A5021876652- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Superconducting and THz Device Technology
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Computational Physics and Python Applications
- Spacecraft and Cryogenic Technologies
- Particle Accelerators and Free-Electron Lasers
- Radio Wave Propagation Studies
- Astronomy and Astrophysical Research
- Superconducting Materials and Applications
- Microwave Engineering and Waveguides
- Gyrotron and Vacuum Electronics Research
- Solar and Space Plasma Dynamics
- DNA and Biological Computing
- Superconductivity in MgB2 and Alloys
- Particle physics theoretical and experimental studies
- Advanced Wireless Communication Techniques
- Climate variability and models
- Particle accelerators and beam dynamics
- Soil Moisture and Remote Sensing
- Ionosphere and magnetosphere dynamics
- Gamma-ray bursts and supernovae
Center for Astrophysics Harvard & Smithsonian
2015-2024
University of Chicago
2021-2023
Kavli Institute for Particle Astrophysics and Cosmology
2022
Harvard University
2013-2021
Harvard University Press
2018-2020
California Institute of Technology
2020
Stanford University
2016-2018
Massachusetts Institute of Technology
2014-2016
SLAC National Accelerator Laboratory
2016
Center for Strategic and International Studies
2001
We report the results of a joint analysis data from BICEP2/Keck Array and Planck. BICEP2 Keck have observed same approximately 400 deg$^2$ patch sky centered on RA 0h, Dec. $-57.5\deg$. The combined maps reach depth 57 nK deg in Stokes $Q$ $U$ band at 150 GHz. Planck has full polarization seven frequencies 30 to 353 GHz, but much less deeply any given region (1.2 $\mu$K 143 GHz). detect 150$\times$353 cross-correlation $B$-modes high significance. fit single- cross-frequency power spectra...
We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to including 2018 observing season. add additional Array observations at 220 GHz 95 previous 95/150/220 dataset. The Q/U maps now reach depths 2.8, 8.8 μK_{CMB} arcmin 95, 150, GHz, respectively, over effective area ≈600 square degrees ≈400 150 GHz. achieve a signal-to-noise ratio on polarized dust emission exceeding that Planck 353 take auto- cross-spectra between...
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...
We present results from an analysis of all data taken by the bicep2/Keck CMB polarization experiments up to and including 2015 observing season. This includes first Keck Array observations at 220 GHz additional 95 150 GHz. The Q U maps reach depths 5.2, 2.9, 26 μKCMB arcmin 95, 150, GHz, respectively, over effective area ≈400 square degrees. achieve a signal noise on polarized dust emission approximately equal that Planck 353 take auto cross spectra between these publicly available WMAP...
Abstract CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding origin evolution universe. Among science cases pursued with CMB-S4, quest for detecting primordial gravitational waves is a central driver experimental design. This work details development forecasting framework that includes power-spectrum-based semianalytic projection tool, targeted explicitly toward...
We report on the design and performance of BICEP3 instrument its first three-year data set collected from 2016 to 2018. is a 52cm aperture, refracting telescope designed observe polarization cosmic microwave background (CMB) degree angular scales at 95GHz. It started science observation South Pole in with 2400 antenna-coupled transition-edge sensor (TES) bolometers. The receiver demonstrated new technologies such as large-diameter alumina optics, Zotefoam infrared filters, flux-activated...
We report on the MIT Epoch of Reionization (MITEoR) experiment, a pathfinder low-frequency radio interferometer whose goal is to test technologies that improve calibration precision and reduce cost high-sensitivity 3D mapping required for 21 cm cosmology. MITEoR accomplishes this by using massive baseline redundancy, which enables both automated correlator reduction. demonstrate quantify power robustness redundancy scalability precision. find parameters precisely describe effect instrument...
Bicep Array is the newest multi-frequency instrument in Bicep/Keck program. It comprised of four 550mm aperture refractive telescopes observing polarization cosmic microwave background (CMB) at 30/40, 95, 150 and 220/270 GHz with over 30,000 detectors. We present an overview receiver, detailing optics, thermal, mechanical, magnetic shielding design. follows Bicep3's modular focal plane concept, upgrades to 6" wafer reduce fabrication higher detector count per module. The first receiver...
We present estimates of line-of-sight distortion fields derived from the 95 GHz and 150 data taken by BICEP2, BICEP3, Keck Array up to 2018 observing season, leading cosmological constraints a study instrumental astrophysical systematics. Cosmological are three concerning gravitational lensing large-scale structure, polarization rotation magnetic or an axion-like field, screening effect patchy reionization. measure amplitude power spectrum $A_L^{\phi\phi}=0.95 \pm 0.20$. constrain rotation,...
ABSTRACT We present measurements of polarization lensing using the 150 GHz maps, which include all data taken by BICEP2 and Keck Array Cosmic Microwave Background experiments up to including 2014 observing season (BK14). Despite their modest angular resolution ( ), excellent sensitivity (∼3 μ K-arcmin) these maps makes it possible directly reconstruct potential only information at larger scales ). From auto-spectrum reconstructed potential, we measure an amplitude spectrum be Planck ΛCDM...
