We present a study of the star-forming properties of a stellar mass-selected sample of galaxies in the GOODS NICMOS Survey ( GNS ) , based on deep Hubble Space Telescope imaging of the GOODS North and South fields .
Using a stellar mass selected sample , combined with HST/ACS and Spitzer data to measure both UV and infrared derived star formation rates , we investigate the star forming properties of a complete sample of \sim 1300 galaxies down to log M _ { * } = 9.5 at redshifts 1.5 < z < 3 .
Eight percent of the sample is made up of massive galaxies with M _ { * } \geq 10 ^ { 11 } \mathrm { M _ { \odot } } .
We derive optical colours , dust extinctions , and ultraviolet and infrared star formation rates ( SFR ) to determine how the star formation rate changes as a function of both stellar mass and time .
Our results show that SFR increases at higher stellar mass such that massive galaxies nearly double their stellar mass from star formation alone over the redshift range studied , but the average value of SFR for a given stellar mass remains constant over this \sim 2 Gyr period .
Furthermore , we find no strong evolution in the SFR for our sample as a function of mass over our redshift range of interest , in particular we do not find a decline in the SFR among massive galaxies , as is seen at z < 1 .
The most massive galaxies in our sample ( log M _ { * } \geq 11 ) have high average star formation rates with values , SFR _ { UV,corr } = 103 \pm 75 ~ { } \mathrm { M _ { \odot } } ~ { } yr ^ { -1 } , yet exhibit red rest-frame ( U - B ) colours at all redshifts .
We conclude that the majority of these red high-redshift massive galaxies are red due to dust extinction .
We find that A _ { 2800 } increases with stellar mass , and show that between 45 % and 85 % of massive galaxies harbour dusty star formation .
These results show that even just a few Gyr after the first galaxies appear , there are strong relations between the global physical properties of galaxies , driven by stellar mass or another underlying feature of galaxies strongly related to the stellar mass .