We present a multi-wavelength analysis of galaxies selected at 450 and 850 \micron from the deepest SCUBA-2 observations in the Extended Groth Strip ( EGS ) field , which have an average depth of \sigma _ { 450 } = 1.9 and \sigma _ { 850 } = 0.46 mJy beam ^ { -1 } over \sim 70 arcmin ^ { 2 } .
The final sample comprises 95 sources : 56 ( 59 % ) are detected at both wavelengths , 31 ( 33 % ) are detected only at 850 \micron , and 8 ( 8 % ) are detected only at 450 \micron .
We identify counterparts for 75 % of the whole sample .
The redshift distributions of the 450 and 850 \micron samples peak at different redshifts with median values of \bar { z } = 1.66 \pm 0.18 and \bar { z } = 2.30 \pm 0.20 , respectively .
However , the two populations have similar IR luminosities , SFRs , and stellar masses , with mean values of 1.5 \pm 0.2 \times 10 ^ { 12 } L _ { \odot } , 150 \pm 20 M _ { \odot } / { yr } , and 9.0 \pm 0.6 \times 10 ^ { 10 } M _ { \odot } , respectively .
This places most of our sources ( \gtrsim 85 % ) on the high-mass end of the ‘ main-sequence ’ of star-forming galaxies .
Exploring the IR excess vs UV-slope ( IRX- \beta ) relation we find that the most luminous galaxies are consistent with the Meurer law , while the less luminous galaxies lie below this relation .
Using the results of a two-dimensional modelling of the HST H _ { 160 } -band imaging , we derive a median Sérsic index of n = 1.4 ^ { +0.3 } _ { -0.1 } and a median half-light radius of r _ { 1 / 2 } = 4.8 \pm 0.4 kpc .
Based on a visual-like classification in the same band , we find that the dominant component for most of the galaxies at all redshifts is a disk-like structure , although there is a transition from irregular disks to disks with a spheroidal component at z \sim 1.4 , which morphologically supports the scenario of SMGs as progenitors of massive elliptical galaxies .