scholarly journals On the possibility of baryon acoustic oscillation measurements at redshift z > 7.6 with the Roman space telescope

2020 ◽  
Vol 498 (4) ◽  
pp. 4955-4970
Author(s):  
Siddharth Satpathy ◽  
Zhaozhou An ◽  
Rupert A C Croft ◽  
Tiziana Di Matteo ◽  
Ananth Tenneti ◽  
...  
Keyword(s):  
Large Scale ◽  
High Redshift ◽  
High Sensitivity ◽  
Acoustic Oscillation ◽  
Detection Sensitivity ◽  
Angular Diameter ◽  
Acoustic Oscillations ◽  
Space Telescope ◽  
Angular Diameter Distance ◽  
High Redshift Universe

ABSTRACT The Nancy Grace Roman Space Telescope (RST), with its field of view and high sensitivity will make surveys of cosmological large-scale structure possible at high redshifts. We investigate the possibility of detecting baryon acoustic oscillations (BAO) at redshifts z > 7.6 for use as a standard ruler. We use data from the hydrodynamic simulation bluetides in conjunction with the gigaparsec-scale Outer Rim simulation and a model for patchy reionization to create mock RST High Latitude Survey grism data for Lyman α emission line selected galaxies at redshifts z = 7.4 to z = 10, covering 2280 deg2. We measure the monopoles of galaxies in the mock catalogues and fit the BAO features. We find that for a line flux of $L = 7\times 10^{-17} \ {\rm erg\, s^{-1}\, cm}^{-2}$, the 5σ detection limit for the current design, the BAO feature is partially detectable (measured in three out of four survey quadrants analysed independently). The resulting root mean square error on the angular diameter distance to z = 7.7 is 7.9 ${{\ \rm per\ cent}}$. If we improve the detection sensitivity by a factor of two (i.e. $L = 3.5\times 10^{-17} \ {\rm erg\, s^{-1}\, cm}^{-2}$), the distance error reduces to $1.4{{\ \rm per\ cent}}$. We caution that many more factors are yet to be modelled, including dust obscuration, the damping wing due to the intergalactic medium, and low redshift interlopers. If these issues do not strongly affect the results, or different observational techniques (such as use of multiple lines) can mitigate them, RST, or similar instruments may be able to constrain the angular diameter distance to the high redshift universe.

scholarly journals Dark Energy Survey Year 1 results: measurement of the baryon acoustic oscillation scale in the distribution of galaxies to redshift 1

2018 ◽  
Vol 483 (4) ◽  
pp. 4866-4883 ◽  
Author(s):  
T M C Abbott ◽  
F B Abdalla ◽  
A Alarcon ◽  
S Allam ◽  
F Andrade-Oliveira ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cold Dark Matter ◽  
Angular Diameter ◽  
Acoustic Oscillations ◽  
Distance Measurements ◽  
Angular Diameter Distance ◽  
Dark Energy Survey ◽  
Trade Offs ◽  
Physical Scale ◽  
Energy Survey

ABSTRACT We present angular diameter distance measurements obtained by locating the baryon acoustic oscillations (BAO) scale in the distribution of galaxies selected from the first year of Dark Energy Survey data. We consider a sample of over 1.3 million galaxies distributed over a footprint of 1336 deg2 with 0.6 < $z$photo < 1 and a typical redshift uncertainty of 0.03(1 + $z$). This sample was selected, as fully described in a companion paper, using a colour/magnitude selection that optimizes trade-offs between number density and redshift uncertainty. We investigate the BAO signal in the projected clustering using three conventions, the angular separation, the comoving transverse separation, and spherical harmonics. Further, we compare results obtained from template-based and machine-learning photometric redshift determinations. We use 1800 simulations that approximate our sample in order to produce covariance matrices and allow us to validate our distance scale measurement methodology. We measure the angular diameter distance, DA, at the effective redshift of our sample divided by the true physical scale of the BAO feature, rd. We obtain close to a 4 per cent distance measurement of DA($z$eff = 0.81)/rd = 10.75 ± 0.43. These results are consistent with the flat Λ cold dark matter concordance cosmological model supported by numerous other recent experimental results.

scholarly journals Baryon acoustic oscillations from the cross-correlation of Lyα absorption and quasars in eBOSS DR14

