II $3_{1}\to4_{0}A^{+}$ 107 013.803(5) 16.134 3.0088 This work Val'tts et al. 1995a$^\star$
II $0_{0}\to1_{-1}E$ 108 893.963(7) 5.490 00.9784 This work Val'tts et al. (1999)$^\star$
I $6_{-1}\to5_{0}E$ 132 890.692(10) 33.316 3.6871 T95 Slysh et al. (1997)$^\star$
I $9_{0}\to8_{1}A^{+}$ 146 618.794(50) 67.679 8.3288 T95 Menten (1991b)
II $8_{0}\to8_{-1}E$ 156 488.868(10) 61.930 6.7830 T95 Slysh et al. (1995a)$^\star$
II $2_{1}\to3_{0}A^{+}$ 156 602.413(10) 9.681 1.9963 T95 Slysh et al. 1995a$^\star$
II $7_{0}\to7_{-1}E$ 156 828.533(10) 49.035 6.2749 T95 Slysh et al. (1995a)$^\star$
II $6_{0}\to6_{-1}E$ 157 048.625(10) 37.749 5.6636 T95 Slysh et al. (1995a)$^\star$
II $5_{0}\to5_{-1}E$ 157 179.017(10) 28.073 4.9589 T95 Slysh et al. (1995a)$^\star$
II $4_{0}\to4_{-1}E$ 157 246.056(10) 20.009 4.1725 T95 Slysh et al. (1995a)$^\star$
II $1_{0}\to1_{-1}E$ 157 270.851(10) 5.490 1.4611 T95 Slysh et al. (1995a)$^\star$
II $3_{0}\to3_{-1}E$ 157 272.369(10) 13.556 3.3178 T95 Slysh et al. (1995a)$^\star$
II $2_{0}\to2_{-1}E$ 157 276.058(10) 8.717 2.4090 T95 Slysh et al. (1995a)$^\star$
I $8_{-1}\to7_{0}E$ 229 758.760(50) 54.266 5.0473 Sastry et al. (1985 Slysh et al. (2002)$^\star$
a Gives the maser type. Interstellar methanol masers are either class I or to II; see text and Menten (1991a,b). b The parity of A symmetry transitions is given as superscript. If the parities of the upper (left) and lower (right) state differ, the parities are given as upper and lower superscript, respectively. c Numbers in parentheses denote the measurement uncertainties in units of the least significant figures. d Lower state level energies are all relative to the ground-state (0+0) level of the A-symmetry species. The E-type ground state (1-1) level is at a 5.490 cm-1 higher energy. e HD73 stands for Heuvel & Dymanus (1973); BR95 for Breckenridge & Kukolich (1995), M 85 for Mehrotra et al. (1985), and T95 for Tsunekawa et al. (1995). f Only the first reference reporting maser emission in this line is given. An asterisk means that this line was earlier detected in thermal emission or absorption. See Lovas (2004) for relevant references. g See Sect. 4.3. for a discussion of these lines. h The 1H hyperfine splitting has been resolved to some extent in the laboratory. For the  $J = 1 \to 1$ transition, four components, spread over 19.4 km s-1, have been observed. The frequency in the table is the one of the strongest component; the intensity weighted average is 1 kHz lower. For the  $J = 3 \to 3$ transition, two components, split by 0.19 km s-1, have been observed.

Source LaTeX | All tables | In the text