Fall 2006 ASTR 2030 Homepage
The Lyman alpha forest
The Lyman alpha line is the strongest spectral line of hydrogen.
In the laboratory it is an ultraviolet line;
in quasars the Lyman alpha line is redshifted into the visible or even infrared.
Quasars typically emit strong Lyman alpha.
Blueward of the emission line is a forest of Lyman alpha absorption lines,
produced by the cosmic web of hydrogen gas along the line of sight
between us and the quasar.
High redshift quasars
Quasars were more common when the Universe was younger
Fall 2006 ASTR 2030 Homepage
Updated 2006 Aug 28
