Thibaut Louis
A5057387448- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Superconducting and THz Device Technology
- Astronomy and Astrophysical Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Advanced Thermodynamic Systems and Engines
- Geophysics and Gravity Measurements
- Physics of Superconductivity and Magnetism
- Astrophysics and Star Formation Studies
- Particle physics theoretical and experimental studies
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Scientific Research and Discoveries
- Adaptive optics and wavefront sensing
- Climate variability and models
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Calibration and Measurement Techniques
- Advanced Frequency and Time Standards
- Railway Systems and Energy Efficiency
- Precipitation Measurement and Analysis
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2020-2025
Université Paris-Saclay
2017-2025
Institut National de Physique Nucléaire et de Physique des Particules
2019-2024
Centre National de la Recherche Scientifique
2017-2024
Université Paris-Sud
2017-2021
Japan Aerospace Exploration Agency
2020
Institut d'Astrophysique de Paris
2016-2020
Observatoire de Paris
2020
GANIL
2018-2020
Centre National d'Études Spatiales
2020
We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from Atacama Cosmology Telescope, using data taken 2013-2016 at 98 150 GHz. The cover more than 17,000 deg$^2$, deepest 600 deg$^2$ with noise levels below 10 $\mu$K-arcmin. use power spectrum derived almost 6,000 these to constrain cosmology. ACT enable a measurement angular scale features in both divergence-like anisotropy, tracing velocity density last-scattering. From one...
We present constraints on cosmological and astrophysical parameters from high-resolution microwave background maps at 148 GHz 218 made by the Atacama Cosmology Telescope (ACT) in three seasons of observations 2008 to 2010. A model primary secondary foreground is fit map power spectra lensing deflection spectrum, including contributions both thermal Sunyaev-Zeldovich (tSZ) effect kinematic (kSZ) effect, Poisson correlated anisotropy unresolved infrared sources, radio correlation between tSZ...
We present the temperature and polarization angular power spectra of CMB measured by Atacama Cosmology Telescope (ACT) from 5400 deg$^2$ 2013-2016 survey, which covers $>$15000 at 98 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related this, show numerous checks for systematic error done before unblinding. Using likelihood cosmological constrain secondary sources anisotropy foreground emission, derive "CMB-only" spectrum that extends...
We present the temperature power spectra of cosmic microwave background (CMB) derived from three seasons data Atacama Cosmology Telescope (ACT) at 148 GHz and 218 GHz, as well cross-frequency spectrum between two channels. detect correct for contamination due to Galactic cirrus in our equatorial maps. results a number tests possible systematic error conclude that any effects are not significant compared statistical errors we quote. Where they overlap, cross-correlate ACT South Pole (SPT)...
We present the temperature and polarization angular power spectra measured by Atacama Cosmology Telescope Polarimeter (ACTPol). analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg$^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...
Future cosmological measurements should enable the sum of neutrino masses to be determined indirectly through their effects on expansion rate Universe and clustering matter. We consider prospects for gravitationally lensed cosmic microwave background (CMB) anisotropies baryon acoustic oscillations (BAOs) in galaxy distribution, examining how projected uncertainty $\ensuremath{\approx}15\text{ }\text{ }\mathrm{meV}$ mass (a $4\ensuremath{\sigma}$ detection minimal mass) might reached over...
We present cosmological constraints from a gravitational lensing mass map covering 9400 sq. deg. reconstructed CMB measurements made by the Atacama Cosmology Telescope (ACT) 2017 to 2021. In combination with BAO (from SDSS and 6dF), we obtain amplitude of matter fluctuations $\sigma_8 = 0.819 \pm 0.015$ at 1.8% precision, $S_8\equiv\sigma_8({\Omega_{\rm m}}/0.3)^{0.5}=0.840\pm0.028$ Hubble constant $H_0= (68.3 1.1)\, \text{km}\,\text{s}^{-1}\,\text{Mpc}^{-1}$ 1.6% precision. A joint...
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,...
We present new measurements of cosmic microwave background (CMB) lensing over $9400$ sq. deg. the sky. These are derived from Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which consists five seasons ACT temperature and polarization observations. determine amplitude power spectrum at $2.3\%$ precision ($43\sigma$ significance) using a novel pipeline that minimizes sensitivity to foregrounds noise properties. To ensure our results robust, we analyze an extensive set null...
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...
