Bibcode
Viel, Matteo; Rubiño-Martin, J. A.; Neyrinck, Mark; Rossi, Graziano; Hernández-Monteagudo, C.; Ross, Ashley J.; Cuesta, Antonio; Génova-Santos, R.; Xia, Jun-Qing; Prada, Francisco; Thomas, Daniel; Brownstein, Joel R.; Schneider, Donald P.; Zhao, Gongbo; Scóccola, C. G.; Brinkmann, Jonathan V.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 438, Issue 2, p.1724-1740
Advertised on:
2
2014
Citations
26
Refereed citations
25
Description
In the context of the study of the integrated Sachs-Wolfe (ISW) effect,
we construct a template of the projected density distribution up to
redshift z ≃ 0.7 by using the luminous galaxies (LGs) from the
Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). We use a
photometric redshift catalogue trained with more than a hundred thousand
galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS) in the
SDSS DR8 imaging area covering nearly one-quarter of the sky. We
consider two different LG samples whose selection matches that of
SDSS-III/BOSS: the low-redshift sample (LOWZ, z ∈ [0.15, 0.5]) and
the constant mass sample (CMASS, z ∈ [0.4, 0.7]). When building the
galaxy angular density templates we use the information from star
density, survey footprint, seeing conditions, sky emission, dust
extinction and airmass to explore the impact of these artefacts on each
of the two LG samples. In agreement with previous studies, we find that
the CMASS sample is particularly sensitive to Galactic stars, which
dominate the contribution to the auto-angular power spectrum below ℓ
= 7. Other potential systematics affect mostly the very low multipole
range (ℓ ∈ [2, 7]), but leave fluctuations on smaller scales
practically unchanged. The resulting angular power spectra in the
multipole range ℓ ∈ [2, 100] for the LOWZ, CMASS and LOWZ+CMASS
samples are compatible with linear Λ cold dark matter
(ΛCDM) expectations and constant bias values of b = 1.98 ±
0.11, 2.08 ± 0.14 and 1.88 ± 0.11, respectively, with no
traces of non-Gaussianity signatures, i.e. f_NL^local=59± 75 at
95 per cent confidence level for the full LOWZ+CMASS sample in the
multipole range ℓ ∈ [4, 100]. After cross-correlating Wilkinson
Microwave Anisotropy Probe 9-year data with the LOWZ+CMASS LG projected
density field, the ISW signal is detected at the level of
1.62-1.69σ. While this result is in close agreement with
theoretical expectations and predictions from realistic Monte Carlo
simulations in the concordance ΛCDM model, it cannot rule out by
itself an Einstein-de Sitter scenario, and has a moderately low signal
compared to previous studies conducted on subsets of this LG sample. We
discuss possible reasons for this apparent discrepancy, and point to
uncertainties in the galaxy survey systematics as most likely sources of
confusion.
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Cosmology with Large Scale Structure Probes
The Cosmic Microwave Background (CMB) contains the statistical information about the early seeds of the structure formation in our Universe. Its natural counterpart in the local universe is the distribution of galaxies that arises as a result of gravitational growth of those primordial and small density fluctuations. The characterization of the
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