\documentstyle{article}
\begin{document}

\begin{table}%t1
 \caption{\label{tab:mlines}Methanol maser transitions -- maser class, frequencies,
lower state energies, line strengths, and laboratory and
astronomical references.}
 %\centerline
{ \begin{tabular}{rllllll}
 \hline \hline   
\noalign{\smallskip}                               
Class$^a$& Transition,~$J_k{=}^b$& Frequency (MHz)$^c$ & ~$E^d_\ell$ (cm$^{-1}$) &~$S\mu^2$ (D$^2$)
& Laboratory ref.$^e$ & Astronomical ref.$^f$\\
\noalign{\smallskip}                               
\hline 
\noalign{\smallskip}
I?$^g$ &\d$1_1\to1_1A^{\mp}$ &\d\d\d834.267(2)$^h$ & \d11.705 & \d1.2129 & Radford (1972)          & Ball et~al. (1970)\\
I?$^g$ &\d$3_{1}\to3_{1}A^{\mp}$ & \d\d5005.32079(20)$^h$ & \d19.703 &\d0.4693 & HD73 & Robinson et~al. (1973)\\
II&\d$5_{1}\to6_{0}A^{+}$   &\d\d6668.5192(8)  & \d33.876 & \d5.0768 & BR95                & Menten (1991)\\
 I&\d$9_{-1}\to8_{-2}E$     &\d\d9936.202(4)   & \d76.102 & \d2.7769 & BR95                & Slysh et~al. (1993)\\
II&\d$2_{0}\to3_{-1}E$      &\d12~178.597(4)    & \d13.556 & \d1.9848 & BR95                & Batrla et~al. (1987)\\
II&\d$2_{1}\to3_{0}E$       &\d19~967.3961(2)   & \d18.803 & \d0.9244 & M~85                 & Wilson et~al. (1985)\\
II&\d$9_{2}\to10_{1}A^{+}$  &\d23~121.0242(5)   & \d98.053 & \d3.1467 & M~85                 & Wilson et~al. (1984)\\
 I&\d$3_{2}\to3_{1 }E$      &\d24~928.707(7)    & \d24.310 & \d2.8073 & This work           & Barrett et~al. (1975)\\
 I&\d$4_{2}\to4_{1}E$       &\d24~933.468(2)    & \d30.764 & \d3.9283 & Gaines et~al. (1974)  & Barrett et~al. (1971}  \\
 I&\d$2_{2}\to2_{1}E$       &\d24~934.382(5)    & \d19.469 & \d1.5948 & Gaines et~al. (1974)  & Barrett et~al. (1975)\\
 I&\d$5_{2}\to5_{1}E$       &\d24~959.0789(4)   & \d38.833 & \d5.0264 & M~85                 & Barrett et~al. (1971)\\
 I&\d$6_{2}\to6_{1}E$       &\d25~018.1225(4)   & \d48.514 & \d6.1287 & M~85                 & Barrett et~al. (1971)\\
 I&\d$7_{2}\to7_{1}E$       &\d25~124.8719(4)   & \d59.809 & \d7.2483 & M~85                 & Barrett et~al. (1971)\\
 I&\d$8_{2}\to8_{1}E$       &\d25~294.4165(2)   & \d72.717 & \d8.3910 & M~85                 & Barrett et~al. (1971)\\
 I&\d$9_{2}\to9_{1}E$       &\d25~541.3979(4)   & \d87.239 & \d9.5570 & M~85                 & Menten et~al. (1986)\\
 I&$10_{2}\to10_{1}E$       &\d25~878.2661(4)   &  103.373 &  10.7398 & M~85                 & Matsakis et~al. (1980)\\
 I&$12_{2}\to12_{1}E$       &\d26~847.233(50)   &  140.478 &  13.0919 & T95                 & Wilson et~al. (1996)\\
 I&$13_{2}\to13_{1}E$       &\d27~472.531(30)   &  161.449 &  14.2057 & T95                 & Wilson et~al. (1996)\\
 I&$14_{2}\to14_{1}E$       &\d28~169.462(30)   &  184.032 &  15.2244 & T95                 & Wilson et~al. (1996)\\
 I&$15_{2}\to15_{1}E$       &\d28~905.812(30)   &  208.226 &  16.0977 & T95                 & Wilson et~al. (1996)\\
II&\d$8_{2}\to9_{1}A^{-}$   &\d28~969.942(50)   & \d83.319 & \d3.0236 & T95                 & Wilson et~al. 1993 \\
 I&$16_{2}\to16_{1}E$       &\d29~636.936(10)   &  234.031 &  16.7716 & T95                 & Wilson et~al. (1996)\\
 I&$17_{2}\to17_{1}E$       &\d30~308.034(10)   &  261.445 &  17.1961 & T95                 & Wilson et~al. (1996)\\