2019 ◽  
Vol 629 ◽  
pp. A86 ◽  
Author(s):  
Michael Blomqvist ◽  
Hélion du Mas des Bourboux ◽  
Nicolás G. Busca ◽  
Victoria de Sainte Agathe ◽  
James Rich ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Acoustic Oscillation ◽  
Companion Paper ◽  
Peak Position ◽  
Sloan Digital Sky Survey ◽  
Acoustic Oscillations ◽  
Microwave Background ◽  
Angular Diameter Distance ◽  
Statistical Precision ◽  
Sky Survey

We present a measurement of the baryon acoustic oscillation (BAO) scale at redshift z = 2.35 from the three-dimensional correlation of Lyman-α (Lyα) forest absorption and quasars. The study uses 266 590 quasars in the redshift range 1.77 <  z <  3.5 from the Sloan Digital Sky Survey (SDSS) Data Release 14 (DR14). The sample includes the first two years of observations by the SDSS-IV extended Baryon Oscillation Spectroscopic Survey (eBOSS), providing new quasars and re-observations of BOSS quasars for improved statistical precision. Statistics are further improved by including Lyα absorption occurring in the Lyβ wavelength band of the spectra. From the measured BAO peak position along and across the line of sight, we determined the Hubble distance DH and the comoving angular diameter distance DM relative to the sound horizon at the drag epoch rd: DH(z = 2.35)/rd = 9.20 ± 0.36 and DM(z = 2.35)/rd = 36.3 ± 1.8. These results are consistent at 1.5σ with the prediction of the best-fit spatially-flat cosmological model with the cosmological constant reported for the Planck (2016) analysis of cosmic microwave background anisotropies. Combined with the Lyα auto-correlation measurement presented in a companion paper, the BAO measurements at z = 2.34 are within 1.7σ of the predictions of this model.

scholarly journals A flexible analytic model of cosmic variance in the first billion years

2020 ◽  
Vol 499 (2) ◽  
pp. 2401-2415
Author(s):  
A C Trapp ◽  
Steven R Furlanetto
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Luminosity Function ◽  
Large Scale ◽  
High Redshift ◽  
Mass Function ◽  
Dark Matter Halo ◽  
Analytic Model ◽  
Stellar Feedback ◽  
High Redshift Universe

ABSTRACT Cosmic variance is the intrinsic scatter in the number density of galaxies due to fluctuations in the large-scale dark matter density field. In this work, we present a simple analytic model of cosmic variance in the high-redshift Universe (z ∼ 5–15). We assume that galaxies grow according to the evolution of the halo mass function, which we allow to vary with large-scale environment. Our model produces a reasonable match to the observed ultraviolet (UV) luminosity functions in this era by regulating star formation through stellar feedback and assuming that the UV luminosity function is dominated by recent star formation. We find that cosmic variance in the UV luminosity function is dominated by the variance in the underlying dark matter halo population, and not by differences in halo accretion or the specifics of our stellar feedback model. We also find that cosmic variance dominates over Poisson noise for future high-z surveys except for the brightest sources or at very high redshifts (z ≳ 12). We provide a linear approximation of cosmic variance for a variety of redshifts, magnitudes, and survey areas through the public python package galcv. Finally, we introduce a new method for incorporating priors on cosmic variance into estimates of the galaxy luminosity function and demonstrate that it significantly improves constraints on that important observable.

scholarly journals The impact of Lyman-α radiative transfer on large-scale clustering in the Illustris simulation

2018 ◽  
Vol 614 ◽  
pp. A31 ◽  
Author(s):  
C. Behrens ◽  
C. Byrohl ◽  
S. Saito ◽  
J. C. Niemeyer
Keyword(s):  
Radiative Transfer ◽  
Selection Bias ◽  
Large Scale ◽  
High Redshift ◽  
Formation Rate ◽  
Acoustic Oscillation ◽  
Density Region ◽  
Space Distortion ◽  
High Density Region ◽  
The Impact

