The Spitzer Extragalactic Representative Volume Survey (SERVS): The
  Environments of High-z SDSS Quasi-Stellar-Objects
  This paper presents a study of the environments of SDSS Quasi-Stellar-Objects
(QSOs) in the Spitzer Extragalactic Representative Volume Survey (SERVS). We
concentrate on the high-redshift QSOs as these have not been studied in large
numbers with data of this depth before. We use the IRAC 3.6-4.5{\mu}m colour of
objects and ancillary r-band data to filter out as much foreground
contamination as possible. This technique allows us to find a significant (>
4-{\sigma}) over-density of galaxies around QSOs in a redshift bin centred on z
~ 2.0 and a (> 2-{\sigma}) over-density of galaxies around QSOs in a redshift
bin centred on z ~ 3.3. We compare our findings to the predictions of a
semi-analytic galaxy formation model, based on the {\Lambda}CDM millennium
simulation, and find for both redshift bins that the model predictions match
well the source-density we have measured from the SERVS data.
