David R. DeBoer
A5027325194- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Planetary Science and Exploration
- Space Science and Extraterrestrial Life
- Antenna Design and Optimization
- Radio Wave Propagation Studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Superconducting and THz Device Technology
- Atmospheric Ozone and Climate
- Astrophysics and Star Formation Studies
- Particle Accelerators and Free-Electron Lasers
- Electromagnetic Compatibility and Measurements
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Space Exploration and Technology
- Millimeter-Wave Propagation and Modeling
- History and Developments in Astronomy
- Soil Moisture and Remote Sensing
- Scientific Research and Discoveries
- Isotope Analysis in Ecology
- Microwave Engineering and Waveguides
University of California, Berkeley
2016-2025
University of Oxford
2025
Search for Extraterrestrial Intelligence
2001-2024
University of Washington
2024
Breakthrough Institute
2022-2023
University of California System
2021
Berkeley College
2019-2021
Astronomy and Space
2011-2015
Commonwealth Scientific and Industrial Research Organisation
2011-2015
National Radio Astronomy Observatory
2014
The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and explore earlier epochs our Cosmic Dawn ($z\sim30$). During these epochs, early stars black holes heated ionized IGM, introducing fluctuations in emission. HERA designed characterize evolution power spectrum constrain timing morphology reionization, properties first galaxies, large-scale structure,...
In this paper, we report new limits on 21cm emission from cosmic reionization based a 135-day observing campaign with 64-element deployment of the Donald C. Backer Precision Array for Probing Epoch Reionization (PAPER) in South Africa. This work extends presented Parsons et al. (2014) more collecting area, longer period, improved redundancy-based calibration, optimal fringe-rate filtering, and power-spectral analysis using quadratic estimators. The result is $2\sigma$ upper limit...
We present new constraints on the 21cm Epoch of Reionization (EoR) power spectrum derived from 3 months observing with a 32-antenna, dual-polarization deployment Donald C. Backer Precision Array for Probing (PAPER) in South Africa. In this paper, we demonstrate efficacy delay-spectrum approach to avoiding foregrounds, achieving over 8 orders magnitude foreground suppression (in $\textrm{mK}^2$). Combining procedure removing off-diagonal covariances arising instrumental systematics, achieve...
A number of experiments are currently working toward a measurement the 21 cm signal from epoch reionization (EoR). Whether or not these deliver detection cosmological emission, their limited sensitivity will prevent them providing detailed information about astrophysics reionization. In this work, we consider what types measurements be enabled by next generation larger EoR telescopes. To calculate type constraints that possible with such arrays, use simple models for instrument, foreground...
Abstract We report upper limits on the Epoch of Reionization 21 cm power spectrum at redshifts 7.9 and 10.4 with 18 nights data (∼36 hr integration) from Phase I Hydrogen Array (HERA). The show evidence for systematics that can be largely suppressed systematic models down to a dynamic range ∼10 9 respect peak foreground power. This yields 95% confidence limit <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi...
Abstract Recently, the Hydrogen Epoch of Reionization Array (HERA) has produced experiment’s first upper limits on power spectrum 21 cm fluctuations at z ∼ 8 and 10. Here, we use several independent theoretical models to infer constraints intergalactic medium (IGM) galaxies during epoch reionization from these limits. We find that IGM must have been heated above adiabatic-cooling threshold by 8, uncertainties about ionization radio background. Combining HERA with complementary observations...
Abstract We report the most sensitive upper limits to date on 21 cm epoch of reionization power spectrum using 94 nights observing with Phase I Hydrogen Epoch Reionization Array (HERA). Using similar analysis techniques as in previously reported limits, we find at 95% confidence that Δ 2 ( k = 0.34 h Mpc −1 ) ≤ 457 mK z 7.9 and 0.36 3496 10.4, an improvement by a factor 2.1 2.6, respectively. These are mostly consistent thermal noise over wide range after our data quality cuts, despite...
The Australia SKA Pathfinder (ASKAP) is a new telescope under development as world-class high-dynamic-range wide-field-of-view survey instrument. It will utilize focal plane phased array feeds on the 36 12-m antennas that compose array. large amounts of data present huge computing challenge, and ASKAP store products in an archive after near real-time pipeline processing. This powerful instrument be deployed at radio-quiet observatory, Murchison Radio-astronomy Observatory midwest region...
ABSTRACT We present a measurement of the abundance carbon monoxide in early universe, utilizing final results from CO Power Spectrum Survey (COPSS). Between 2013 and 2015, we performed observations with Sunyaev–Zel’dovich Array to measure aggregate emission <?CDATA $z\sim 3$?> galaxies intensity mapping technique. Data were collected on 19 fields, covering an area 0.7 square degrees, over frequency range $27\mbox{--}35\,\mathrm{GHz}$?> . With these data, along data analyzed COPSS I, are able...
Abstract This paper presents the design and deployment of Hydrogen Epoch Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements Reionization. First results from I array are published early 2022, system nearing completion. We describe discuss progress on commissioning future upgrades. As designated Square Kilometre pathfinder instrument, we also show number “case studies” that investigate systematics seen while system, which...
