Alexander van Engelen
A5060015839- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Superconducting and THz Device Technology
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Computational Physics and Python Applications
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- Particle physics theoretical and experimental studies
- Space Science and Extraterrestrial Life
- Relativity and Gravitational Theory
- Neutrino Physics Research
- Medical Imaging Techniques and Applications
- Astro and Planetary Science
- Radiomics and Machine Learning in Medical Imaging
Arizona State University
2020-2025
Canadian Institute for Theoretical Astrophysics
2015-2020
University of Toronto
2014-2020
Earth and Space Research
2020
The University of Tokyo
2017
Kavli Institute for the Physics and Mathematics of the Universe
2017
California Institute of Technology
2017
Jet Propulsion Laboratory
2017
McGill University
2010-2015
Stony Brook University
2013-2015
We present a measurement of the angular power spectrum cosmic microwave background (CMB) using data from South Pole Telescope (SPT). The consist 790 deg2 sky observed at 150 GHz during 2008 and 2009. Here we over multipole range 650 < ℓ 3000, where it is dominated by primary CMB anisotropy. combine this with spectra seven-year Wilkinson Microwave Anisotropy Probe (WMAP) release to constrain cosmological models. find that SPT WMAP are consistent each other and, when combined, well fit...
This book lays out the scientific goals to be addressed by next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned consist of dedicated telescopes at South Pole, high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies crossing critical thresholds in search for B-mode polarization signature primordial gravitational waves, determination number...
We present a measurement of the cosmic microwave background (CMB) temperature power spectrum using data from recently completed South Pole Telescope Sunyaev–Zel'dovich (SPT-SZ) survey. This is made observations 2540 deg2 sky with arcminute resolution at 150 GHz, and improves upon previous measurements SPT by tripling area. report CMB anisotropy over multipole range 650 < ℓ 3000. fit bandpowers, combined 7 yr Wilkinson Microwave Anisotropy Probe (WMAP7) data, six-parameter ΛCDM cosmological...
We present a detection-significance-limited catalog of 21 Sunyaev-Zel'dovich selected galaxy clusters. These clusters, along with 1 unconfirmed candidate, were identified in 178 deg^2 sky surveyed 2008 by the South Pole Telescope to depth 18 uK-arcmin at 150 GHz. Optical imaging from Blanco Cosmology Survey (BCS) and Magellan telescopes provided photometric (and some cases spectroscopic) redshift estimates, redshifts ranging z=0.15 z>1, median z = 0.74. Of confirmed three previously as...
We use South Pole Telescope data from 2008 and 2009 to detect the non-Gaussian signature in cosmic microwave background (CMB) produced by gravitational lensing measure power spectrum of projected potential. constrain ratio measured amplitude signal that expected a fiducial ΛCDM cosmological model be 0.86 ± 0.16, with no disfavored at 6.3σ. Marginalizing over models allowed Wilkinson Microwave Anisotropy Probe (WMAP7) results measurement Alens = 0.90 0.19, indicating matter fluctuations...
We present a catalog of galaxy cluster candidates, selected through their Sunyaev–Zel'dovich (SZ) effect signature in the first 720 deg2 South Pole Telescope (SPT) survey. This area was mapped with SPT 2008 and 2009 austral winters to depth ∼18 μKCMB-arcmin at 150 GHz; 550 it also ∼44 95 GHz. Based on optical imaging all 224 candidates near-infrared majority we have found and/or infrared counterparts for 158, which then classify as confirmed clusters. Of these 158 clusters, 135 were...
ABSTRACT We present the first three-frequency South Pole Telescope (SPT) cosmic microwave background (CMB) power spectra. The band powers presented here cover angular scales 2000 < ℓ 9400 in frequency bands centered at 95, 150, and 220 GHz. At these frequencies scales, a combination of primary CMB anisotropy, thermal kinetic Sunyaev–Zel'dovich (SZ) effects, radio galaxies, infrared (CIB) contributes to signal. combine Planck /HFI SPT data GHz constrain amplitude shape CIB spectrum find...
We explore extensions to the $\Lambda$CDM cosmology using measurements of cosmic microwave background (CMB) from recent SPT-SZ survey, along with data WMAP7 and $H_0$ BAO. check for consistency within between these datasets, find some tension. The CMB alone gives weak support physics beyond $\Lambda$CDM, due a slight trend relative decreasing power towards smaller angular scales. While it may be statistical fluctuation, this could also explained by several extensions. consider running index...
We present the temperature and polarization angular power spectra measured by Atacama Cosmology Telescope Polarimeter (ACTPol). analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg$^2$ of sky on celestial equator. use these spectra, with MBAC camera ACT 2008-10, in combination Planck WMAP to estimate cosmological parameters temperature, polarization, temperature-polarization cross-correlations. find new ACTPol be consistent LCDM model. The...
