Particle mesh simulations of the Lyman-alpha forest and the signature of
  Baryon Acoustic Oscillations in the intergalactic medium
  We present a set of ultra-large particle-mesh simulations of the LyA forest
targeted at understanding the imprint of baryon acoustic oscillations (BAO) in
the inter-galactic medium. We use 9 dark matter only simulations which can, for
the first time, simultaneously resolve the Jeans scale of the intergalactic gas
while covering the large volumes required to adequately sample the acoustic
feature. Mock absorption spectra are generated using the fluctuating
Gunn-Peterson approximation which have approximately correct flux probability
density functions (PDFs) and small-scale power spectra. On larger scales there
is clear evidence in the redshift space correlation function for an acoustic
feature, which matches a linear theory template with constant bias. These
spectra, which we make publicly available, can be used to test pipelines, plan
future experiments and model various physical effects. As an illustration we
discuss the basic properties of the acoustic signal in the forest, the scaling
of errors with noise and source number density, modified statistics to treat
mean flux evolution and misestimation, and non-gravitational sources such as
fluctuations in the photo-ionizing background and temperature fluctuations due
to HeII reionization.
