Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2208.00540

The Uchuu-SDSS galaxy lightcones: a clustering, RSD and BAO study

C. A. Dong-Páez·A. Smith·A. O. Szewciw·J. Ereza·M. H. Abdullah·C. Hernández-Aguayo·S. Trusov·F. Prada·A. Klypin·T. Ishiyama·A. Berlind·P. Zarrouk·J. López Cacheiro·J. Ruedas
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present the data release of the Uchuu-SDSS galaxies: a set of 32 high-fidelity galaxy lightcones constructed from the large Uchuu 2.1 trillion particle $N$-body simulation using Planck cosmology. We adopt subhalo abundance matching to populate the Uchuu-box halo catalogues with SDSS galaxy luminosities. These cubic box galaxy catalogues generated at several redshifts are combined to create the set of lightcones with redshift-evolving galaxy properties. The Uchuu-SDSS galaxy lightcones are built to reproduce the footprint and statistical properties of the SDSS main galaxy survey, along with stellar masses and star formation rates. This facilitates direct comparison of the observed SDSS and simulated Uchuu-SDSS data. Our lightcones reproduce a large number of observational results, such as the distribution of galaxy properties, the galaxy clustering, the stellar mass functions, and the halo occupation distributions. Using the simulated and real data we select samples of bright red galaxies at $z_\mathrm{eff}=0.15$ to explore Redshift Space Distortions and Baryon Acoustic Oscillations (BAO) utilizing a full-shape analytical model of the two-point correlation function. We create a set of 5100 galaxy lightcones using GLAM N-body simulations to compute covariance errors. We report a $\sim 30\%$ precision increase on $fσ_8$, due to our better estimate of the covariance matrix. From our BAO-inferred $α_{\parallel}$ and $α_{\perp}$ parameters, we obtain the first SDSS measurements of the Hubble and angular diameter distances $D_\mathrm{H}(z=0.15) / r_d = 27.9^{+3.1}_{-2.7}$, $D_\mathrm{M}(z=0.15) / r_d = 5.1^{+0.4}_{-0.4}$. Overall, we conclude that the Planck LCDM cosmology nicely explains the observed large-scale structure statistics of SDSS. All data sets are made publicly available.

Explore related subjects

astro-ph.COastro-ph.GA

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C. A. Dong-Páez, A. Smith, A. O. Szewciw, J. Ereza, M. H. Abdullah, C. Hernández-Aguayo, S. Trusov, F. Prada, A. Klypin, T. Ishiyama, A. Berlind, P. Zarrouk, J. López Cacheiro, J. Ruedas. 2022-07-31. The Uchuu-SDSS galaxy lightcones: a clustering, RSD and BAO study. https://arxiv.org/abs/2208.00540

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

The SRG/eROSITA all-sky survey: X-ray scaling relations of galaxy groups and clusters in the western Galactic hemisphere

The soft X-ray telescope on board the SRG mission, eROSITA, has produced the largest sample to date of galaxy groups and clusters detected via their intracluster and intragroup medium emission. Scaling relations between the intrinsic properties of these systems provide valuable insight into their formation and evolution. In this work, we investigated the scaling relations between key physical properties, such as soft band X-ray luminosity, temperature, gas mass, and the low-scatter mass proxy $Y_{\rm X}$, for the galaxy groups and clusters detected in the first eROSITA All-Sky Survey (eRASS1). Our analysis fully accounts for selection effects and the redshift evolution of the observable distributions. We constructed a high-purity sample of $3061$ galaxy groups and clusters spanning the redshift range of $0.05 3$~keV, our inferred $L_{\rm X}-T$ relation is consistent with simulation models that include strong or stronger AGN feedback.

astro-ph.CO↗
arXiv2026

Constraints of Big Bang Nucleosynthesis and Cosmological Observations on varying Higgs VEV

The Higgs vacuum expectation value (VEV) alters both the electroweak and strong interaction rates. We study both effects on Big Bang Nucleosynthesis (BBN) and seek concordance between observed primordial abundances of light elements and cosmological constraints from cosmic microwave background (CMB) fluctuations and anisotropies. We find a strong negative correlation between primordial 4He abundance and the Higgs VEV. Consequently, using a 1.58% uplift of the Higgs VEV during BBN from the current value, an agreement can be achieved among the new primordial 4He abundance, observed by the EMPRESS group, Deuterium abundance determined from absorption lines in the Lyman-alpha forest along the line-of-sight of high-redshift quasars, and the lithium abundance on the Spite plateau. This agreement requires a baryon-to-photon ratio different from the CMB determination, indicating the need for non-standard cosmological evolution between BBN and recombination epochs.We also demonstrate that a 0.2% uplift in the Higgs VEV can partially alleviate the "cosmic Li problem", keeping consistency with the CMB with remaining discrepancy potentially accounted for by stellar depletion mechanisms.

astro-ph.CO↗
arXiv2026

Probing Helium Reionization Through the $^{3}\mathrm{He}^{+}$ Hyperfine Transition Line

We investigate the hyperfine transition of $^{3}\mathrm{He}^{+}$ as a promising probe of the IGM during the final stages of helium reionization. Utilising the most recent helium reionization simulation, we generate three-dimensional maps of the 3.5cm ($8.67$,GHz) differential brightness temperature and analyze its evolution. Our `fiducial' results show that the volume-averaged brightness temperature declines rapidly from $\sim 10^{-2}\,μ\mathrm{K}$ (in the `optimistic' approach, i.e. $T_{\rm s} = T_{\rm gas}$, $\sim 1,μ\mathrm{K}$) at $z = 3$ to $\sim 8 \times 10^{-5},μ\mathrm{K}$ ($\sim 2.5 \times 10^{-3},μ\mathrm{K}$) by $z = 2.3$, tracing the He,\textsc{ii} to He,\textsc{iii} transition driven by quasars. The power spectrum of the 3.5cm signal exhibits a scale-dependent evolution, peaking on small scales and declining as reionization progresses. We explore the cross-correlation of the 3.5cm transition line with the distribution of AGNs, which shows a transition from positive to negative correlation as ionized regions grow. Although current observational upper limits lie several orders of magnitude above theoretical predictions, future radio arrays such as \texttt{SKA-mid} offer promising prospects. Overall, this study highlights the $^{3}\mathrm{He}^{+}$ hyperfine transition as a sensitive tracer of the thermal and ionization history of the IGM during helium reionization. The predicted signal is also subject to additional uncertainty from spin temperature modelling, and the true amplitude is expected to lie between the limiting cases explored in this work.

astro-ph.CO↗