[mmaimcal] 2.735*(1+z)

[Harvey Liszt]

For laughs, here is what happens to Tr (the brightness of CO lines 
above the local CMB) solely as a function of z. That is, a self-consistent 
model of a local galactic dark cloud with total H column density
2*NH2 = 1e22 cm^-2 and n(H2) = 1250/cc, heated and cooled by all the 
standard local heating and cooling processes, is put at different
z where T_CMB = 2.735*(1+z).

So the balance shifts toward higher J-lines but at the expense of
a weakening of all of them.  Of course the amount of energy coming
out varies as something like j**3 x Tr.

             Tr			    Tex
z    (1-0) (2-1)  (3-2)     (1-0)  (2-1)  (3-2)
------------------------------------------------
0     4.89  3.66   2.35      8.19   8.18   8.00
1     3.63  3.13   2.42      9.29   9.27   9.18
2     2.85  2.60   2.24     11.14  11.11  11.07
3     2.42  2.28   2.06     13.40  13.38  13.35
4     2.07  1.99   1.84     15.77  15.76  15.72

regards, Harvey