matvis: A matrix-based visibility simulator for fast forward modelling of many-element 21 cm arrays

Kavli Affiliate: Jacqueline N. Hewitt

| First 5 Authors: Piyanat Kittiwisit, Steven G. Murray, Hugh Garsden, Philip Bull, Christopher Cain

| Summary:

Detection of the faint 21 cm line emission from the Cosmic Dawn and Epoch of
Reionisation will require not only exquisite control over instrumental
calibration and systematics to achieve the necessary dynamic range of
observations but also validation of analysis techniques to demonstrate their
statistical properties and signal loss characteristics. A key ingredient in
achieving this is the ability to perform high-fidelity simulations of the kinds
of data that are produced by the large, many-element, radio interferometric
arrays that have been purpose-built for these studies. The large scale of these
arrays presents a computational challenge, as one must simulate a detailed sky
and instrumental model across many hundreds of frequency channels, thousands of
time samples, and tens of thousands of baselines for arrays with hundreds of
antennas. In this paper, we present a fast matrix-based method for simulating
radio interferometric measurements (visibilities) at the necessary scale. We
achieve this through judicious use of primary beam interpolation, fast
approximations for coordinate transforms, and a vectorised outer product to
expand per-antenna quantities to per-baseline visibilities, coupled with
standard parallelisation techniques. We validate the results of this method,
implemented in the publicly-available matvis code, against a high-precision
reference simulator, and explore its computational scaling on a variety of
problems.

| Search Query: ArXiv Query: search_query=au:”Jacqueline N. Hewitt”&id_list=&start=0&max_results=3

Read More