The Acoustic Peak in the Lyman Alpha Forest
  We present the first simulation of the signature of baryonic acoustic
oscillations (BAO) in Lyman alpha forest data containing 180,000 mock quasar
sight-lines. We use eight large dark-matter only simulations onto which we
paint the Lyman alpha field using the fluctuating Gunn-Peterson approximation.
We argue that this approach should be sufficient for the mean signature on the
scales of interest. Our results indicate that Lyman alpha flux provides a good
tracer of the underlying dark matter field on large scales and that redshift
space distortions are well described by a simple linear theory prescription. We
compare Fourier and configuration space approaches to describing the signal and
argue that configuration space statistics provide useful data compression. We
also investigate the effect of a fluctuating photo-ionizing background using a
simplified model and find that such fluctuations do add smooth power on large
scales. The acoustic peak position is, however, unaffected for small amplitude
fluctuations (<10%). Larger amplitude fluctuations make the recovery of the BAO
signal more difficult and may degrade the achievable significance of the
measurement.