We use measurements from the South Pole Telescope (SPT) Sunyaev Zel'dovich (SZ) cluster survey in combination with X-ray to constrain cosmological parameters. present a statistical method that fits for scaling relations of SZ and observables mass while jointly fitting cosmology. The is generalizable multiple observables, self-consistently accounts effects selection uncertainties calibration on derived constraints. apply this data set consisting an SZ-selected catalog 18 galaxy clusters at z...
The imprint left on the cosmic microwave background (CMB) from CMB photons scattering off high-energy electrons in galaxies and clusters is known as Sunyaev-Zel'dovich (SZ) effect subject of these two papers Atacama Cosmology Telescope (ACT). ACT measurements combined with those Planck BOSS are shown to provide a rich picture electron gas thermodynamics galactic cluster medium. This can be used test improve cosmological simulations relevant for upcoming experiments.
The early dark energy (EDE) scenario aims to increase the value of Hubble constant (${H}_{0}$) inferred from cosmic microwave background (CMB) data over that found in standard cosmological model ($\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$), via introduction a new form density Universe. EDE component briefly accelerates expansion just prior recombination, which reduces physical size sound horizon imprinted CMB. Previous work has nonzero is not preferred by Planck CMB power spectrum alone,...
Abstract We present tomographic measurements of structure growth using cross-correlations Atacama Cosmology Telescope (ACT) DR6 and Planck cosmic microwave background (CMB) lensing maps with the unWISE Blue Green galaxy samples, which span redshift ranges 0.2 ≲ z 1.1 0.3 1.8, respectively. improve on prior not just by making use new, high-precision ACT maps, but also including additional spectroscopic data for calibration analyzing our a more flexible theoretical model. determine amplitude...
Abstract We investigate the impact and mitigation of extragalactic foregrounds for cosmic microwave background (CMB) lensing power spectrum analysis Atacama Cosmology Telescope (ACT) data release 6 (DR6) data. Two independent sky simulations are used to test a range strategies. demonstrate that finding then subtracting point sources, models clusters, using profile bias-hardened estimator together reduce fractional biases well below statistical uncertainties, with inferred amplitude, A lens ,...
We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months observing. Four regions sky covering a total 270 square degrees were mapped an angular resolution $1.3'$. The map noise levels four are between 11 17 $\mu$K-arcmin. present TT, TE, EE, TB, EB, BB power spectra from these regions. observed E-mode spectrum, displaying six acoustic peaks range...
We present first results on the cooling properties derived from Chandra X-ray observations of 83 high-redshift (0.3 < z 1.2) massive galaxy clusters selected by their Sunyaev–Zel'dovich signature in South Pole Telescope data. measure each cluster's central time, entropy, and mass deposition rate, compare these to those for local cluster samples. find no significant evolution ∼ 0 1 distribution properties, suggesting that cores is stable over long periods time. also average cool core entropy...
We present measurements of secondary cosmic microwave background (CMB) anisotropies and infrared (CIB) fluctuations using data from the South Pole Telescope (SPT) covering complete 2540 sq.deg. SPT-SZ survey area. Data in three frequency bands centered at 95, 150, 220 GHz, are used to produce six angular power spectra (three single-frequency auto-spectra cross-spectra) multipole range 2000 < ell 11000 (angular scales 5' > \theta 1'). These most precise 2500 these frequencies. The main...
The epoch of reionization is a milestone cosmological structure formation, marking the birth first objects massive enough to yield large numbers ionizing photons. mechanism and timescale remain largely unknown. Measurements CMB Doppler effect from bubbles embedded in large-scale velocity streams (the patchy kinetic Sunyaev-Zel'dovich effect) can constrain duration reionization. When combined with polarization measurements, evolution ionized fraction be inferred. Using new multi-frequency...
We report a measurement of the power spectrum cosmic microwave background (CMB) lensing from two seasons Atacama Cosmology Telescope Polarimeter (ACTPol) CMB data. The is extracted both temperature and polarization data using quadratic estimators. obtain results that are consistent with expectation best-fit Planck LCDM model over range multipoles L=80-2100, an amplitude A_lens = 1.06 +/- 0.15 (stat.) 0.06 (sys.) relative to Planck. Our gives sigma_8 Omega_m^0.25 0.643 0.054; including baryon...
We use microwave temperature maps from two seasons of data the Atacama Cosmology Telescope (ACTPol) at 146 GHz, together with Constant Mass CMASS galaxy sample Baryon Oscillation Spectroscopic Survey to measure kinematic Sunyaev-Ze\v{l}dovich (kSZ) effect over redshift range z = 0.4 - 0.7. positions and continuity equation obtain a reconstruction line-of-sight velocity field. stack cosmic background location each halo, weighted by corresponding reconstructed velocity. The resulting best fit...