A5041165676- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- International Law and Human Rights
- European Criminal Justice and Data Protection
- Judicial and Constitutional Studies
- Stellar, planetary, and galactic studies
- European and International Law Studies
- Legal principles and applications
- Geophysics and Gravity Measurements
- Astronomy and Astrophysical Research
- Superconducting and THz Device Technology
- Criminal Law and Evidence
- Astro and Planetary Science
- Conflict of Laws and Jurisdiction
- Pulsars and Gravitational Waves Research
- Structural Behavior of Reinforced Concrete
- Law, logistics, and international trade
- Mechanical Behavior of Composites
- Antenna Design and Optimization
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
University of Cambridge
2010-2025
University of Glasgow
2017-2024
University of Southampton
2014-2023
Australian National University
1978-2023
Texas A&M University
2023
University of Chicago
2023
Heidelberg University
2023
University of Nottingham
2023
University of Washington
2023
Eindhoven University of Technology
2023
We present results of the coordinated observing campaign that made first subarcsecond localization a Fast Radio Burst, FRB 121102. During this campaign, we simultaneous detection an burst by multiple telescopes: VLA at 3 GHz and Arecibo Observatory 1.4 GHz. Of nine bursts detected Very Large Array GHz, four had coverage other observatories. use multi-observatory constraints modeling seen only to confirm earlier showing spectra are not well modeled power law. find characterized ~500 MHz...
The Arcminute Microkelvin Imager is a pair of interferometer arrays operating with six frequency channels spanning 13.9-18.2 GHz, very high sensitivity to angular scales 30''-10'. telescope aimed principally at Sunyaev-Zel'dovich imaging clusters galaxies. We discuss the design and describe explain its electronic mechanical systems.
ABSTRACT We present QUIJOTE intensity and polarization maps in four frequency bands centred around 11, 13, 17, 19 GHz, covering approximately 29 000 deg2, including most of the northern sky region. These result from 9000 h observations taken between May 2013 June 2018 with first multifrequency instrument (MFI), have angular resolutions 1°, sensitivities within range 35–40 µK per 1° beam, being a factor ∼2–4 worse intensity. discuss data processing pipeline employed, basic characteristics...
We present deep Ka-band (ν≈ 33 GHz) observations of the cosmic microwave background (CMB) made with extended Very Small Array (VSA). This configuration produces a naturally weighted synthesized FWHM beamwidth ∼11 arcmin, which covers an ℓ range 300 to 1500. On these scales, foreground extragalactic sources can be major source contamination CMB anisotropy. problem has been alleviated by identifying at 15 GHz Ryle Telescope and then monitoring using single-baseline interferometer collocated...
The well-known Fourier Transform relationship between the complex illumination function and diffraction pattern of an aperture has been applied to measurements reception patterns dishes 5-km telescope; results have provided contour maps showing distribution reflector surface errors with accuracy ~ 0.1 mm. By repeating at different zenith angles structural deflections due gravity were investigated.
In this paper, we present Q-U-I JOint Tenerife Experiment (QUIJOTE) 10–20 GHz observations (194 h in total over ≈250 deg2) intensity and polarisation of G159.6-18.5, one the most widely studied regions harbouring anomalous microwave emission (AME). By combining with other publicly available data, achieve precise spectrum AME measured to date an individual region, 13 independent data points between 10 50 being dominated by emission. The four QUIJOTE provide first confirmation downturn at low...
The Arcminute Microkelvin Imager (AMI) telescopes located at the Mullard Radio Astronomy Observatory near Cambridge have been significantly enhanced by implementation of a new digital correlator with 1.2 MHz spectral resolution. This system has replaced 750-MHz resolution analogue lag-based correlator, and was designed to mitigate effects radio frequency interference, particularly from geostationary satellites that contaminate observations low declinations. upgraded instrument consists 18...
Abstract The deaths of massive stars are sometimes accompanied by the launch highly relativistic and collimated jets. If jet is pointed towards Earth, we observe a ‘prompt’ gamma-ray burst due to internal shocks or magnetic reconnection events within jet, followed long-lived broadband synchrotron afterglow as interacts with circumburst material. While there solid observational evidence that emission from multiple contributes signature, detailed studies reverse shock, which travels back into...
We have observed the cosmic microwave background (CMB) in three regions of sky using Very Small Array (VSA) an extended configuration with antennas beamwidth 2° at 34 GHz. Combined data from previous VSA observations a more compact array larger beamwidth, we measure power spectrum primordial CMB anisotropies between angular multipoles ℓ= 160 and 1400. Such measurements high ℓ are vital for breaking degeneracies parameter estimation other cosmological data. The clearly resolves first acoustic...
The fields chosen for the first observations of cosmic microwave background with Very Small Array have been surveyed Ryle Telescope at 15 GHz. We covered three regions around RA 00h20m Dec +30deg, 09h40m +32deg and 15h40m +43deg (J2000), an area 520 deg^2. There are 465 sources above current completeness limit approximately 25 mJy, although a total ~760 detected, some as faint 10 mJy. This paper describes our techniques observation data analysis; it also includes source counts discussion...
