scholarly journals Cosmology with stacked cluster weak lensing and cluster–galaxy cross-correlations

2019 ◽  
Vol 491 (3) ◽  
pp. 3061-3081 ◽  
Author(s):  
Andrés N Salcedo ◽  
Benjamin D Wibking ◽  
David H Weinberg ◽  
Hao-Yi Wu ◽  
Douglas Ferrer ◽  
...  
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Nuisance Parameter ◽  
Mass Function ◽  
Weak Lensing ◽  
Small Scale ◽  
Density Parameter ◽  
Cluster Galaxy ◽  
Dark Energy Survey ◽  
Galaxy Population

ABSTRACT Cluster weak lensing is a sensitive probe of cosmology, particularly the amplitude of matter clustering σ8 and matter density parameter Ωm. The main nuisance parameter in a cluster weak lensing cosmological analysis is the scatter between the true halo mass and the relevant cluster observable, denoted $\sigma _{\ln M_\mathrm{ c}}$. We show that combining the cluster weak lensing observable ΔΣ with the projected cluster–galaxy cross-correlation function wp,cg and galaxy autocorrelation function wp,gg can break the degeneracy between σ8 and $\sigma _{\ln M_\mathrm{ c}}$ to achieve tight, per cent-level constraints on σ8. Using a grid of cosmological N-body simulations, we compute derivatives of ΔΣ, wp,cg, and wp,gg with respect to σ8, Ωm, $\sigma _{\ln M_\mathrm{ c}}$, and halo occupation distribution (HOD) parameters describing the galaxy population. We also compute covariance matrices motivated by the properties of the Dark Energy Survey cluster and weak lensing survey and the BOSS CMASS galaxy redshift survey. For our fiducial scenario combining ΔΣ, wp,cg, and wp,gg measured over 0.3−30.0 h−1 Mpc, for clusters at z = 0.35−0.55 above a mass threshold Mc ≈ 2 × 1014 h−1 M⊙, we forecast a $1.4{{\ \rm per\ cent}}$ constraint on σ8 while marginalizing over $\sigma _{\ln M_\mathrm{ c}}$ and all HOD parameters. Reducing the mass threshold to 1 × 1014 h−1 M⊙ and adding a z = 0.15−0.35 redshift bin sharpens this constraint to $0.8{{\ \rm per\ cent}}$. The small-scale (rp < 3.0 h−1 Mpc) ‘mass function’ and large-scale (rp > 3.0 h−1 Mpc) ‘halo-mass cross-correlation’ regimes of ΔΣ have comparable constraining power, allowing internal consistency tests from such an analysis.

scholarly journals Extended lens reconstructions with grale: exploiting time-domain, substructural, and weak lensing information

2020 ◽  
Vol 494 (3) ◽  
pp. 3253-3274
Author(s):  
Jori Liesenborgs ◽  
Liliya L R Williams ◽  
Jenny Wagner ◽  
Sven De Rijcke
Keyword(s):  
Mass Density ◽  
Gravitational Lens ◽  
Weak Lensing ◽  
Small Scale ◽  
Source Position ◽  
Cluster Galaxy ◽  
Weak Inversion ◽  
Sufficient Detail ◽  
Inversion Techniques

ABSTRACT The information about the mass density of galaxy clusters provided by the gravitational lens effect has inspired many inversion techniques. In this article, updates to the previously introduced method in grale are described, and explored in a number of examples. The first looks into a different way of incorporating time delay information, not requiring the unknown source position. It is found that this avoids a possible bias that leads to ‘overfocusing’ the images, i.e. providing source position estimates that lie in a considerably smaller region than the true positions. The second is inspired by previous reconstructions of the cluster of galaxies MACS J1149.6+2223, where a multiply imaged background galaxy contained a supernova, SN Refsdal, of which four additional images were produced by the presence of a smaller cluster galaxy. The inversion for the cluster as a whole was not able to recover sufficient detail interior to this quad. We show how constraints on such different scales, from the entire cluster to a single member galaxy, can now be used, allowing such small-scale substructures to be resolved. Finally, the addition of weak lensing information to this method is investigated. While this clearly helps recover the environment around the strong lensing region, the mass sheet degeneracy may make a full strong and weak inversion difficult, depending on the quality of the ellipticity information at hand. We encounter ring-like structure at the boundary of the two regimes, argued to be the result of combining strong and weak lensing constraints, possibly affected by degeneracies.