 I&\d$4_{-1}\to3_{0}E$      &\d36~169.265(30)   & \d18.803 & \d2.5184 & T95                 & Morimoto et~al. (1985)$^\star$ \\
II&\d$7_{-2}\to8_{-1}E$     &\d37~703.700(30)   & \d61.930 & \d2.4051 & T95                 & Haschick et~al. (1989)\\
II&\d$6_{2}\to5_{3}A^{+}$   &\d38~293.268(50)   & \d58.813 & \d0.9488 & T95                 & Haschick et~al. (1989)\\
II&\d$6_{2}\to5_{3}A^{-}$   &\d38~452.677(50)   & \d58.813 & \d0.9495 & T95                 & Haschick et~al. (1989)\\
 I&\d$7_{0}\to6_{1}A^{+}$   &\d44~069.410(10)   & \d43.694 & \d6.1380 & T95                 & Morimoto et~al. (1985)\\
 I&\d$5_{-1}\to4_{0}E$      &\d84~521.169(10)   & \d25.254 & \d3.0830 & This work           & Batrla \& Menten (1988)$^\star$ \\
II&\d$7_{2}\to6_{3}A^{-}$   &\d86~615.600(5)    & \d68.493 & \d1.3578 & This work           & Sutton et~al. (2001)$^\star$\\
II&\d$7_{2}\to6_{3}A^{+}$   &\d86~902.949(5)    & \d68.493 & \d1.3596 & This work           & Sutton et~al. (2001)$^\star$\\
 I&\d$8_{0}\to7_{1}A^{+}$   &\d95~169.463(10)   & \d54.888 & \d7.2211 & This work           & Plambeck \&\ Wright (1988)$^\star$\\
 I&$11_{-1}\to10_{-2}E$     & 104~300.414(7)    &  106.779 & \d3.4141 & This work          & Voronkov et~al. (2004)$^\star$\\
II&\d$3_{1}\to4_{0}A^{+}$   & 107~013.803(5)    & \d16.134 & \d3.0088 & This work           & Val'tts et~al. 1995a$^\star$\\
II&\d$0_{0}\to1_{-1}E$      & 108~893.963(7)    &\d\d5.490 & \d0.9784 & This work           & Val'tts et~al. (1999)$^\star$\\
 I&\d$6_{-1}\to5_{0}E$      & 132~890.692(10)   & \d33.316 & \d3.6871 & T95                 & Slysh et~al. (1997)$^\star$\\
I&\d$9_{0}\to8_{1}A^{+}$    & 146~618.794(50)   & \d67.679 & \d8.3288 & T95                 & Menten (1991b)     \\
II&\d$8_{0}\to8_{-1}E$      & 156~488.868(10)   & \d61.930 & \d6.7830 & T95                 & Slysh et~al. (1995a)$^\star$\\
II&\d$2_{1}\to3_{0}A^{+}$   & 156~602.413(10)   &\d\d9.681 & \d1.9963 & T95                 & Slysh et~al. 1995a$^\star$\\
II&\d$7_{0}\to7_{-1}E$      & 156~828.533(10)   & \d49.035 & \d6.2749 & T95                 & Slysh et~al. (1995a)$^\star$ \\
II&\d$6_{0}\to6_{-1}E$      & 157~048.625(10)   & \d37.749 & \d5.6636 & T95                 & Slysh et~al. (1995a)$^\star$\\
II&\d$5_{0}\to5_{-1}E$      & 157~179.017(10)   & \d28.073 & \d4.9589 & T95                 & Slysh et~al. (1995a)$^\star$\\
II&\d$4_{0}\to4_{-1}E$      & 157~246.056(10)   & \d20.009 & \d4.1725 & T95                 & Slysh et~al. (1995a)$^\star$\\
II&\d$1_{0}\to1_{-1}E$      & 157~270.851(10)   &\d\d5.490 & \d1.4611 & T95                 & Slysh et~al. (1995a)$^\star$\\
II&\d$3_{0}\to3_{-1}E$      & 157~272.369(10)   & \d13.556 & \d3.3178 & T95                 & Slysh et~al. (1995a)$^\star$\\
II&\d$2_{0}\to2_{-1}E$      & 157~276.058(10)   &\d\d8.717 & \d2.4090 & T95                 & Slysh et~al. (1995a)$^\star$\\
 I&\d$8_{-1}\to7_{0}E$      & 229~758.760(50)   & \d54.266 & \d5.0473 & Sastry et~al. (1985}  & Slysh et~al. (2002)$^\star$\\
\noalign{\smallskip}
 \hline
 \end{tabular}
\smallskip
$^a$ 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 {\it 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 \textit{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~$^1$H 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.
