Combined spectrum of 13 GDDS galaxies

Combined spectrum of 13 GDDS galaxies with ISM absorption lines (lower spectrum). Absorption features are marked with dotted lines. As a reference, a composite spectrum (shown in black) of 14 local starburst dwarf galaxies observed with HST/FOS is shown (top spectrum in red, courtesy of C. Tremonti). The dotted curve at the bottom indicates the level of the noise in the GDDS combined spectrum.