We present the results of a |$^{12}\text {CO}\enspace J = 2-1$| survey sample IRAS sources representative low-mass young (|$\lesssim 2.5\times 10^5$| yr) stellar objects embedded in dark molecular clouds. Several new outflows were identified and mapped. The reveals that |$\gtrsim70$| per cent have associated outflow activity, suggesting most, if not all, stars undergo at some stage during their early evolution. statistically implied durations are |$\sim 1.5-2\times yr, i.e. an order...
The QUIJOTE (Q-U-I JOint Tenerife) CMB Experiment will operate at the Teide Observatory with aim of characterizing polarisation and other processes Galactic extragalactic emission in frequency range 10-40GHz large medium angular scales. first two telescopes multi-frequency (10-30GHz) instrument are already built have been tested laboratory. QUIJOTE-CMB be a valuable complement low frequencies for Planck mission, required sensitivity to detect primordial gravitational-wave component if...
We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, conjunction with a variety of other cosmic microwave background (CMB) and external priors. Within flat Λ cold dark matter (ΛCDM) model, we find that inclusion high-resolution from VSA modifies limits on as compared to those suggested Wilkinson Microwave Anisotropy Probe (WMAP) alone, while still remaining compatible their estimates. Ωbh2= 0.0234+0.0012−0.0014, Ωdmh2=...
We have observed an area of approximatley 27 deg^2 to rms noise level less than 0.2 mJy at 15.7 GHz, using the Arcminute Microkelvin Imager Large Array. These observations constitute most sensitive radio-source survey any extent (greater approximately deg^2) above 1.4 GHz. This paper presents techniques employed for observing, mapping and source extraction. used a systematic procedure extracting information producing catalogues, from maps with varying uv-coverage. performed simulations test...
The first results from the Tenth Cambridge (10C) Survey of Radio Sources, carried out using AMI Large Array (LA) at an observing frequency 15.7 GHz, are presented. survey fields cover area approximately 27 sq. degrees to a flux-density completeness 1 mJy. Results for some deeper areas, covering 12 degrees, wholly contained within total areas and complete 0.5 mJy, also both is estimated be least 93 per cent. source catalogue contains 1897 entries available www.mrao.cam.ac.uk/surveys/10C. It...
We present the power spectrum of fluctuations in cosmic microwave background detected by Very Small Array (VSA) its first season observations compact configuration. find clear detections and second acoustic peaks at ℓ≈ 200 ≈550, plus detection on scales up to ℓ= 800. The VSA is very good agreement with results BOOMERanG, DASI MAXIMA telescopes despite differing potential systematic errors.
We have observed a 2° × area of sky at frequencies 15.5 and 16.5 GHz with the Cambridge Cosmic Anisotropy Telescope (CAT). Comparison earlier measurements 13.5 shows that structure arises predominantly from cosmic microwave background. The broadband power, averaged over spherical harmonic multipole orders between 330 680, is (ΔT/T) = 2.0+ 0.4−0.4 10-5, which consistent predictions standard COBE-normalized, cold dark matter model.
Accurate calibration of data is essential for the current generation CMB experiments. Using from Very Small Array (VSA), we describe procedures which will lead to an accuracy 1 percent or better experiments such as VSA and CBI. Particular attention paid stability receiver systems, quality site frequent observations reference sources. At 30 GHz careful correction atmospheric emission absorption shown be achieving precision. The sources a relative flux density was achieved included Cas A, Cyg...
The dust feature G159.6--18.5 in the Perseus region has previously been observed with COSMOSOMAS experiment \citep{Watson:05} on angular scales of $\approx$ 1$^{\circ}$, and was found to exhibit anomalous microwave emission. We present new observations this feature, performed Very Small Array (VSA) at 33 GHz, help increase understanding nature On VSA ($\approx$ 10 -- 40$^{\prime}$), consists five distinct components, each which have individually analysed. All these components are an excess...
ABSTRACT As a means of characterizing the diffusion parameters fiber reinforced polymer (FRP) composites within relatively short time frame, potential use term tests on epoxy films to predict long‐term behavior is investigated. Reference made literature assess effectiveness Fickian and anomalous models describe solution uptake in epoxies. The influence differing exposure conditions epoxies, particular effect type temperature, are explored. Experimental results, where desiccated (D) or...
We report on late time radio and X-ray observations of the tidal disruption event candidate ASASSN-14li, covering first 1000 days decay phase. For $\sim200$ emission fade in concert. This phase is better fit by an exponential at wavelengths, while well described either or canonical $t^{-5/3}$ assumed for events. The correlation between during this period can be as $L_{R}\propto L_{X}^{1.9\pm0.2}$. After 400 $15.5\,\textrm{GHz}$ has reached a plateau level $244\pm8\,\mu\textrm{Jy}$ which it...
We detail the REACH radiometric system designed to enable measurements of 21-cm neutral hydrogen line. Included is radiometer architecture and end-to-end simulations as well a discussion challenges intrinsic highly-calibratable development. Following this, we share laboratory results based on calculation noise wave parameters utilising an over-constrained least squares approach. For five hours integration custom-made source with comparable impedance that antenna used in field, demonstrate...