\end{table}\begin{table}%T2
 \caption{\label{tab:dlines}Accurately known methanol transitions detected or potentially
   detectable in dark clouds, frequencies, lower state energies,
   line strengths, and laboratory and dark cloud references.}
 %\centerline
{
 \begin{tabular}{cllllll}
 \hline \hline   
\noalign{\smallskip}                               
Maser$^{a}$&Transition,~$J_k{=}^b$& Frequency (MHz)$^c$ &~$E_\ell^d$ (cm$^{-1}$) &~$S\mu^2$ (D$^2$)
& Laboratory ref.$^e$ & Dark cloud ref.$^f$\\
\noalign{\smallskip}                               
\hline 
\noalign{\smallskip}
I?&$1_{1}\to1_{1}A^{\mp}$&\d\d\d834.267(2)    &  11.705 & 1.2129 & Radford (1972) &\textit{Slysh et~al. (1995b)}\\
 &$2_{1}\to2_{1}A^{\mp}$ & \d\d2502.7785(10)  &  14.904 & 0.6725 & HD73         & ND \\
I?&$3_{1}\to3_{1}A^{\mp}$& \d\d5005.32079(20) &  19.703 & 0.4693 & HD73         &\textit{Kalenski{\u i} et~al. (2004)}\\
II&$2_{0}\to3_{-1}E^f$   &  \d12~178.595(3)    &  13.556 & 1.9848 & Gaines et~al. (1974) & Walmsley et~al. (1988)\\
II&$2_{1}\to3_{0}E$      &  \d19~967.3961(2)   &  18.803 & 0.9224 & M~85 \\
I&$2_{2}\to2_{1}E$       &  \d24~934.382(5)    &  19.469 & 1.5948 & Gaines et~al. (1974)\\
I&$4_{-1}\to3_{0}E$      &  \d36~169.265(30)   &  18.803 & 2.5184 & T95 \\
&$1_{0}\to0_{0}A^+$      &  \d48~372.4558(7)   & \d0.000 & 0.8086 & HD73        & Friberg et~al. (1988)\\
&$1_{0}\to0_{0}E$        &  \d48~376.892(10)   & \d9.122 & 0.8084 & T95         & \textit{Kaifu et~al. (2004)}\\
&$1_{0}\to2_{-1}E$       &  \d60~531.489(10)   & \d8.717 & 1.4742 & This work   & NO \\
&$1_{1}\to2_{0}E$        &  \d68~305.640(20)   &  13.963 & 0.4573 & This work \\
&$2_{1}\to1_{1}A^+$      &  \d95~914.309(5)    &  11.705 & 1.2141 & This work \\
&$2_{-1}\to1_{-1}E$      &  \d96~739.362(5)    & \d5.490 & 1.2133 & This work  & Friberg et~al. (1988)\\
&$2_{0}\to1_{0}A^+$      &  \d96~741.375(5)    & \d1.614 & 1.6171 & This work  & Friberg et~al. (1988)\\
&$2_{0}\to1_{0}E$        &  \d96~744.550(5)    &  10.736 & 1.6167 & This work  & Friberg et~al. (1988)\\
&$2_{1}\to1_{1}E$        &  \d96~755.511(5)    &  16.241 & 1.2443 & This work  & Menten et~al. (1988)\\
&$2_{1}\to1_{1}A^-$      &  \d97~582.804(7)    &  11.733 & 1.2141 & This work \\
II&$3_{1}\to4_{0}A^+$    &   107~013.803(5)    &  16.134 & 3.0088 & This work \\
II&$0_{0}\to1_{-1}E$     &   108~893.963(7)    & \d5.490 & 0.9784 & This work   & Turner (1998)\\
&$2_{2}\to1_{1}E$        &   121~689.975(10)   &  16.241 & 2.8297 & T95         \\
