SEARCH · Search NASA

Results for “Sunyaev-Zeldovich effect”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

64 records · Page 4

All sources NASA NTRS DOE OSTI

DOE OSTI2023

Redshift Evolution of the Feedback–Cooling Equilibrium in the Core of 48 SPT Galaxy Clusters: A Joint Chandra–SPT–ATCA Analysis

We analyze the cooling and feedback properties of 48 galaxy clusters at redshifts 0.4 < z < 1.3 selected from the South Pole Telescope (SPT) catalogs to evolve like the progenitors of massive and well-studied systems at z ~ 0. We estimate the radio power at the brightest cluster galaxy (BCG) location of each cluster from an analysis of Australia Telescope Compact Array data. Assuming that the scaling relation between the radio power and active galactic nucleus (AGN) cavity power P cav observed at low redshift does not evolve with redshift, we use these measurements in order to estimate the expected AGN cavity power in the core of each system. We estimate the X-ray luminosity within the cooling radius L cool of each cluster from a joint analysis of the available Chandra X-ray and SPT Sunyaev–Zel'dovich (SZ) data. This allows us to characterize the redshift evolution of the P cav /L cool ratio. When combined with low-redshift results, these constraints enable investigations of the properties of the feedback–cooling cycle across 9 Gyr of cluster growth. We model the redshift evolution of this ratio measured for cool-core clusters by a log-normal distribution Log-N (α + βz, σ 2 ) and constrain the slope of the mean evolution to β = -0.05 ± 0.47. This analysis improves the constraints on the slope of this relation by a factor of two. We find no evidence of redshift evolution of the feedback–cooling equilibrium in these clusters, which suggests that the onset of radio-mode feedback took place at an early stage of cluster formation. High values of P cav /L cool are found at the BCG location of noncool-core clusters, which might suggest that the timescales of the AGN feedback cycle and the cool core–noncool core transition are different. This work demonstrates that the joint analysis of radio, SZ, and X-ray data solidifies the investigation of AGN feedback at high redshifts.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2025

Superclustering with the Atacama Cosmology Telescope and Dark Energy Survey. II. Anisotropic Large-scale Coherence in Hot Gas, Galaxies, and Dark Matter

Statistics that capture the directional dependence of the baryon distribution in the cosmic web enable unique tests of cosmology and astrophysical feedback. We use constrained oriented stacking of thermal Sunyaev–Zel’dovich (tSZ) maps to measure the anisotropic distribution of hot gas 2.5–40 Mpc away from galaxy clusters embedded in massive filaments and superclusters. The cluster selection and orientation (at a scale of ∼15 Mpc) use Dark Energy Survey (DES) Year 3 data, while expanded tSZ maps from the Atacama Cosmology Telescope Data Release 6 enable a ∼3× more significant measurement of the extended gas compared to the technique’s proof-of-concept. Decomposing stacks into cosine multipoles of order m , we detect a dipole ( m = 1) and quadrupole ( m = 2) at 8σ–10σ, as well as evidence for m = 4 signal at up to 6σ, indicating sensitivity to late-time non-Gaussianity. We compare to Cardinal simulations with spherical gas models pasted onto dark matter halos. The fiducial tSZ data can discriminate between two models that deplete pressure differently in low-mass halos (mimicking astrophysical feedback), preferring higher average pressure in extended structures. However, uncertainty in the amount of cosmic infrared background contamination reduces the constraining power. Additionally, we apply the technique to DES galaxy density and weak lensing to study for the first time their oriented relationships with tSZ. In the tSZ-to-lensing relation, averaged on 7.5 Mpc (transverse) scales, we observe dependence on redshift but not shape or radial distance. Thus, on large scales, the superclustering of gas pressure, galaxies, and total matter is coherent in shape and extent.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2022

CCAT-prime Collaboration: Science Goals and Forecasts with Prime-Cam on the Fred Young Submillimeter Telescope

Abstract We present a detailed overview of the science goals and predictions for the Prime-Cam direct-detection camera–spectrometer being constructed by the CCAT-prime collaboration for dedicated use on the Fred Young Submillimeter Telescope (FYST). The FYST is a wide-field, 6 m aperture submillimeter telescope being built (first light in late 2023) by an international consortium of institutions led by Cornell University and sited at more than 5600 m on Cerro Chajnantor in northern Chile. Prime-Cam is one of two instruments planned for FYST and will provide unprecedented spectroscopic and broadband measurement capabilities to address important astrophysical questions ranging from Big Bang cosmology through reionization and the formation of the first galaxies to star formation within our own Milky Way. Prime-Cam on the FYST will have a mapping speed that is over 10 times greater than existing and near-term facilities for high-redshift science and broadband polarimetric imaging at frequencies above 300 GHz. We describe details of the science program enabled by this system and our preliminary survey strategies.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS1998