scholarly journals Testing the reliability of fast methods for weak lensing simulations: wl-moka on pinocchio

2020 ◽  
Vol 496 (2) ◽  
pp. 1307-1324
Author(s):  
Carlo Giocoli ◽  
Pierluigi Monaco ◽  
Lauro Moscardini ◽  
Tiago Castro ◽  
Massimo Meneghetti ◽  
...  
Keyword(s):  
Large Scale ◽  
Initial Conditions ◽  
Mass Density ◽  
Cosmological Parameters ◽  
Power Spectra ◽  
Mass Function ◽  
Parametric Models ◽  
Weak Lensing ◽  
Approximate Methods ◽  
Percent Accuracy

ABSTRACT The generation of simulated convergence maps is of key importance in fully exploiting weak lensing by large-scale structure (LSS) from which cosmological parameters can be derived. In this paper, we present an extension of the pinocchio code that produces catalogues of dark matter haloes so that it is capable of simulating weak lensing by Modify LSS into Large Scale Structures (LSS). Like wl-moka, the method starts with a random realization of cosmological initial conditions, creates a halo catalogue and projects it on to the past light-cone, and paints in haloes assuming parametric models for the mass density distribution within them. Large-scale modes that are not accounted for by the haloes are constructed using linear theory. We discuss the systematic errors affecting the convergence power spectra when Lagrangian perturbation theory at increasing order is used to displace the haloes within pinocchio, and how they depend on the grid resolution. Our approximate method is shown to be very fast when compared to full ray-tracing simulations from an N-body run and able to recover the weak lensing signal, at different redshifts, with a few percent accuracy. It also allows for quickly constructing weak lensing covariance matrices, complementing pinocchio’s ability of generating the cluster mass function and galaxy clustering covariances and thus paving the way for calculating cross-covariances between the different probes. This work advances these approximate methods as tools for simulating and analysing survey data for cosmological purposes.

Radar based rainfall forecast for sewage systems control

2001 ◽  
Vol 43 (5) ◽  
pp. 79-86 ◽  
Author(s):  
H. Aspegren ◽  
C. Bailly ◽  
A. Mpé ◽  
N. Bazzurro ◽  
A. Morgavi ◽  
...  
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Cross Correlation ◽  
Small Scale ◽  
Water Industry ◽  
Short Term ◽  
Radar Images ◽  
Rainfall Forecast ◽  
Increasing Demand ◽  
Sewage Systems

There has been an increasing demand for accurate rainfall forecast in urban areas from the water industry. Current forecasting systems provided mainly by meteorological offices are based on large-scale prediction and are not well suited for this application. In order to devise a system especially designed for the dynamic management of a sewerage system the “RADAR” project was launched. The idea of this project was to provide a short-term small-scale prediction of rain based on radar images. The prediction methodology combines two methods. An extrapolation method based on a sophisticated cross correlation of images is optimised by a neural network technique. Three different application sites in Europe have been used to validate the system.

scholarly journals Ridges in the Dark Energy Survey for cosmic trough identification

2020 ◽  
Vol 500 (1) ◽  
pp. 859-870
Author(s):  
Ben Moews ◽  
Morgan A Schmitz ◽  
Andrew J Lawler ◽  
Joe Zuntz ◽  
Alex I Malz ◽  
...  
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Mass Density ◽  
Mean Shift ◽  
Large Scale Structure ◽  
Wasserstein Distance ◽  
Scale Structure ◽  
Weak Lensing ◽  
Dark Energy Survey ◽  
Energy Survey

ABSTRACT Cosmic voids and their corresponding redshift-projected mass densities, known as troughs, play an important role in our attempt to model the large-scale structure of the Universe. Understanding these structures enables us to compare the standard model with alternative cosmologies, constrain the dark energy equation of state, and distinguish between different gravitational theories. In this paper, we extend the subspace-constrained mean shift algorithm, a recently introduced method to estimate density ridges, and apply it to 2D weak lensing mass density maps from the Dark Energy Survey Y1 data release to identify curvilinear filamentary structures. We compare the obtained ridges with previous approaches to extract trough structure in the same data, and apply curvelets as an alternative wavelet-based method to constrain densities. We then invoke the Wasserstein distance between noisy and noiseless simulations to validate the denoising capabilities of our method. Our results demonstrate the viability of ridge estimation as a precursor for denoising weak lensing observables to recover the large-scale structure, paving the way for a more versatile and effective search for troughs.

scholarly journals The galaxy population within the virial radius of the Perseus cluster