Context. Lyman-α emitters (LAEs) are a promising probe of the large-scale structure at high redshift, z ≳ 2. In particular, the Hobby-Eberly Telescope Dark Energy Experiment aims at observing LAEs at 1.9 < z < 3.5 to measure the baryon acoustic oscillation (BAO) scale and the redshift-space distortion (RSD). However, it has been pointed out that the complicated radiative transfer (RT) of the resonant Lyman-α emission line generates an anisotropic selection bias in the LAE clustering on large scales, s ≳ 10 Mpc. This effect could potentially induce a systematic error in the BAO and RSD measurements. Also, there exists a recent claim to have observational evidence of the effect in the Lyman-α intensity map, albeit statistically insignificant. Aims. We aim at quantifying the impact of the Lyman-α 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-α luminosity to an intrinsic one, which we call the “observed fraction”, at 2 < z < 6. Methods. We apply our Lyman-α RT code by post-processing the full Illustris simulations. We simply assume that the intrinsic luminosity of the Lyman-α 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. Results. We find little correlation between large-scale environment and the observed fraction induced by the RT, and hence a smaller anisotropic selection bias than has previously been claimed. We argue that the anisotropy was overestimated in previous work due to 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, that is, ~1 physical kpc. We also find that the correlation can be further enhanced by assumptions in modeling intrinsic Lyman-α emission.

scholarly journals Hubble trouble or Hubble bubble?

2018 ◽  
Vol 27 (09) ◽  
pp. 1850102 ◽  
Author(s):  
Antonio Enea Romano
Keyword(s):  
Large Scale ◽  
High Redshift ◽  
Cosmological Parameters ◽  
Density Field ◽  
Density Contrast ◽  
Recent Analysis ◽  
Inversion Method ◽  
Linear Perturbation ◽  
Luminosity Distance ◽  
Angular Diameter Distance

The recent analysis of low-redshift supernovae (SN) has increased the apparent tension between the value of [Formula: see text] estimated from low and high redshift observations such as the cosmic microwave background (CMB) radiation. At the same time other observations have provided evidence of the existence of local radial inhomogeneities extending in different directions up to a redshift of about [Formula: see text]. About [Formula: see text] of the Cepheids used for SN calibration are directly affected because they are located along the directions of these inhomogeneities. We compute with different methods the effects of these inhomogeneities on the low-redshift luminosity and angular diameter distance using an exact solution of the Einstein’s equations, linear perturbation theory and a low-redshift expansion. We confirm that at low redshift the dominant effect is the nonrelativistic Doppler redshift correction, which is proportional to the volume averaged density contrast and to the comoving distance from the center. We derive a new simple formula relating directly the luminosity distance to the monopole of the density contrast, which does not involve any metric perturbation. We then use it to develop a new inversion method to reconstruct the monopole of the density field from the deviations of the redshift uncorrected observed luminosity distance respect to the [Formula: see text]CDM prediction based on cosmological parameters obtained from large scale observations. The inversion method confirms the existence of inhomogeneities whose effects were not previously taken into account because the [Formula: see text] [G. Lavaux and M. J. Hudson, Mon. Not. R. Astron. Soc. 416 (2011) 2840] density field maps used to obtain the peculiar velocity [J. Carrick et al., Mon. Not. R. Astron. Soc. 450 (2015) 317] for redshift correction were for [Formula: see text], which is not a sufficiently large scale to detect the presence of inhomogeneities extending up to [Formula: see text]. The inhomogeneity does not affect the high redshift luminosity distance because the volume averaged density contrast tends to zero asymptotically, making the value of [Formula: see text] obtained from CMB observations insensitive to any local structure. The inversion method can provide a unique tool to reconstruct the density field at high redshift where only SN data is available, and in particular to normalize correctly the density field respect to the average large scale density of the Universe.

scholarly journals What we learn from the Frontier Fields cluster MACS J0416.1-2403

2015 ◽  
Vol 11 (A29B) ◽  
pp. 787-790
Author(s):  
S. H. Suyu ◽  
C. Grillo ◽  
P. Rosati
Keyword(s):  
Mass Distribution ◽  
Hubble Space Telescope ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Essential Elements ◽  
Central Mass ◽  
Great Opportunity ◽  
Space Telescope ◽  
James Webb Space Telescope ◽  
High Redshift Universe

