The C-Band All-Sky Survey (C-BASS): Template Fitting of Diffuse Galactic Microwave Emission in the Northern Sky

ArXiv 2202.10411 (2022)

Authors:

SE Harper, C Dickinson, A Barr, R Cepeda-Arroita, RDP Grumitt, HM Heilgendorff, L Jew, JL Jonas, ME Jones, JP Leahy, J Leech, TJ Pearson, MW Peel, ACS Readhead, AC Taylor

MID-Radio Telescope, single pixel feed packages for the square kilometre array: an overview

IEEE Journal of Microwaves Institute of Electrical and Electronics Engineers 1:1 (2021) 428-437

Authors:

Angela Taylor, Michael Jones, Jamie Leech, andre Hector, Lei Liu, Robert Watkins, A Pellegrini

Abstract:

The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, enabling science with unprecedented detail and survey speed. The project spans over a decade and is now at a mature stage, ready to enter the construction and integration phase. In the fully deployed state, the MID-Telescope consists of a 150-km diameter array of offset Gregorian antennas installed in the radio quiet zone of the Karoo desert (South Africa). Each antenna is equipped with three feed packages, that are precision positioned in the sub-reflector focus by a feed indexer platform. The total observational bandwidth (0.35-15.4GHz) is segmented into seven bands. Band 1 (0.35 – 1.05 GHz) and Band 2 (0.95 – 1.76 GHz) are implemented as individual feed packages. The remaining five bands (Bands 3, 4, 5a, 5b, and 6) are combined in a single feed package. Initially only Band 5a (4.6 – 8.5 GHz) and Band 5b (8.3 – 15.4 GHz) will be installed. This paper provides an overview of recent progress on design, test and integration of each feed package as well as project and science goals, timeline and path to construction.

MID-Radio Telescope, Single Pixel Feed Packages for the Square Kilometre Array: An Overview

IEEE Journal of Microwaves Institute of Electrical and Electronics Engineers (2021)

Authors:

Alice Pellegrini, Jonas Flygare, Isak P Theron, Robert Lehmensiek, Adriaan Peens-Hough, Jamie Leech, Michael E Jones, Angela C Taylor, Robert EJ Watkins, Lei Liu, Andre Hector, Biao Du, Yang Wu

Abstract:

The Square Kilometre Array (SKA) project is an international effort to build the world s largest radio telescope, enabling science with unprecedented detail and survey speed. The project spans over a decade and is now at a mature stage, ready to enter the construction and integration phase. In the fully deployed state, the MID-Telescope consists of a 150-km diameter array of offset Gregorian antennas installed in the radio quiet zone of the Karoo desert (South Africa). Each antenna is equipped with three feed packages, that are precision positioned in the sub-reflector focus by a feed indexer platform. The total observational bandwidth (0.35-15.4GHz) is segmented into seven bands. Band 1 (0.35-1.05GHz) and Band 2 (0.95-1.76GHz) are implemented as individual feed packages. The remaining five bands (Bands 3, 4, 5a, 5b, and 6) are combined in a single feed package. Initially only Band 5a (4.6-8.5GHz) and Band 5b (8.3-15.4GHz) will be installed. This paper provides an overview of recent progress on design, test and integration of each feed package as well as project and science goals, timeline and path to construction.

Characterizing the performance of high-speed data converters for RFSoC-based radio astronomy receivers

Monthly Notices of the Royal Astronomical Society Oxford University Press 501:4 (2020) 5096-5104

Authors:

Chao Liu, Michael Jones, Angela Taylor

Abstract:

RF system-on-chip (RFSoC) devices provide the potential for implementing a complete radio astronomy receiver on a single board, but performance of the integrated analogue-to-digital converters (ADCs) is critical. We have evaluated the performance of the data converters in the Xilinx ZU28DR RFSoC, which are 12-bit, 8-fold interleaved converters with a maximum sample speed of 4.096 Giga-sample per second (GSPS). We measured the spurious-free dynamic range (SFDR), signal-to-noise and distortion (SINAD), effective number of bits (ENOB), intermodulation distortion (IMD), and cross-talk between adjacent channels over the bandwidth of 2.048 GHz. We both captured data for off-line analysis with floating-point arithmetic, and implemented a real-time integer arithmetic spectrometer on the RFSoC. The performance of the ADCs is sufficient for radio astronomy applications and close to the vendor specifications in most of the scenarios. We have carried out spectral integrations of up to 100 s and stability tests over tens of hours and find thermal noise-limited performance over these time-scales.

Resolved observations at 31 GHz of spinning dust emissivity variations in rho Oph

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 495:3 (2020) 3482-3493

Authors:

Carla Arce-Tord, Matias Vidal, Simon Casassus, Miguel Carcamo, Clive Dickinson, Brandon S Hensley, Ricardo Genova-Santos, J Richard Bond, Michael E Jones, Anthony CS Readhead, Angela C Taylor, J Anton Zensus

Abstract:

© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. The ρ Oph molecular cloud is one of the best examples of spinning dust emission, first detected by the cosmic background imager (CBI). Here, we present 4.5 arcmin observations with CBI 2 that confirm 31 GHz emission from ρ Oph W, the PDR exposed to B-Type star HD 147889, and highlight the absence of signal from S1, the brightest IR nebula in the complex. In order to quantify an association with dust-related emission mechanisms, we calculated correlations at different angular resolutions between the 31 GHz map and proxies for the column density of IR emitters, dust radiance, and optical depth templates. We found that the 31 GHz emission correlates best with the PAH column density tracers, while the correlation with the dust radiance improves when considering emission that is more extended (from the shorter baselines), suggesting that the angular resolution of the observations affects the correlation results. A proxy for the spinning dust emissivity reveals large variations within the complex, with a dynamic range of 25 at 3σ and a variation by a factor of at least 23, at 3σ, between the peak in ρ Oph W and the location of S1, which means that environmental factors are responsible for boosting spinning dust emissivities locally.