Redshift (IMAGE)
Caption
This figure shows the relation between redshift and the age of the universe. Redshift occurs when light shifts to longer, redder wavelengths as it travels across the ever-expanding universe. More pronounced redshift means the light has been traveling longer, from farther away; therefore the degree of redshift allows astronomers to know how far back in time they are looking. The two high-redshift galaxies in this study, shown at redshift 7-7.5, are very distant, and their light was emitted when the universe only 700 million years old. The timeline shows several major events in the history of the universe, beginning with the Big Bang and advancing through the haze of the "Dark Ages," the formation of the first stars and galaxies, and eventually arriving at the present day, with normal galaxies like our Milky Way. The yellow bars next to the two high-redshift galaxies show the time period during which most of their stars formed. These galaxies might be the first in the universe to have formed, shortly after the first stars.
Credit
Image courtesy Ivo Labbé
Usage Restrictions
None
License
Licensed content