2020 ◽  
Vol 640 ◽  
pp. A30
Author(s):  
H. Meusinger ◽  
C. Rudolf ◽  
B. Stecklum ◽  
M. Hoeft ◽  
R. Mauersberger ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Mass Function ◽  
Wide Field ◽  
Nearby Galaxy ◽  
Cluster Galaxy ◽  
Cluster Galaxies ◽  
The Galaxy ◽  
Galaxy Population ◽  
Galaxy Luminosity Function ◽  
Perseus Cluster

Context. The Perseus cluster is one of the most massive nearby galaxy clusters and is fascinating in various respects. Though the galaxies in the central cluster region have been intensively investigated, an analysis of the galaxy population in a larger field is still outstanding. Aims. This paper investigates the galaxies that are brighter than B ≈ 20 within a field corresponding to the Abell radius of the Perseus cluster. Our first aim is to compile a new catalogue in a wide field around the centre of the Perseus cluster. The second aim of this study is to employ this catalogue for a systematic study of the cluster galaxy population with an emphasis on morphology and activity. Methods. We selected the galaxies in a 10 square degrees field of the Perseus cluster on Schmidt CCD images in B and Hα in combination with SDSS images. Morphological information was obtained both from the “eyeball” inspection and the surface brightness profile analysis. We obtained low-resolution spectra for 82 galaxies and exploited the spectra archive of SDSS and redshift data from the literature. Results. We present a catalogue of 1294 galaxies with morphological information for 90% of the galaxies and spectroscopic redshifts for 24% of them. We selected a heterogeneous sample of 313 spectroscopically confirmed cluster members and two different magnitude-limited samples with incomplete redshift data. These galaxy samples were used to derive such properties as the projected radial velocity dispersion profile, projected radial density profile, galaxy luminosity function, supermassive black hole mass function, total stellar mass, virial mass, and virial radius, to search for indications of substructure, to select active galaxies, and to study the relation between morphology, activity, density, and position. In addition, we present brief individual descriptions of 18 cluster galaxies with conspicuous morphological peculiarities.

scholarly journals RCSLenS: testing gravitational physics through the cross-correlation of weak lensing and large-scale structure

2015 ◽  
Vol 456 (3) ◽  
pp. 2806-2828 ◽  
Author(s):  
Chris Blake ◽  
Shahab Joudaki ◽  
Catherine Heymans ◽  
Ami Choi ◽  
Thomas Erben ◽  
...  
Keyword(s):  
Large Scale ◽  
Cross Correlation ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Weak Lensing ◽  
The Cross

scholarly journals The stellar mass function of galaxies in Planck-selected clusters at 0.5 < z < 0.7: new constraints on the timescale and location of satellite quenching

2018 ◽  
Vol 618 ◽  
pp. A140 ◽  
Author(s):  
Remco F. J. van der Burg ◽  
Sean McGee ◽  
Hervé Aussel ◽  
Håkon Dahle ◽  
Monique Arnaud ◽  
...  
Keyword(s):  
Mass Function ◽  
Stellar Mass ◽  
Quenching Mechanism ◽  
Cluster Galaxy ◽  
Star Forming ◽  
Quenching Efficiency ◽  
Quenching Process ◽  
The Galaxy ◽  
Using Data ◽  
Galaxy Population

We study the abundance of star-forming and quiescent galaxies in a sample of 21 clusters at 0.5 <  z <  0.7, detected with the Planck satellite. Thanks to the large volume probed by Planck, these systems are extremely massive, and provide an excellent laboratory to study any environmental effects on their galaxies’ properties. We measure the cluster galaxy stellar mass function (SMF), which is a fundamental observable to study and constrain the formation and evolution of galaxies. Our measurements are based on homogeneous and deep multi-band photometry spanning from the u- to the Ks-band for each cluster and are supported by spectroscopic data from different programs. The galaxy population is separated into quiescent and star-forming galaxies based on their rest-frame U−V and V−J colours. The SMF is compared to that of field galaxies at the same redshifts using data from the COSMOS/UltraVISTA survey. We find that the shape of the SMF of star-forming galaxies does not depend on environment, while the SMF of quiescent galaxies has a significantly steeper low-mass slope in the clusters compared to the field. This indicates that a different quenching mechanism is at play in clusters compared to the field, accentuated by a quenched fraction that is much higher in the clusters. We estimate the environmental quenching efficiency (fEQ), that is, the probability for a galaxy that would normally be star forming in the field to be quenched due to its environment. The fEQ shows no stellar-mass dependence in any environment, but it increases from 40% in the cluster outskirts to ∼90% in the cluster centres. The radial signature of fEQ provides constraints on where the dominant quenching mechanism operates in these clusters and on what timescale. Exploring these using a simple model based on galaxy orbits obtained from an N-body simulation, we find a clear degeneracy between both parameters. For example, the quenching process may either be triggered on a long (∼3 Gyr) timescale at large radii (r  ∼  8 R500), or happen well within 1 Gyr at r <  R500. The radius where quenching is triggered is at least rquench >  0.67 R500 (95%CL). The ICM density at this location (as probed with XMM-Newton) suggests that ram-pressure stripping of the cold gas is a likely cause of quenching. In addition to this cluster-quenching mechanism, we find that 20–32%, depending on the cluster-specific quenching process, of accreted galaxies were already pre-processed (i.e. quenched by the surrounding overdensities) before they fell into the clusters.

