The peculiar motion of the proto-objects relative to the CBR causes one new mechanism for the formation of SSF's: decay of the high energy photons to some new ones. In this case the number of new photons at low frequency becomes equal to the number of the photons at high frequency, which are much more abundant. This process leads to the effective enhancement of the SSF in the centimeter and decimeter wavelength region by a factor of about 1000. It provides us with the possibility of searching for proto-objects at z = 100-300 with the primordial abundance of the chemical elements at the level which is predicted by a pure Big Bang model.
These objects should look like extended diffused clouds with the emission in narrow lines, corresponding to the rotational transitions in these molecules. The width of these lines depends on the size of the proto-object and can be about 1% for standard objects in our Universe. But the most probable wavelength (and corresponding redshift) interval, where each molecule can be seen is not very broad (Fig. 2). So it is possible to investigate several different epochs of the early Universe by observations of the appropriate molecule. For some other possible molecules (like H2 He , 3 He4 He , H2 Li ,...) needs special calculations of the factor , using the method by Dubrovich and Lipovka (1995).
The observations at a level of , and angular scales of about 1 with the frequency resolution , can provide us with non-trivial information about the early Universe. Here we have described the process, which is rather model-independent and we have not considered any chemical element heavier than Li. So, the value of all fluctuations estimated here must be considered as the lower limits to the amplitude of SSF's.
© European Southern Observatory (ESO) 1997
Online publication: May 26, 1998