N. W. Halverson
A5004576908- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Superconducting and THz Device Technology
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Geophysics and Gravity Measurements
- Microwave Engineering and Waveguides
- Gamma-ray bursts and supernovae
- Physics of Superconductivity and Magnetism
- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Calibration and Measurement Techniques
- Antenna Design and Optimization
- Particle physics theoretical and experimental studies
- Computational Physics and Python Applications
- Optical Coatings and Gratings
- Thermal Radiation and Cooling Technologies
- Satellite Communication Systems
- Advanced Thermodynamic Systems and Engines
- Scientific Research and Discoveries
- Advanced Antenna and Metasurface Technologies
University of Colorado System
2008-2025
University of Colorado Boulder
2015-2024
Institut de Recherche en Astrophysique et Planétologie
2024
Laboratory for Atmospheric and Space Physics
2014-2023
Université Paris-Sud
2020
Université Toulouse III - Paul Sabatier
2020
Cardiff University
2009-2020
Centre National de la Recherche Scientifique
2020
Stockholm University
2020
Institut d'Astrophysique Spatiale
2020
We present measurements of anisotropy in the cosmic microwave background (CMB) from first season observations with Degree Angular Scale Interferometer (DASI). The instrument was deployed at South Pole austral summer 1999-2000, and we made throughout following winter. a measurement CMB angular power spectrum range 100 < l 900 nine bands fractional uncertainties 10%-20% dominated by sample variance. In this paper, review formalism used analysis, particular use constraint matrices to project...
The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset Gregorian telescope with 966 pixel, multicolor, millimeter-wave, bolometer camera. It located at the Amundsen-Scott station in Antarctica. design of SPT emphasizes careful control spillover and scattering, to minimize noise false signals due ground pickup. key initial project large-area survey wavelengths 3, 2, 1.3 mm, detect clusters galaxies via Sunyaev-Zel'dovich effect measure small-scale angular power spectrum cosmic...
We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg$^2$ South Pole Telescope (SPT) data. This work represents the complete sample detected at high significance in 2500-square-degree SPT-SZ survey, which was completed 2011. A total 677 (409) cluster candidates are identified above signal-to-noise threshold $\xi$ =4.5 (5.0). Ground- and space-based optical near-infrared (NIR) imaging confirms overdensities similarly colored galaxies...
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...
We present the science case, reference design, and project plan for Stage-4 ground-based cosmic microwave background experiment CMB-S4.
We describe the design of a new polarization sensitive receiver, spt-3g, for 10-meter South Pole Telescope (spt). The spt-3g receiver will deliver factor ~20 improvement in mapping speed over current spt-pol. sensitivity enable advance from statistical detection B-mode anisotropy power to high signal-to-noise measurements individual modes, i.e., maps. This lead precise (~0.06 eV) constraints on sum neutrino masses with potential directly address mass hierarchy. It allow separation lensing...
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...
Gravitational lensing of the cosmic microwave background generates a curl pattern in observed polarization. This "B-mode" signal provides measure projected mass distribution over entire observable Universe and also acts as contaminant for measurement primordial gravity-wave signals. In this Letter we present first detection gravitational B modes, using first-season data from polarization-sensitive receiver on South Pole Telescope (SPTpol). We construct template B-mode by combining E-mode...
We report the results of an 87 square-degree point-source survey centered at R.A. 5h30m, decl. -55 deg. taken with South Pole Telescope (SPT) 1.4 and 2.0 mm wavelengths arc-minute resolution milli-Jansky depth. Based on ratio flux in two bands, we separate detected sources into populations, one consistent synchrotron emission from active galactic nuclei (AGN) thermal dust. present source counts for each population 11 to 640 mJy 4.4 800 mm. The are dominated by synchrotron-dominated across...
Using the Atacama Large Millimeter/submillimeter Array, we have conducted a blind redshift survey in 3 mm atmospheric transmission window for 26 strongly lensed dusty star-forming galaxies (DSFGs) selected with South Pole Telescope. The sources were to S1.4 > 20 mJy and dust-like spectrum and, remove low-z sources, not bright radio (S843 MHz < 6 mJy) or far-infrared counterparts (S100 μm 1 Jy, S60 200 mJy). We robustly detect 44 line features our survey, which identify as redshifted emission...
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 report a measurement of the B-mode polarization power spectrum in cosmic microwave background (CMB) using Polarbear experiment Chile. The faint signature carries information about universe's entire history gravitational structure formation, and inflation that may have occurred very early universe. Our covers angular multipole range 500 < ℓ 2100 is based on observations an effective sky area 25 with 35 resolution at 150 GHz. On these scales, lensing CMB by intervening universe expected to...
(abridged) We present cosmological constraints obtained from galaxy clusters identified by their Sunyaev-Zel'dovich effect signature in the 2500 square degree South Pole Telescope Sunyaev Zel'dovich survey. consider 377 cluster candidates at z>0.25 with a detection significance greater than five, corresponding to 95% purity threshold for compute on models using measured abundance as function of mass and redshift. include additional multi-wavelength observations, including Chandra X-ray data...
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 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...
We present measurements of the $E$-mode ($EE$) polarization power spectrum and temperature-$E$-mode ($TE$) cross-power cosmic microwave background using data collected by SPT-3G, latest instrument installed on South Pole Telescope. This analysis uses observations a $1500\text{ }\text{ }{\mathrm{deg}}^{2}$ region at 95, 150, 220 GHz taken over four-month period in 2018. report binned values $EE$ $TE$ spectra angular multipole range $300\ensuremath{\le}\ensuremath{\ell}<3000$, multifrequency...
We present measurements of the $E$-mode polarization angular auto-power spectrum ($EE$) and temperature-$E$-mode cross-power ($TE$) cosmic microwave background (CMB) using 150 GHz data from three seasons SPTpol observations. report power spectra over spherical harmonic multipole range $50 < \ell \leq 8000$, detect nine acoustic peaks in $EE$ with high signal-to-noise ratio. These are most sensitive to date $TE$ at $\ell > 1050$ 1475$, respectively. The observations cover 500 deg$^2$, a...