Radio Sources in Galaxy Clusters at 28.5 GHz

We present serendipitous observations of radio sources at 28.5 GHz (1 cm), which resulted from our program to image thermal Sunyaev-Zeldovich (SZ) effect in 56 galaxy clusters. In a total area of about 0.8 degrees sq., we find 64 radio sources with fluxes down to - 0.4 mJy (> 4sigma,), and within 250" from the pointing centers. The spectral indices (S varies as v(sup -alpha) of 54 sources with published low frequency flux densities range from -0.6 approximately < alpha and alpha approximately < 2 with a mean of 0.77 +/- 0.06, and a median of 0.84. Extending low frequency surveys of radio sources towards galaxy clusters CL 0016+16, Abell 665, and Abell 2218 to 28.5 GHz, and selecting sources with S(sub l.4GHz) >/= 7 mJy to form an unbiased sample, we find a mean spectral index of 0.71 +/- 0.08 and a median of 0.71. We find 4 to 7 times more sources predicted from a low frequency survey in areas without galaxy clusters. This excess cannot be accounted for by gravitational lensing of a background radio population by cluster potentials, indicating most of the detected sources are associated with galaxy clusters. The differential source count slope, gamma is approximately 1.96 (dN/dS varies as S(exp -gamma)), is flatter than what is expected for a nonevolving Euclidean population (gamma = 2.5). For the cluster Abell 2218, the presence of unsubtracted radio sources with S(sub 28.5GHz) is approximately < 0.5 mJy (- 5 sigma), can only contribute to temperature fluctuations at a level of DeltaT is approximately 10 to 25 microK. The corresponding error due to radio point source contamination in the Hubble constant derived through a combined analysis of 28.5 GHz SZ images and X-ray emission observations ranges from 1% to 6%.

Cooray, Asantha R.↗

NASA NTRS2019

An ALMA+ACA measurement of the shock in the Bullet Cluster

Context: The thermal Sunyaev-Zeldovich (SZ) effect presents a relatively new tool for characterizing galaxy cluster merger shocks, traditionally studied through X-ray observations. Widely regarded as the “textbook example” of a cluster merger bow shock, the western, most-prominent shock front in the Bullet Cluster (1E0657-56) represents the ideal test case for such an SZ study. Aims: We aim to characterize the shock properties using deep, high-resolution interferometric SZ effect observations in combination with priors from an independent X-ray analysis. Methods: Our analysis technique relies on the reconstruction of a parametric model for the SZ signal by directly and jointly fitting data from the Atacama Large Millimeter/submillimeter Array (ALMA) and Atacama Compact Array (ACA) in Fourier space. Results: The ALMA+ACA data are primarily sensitive to the electron pressure difference across the shock front. To estimate the shock Mach number M, this difference can be combined with the value for the upstream electron pressure derived from an independent Chandra X-ray analysis. In the case of instantaneous electron-ion temperature equilibration, we find M = 2.08 (+0.12,−0.12), in ≈ 2.4σ tension with the independent constraint from Chandra, M(X)= 2.74 ± 0.25. The assumption of purely adiabatic electron temperature change across the shock leads to M = 2.53 (+0.33,−0.25), in better agreement with the X-ray estimate M(X) = 2.57 ± 0.23 derived for the same heating scenario. Conclusion: We have demonstrated that interferometric observations of the thermal SZ effect provide constraints on the properties of the shock in the Bullet Cluster that are highly complementary to X-ray observations. The combination of X-ray and SZ data yields a powerful probe of the shock properties, capable of measuring M and addressing the question of electron-ion equilibration in cluster shocks. Our analysis is however limited by systematics related to the overall cluster geometry and the complexity of the post-shock gas distribution. To overcome these limitations, a simultaneous, joint-likelihood analysis of SZ and X-ray data is needed.