&$3_{1}\to2_{1}A^+$      &   143~865.801(10)   &  14.904 & 2.1584 & T95         \\
&$3_{0}\to2_{0}E$        &   145~093.707(10)   &  13.963 & 2.4249 & T95         \\
&$3_{-1}\to2_{-1}E$      &   145~097.370(10)   & \d8.717 & 2.1569 & T95         & Turner (1998)\\
&$3_{0}\to2_{0}A^+$      &   145~103.152(10)   & \d4.840 & 2.4257 & T95         & Turner (1998)\\
&$3_{1}\to2_{1}E$        &   145~131.855(10)   &  19.469 & 2.2119 & T95         \\
&$3_{1}\to2_{1}A^-$      &   146~368.342(50)   &  14.988 & 2.1585 & T95         \\
II&$2_{1}\to3_{0}A^+$    &   156~602.413(10)   & \d9.681 & 1.9963 & T95         \\
II&$1_{0}\to1_{-1}E$     &   157~270.851(10)   & \d5.490 & 1.4611 & T95         \\
II&$3_{0}\to3_{-1}E$     &   157~272.369(10)   &  13.556 & 3.3178 & T95         \\
II&$2_{0}\to2_{-1}E$     &   157~276.058(10)   & \d8.717 & 2.4090 & T95         \\
&$1_{1}\to1_{0}E$        &   165~050.195(10)   &  10.736 & 1.3466 & T95         \\
&$2_{1}\to2_{0}E$        &   165~061.156(10)   &  13.963 & 2.2373 & T95         \\
&$3_{1}\to3_{0}E$        &   165~099.271(10)   &  18.803 & 3.1170 & T95         \\
&$3_{2}\to2_{1}E$        &   170~060.581(10)   &  19.469 & 3.1205 & T95         & ND \\
&$4_{1}\to3_{1}A^+$      &   191~810.509(10)   &  19.703 & 3.0352 & T95         & ND \\
&$4_{0}\to3_{0}E$        &   193~415.367(10)   &  18.803 & 3.2327 & T95         & ND \\
&$4_{-1}\to3_{-1}E$      &   193~441.610(10)   &  13.556 & 3.0330 & T95         & ND \\
&$4_{0}\to3_{0}A^+$      &   193~454.361(10)   & \d9.681 & 3.2342 & T95         & ND \\
&$4_{1}\to3_{1}A^-$      &   195~146.760(10)   &  19.870 & 3.0353 & T95         & ND \\
\noalign{\smallskip} \hline
\end{tabular}}
\smallskip
For nomenclature see also notes to Table~\ref{tab:mlines}.
$^a$ I and~II mean that these lines are class~I and~II~maser
transitions, respectively, in some non-dark cloud regions (see Table~\ref{tab:mlines}).
$^f$ Only references reporting the first detection of a line in  cold
($T\approx 10$~K) dark clouds  are listed.
For non-dark cloud astronomical references to first detections,
see Lovas (2003).  "ND'' means that no astronomical
detection is reported in the latter reference; "NO'' means that
the line is not observable from the ground.
$^g$ This line appears in enhanced absorption (i.e. is over-cooled)
against the cosmological microwave background radiation.
References in italics report observations of a given
line that did not yield its detection.