We present the strongest constraints to date on anisotropies of cosmic microwave background (CMB) polarization rotation derived from 150 GHz data taken by BICEP2 Keck Array CMB experiments up and including 2014 observing season (BK14). The definition angle in BK14 maps has gone through self-calibration which overall is adjusted minimize observed $TB$ $EB$ power spectra. After this procedure, $QU$ lose sensitivity a uniform but are still sensitive rotation. This analysis places rotation,...
BICEP3 is a $550~mm$ aperture telescope with cold, on-axis, refractive optics designed to observe at the $95~GHz$ band from South Pole. It newest member of BICEP/Keck family inflationary probes specifically measure polarization cosmic microwave background (CMB) degree-angular scales. house 1280 dual-polarization pixels, which, when fully-populated, totals $\sim$9$\times$ number pixels in single Keck receiver, thus further advancing program's mapping speed. was deployed during austral summer...
We present a constraint on the tensor-to-scalar ratio, $r$, derived from measurements of cosmic microwave background (CMB) polarization $B$-modes with "delensing," whereby uncertainty $r$ contributed by sample variance gravitational lensing is reduced cross-correlating against $B$-mode template. This template constructed combining an estimate polarized CMB tracer projected large-scale structure. The large-scale-structure used map infrared Planck satellite data, while comes combination South...
Abstract We characterize Galactic dust filaments by correlating BICEP/Keck and Planck data with polarization templates based on neutral hydrogen (H i ) observations. Dust is important for both our understanding of astrophysical processes in the interstellar medium (ISM) search primordial gravitational waves cosmic microwave background (CMB). In diffuse ISM, H strongly correlated partly organized into that are aligned local magnetic field. analyze deep at 95, 150, 220 GHz, over...
Bicep3 is a 520mm aperture, compact two-lens refractor designed to observe the polarization of cosmic microwave background (CMB) at 95 GHz. Its focal plane consists modularized tiles antenna-coupled transition edge sensors (TESs), similar those used in Bicep2 and Keck Array. The increased per-receiver optical throughput compared Bicep2/Keck Array, due both its faster f=1:7 optics larger more than doubles combined mapping speed Bicep/Keck program. receiver was recently upgraded full...
We present an improved search for axionlike polarization oscillations in the cosmic microwave background (CMB) with observations from Keck Array. An all-sky, temporally sinusoidal rotation of CMB polarization, equivalent to a time-variable birefringence, is observable manifestation local axion field and potentially allows polarimeter detect dark matter directly. describe improvements method presented previous work, we demonstrate updated expanded dataset consisting 2012--2015 observing...
BICEP3 is a 520mm aperture on-axis refracting telescope observing the polarization of cosmic microwave background (CMB) at 95GHz in search B-mode signal originating from ationary gravitational waves. BICEP3's focal plane populated with modularized tiles antenna-coupled transition edge sensor (TES) bolometers. was deployed to South Pole during 2014-15 austral summer and has been operational since. During 2016-17 summer, we implemented changes optical elements that lead better noise...
We present a new method for interferometric imaging that is ideal the large fields of view and compact arrays common in 21 cm cosmology. first demonstrate with simulations two very different low-frequency interferometers, Murchison Widefield Array MIT Epoch Reionization (MITEoR) experiment. then apply to MITEoR data set collected 2013 July obtain northern sky map from 128 175 MHz at ∼2° resolution find an overall spectral index −2.73 ± 0.11. The success this bodes well upcoming redundant...
A linear polarization field on the sphere can be uniquely decomposed into an E-mode and a B-mode component. These two components are analytically defined in terms of spin-2 spherical harmonics. Maps that contain filtered modes partial sky also components. However, lack full information prevents orthogonally separating these using In this paper, we present technique for decomposing incomplete map E B eigenmodes pixel covariance observed map. This method is found to define presence both...
Precision measurements of cosmic microwave background (CMB) polarization require extreme control instrumental systematics. In a companion paper we have presented cosmological constraints from observations with the BICEP2 and Keck Array experiments up to including 2015 observing season (BK15), resulting in deepest CMB maps date statistical sensitivity tensor-to-scalar ratio $\sigma(r) = 0.020$. this work characterize beams constrain potential systematic contamination main beam shape mismatch...
We present a search for axionlike polarization oscillations in the cosmic microwave background (CMB) with observations from Keck Array. A local axion field induces an all-sky, temporally sinusoidal rotation of CMB polarization. polarimeter can thus function as direct-detection experiment dark matter. develop techniques to extract oscillation signal. Many elements method are generic polarimetry experiments and be adapted other datasets. As first demonstration, we process data 2012 observing...
This Snowmass 2021 White Paper describes the Cosmic Microwave Background Stage 4 project CMB-S4, which is designed to cross critical thresholds in our understanding of origin and evolution Universe, from highest energies at dawn time through growth structure present day. We provide an overview science case, technical design, plan.
BICEP3 is a small-aperture refracting cosmic microwave background (CMB) telescope designed to make sensitive polarization maps in pursuit of potential B-mode signal from inflationary gravitational waves. It the latest BICEP/Keck Array series CMB experiments at South Pole, which has provided most stringent constraints on inflation date. For 2016 observing season, was outfitted with full suite 2400 optically coupled detectors operating 95 GHz. In these proceedings we report far field beam...