AbstractThe Frontier Fields cluster MACS J0416.1-2403 with its extensive imaging and spectroscopic data sets provides a great opportunity to study the mass distribution of the galaxy cluster and members, the high-redshift Universe and cosmology. By taking advantage of the observations in the 16 Hubble Space Telescope imaging bands of the Cluster Lensing And Supernova survey with Hubble (CLASH) survey and our large spectroscopic follow-up program with the VIsible Multi-Object Spectrograph (VIMOS) on the Very Large Telescope (VLT), we have been able to identify and obtain the spectroscopic redshifts of 10 important strong lensing systems in this cluster. Furthermore, we have selected and modeled the mass distribution of ~200 candidate cluster members residing in the inner regions of the cluster. We present the results on the model-predicted central mass profile and subhalo population, which are detailed in Grillo et al. (2015). Work is underway to quantify the effects of line-of-sight structures. These are essential elements to make progress in our understanding of the dark matter distribution in massive galaxy clusters and of the distant Universe within the current Frontier Fields initiative and before the advent of the James Webb Space Telescope.

scholarly journals The constraint of H0 from galaxy clusters and Hubble parameter data

2017 ◽  
Vol 26 (11) ◽  
pp. 1750129
Author(s):  
Hai Huang ◽  
Long Huang
Keyword(s):  
Hubble Parameter ◽  
High Redshift ◽  
Confidence Region ◽  
Angular Diameter ◽  
Observation Data ◽  
Luminosity Distance ◽  
Dynamical Equations ◽  
Angular Diameter Distance ◽  
Acceleration Rate ◽  
Distance Formula

Using comoving distance [Formula: see text] and angular diameter distance [Formula: see text], we recalculate parameters describing kinematical state of the universe, still combining the kinematical model of universe but not relying on dynamical equations for gravity. Comoving distance [Formula: see text] comes from Hubble data [Formula: see text] and is more reliable. Angular diameter distance [Formula: see text] comes from SZE (Sunyaev–Zel’dovich Effect) and X-ray data, and needs calibration. In low redshift case, we use expansion of relation between luminosity distance and redshift about redshift [Formula: see text]; in high redshift case, we take variable substitution [Formula: see text], and expand the relation between luminosity distance and redshift about variable [Formula: see text] in order to reduce computational errors. Finally, we get the more precise value of Hubble parameter [Formula: see text] km ⋅ s[Formula: see text], corresponding to [Formula: see text] uncertainty in [Formula: see text] confidence region, also deceleration factor [Formula: see text] and acceleration rate [Formula: see text], and their statistical values and probability graph. We compare the values of [Formula: see text], [Formula: see text] and [Formula: see text] with those obtained from other observation data and model.

scholarly journals Clustering in the Simulated Hα Galaxy Redshift Survey from Nancy Grace Roman Space Telescope

2020 ◽  
Author(s):  
Zhongxu Zhai ◽  
Chia-Hsun Chuang ◽  
Yun Wang ◽  
Andrew Benson ◽  
Gustavo Yepes
Keyword(s):  
Dark Energy ◽  
Galaxy Formation ◽  
Growth Parameter ◽  
Real Data ◽  
Acoustic Oscillation ◽  
Large Set ◽  
Space Telescope ◽  
Angular Diameter Distance ◽  
Redshift Survey ◽  
Galaxy Redshift

Abstract We present a realistic 2000 deg2 Hα galaxy mock catalog with 1 &lt; z &lt; 2 for the Nancy Grace Roman Space Telescope galaxy redshift survey, the High Latitude Spectroscopic Survey (HLSS), created using Galacticus, a semi-analytical galaxy formation model, and high resolution cosmological N-body simulations. Galaxy clustering can probe dark energy and test gravity via baryon acoustic oscillation (BAO) and redshift space distortion (RSD) measurements. Using our realistic mock as the simulated Roman HLSS data, and a covariance matrix computed using a large set of approximate mocks created using EZmock, we investigate the expected precision and accuracy of the BAO and RSD measurements using the same analysis techniques used in analyzing real data. We find that the Roman Hα galaxy survey alone can measure the angular diameter distance with 2% uncertainty, the Hubble parameter with 3-6% uncertainty, and the linear growth parameter with 7% uncertainty, in each of four redshift bins. Our realistic forecast illustrates the power of the Roman galaxy survey in probing the nature of dark energy and testing gravity.

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