scholarly journals The impact of baryonic physics and massive neutrinos on weak lensing peak statistics

2019 ◽  
Vol 488 (3) ◽  
pp. 3340-3357 ◽  
Author(s):  
Matthew Fong ◽  
Miyoung Choi ◽  
Victoria Catlett ◽  
Brandyn Lee ◽  
Austin Peel ◽  
...  
Keyword(s):  
Neutrino Mass ◽  
Large Scale ◽  
Cosmological Parameters ◽  
Mass Function ◽  
Weak Lensing ◽  
The Bahamas ◽  
Massive Neutrinos ◽  
Evolution Of Structure ◽  
The Impact ◽  
The Universe

ABSTRACT We study the impact of baryonic processes and massive neutrinos on weak lensing peak statistics that can be used to constrain cosmological parameters. We use the BAHAMAS suite of cosmological simulations, which self-consistently include baryonic processes and the effect of massive neutrino free-streaming on the evolution of structure formation. We construct synthetic weak lensing catalogues by ray tracing through light-cones, and use the aperture mass statistic for the analysis. The peaks detected on the maps reflect the cumulative signal from massive bound objects and general large-scale structure. We present the first study of weak lensing peaks in simulations that include both baryonic physics and massive neutrinos (summed neutrino mass Mν = 0.06, 0.12, 0.24, and 0.48 eV assuming normal hierarchy), so that the uncertainty due to physics beyond the gravity of dark matter can be factored into constraints on cosmological models. Assuming a fiducial model of baryonic physics, we also investigate the correlation between peaks and massive haloes, over a range of summed neutrino mass values. As higher neutrino mass tends to suppress the formation of massive structures in the Universe, the halo mass function and lensing peak counts are therefore modified as a function of Mν. Over most of the S/N range, the impact of fiducial baryonic physics is greater (less) than neutrinos for 0.06 and 0.12 (0.24 and 0.48) eV models. Both baryonic physics and massive neutrinos should be accounted for when deriving cosmological parameters from weak lensing observations.

scholarly journals Halo exclusion criteria impacts halo statistics

2019 ◽  
Vol 489 (3) ◽  
pp. 4170-4175 ◽  
Author(s):  
Rafael García ◽  
Eduardo Rozo
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Mass Function ◽  
Exclusion Criteria ◽  
Simulation Data ◽  
Dark Energy Survey ◽  
Current State ◽  
Statistical Precision ◽  
Energy Survey ◽  
Cluster Abundance

ABSTRACT Every halo-finding algorithm must make a critical yet relatively arbitrary choice: it must decide which structures are parent haloes, and which structures are subhaloes of larger haloes. We refer to this choice as percolation. We demonstrate that the choice of percolation impacts the statistical properties of the resulting halo catalogue. Specifically, we modify the halo-finding algorithm rockstar to construct three different halo catalogues from the same simulation data, each with identical mass definitions, but different choice of percolation. The resulting haloes exhibit significant differences in both halo abundance and clustering properties. Differences in the halo mass function reach 6 per cent for haloes of mass $10^{13}\ h^{-1}\ {\rm {\rm M}_{\odot }}$, larger than the few per cent precision necessary for current cluster abundance experiments such as the Dark Energy Survey. Comparable differences are observed in the large-scale clustering bias, while differences in the halo–matter correlation function reach 30 per cent on translinear scales. These effects can bias weak-lensing estimates of cluster masses at a level comparable to the statistical precision of current state-of-the-art experiments.

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