\end{table}\begin{table}%T3
 \caption{\label{tab:olines}Other methanol transitions measured in the course of the
present investigation.}
 %\centerline
{
 \begin{tabular}{lllllllll}
 \hline \hline   
\noalign{\smallskip}                               
$v_t$& Transition,~$J_k{=}^b$& Frequency (MHz)$^c$ & & &~$v_t$& Transition,~$J_k=^b$& Frequency (MHz)$^c$ & \\
\noalign{\smallskip}                               
\hline 
\noalign{\smallskip}
     0 & \d$4_{3}\to5_{2}A^-$      & \d10~058.268(2)       &    & &   1 & \d$2_{-1}\to1_{-1}E$      & \d96~501.705(10)      &    \\
     0 &~$32_{2}\to32_{1}E$        & \d11~841.902(1)       & ND & &   1 & \d$2_{0}\to1_{0}A^+$      & \d96~513.675(10)      &    \\
     0 &~$31_{2}\to31_{1}E$        & \d14~407.777(1)       & ND & &   1 & \d$2_{1}\to1_{1}A^-$      & \d96~588.582(5)       &    \\
     0 &~$32_{8}\to31_{9}E$        & \d14~446.665(1)       & ND & &   0 &~$21_{6}\to22_{5}A^-$      & \d97~677.738(5)       &    \\
     0 &~$30_{2}\to30_{1}E$        & \d16~941.190(1)       & ND & &   0 &~$21_{6}\to22_{5}A^+$      & \d97~678.857(7) &    \\
     0 & \d$6_{1}\to6_{1}A^{\mp}$  & \d17~513.342(2)x      & ND & &   0 &~$15_{1}\to15_{1}A^{\mp}$  & \d99~602.078(10)      & ND \\
     0 &~$29_{2}\to29_{1}E$        & \d19~390.121(6)       & ND & &   0 & \d$9_{-2}\to9_{1}E$       &  101~737.173(20)      &    \\
     1 &~$10_{1}\to11_{2}A^+$      & \d20~970.651(1)       &    & &   0 &~$10_{-2}\to10_{1}E$       &  102~122.667(10)      &    \\
     1 &~$12_{2}\to11_{1}A^-$      & \d21~550.300(6)       &    & &   0 &~$11_{-2}\to11_{1}E$       &  102~658.046(7)       &    \\
     0 &~$28_{2}\to28_{1}E$        & \d21~708.662(5)       & ND & &   0 &~$22_{-2}\to22_{2}E$       &  102~704.298(20)      & ND \\
     0 &~$27_{2}\to27_{1}E$        & \d23~854.261(6)       & ND & &   1 &~$15_{-2}\to16_{-3}E$      &  102~957.691(7)       &    \\
     0 &~$26_{2}\to26_{1}E$        & \d25~787.125(10)      & ND & &   0 &~$12_{-2}\to12_{1}E$       &  103~381.146(5)       &    \\
     1 &~$10_{1}\to11_{2}A^-$      & \d26~120.584(10)      & ND & &   0 &~$13_{-3}\to12_{-4}E$      &  104~060.657(10)      &    \\
     0 & \d$8_{2}\to9_{1}A^+$      & \d66~947.895(20)      & ND & &   0 &~$13_{-2}\to13_{1}E$       &  104~336.562(7)       &    \\
     0 &~$11_{1}\to10_{2}A^-$      & \d76~247.283(5)       &    & &   0 &~$10_{4}\to11_{3}A^-$      &  104~354.819(5)       &    \\
     0 & \d$5_{0}\to4_{1}E$        & \d76~509.668(7)       &    & &   0 &~$10_{4}\to11_{3}A^+$      &  104~410.446(5)       &    \\
     0 &~$15_{-2}\to15_{2}E$       & \d78~254.011(20)      & ND & &   0 &~$13_{1}\to12_{2}A^+$      &  105~063.691(5)       &    \\
     0 & \d$7_{2}\to8_{1}A^-$      & \d80~993.241(7)       &    & &   0 &~$14_{-2}\to14_{1}E$       &  105~576.290(10)      &    \\
     0 &~$17_{-2}\to17_{2}E$       & \d81~318.424(20)      & ND & &   0 &~$15_{-2}\to15_{1}E$       &  107~159.820(10)      &    \\
     0 &~$18_{-2}\to18_{2}E$       & \d83~792.561(10)      & ND & &   0 &~$26_{0}\to26_{-1}E$       &  109~136.883(7)       &    \\
