Tests of Acoustic Scale Shifts in Halo-based Mock Galaxy Catalogues. (arXiv:1906.04262v1 [astro-ph.CO])

Tests of Acoustic Scale Shifts in Halo-based Mock Galaxy Catalogues. (arXiv:1906.04262v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Yutong_D/0/1/0/all/0/1">Duan Yutong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eisenstein_D/0/1/0/all/0/1">Daniel Eisenstein</a>

We utilise mock catalogues from high-accuracy cosmological $N$-body
simulations to quantify shifts in the recovery of the acoustic scale that could
potentially result from galaxy clustering bias. The relationship between
galaxies and dark matter halos presents a complicated source of systematic
errors in modern redshift surveys, particularly when aiming to make
cosmological measurements to sub-percent precision. Apart from a scalar, linear
bias parameter accounting for the density contrast ratio between matter tracers
and the true matter distribution, other types of galaxy bias, such as assembly
and velocity biases, may also significantly alter clustering signals from small
to large scales. We create mocks based on generalised halo occupation
populations of 36 periodic boxes from the abacuscosmos release with. In a
total volume of $48 , h^{-3} mathrm{Gpc}^3$, we test various biased models
along with an unbiased base case. Two reconstruction methods are applied to
galaxy samples and the apparent acoustic scale is derived by fitting the
two-point correlation function multipoles. With respect to the baseline, we
find a $0.3%$ shift in the line-of-sight acoustic scale for one variation in
the satellite galaxy population, and we find an $0.7%$ shift for an extreme
level of velocity bias of the central galaxies. All other bias models are
consistent with zero shift at the $0.2%$ level after reconstruction. We note
that the bias models explored are relatively large variations, producing
sizeable and likely distinguishable changes in small-scale clustering, the
modelling of which would further calibrate the BAO standard ruler.

We utilise mock catalogues from high-accuracy cosmological $N$-body
simulations to quantify shifts in the recovery of the acoustic scale that could
potentially result from galaxy clustering bias. The relationship between
galaxies and dark matter halos presents a complicated source of systematic
errors in modern redshift surveys, particularly when aiming to make
cosmological measurements to sub-percent precision. Apart from a scalar, linear
bias parameter accounting for the density contrast ratio between matter tracers
and the true matter distribution, other types of galaxy bias, such as assembly
and velocity biases, may also significantly alter clustering signals from small
to large scales. We create mocks based on generalised halo occupation
populations of 36 periodic boxes from the abacuscosmos release with. In a
total volume of $48 , h^{-3} mathrm{Gpc}^3$, we test various biased models
along with an unbiased base case. Two reconstruction methods are applied to
galaxy samples and the apparent acoustic scale is derived by fitting the
two-point correlation function multipoles. With respect to the baseline, we
find a $0.3%$ shift in the line-of-sight acoustic scale for one variation in
the satellite galaxy population, and we find an $0.7%$ shift for an extreme
level of velocity bias of the central galaxies. All other bias models are
consistent with zero shift at the $0.2%$ level after reconstruction. We note
that the bias models explored are relatively large variations, producing
sizeable and likely distinguishable changes in small-scale clustering, the
modelling of which would further calibrate the BAO standard ruler.

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