FIGURE 2.6 Top: Schematic of the evolution from left to right of an inflationary universe to recombination to reionization and first star/galaxy formation to today’s Earth-bound telescopes. Overlaid in tiles are predicted 21-cm signals from the Murchison Widefield Array. SOURCE: S. Furlanetto, University of California, Los Angeles; J. Lazio, JPL; and C. Lonsdale, MIT-Haystack. Bottom: The same signals detected at 150 MHz in an all-sky map from the Precision Array to Probe the Epoch of Reionization. SOURCE: A.R. Parsons, D.C. Backer, R.F. Bradley, J.E. Aguirre, E.E. Benoit, C.L. Carilli, G.S. Foster, N.E. Gugliucci, D. Herne, D.C. Jacobs, M.J. Lynch, et al., The precision array for probing the epoch of re-ionization: Eight station results, Astronomical Journal 139(4):1468-1480, 2010.
holes and quasars at very great distances. Although the “first stars” are most likely too faint to observe individually, they should form in the collapsing clumps of gas that are the small building blocks of future galaxies like our Milky Way. ALMA and the EVLA will detect and conduct studies of many of these protogalaxies. JWST should be able to image them as well, while the proposed next generation of giant ground-based optical-infrared telescopes would investigate these first objects in