Hong Guo, Idit Zehavi, Zheng Zheng
In fiber-fed galaxy redshift surveys, the finite size of the fiber plugs
prevents two fibers from being placed too close to one another, limiting the
ability of studying galaxy clustering on all scales. We present an accurate and
unbiased method for correcting such fiber collision effects in galaxy
clustering statistics based on spectroscopic observations. The target galaxy
sample is divided into two distinct populations according to the targeting
algorithm of fiber placement, one free of fiber collisions and the other
consisting of collided galaxies. The clustering statistics are a combination of
the contributions from these two populations. Our method makes use of
observations in tile overlap regions to measure the contributions from the
collided population, and to therefore recover the full clustering statistics.
The method is rooted in solid theoretical ground and is tested extensively on
mock galaxy catalogs. We demonstrate that our method can well recover the
projected and the full three-dimensional redshift-space two-point correlation
functions on scales both below and above the fiber collision scale, superior to
the commonly used nearest neighbor and angular correction methods. The
correction accuracy of our method is only limited by sample variance, which
scales down with (the square root of) the volume probed. For a sample similar
to the final SDSS-III BOSS galaxy sample, the correction error is expected to
be at the level of 1% on scales ~ 0.1-30 Mpc/h for the two-point correlation
functions. Our correction method, which can be generalized to other clustering
statistics as well, enables accurate measurements of full three-dimensional
galaxy clustering on all scales with galaxy redshift surveys.
View original:
http://arxiv.org/abs/1111.6598
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