Echography of the Early Universe by Observing Primoridal Molecules

F. Melchiorri, B. Melchiorri
Dept. of Physics of Rome University

P. Encrenaz, R. Maoli, M. Signore
DEMIRM, Observatoire de Paris

In the range of redshifts 1000 > z > 10 the matter in the Universe is expected to be neutral and cold: high density regions characterize the loci of galaxy formation . These conditions are ideal for molecular formation. The interaction between CBR photons and molecules (resonant scattering) may be the most important signature in the millimetric and submillimetric region of the spectrum. We discuss the role of LiH as a tracer of high density regions in primordial structures and the possibility of detecting it toward primordial galaxies by high spatial resolution observations of the redshifted LiH lines.

Abstract submitted for Science with the Atacama Large Millimeter Array, 6 - 8 October 1999, Washington, D.C.