We study the global scaling-laws of 51 compact field galaxies with redshifts z \sim 0.2 - 1.3 and apparent magnitudes I _ { 814 } < 23.74 in the flanking fields of the Hubble Deep Field .
Roughly 60 % of the 45 compact emission-line galaxies have sizes , surface brightnesses , luminosities , velocity widths , excitations , star formation rates ( SFR ) , and mass-to-light ratios characteristic of young star-forming HII galaxies .
The remaining 40 % form a more heterogeneous class of evolved starbursts , similar to local disk starburst galaxies .
Without additional star formation , HII-like distant compacts will most likely fade to resemble today ’ s spheroidal galaxies such as NGC 205 .
Our sample implies a lower limit for the global comoving SFR density of \sim 0.004 M _ { \odot } yr ^ { -1 } Mpc ^ { -3 } at z = 0.55 , and \sim 0.008 M _ { \odot } yr ^ { -1 } Mpc ^ { -3 } at z = 0.85 .
These values , when compared to a similar sample of local galaxies , support a history of the universe in which the SFR density declines by a factor \sim 10 from z = 1 to today .
From the comparison with the SFR densities derived from previous data sets , we conclude that compact emission-line galaxies , though only \sim 20 % of the general field population , may contribute as much as \sim 45 % to the global SFR of the universe at 0.4 < z < 1 .