[Previous] | [Session 49] | [Next]
Y.C. Pei, S.M. Fall, M.G. Hauser (STScI)
We present a set of coupled equations that tie together the stellar, gaseous, chemical, and radiation constituents, all averaged over the galaxy population and viewed globally in the universe. By inputting the available data from quasar absorption line surveys, deep optical imaging surveys, and the extragalactic infrared background measurements, we obtain solutions of the cosmic histories of stars, interstellar gas, heavy elements, dust, and radiation from stars and dust in galaxies. Our solutions match remarkably well the DIRBE and FIRAS measurements of the cosmic infrared background, and are in excellent agreement with a wide variety of observational data that were not input to our models. Our studies illustrate that a wide variety of different observations of galaxies by means of quasar absorption lines, optical imaging and redshift surveys, and extragalactic background measurements can be brought together to provide a coherent picture of what the cosmic history of galaxies was like over much of the Hubble time. In particular, the process of galaxy formation may have undergone different evolutionary phases: (1) an early period of substantial inflow to assemble interstellar gas at z > 3; (2) a subsequent period of intense star formation and chemical enrichment at 1 < z < 3; and (3) a recent period of rapid decline in the gas content, star formation rate, ultraviolet and optical emissivity, and far-infrared dust emission at z < 1.
The author(s) of this abstract have provided an email address for comments about the abstract: pei@stsci.edu