308 research outputs found
The impact of Lyman- radiative transfer on large-scale clustering in the Illustris simulation
Lyman- emitters (LAEs) are a promising probe of the large-scale
structure at high redshift, . In particular, the Hobby-Eberly
Telescope Dark Energy Experiment aims at observing LAEs at 1.9 3.5 to
measure the Baryon Acoustic Oscillation (BAO) scale and the Redshift-Space
Distortion (RSD). However, Zheng et al. (2011) pointed out that the complicated
radiative transfer (RT) of the resonant Lyman- emission line generates
an anisotropic selection bias in the LAE clustering on large scales, Mpc. This effect could potentially induce a systematic error in the BAO and
RSD measurements. Also, Croft et al. (2016) claims an observational evidence of
the effect in the Lyman- intensity map, albeit statistically
insignificant. We aim at quantifying the impact of the Lyman- RT on the
large-scale galaxy clustering in detail. For this purpose, we study the
correlations between the large-scale environment and the ratio of an apparent
Lyman- luminosity to an intrinsic one, which we call the `observed
fraction', at . We apply our Lyman- RT code by post-processing
the full Illustris simulations. We simply assume that the intrinsic luminosity
of the Lyman- emission is proportional to the star formation rate of
galaxies in Illustris, yielding a sufficiently large sample of LAEs to measure
the anisotropic selection bias. We find little correlations between large-scale
environment and the observed fraction induced by the RT, and hence a smaller
anisotropic selection bias than what was claimed by Zheng et al. (2011). We
argue that the anisotropy was overestimated in the previous work due to the
insufficient spatial resolution: it is important to keep the resolution such
that it resolves the high density region down to the scale of the interstellar
medium, physical kpc. (abridged)Comment: 11 pages, published in A&
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