     0 &~$13_{-3}\to14_{-2}E$      & \d84~423.776(5)       &    & &   0 &~$16_{-2}\to16_{1}E$       &  109~153.107(10)      &    \\
     1 &~$13_{10}\to13_{11}E$      & \d84~930.946(10)      & ND & &   0 &~$23_{-2}\to23_{2}E$       &  110~060.492(20)      & ND \\
     1 &~$14_{10}\to14_{11}E$      & \d85~346.076(7)       & ND & &   0 &~$18_{0}\to17_{3}E$        &  111~254.256(20)      & U  \\
     0 & \d$6_{-2}\to7_{-1}E$      & \d85~568.084(10)      &    & &   0 & \d$7_{2}\to8_{1}A^+$      &  111~289.550(10)      &    \\
     1 &~$15_{10}\to15_{11}E$      & \d85~773.092(7)       & ND & &   0 &~$17_{-2}\to17_{1}E$       &  111~626.449(15)T     &    \\
     0 &~$19_{-2}\to19_{2}E$       & \d87~066.748(10)      & ND & &   0 &~$14_{-3}\to15_{2}E$       &  112~490.953(15)      & ND \\
     0 &~$14_{1}\to14_{1}A^{\mp}$  & \d87~241.339(10)      & ND & &   0 &~$16_{1}\to16_{1}A^{\mp}$  &  112~745.243(10)      & ND \\
     0 & \d$8_{-4}\to9_{-3}E$      & \d89~505.808(5)       &    & &   0 &~$25_{0}\to25_{-1}E$       &  113~408.094(7)       & ND \\
     0 &~$20_{-2}\to20_{2}E$       & \d91~254.686(10)      & ND & &   0 &~$18_{-2}\to18_{1}E$       &  114~650.861(5)       &    \\
     1 & \d$1_{0}\to2_{1}E$        & \d93~196.673(10)      &    & &   0 &~$19_{-3}\to20_{0}E$       &  115~800.166(20)      & ND \\
     1 &~$10_{-7}\to11_{-6}E$      & \d94~022.734(10)      & ND & &   0 &~$24_{0}\to24_{-1}E$       &  117~636.228(10)      & NO \\
     0 & \d$8_{3}\to9_{2}E$        & \d94~541.765(5)       & ND & &   1 &~$10_{2}\to9_{3}E$         &  118~156.280(10)      & NO \\
     0 &~$19_{7}\to20_{6}A$        & \d94~814.987(10)      & ND & &   1 & \d$8_{1}\to9_{2}A^+$      &  118~207.927(5)       & NO \\
     1 & \d$2_{1}\to1_{1}A^+$      & \d96~396.040(7)       &    & &   0 &~$19_{-2}\to19_{1}E$       &  118~293.492(5)       & NO \\
     0 &~$21_{-2}\to21_{2}E$       & \d96~446.619(15)      &    & &   1 &~$17_{6}\to18_{5}A$        &  118~481.011(5)       & NO \\
     1 & \d$2_{1}\to1_{1}E$        & \d96~492.152(7)       &    & &   0 &~$24_{-2}\to24_{2}E$       &  118~522.453(15)      & NO \\
     1 & \d$2_{0}\to1_{0}E$        & \d96~493.540(10)      &    & &     &                           &                      &     \\
\noalign{\smallskip}
 \hline
 \end{tabular}}
\smallskip
For nomenclature see notes to Table~\ref{tab:mlines}.
Tsunekawa et~al. (1995) give 111~626.846(30) MHz for the frequency
of the line marked with T; we suspect a typographical error,
see Sect.~4.1, where also some assignments for~$J > 30$ are discussed.
Heuvel \& Dymanus (1973) give 17~513.34127(20)~MHz for the unsplit
position of the line  marked with x.
All lines, except those marked "ND''  have been
detected in astronomical sources.
See Lovas (2004) for references to first detections.
"ND'' means that no astronomical detection is reported
in the latter reference.
"U'' means that this line is listed as unidentified in Lovas (2004).
\end{table}

\end{document}
