B. A. Benson
A5030495784- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Superconducting and THz Device Technology
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Adaptive optics and wavefront sensing
- Physics of Superconductivity and Magnetism
- Astronomical Observations and Instrumentation
- Microwave Engineering and Waveguides
- History and Developments in Astronomy
- Radio Frequency Integrated Circuit Design
- Geophysics and Gravity Measurements
- Particle physics theoretical and experimental studies
- Advanced Thermodynamic Systems and Engines
- Particle Accelerators and Free-Electron Lasers
- Spacecraft Design and Technology
- Satellite Communication Systems
- Solar and Space Plasma Dynamics
University of Chicago
2016-2025
Fermi National Accelerator Laboratory
2016-2025
Netherlands Institute for Radio Astronomy
2020-2025
Kavli Institute for Particle Astrophysics and Cosmology
2012-2023
Argonne National Laboratory
2016-2023
Cardiff University
2023
McGill University
2023
University of Illinois Chicago
2023
University of Missouri–Kansas City
2018
Lawrence Berkeley National Laboratory
2015
We present the first Event Horizon Telescope (EHT) observations of Sagittarius A* (Sgr A$^*$), Galactic center source associated with a supermassive black hole. These were conducted in 2017 using global interferometric array eight telescopes operating at wavelength $\lambda=1.3\,{\rm mm}$. The EHT data resolve compact emission region intrahour variability. A variety imaging and modeling analyses all support an image that is dominated by bright, thick ring diameter $51.8 \pm 2.3$\,\uas (68\%...
We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg$^2$ $griz$ imaging data the first year Dark Energy Survey (DES Y1). combine three two-point functions: (i) cosmic shear correlation function 26 million source galaxies in four redshift bins, (ii) angular autocorrelation 650,000 luminous red five (iii) galaxy-shear cross-correlation positions shears. To demonstrate robustness these results, we use independent pairs...
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.
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...
Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This synchrotron radiation probes structure of magnetic fields and plasma properties near hole. Here we compare resolved polarization observed by EHT, along with simultaneous unresolved Atacama Large Millimeter/submillimeter Array, to expectations from theoretical models. The low fractional linear image suggests that is scrambled scales...
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...
Astrophysical black holes are expected to be described by the Kerr metric. This is only stationary, vacuum, axisymmetric metric, without electromagnetic charge, that satisfies Einstein's equations and does not have pathologies outside of event horizon. We present new constraints on potential deviations from prediction based 2017 EHT observations Sagittarius A* (Sgr A*). calibrate relationship between geometrically defined hole shadow observed size ring-like images using a library includes...
Abstract In this paper we provide a first physical interpretation for the Event Horizon Telescope's (EHT) 2017 observations of Sgr A*. Our main approach is to compare resolved EHT data at 230 GHz and unresolved non-EHT from radio X-ray wavelengths predictions library models based on time-dependent general relativistic magnetohydrodynamics simulations, including aligned, tilted, stellar-wind-fed simulations; radiative transfer performed assuming both thermal nonthermal electron distribution...
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...
Abstract In 2017 April, the Event Horizon Telescope (EHT) observed near-horizon region around supermassive black hole at core of M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology. This structure originates from synchrotron emission produced by relativistic plasma located in immediate vicinity hole. Here we present corresponding linear-polarimetric EHT images center M87. We find that only part ring is significantly polarized. The...
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...
Abstract We present the first event-horizon-scale images and spatiotemporal analysis of Sgr A* taken with Event Horizon Telescope in 2017 April at a wavelength 1.3 mm. Imaging has been conducted through surveys over wide range imaging assumptions using classical CLEAN algorithm, regularized maximum likelihood methods, Bayesian posterior sampling method. Different prescriptions have used to account for scattering effects by interstellar medium toward Galactic center. Mitigation rapid intraday...
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 combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $\Lambda$CDM model minimal neutrino mass ($\sum m_\nu = 0.06$ eV) we find $H_0=67.2^{+1.2}_{-1.0}$ km/s/Mpc (68% CL). This result is completely independent of constant measurements based on distance ladder, Cosmic Microwave Background (CMB) anisotropies (both temperature polarization), strong...
We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at position supermassive black hole Sagittarius A* (Sgr A*), collected during 2017 April 5--11 campaign. The observations were carried out with eight facilities six locations across globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. majority emission arises from horizon scales, where intrinsic structural variability is detected on timescales minutes hours. effects...
In this paper we quantify the temporal variability and image morphology of horizon-scale emission from Sgr A*, as observed by EHT in 2017 April at a wavelength 1.3 mm. We find that A* data exhibit exceeds what can be explained uncertainties or effects interstellar scattering. The magnitude substantial fraction correlated flux density, reaching $\sim$100\% on some baselines. Through an exploration simple geometric source models, demonstrate ring-like morphologies provide better fits to than...