We present a suite of high resolution radiation hydrodynamic simulations of a small patch ( 1 { kpc } ^ { 2 } ) of the inter-stellar medium ( ISM ) performed with Arepo-RT , with the aim to quantify the efficacy of various feedback processes like supernovae explosions ( SNe ) , photoheating and radiation pressure in low gas surface density galaxies ( \Sigma _ { gas } \simeq 10 { M } _ { \odot } { pc } ^ { -2 } ) .
We show that radiation fields decrease the star formation rate and therefore the total stellar mass formed by a factor of \sim 2 .
This increases the gas depletion timescale and brings the simulated Kennicutt-Schmidt relation closer to the observational estimates .
Radiation feedback coupled with SNe is more efficient at driving outflows with the mass and energy loading increasing by a factor of \sim 10 .
This increase is mainly driven by the additional entrainment of medium density ( 10 ^ { -2 } \leq n < 1 { cm } ^ { -3 } ) , warm ( 300 { K } \leq T < 8000 { K } ) material .
Therefore including radiation fields tends to launch colder , denser and higher mass and energy loaded outflows .
This is because photoheating of the high density gas around a newly formed star over-pressurises the region , causing it to expand .
This reduces the ambient density in which the SNe explode by a factor of 10 - 100 which in turn increases their momentum output by a factor of \sim 1.5 - 2.5 .
Finally , we note that in these low gas surface density environments , radiation fields primarily impact the ISM via photoheating and radiation pressure has only a minimal role in regulating star formation .