This work describes a new instrument optimized for detection of the neutral hydrogen 21cm power spectrum between redshifts 0.5-1.5: Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) Array. BAOBAB will build on efforts first generation experiments which are targeting signal from Epoch Reionization at z ~ 10. At 1, emission in self-shielded overdense halos also presents an accessible signal, since dominant, synchrotron foreground is considerably fainter than redshift The principle...
This paper describes the system architecture of a newly constructed radio telescope - Boolardy Engineering Test Array, which is prototype Australian Square Kilometre Array Pathfinder telescope. Phased array feed technology used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test described here 6-antenna interferometer, fitted signal processing hardware capable forming at least 9 dual-polarisation simultaneously, allowing several...
The epoch of reionization power spectrum is expected to evolve strongly with redshift, and it this variation cosmic history that will allow us begin place constraints on the physics reionization. primary obstacle measurement EoR bright foreground emission. We present an analysis observations from Donald C. Backer Precision Array for Probing Epoch Reionization (PAPER) telescope which new limits HI over redshift range $7.5<z<10.5$, extending previously published single results cover full...
Radio wavelengths can probe altitudes in Jupiter's atmosphere below its visible cloud layers. We used the Very Large Array to map this unexplored region down ~8 bar, ~100 kilometers clouds. Our maps reveal a dynamically active planet at pressures less than 2 3 bar. A radio-hot belt exists, consisting of relatively transparent regions (a low ammonia concentration, NH3 being dominant source opacity) probing depths over bar; these probably coincide with 5-micrometer hot spots. Just south we...
The Breakthrough Listen Initiative is undertaking a comprehensive search for radio and optical signatures from extraterrestrial civilizations. An integral component of the project design implementation wide-bandwidth data recorder signal processing systems. capabilities these systems, particularly at frequencies, directly determine survey speed; further, given fixed observing time spectral coverage, they sensitivity as well. Here, we detail recording system deployed 100 m aperture Robert C....
We report the discovery of a new 21-cm HI absorption system using commissioning data from Boolardy Engineering Test Array Australian Square Kilometre Pathfinder (ASKAP). Using 711.5 - 1015.5 MHz band ASKAP we were able to conduct blind search for line in continuous redshift range between $z = 0.4$ and 1.0, which has, until now, remained largely unexplored. The is detected at 0.44$ towards GHz-peaked spectrum radio source PKS B1740$-$517 demonstrates ASKAP's excellent capability performing...
Breakthrough Listen is the most comprehensive and sensitive search for extraterrestrial intelligence (SETI) to date, employing a collection of international observational facilities including both radio optical telescopes. During first three years program, thousands targets have been observed with Green Bank Telescope (GBT), Parkes Automated Planet Finder. At GBT Parkes, observations performed ranging from 700 MHz 26 GHz, raw data volumes averaging over 1PB / day. A pseudo-real time software...
We present constraints on both the kinetic temperature of intergalactic medium (IGM) at z=8.4, and models for heating IGM high-redshift with X-ray emission from first collapsed objects. These are derived using a semi-analytic method to explore new measurements 21 cm power spectrum Donald C. Backer Precision Array Probing Epoch Reionization (PAPER), which were presented in companion paper, Ali et al. (2015). Twenty-one spectra amplitudes hundreds mK^2 can be generically produced if is...
Abstract The Epoch of Reionization (EoR) is an uncharted era in our universe’s history during which the birth first stars and galaxies led to ionization neutral hydrogen intergalactic medium. There are many experiments investigating EoR by tracing 21 cm line hydrogen. Because this signal very faint difficult isolate, it crucial develop analysis techniques that maximize sensitivity suppress contaminants data. It also imperative understand trade-offs between different methods their effects on...
ABSTRACT Unaccounted for systematics from foregrounds and instruments can severely limit the sensitivity of current experiments detecting redshifted 21 cm signals Epoch Reionization (EoR). Upcoming are faced with a challenge to deliver more collecting area per antenna element without degrading data systematics. This paper its companions show that dishes viable achieving this balance using Hydrogen Array (HERA) as an example. Here, we specifically identify spectral associated power pattern...
We present a study of internal reflection and cross coupling systematics in Phase I the Hydrogen Epoch Reionization Array (HERA). In companion paper, we outlined mathematical formalism for such presented algorithms modeling removing them from data. this work, apply these techniques to data HERA's first observing season as method demonstration. The show evidence that, without removal, would hinder detection 21 cm power spectrum targeted EoR line-of-sight modes range 0.2 < k_parallel 0.5\ h^-1...
Abstract We present limits on the 21 cm power spectrum from Epoch of Reionization using data 64 antenna configuration Donald C. Backer Precision Array for Probing (PAPER) analyzed through a pipeline independent previous PAPER analyses. Previously reported results have been found to contain significant signal loss. Several lossy steps pipelines not included in this analysis, namely delay-based foreground filtering, optimal fringe-rate and empirical covariance-based estimators. Steps that...
Abstract A line of sight toward the Galactic Center (GC) offers largest number potentially habitable systems any direction in sky. The Breakthrough Listen program is undertaking most sensitive and deepest targeted SETI surveys GC. Here, we outline our observing strategies with Robert C. Byrd Green Bank Telescope (GBT) Parkes telescope to conduct 600 hr deep observations across 0.7–93 GHz. We report preliminary results from survey for extraterrestrial intelligence (ETI) beacons 1–8 GHz 7.0...