Using observations in the COSMOS field , we report an intriguing correlation between the star formation activity of massive ( \sim 10 ^ { 11.4 } M _ { \odot } ) central galaxies , their stellar masses , and the large-scale ( \sim 10 Mpc ) environments of their group-mass ( \sim 10 ^ { 13.6 } M _ { \odot } ) dark matter halos .
Probing the redshift range z = [ 0.2 , 1.0 ] , our measurements come from two independent sources : an X-ray detected group catalog and constraints on the stellar-to-halo mass relation derived from a combination of clustering and weak lensing statistics .
At z = 1 , we find that the stellar mass in star-forming centrals is a factor of two less than in passive centrals at the same halo mass .
This implies that the presence or lack of star formation in group-scale centrals can not be a stochastic process .
By z = 0 , the offset reverses , probably as a result of the different growth rates of these objects .
A similar but weaker trend is observed when dividing the sample by morphology rather than star formation .
Remarkably , we find that star-forming centrals at z \sim 1 live in groups that are significantly more clustered on 10 Mpc scales than similar mass groups hosting passive centrals .
We discuss this signal in the context of halo assembly and recent simulations , suggesting that star-forming centrals prefer halos with higher angular momentum and/or formation histories with more recent growth ; such halos are known to evolve in denser large-scale environments .
If confirmed , this would be evidence of an early established link between the assembly history of halos on large scales and the future properties of the galaxies that form inside them .