Luca Di Mascolo↗

NASA NTRS2016

Weak-Lensing Mass Calibration of the Atacama Cosmology Telescope Equatorial Sunyaev-Zeldovich Cluster Sample with the Canada-France-Hawaii Telescope Stripe 82 Survey

Mass calibration uncertainty is the largest systematic effect for using clustersof galaxies to constrain cosmological parameters. We present weak lensing mass measurements from the Canada-France-Hawaii Telescope Stripe 82 Survey for galaxy clusters selected through their high signal-to-noise thermal Sunyaev-Zeldovich (tSZ) signal measured with the Atacama Cosmology Telescope (ACT). For a sample of 9 ACT clusters with a tSZ signal-to-noise greater than five, the average weak lensing mass is (4.8 plus or minus 0.8) times 10 (sup 14) solar mass, consistent with the tSZ mass estimate of (4.7 plus or minus 1.0) times 10 (sup 14) solar mass, which assumes a universal pressure profile for the cluster gas. Our results are consistent with previous weak-lensing measurements of tSZ-detected clusters from the Planck satellite. When comparing our results, we estimate the Eddington bias correction for the sample intersection of Planck and weak-lensing clusters which was previously excluded.

Battaglia, N.↗

NASA NTRS2011

The Atacama Cosmology Telescope: ACT-CL J0102-4215 "El Gordo," a Massive Merging Cluster at Redshift 0.87

We present a detailed analysis from new multi-wavelength observations of the exceptional galaxy cluster ACT-CL J0102-4915, likely the most massive, hottest, most X-ray luminous and brightest Sunyaev-Zel'dovich (SZ) effect cluster known at redshifts greater than 0.6. The Atacama Cosmology Telescope (ACT) collaboration discovered ACT-CL J0102-4915 as the most significant Sunyaev-Zeldovich (SZ) decrement in a sky survey area of 755 square degrees. Our VLT/FORS2 spectra of 89 member galaxies yield a cluster redshift, z = 0.870, and velocity dispersion, sigma(gal) +/- 1321 106 km s-1. Our Chandra observations reveal a hot and X-ray luminous system with an integrated temperature of T(X) = 14:5 +/- 0:1 keV and 0.5 2.0 keV band luminosity of L(X) = (2:19 0:11) 1045 h(exp -2)70erg s-1. We obtain several statistically consistent cluster mass estimates; using empirical mass scaling relations with velocity dispersion, X-ray Y(X) , and integrated SZ distortion, we estimate a cluster mass of M(200) = (2:16 +/- 0:32) 10(exp 15) h(exp-1) 70M compared to the Sun. We constrain the stellar content of the cluster to be less than 1% of the total mass, using Spitzer IRAC and optical imaging. The Chandra and VLT/FORS2 optical data also reveal that ACT-CL J0102-4915 is undergoing a major merger between components with a mass ratio of approximately 2 to 1. The X-ray data show significant temperature variations from a low of 6:6 +/- 0:7 keV at the merging low-entropy, high-metallicity, cool core to a high of 22 +/- 6 keV. We also see a wake in the X-ray surface brightness and deprojected gas density caused by the passage of one cluster through the other from which we estimate a merger speed of around 1300 km s(exp -1) for an assumed merger timescale of 1 Gyr. ACTCL J0102-4915 is possibly a high-redshift analog of the famous Bullet Cluster. Such a massive cluster at this redshift is rare, although consistent with the standard CDM cosmology in the lower part of its allowed mass range. Massive, high-redshift mergers like ACT-CL J0102-4915 are unlikely to be reproduced in the current generation of numerical N-body cosmological simulations.

Menanteau, Felipe↗

NASA NTRS2012

The Atacama Cosmology Telescope: ACT-CL J0102-4915 'EL GORDO', A Massive Merging Cluster at Redshift 0.87

