The Herschel Extragalactic Legacy Project (HELP*) brings together a vast range of data from many different astronomical observatories. The focus is on the Herschel data which maps the dust obscured star formation. With this unique combination of datasets we want to determine how the star formation main sequence depends on environment. We determined the galaxy density field in COSMOS using photometric redshifts (Ilbert et al. 2013) in combination with an adaptive gaussian kernel. We classified galaxies according to their environment in this density field.
The confusion noise in the Herschel images limits the degree to which we can determine which galaxies are responsible for the FIR emission. By using SIMSTACK (Viero et al. 2013) we get around this problem by simultaneously fitting populations of galaxies detected in the optical/NIR. Adapting this technique we can directly determine the offset of the main-sequence of star-formation in each environment. This gives us a new insight in star formation in different environments and how this changes over redshift. Our preliminary results suggest no significant variations of the main sequence in different environments.

*herschel.sussex.ac.uk