Observations of the millimeter sky contain valuable information on a number signals, including blackbody cosmic microwave background (CMB), Galactic emissions, and Compton-y distortion due to thermal Sunyaev-Zel'dovich (tSZ) effect. Extracting new insight into cosmological astrophysical questions often requires combining multiwavelength observations spectrally isolate one component. In this work, we present arc-minute-resolution map, which traces out line-of-sight-integrated electron...
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...
The Atacama Cosmology Telescope has measured the angular power spectra of microwave fluctuations to arcminute scales at frequencies 148 and 218 GHz, from three seasons data. At small in primordial Cosmic Microwave Background (CMB) become increasingly obscured by extragalactic foregounds secondary CMB signals. We present results a nine-parameter model describing these effects, including thermal kinematic Sunyaev-Zel'dovich (tSZ kSZ) power; clustered Poisson-like Infrared (CIB) sources, their...
The Atacama Cosmology Telescope (ACT) is designed to make high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3 degree field view, 100 mK cryogenics with continuous cooling, and meta material anti-reflection coatings. ACTPol comprises three arrays separate cryogenic optics: two central frequency 148 GHz...
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...
Future arcminute resolution polarization data from ground-based Cosmic Microwave Background (CMB) observations can be used to estimate the contribution temperature power spectrum primary anisotropies and uncover signature of reionization near ℓ=1500 in small angular-scale measurements. Our projections are based on combining expected small-scale E-mode measurements Advanced ACTPol range 300<ℓ<3000 with simulated full Planck mission low intermediate ℓ region, 2<ℓ<2000. We show that six basic...
We present a catalog of 182 galaxy clusters detected through the Sunyaev-Zel'dovich effect by Atacama Cosmology Telescope in contiguous 987.5 deg$^{2}$ field. The were as SZ decrements applying matched filter to 148 GHz maps that combine original ACT equatorial survey with data from first two observing seasons using ACTPol receiver. Optical/IR confirmation and redshift measurements come combination large public surveys our own follow-up observations. Where necessary, we measured photometric...
We construct cosmic microwave background lensing mass maps using data from the 2014 and 2015 seasons of observations with Atacama Cosmology Telescope (ACT). These cover 2100 square degrees sky overlap a wide variety optical surveys. The are signal dominated on large scales have fidelity such that their correlation infrared is clearly visible by eye. also create thermal Sunyaev-Zel'dovich contamination removed novel cleaning procedure only slightly degrades signal-to-noise ratio....
Optimal analyses of many signals in the cosmic microwave background (CMB) require map-level extraction individual components sky, rather than measurements at power spectrum level alone. To date, nearly all component separation CMB has been performed exclusively using satellite data. In this paper, we implement a method based on internal linear combination (ILC) approach which have designed to optimally account for anisotropic noise (in 2D Fourier domain) often found ground-based experiments....
This paper presents a maximum-likelihood algorithm for combining sky maps with disparate coverage, angular resolution and spatially varying anisotropic noise into single map of the sky. We use this to merge hundreds individual covering 2008-2018 ACT observing seasons, resulting in by far deepest released so far. also combine full Planck maps, that have best features both ACT: Planck's nearly white on intermediate large scales ACT's high-resolution sensitivity small scales. The cover over...
We measure the cross-correlation of Atacama Cosmology Telescope CMB lensing convergence maps with quasar made from Sloan Digital Sky Survey DR8 SDSS-XDQSO photometric catalog. The lensing-quasar cross-power spectrum is detected for first time at a significance 3.8 sigma, which directly confirms that distribution traces mass high redshifts z>1. Our detection passes number null tests and systematic checks. Using this spectrum, we amplitude linear bias assuming template its redshift...
Recent data from the WMAP, ACT and SPT experiments provide precise measurements of cosmic microwave background temperature power spectrum over a wide range angular scales. The combination these observations is well fit by standard, spatially flat LCDM cosmological model, constraining six free parameters to within few percent. scalar spectral index, n_s = 0.9690 +/- 0.0089, less than unity at 3.6 sigma level, consistent with simple models inflation. damping tail high resolution, combined...
We present evidence of the gravitational lensing cosmic microwave background by 10(13) solar mass dark matter halos. Lensing convergence maps from Atacama Cosmology Telescope Polarimeter (ACTPol) are stacked at positions around 12 000 optically selected CMASS galaxies SDSS-III/BOSS survey. The mean signal is consistent with simulated halo profiles and favored over a null 3.2σ significance. This result demonstrates potential to probe distribution in galaxy group cluster