We present a detailed analysis from new multi-wavelength observations of the exceptional galaxy cluster ACT-CL J0102−4915, likely the most massive, hottest, most X-ray luminous and brightest Sunyaev-Zel'dovich (SZ) effect cluster known at redshifts greater than 0.6. The Atacama Cosmology Telescope (ACT) collaboration discovered ACT-CL J0102−4915 as the most significant Sunyaev-Zeldovich (SZ) decrement in a sky survey area of 755 square degrees. Our VLT/FORS2 spectra of 89 member galaxies yield a cluster redshift, z = 0.870, and velocity dispersion, sigma(sub gal) = 1321+/-106 km s−1. Our Chandra observations reveal a hot and X-ray luminous system with an integrated temperature of T(sub X) = 14.5+/-1.0 keV and 0.5-2.0 keV band luminosity of L(sub X) = (2.19+/-0.11)×10(sup 45) h(sup −2)(sub 70) erg s−1. We obtain several statistically consistent cluster mass estimates; using empirical mass scaling relations with velocity dispersion, X-ray Y(sub X), and integrated SZ distortion, we estimate a cluster mass of M(sub 200a) = (2.16+/-0.32)×1015 h(sup −1)(sub 70) solar mass. We constrain the stellar content of the cluster to be less than 1% of the total mass, using Spitzer IRAC and optical imaging. The Chandra and VLT/FORS2 optical data also reveal that ACT-CL J0102−4915 is undergoing a major merger between components with a mass ratio of approximately 2 to 1. The X-ray data show significant temperature variations from a low of 6.6+/-0.7 keV at the merging low-entropy, high-metallicity, cool core to a high of 22+/-6 keV. We also see a wake in the X-ray surface brightness and deprojected gas density caused by the passage of one cluster through the other. Archival radio data at 843 MHz reveal diffuse radio emission that, if associated with the cluster, indicates the presence of an intense double radio relic, hosted by the highest redshift cluster yet. ACT-CL J0102−4915 is possibly a high-redshift analog of the famous Bullet Cluster. Such a massive cluster at this redshift is rare, although consistent with the standard ΛCDM cosmology in the lower part of its allowed mass range. Massive, highredshift mergers like ACT-CL J0102−4915 are unlikely to be reproduced in the current generation of numerical N-body cosmological simulations.

cosmology observations↗

DOE OSTI2021

Atacama Cosmology Telescope measurements of a large sample of candidates from the Massive and Distant Clusters of WISE Survey

Galaxy clusters are an important tool for cosmology, and their detection and characterization are key goals for current and future surveys. Using data from the Wide-field Infrared Survey Explorer (WISE), the Massive and Distant Clusters of WISE Survey (MaDCoWS) located 2839 significant galaxy overdensities at redshifts 0.7 ≲ z ≲ 1.5, which included extensive follow-up imaging from the Spitzer Space Telescope to determine cluster richnesses. Concurrently, the Atacama Cosmology Telescope (ACT) has produced large area millimeter-wave maps in three frequency bands along with a large catalog of Sunyaev-Zeldovich (SZ)-selected clusters as part of its Data Release 5 (DR5). Aims. We aim to verify and characterize MaDCoWS clusters using measurements of, or limits on, their thermal SZ effect signatures. Here, we also use these detections to establish the scaling relation between SZ mass and the MaDCoWS-defined richness.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS2016

Evidence for the Thermal Sunyaev Zeldovich Effect Associated with Quasar Feedback

Using a radio-quiet subsample of the Sloan Digital Sky Survey spectroscopic quasar catalogue, spanning redshifts 0.5-3.5, we derive the mean millimetre and far-infrared quasar spectral energy distributions (SEDs) via a stacking analysis of Atacama Cosmology Telescope and Herschel-Spectral and Photometric Imaging REceiver data. We constrain the form of the far-infrared emission and find 3 sigma-4 sigma evidence for the thermal Sunyaev-Zel'dovich (SZ) effect, characteristic of a hot ionized gas component with thermal energy (6.2 plus or minus 1.7) × 10 (exp 60) erg. This amount of thermal energy is greater than expected assuming only hot gas in virial equilibrium with the dark matter haloes of (1-5) × 10(exp 12) h(exp −1) solar mass that these systems are expected to occupy, though the highest quasar mass estimates found in the literature could explain a large fraction of this energy. Our measurements are consistent with quasars depositing up to (14.5 +/- 3.3)tau (sub 8)(exp -1) per cent of their radiative energy into their circumgalactic environment if their typical period of quasar activity is tau(sub 8) x 108 yr. For high quasar host masses, approximately 10(exp 13) h(exp −1) solar mass, this percentage will be reduced. Furthermore, the uncertainty on this percentage is only statistical and additional systematic uncertainties enter at the 40 per cent level. The SEDs are dust dominated in all bands and we consider various models for dust emission. While sufficiently complex dust models can obviate the SZ effect, the SZ interpretation remains favoured at the 3 sigma-4 sigma level for most models.

Sunyaev-Zeldovich (SZ)↗