A5089872035- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Superconducting and THz Device Technology
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Advanced Frequency and Time Standards
- Astronomy and Astrophysical Research
- Antenna Design and Optimization
- Advancements in PLL and VCO Technologies
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Jewish and Middle Eastern Studies
- GNSS positioning and interference
- Middle East Politics and Society
- Terahertz technology and applications
- Astrophysical Phenomena and Observations
- Soil Moisture and Remote Sensing
- Advanced Fiber Optic Sensors
- Diaspora, migration, transnational identity
- Quantum chaos and dynamical systems
- Photonic and Optical Devices
- Cosmology and Gravitation Theories
- Ocular and Laser Science Research
Munich University of Applied Sciences
2015-2019
University of Oxford
2012-2018
Esslingen University of Applied Sciences
2010-2013
Atacama Large Millimeter Submillimeter Array
2012
University of Cambridge
2006-2008
Cavendish Hospital
2002
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.
The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting imprint of inflationary gravitational waves at large angular scales (~ 1 degree). Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4 m side-fed Dragonian telescope. polarimeters which form focal planes use highly compact design based High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements...
The C-Band All-Sky Survey (C-BASS) is an all-sky full-polarisation survey at a frequency of 5 GHz, designed to provide complementary data the surveys WMAP and Planck, future CMB B-mode polarization imaging surveys. observing has been chosen signal that dominated by Galactic synchrotron emission, but suffers little from Faraday rotation, so measured directions good template for higher observations, carry direct information about magnetic field. Telescopes in both northern southern hemispheres...
We present an analysis of the diffuse emission at 5 GHz in first quadrant Galactic plane using two months preliminary intensity data taken with C-Band All Sky Survey (C-BASS) northern instrument Owens Valley Radio Observatory, California. Combining C-BASS maps ancillary to make temperature-temperature plots we find synchrotron spectral indices $\beta = -2.65 \pm 0.05$ between 0.408 and $ \beta -2.72 0.09$ 1.420 for $-10^{\circ} < |b| -4^{\circ}$, $20^{\circ} l 40^{\circ}$. Through...
The C-Band All-Sky Survey is a project to map the full sky in total intensity and linear polarization at 5 GHz. northern component of survey uses broad-band single-frequency analogue receiver fitted 6.1-m telescope Owens Valley Radio Observatory California, USA. architecture combines continuous-comparison radiometer correlation polarimeter single for stable simultaneous measurement both polarization, using custom-designed components. measures temperature difference between...
The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These will be used (with other surveys) separate the several astrophysical components contributing microwave emission, particular allow an accurate map synchrotron produced for subtraction foregrounds from measurements polarized Cosmic Microwave Background. We describe design analog instrument, optics our 6.1 m dish Owens Valley Radio...
Aims.We describe a 6–12 GHz analogue correlator that has been developed for use in radio interferometers.
We report the first detection of a Sunyaev-Zel'dovich (S-Z) decrement with Arcminute Microkelvin Imager (AMI). have made commissioning observations towards cluster A1914 and measured an integrated flux density -8.61 mJy in uv-tapered map noise level 0.19 mJy/beam. find that spectrum decrement, six channels between 13.5-18GHz, is consistent expected for S-Z effect. The sensitivity telescope figures used our simulations surveys AMI.
We present the design and testing of a 2-20 GHz continuum band analog lag correlator with 16 frequency channels for astronomical interferometry. The has been designed future use prototype single-baseline interferometer operating at 185-275 GHz. uses broadband Wilkinson divider tree integral thin-film resistors implemented on an alumina substrate, custom-made InGaP/GaAs Gilbert Cell multipliers. fully bench-tested, together necessary readout electronics acquisition output signals. results...
We present an interesting Sunyaev-Zel'dovich (SZ) detection in the first of Arcminute Microkelvin Imager (AMI) 'blind', degree-square fields to have been observed down our target sensitivity 100{\mu}Jy/beam. In follow-up deep pointed observations SZ effect is detected with a maximum peak decrement greater than 8 \times thermal noise. No corresponding emission visible ROSAT all-sky X-ray survey and no cluster evident Palomar optical survey. Compared existing images distant clusters, extent...
We describe the development of two circularly symmetric antennas with high polarization purity and low spill-over. Both were designed to be used in an all-sky intensity survey at 5 GHz (the C-Band All-Sky Survey, C-BASS). The requirements call for very cross-polar signal levels far-out sidelobes. Two different existing antennas, 6.1-m 7.6-m diameter primaries, adapted by replacing feed secondary optics, resulting identical beam performances 0.73 <sup...
We present the antenna design for a radio interferometer, Arcminute Microkelvin Imager, together with its beam pattern measurement. Our aim was to develop low-cost system high aperture efficiency and low ground-spill across frequency range 12-18GHz. use modified cassegrain consisting of commercially-available paraboloidal primary mirror diameter 3.7m, shaped secondary mirror. The is oversized respect ray-optics has surface that bent towards near outer edge using square term shaping. antennas...
Stabilizing the gain of a radio astronomy receiver is great importance for sensitive intensity mapping. In this paper we discuss stabilization method using continuous-wave reference signal injected into chain and tracked in single channel spectrometer to correct variations receiver. This depends on fact that fluctuations are strongly correlated across frequency band, which can show case our experimental setup. especially suited receivers with digital back-end high spectral resolution...
The Arcminute MicroKelvin Imager (AMI) is an instrument currently under construction in Cambridge designed to produce a survey of galaxy clusters via the Sunyaev-Zel’dovich effect. It consists two interferometric arrays, both operating at 12–18 GHz; one ten 3.7-m antennas provide good temperature sensitivity arcminute-scale structures, and eight 13-m (the present Ryle Telescope) flux for removing contaminating radio sources. telescope due be observing by 2003, will public clusters, as well...