How does galaxy environment matter?

For some obscure reason blogger does not let me put on my text here fully, so see the first comment for that....

In 1009.1619 Nilsson et al ('Stellar populations of z=1 LBGs from ACS slitless grism spectra') the authors perform sliless spectroscopy on a small sample of z~1 LBGs and perform SED fitting on these. They compare the SED fitting results to broadband photometry SED fitting and find that the addition of slitless (high S/N, low spectral resolution) spectroscopy helps greatly in narrowing the allowed range of solutions of the stellar population.

The stellar populations are very well fit by a single SSP or by a continuous SFR, a second SSP has a best fit mass of ~0. Stellar masses, ages and extinction are very well constrained (~10^10 Msun, few-few tens of Myrs, 0.5-2 mag A_V), but the metallicity is not constrained at all.