Are Young Galaxies Visible?
Abstract
The purpose of this paper is to assess the general possibility of observing distant, newly formed galaxies. To this end a simple model of galaxy formation is introduced. According to the model galaxies should go through a phase of high luminosity in early stages of their evolution. The estimated luminosity for a galaxy resembling our own is 3 X 1046 ergs/sec, roughly 700 times higher than the present luminosity. The bright phase would occur at an epoch of about 1.5 X 108 years, corresponding to a redshift between 10 and 30, depending on the cosmological model assumed. The possibility of detecting individual young galaxies against the background of the night sky is discussed. Although the young galaxies would be numerous and would have sufficiently large angular diameters to be easily resolved, most of the radiation from the young galaxies would arrive at wavelengths of 1-3 where detection is difficult. However, it seems possible that the Lyman-a line might be detected if it is a strong feature of the spectra of young galaxies. It is also shown how such an experiment might help us to distinguish between various cosmological models.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1967
- DOI:
- 10.1086/149079
- Bibcode:
- 1967ApJ...147..868P