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We forecast the sensitivity with which the Murchison Widefield Array (MWA) can measure the 21 cm power spectrum of cosmic hydrogen, using radiative transfer simulations to model reionization and the 21 cm signal. The MWA is sensitive to…

Astrophysics · Physics 2009-11-13 Adam Lidz , Oliver Zahn , Matthew McQuinn , Matias Zaldarriaga , Lars Hernquist

We analyse a 154 MHz image made from a 12 h observation with the Murchison Widefield Array (MWA) to determine the noise contribution and behaviour of the source counts down to 30 mJy. The MWA image has a bandwidth of 30.72 MHz, a…

The Planck mission detected thousands of extragalactic radio sources at frequencies from 28 to 857 GHz. Planck's calibration is absolute (in the sense that it is based on the satellite's annual motion around the Sun and the temperature of…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 B. Partridge , M. López-Caniego , R. A. Perley , J. Stevens , B. J. Butler , G. Rocha , B. Walter , A. Zacchei

We present the characterization and definitive flux calibration of the Far-Infrared Field Integral Line Spectrometer (FIFI-LS) instrument on-board SOFIA. The work is based on measurements made in the laboratory with an internal calibrator…

Instrumentation and Methods for Astrophysics · Physics 2023-10-03 Dario Fadda , Sebastian Colditz , Christian Fischer , William D. Vacca , Jason Chu , Melanie Clarke , Randolf Klein , Alfred Krabbe , Robert Minchin , Albrecht Poglitsch

Detection of the fluctuations in 21 cm line emission from neutral hydrogen during the Epoch of Reionization in thousand hour integrations poses stringent requirements on calibration and image quality, both of which necessitate accurate…

Solar radio emission, especially at metre-wavelengths, is well known to vary over small spectral ($\lesssim$100\,kHz) and temporal ($<1$\,s) spans. It is comparatively recently, with the advent of a new generation of instruments, that it…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Surajit Mondal , Atul Mohan , Divya Oberoi , John S. Morgan , Leonid Benkevitch , Colin J. Lonsdale , Meagan Crowley , Iver H. Cairns

Star surveys and model analyses show that many stars have absolute stable fluxes as good as 3% in 0.3-35{\mu}m wavebands and about 1% in the visible wavebands. The relative flux calibrations between stars are better than 0.2%. Some stars…

Instrumentation and Methods for Astrophysics · Physics 2017-07-10 Chun Xu

The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astronomical observations has revolutionised radio astronomy. Despite their construction from static, relatively simple dipoles, the sheer…

Instrumentation and Methods for Astrophysics · Physics 2021-02-02 A. Chokshi , J. L. B. Line , N. Barry , D. Ung , D. Kenney , A. McPhail , A. Williams , R. L. Webster

The interferometric technique known as peeling addresses many of the challenges faced when observing with low-frequency radio arrays, and is a promising tool for the associated calibration systems. We investigate a real-time peeling…

We present the first spectroscopic images of solar radio transients from the prototype for the Murchison Widefield Array (MWA), observed on 2010 March 27. Our observations span the instantaneous frequency band 170.9-201.6 MHz. Though our…

It is critical for James Webb Space Telescope (JWST) science that instrumental units are converted to physical units. We detail the design of the JWST absolute flux calibration program that has the core goal of ensuring a robust flux…

We present Murchison Widefield Array (MWA) monitoring of the Kepler K2 mission Fields 3, 4, and 5 at frequencies of 155 and 186 MHz, from observations contemporaneous with the K2 observations. This work follows from previous MWA and GMRT…

High Energy Astrophysical Phenomena · Physics 2019-07-10 S. J. Tingay , P. J Hancock

We present and evaluate several strategies to search for prompt, low-frequency radio emission associated with gravitational wave transients using the Murchison Widefield Array (MWA). As we are able to repoint the MWA on timescales of tens…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 D. L. Kaplan , T. Murphy , A. Rowlinson , S. D. Croft , R. B. Wayth , C. M. Trott

A diverse array of science goals require accurate flux calibration of observations with the Atacama Large Millimeter/Submillimeter array (ALMA), however, this goal remains challenging due to the stochastic time-variability of the ``grid''…

Instrumentation and Methods for Astrophysics · Physics 2020-11-25 Logan Francis , Doug Johnstone , Gregory Herczeg , Todd R. Hunter , Daniel Harsono

As the precision frontier of astrophysics advances towards the one millimagnitude level, flux calibration of photometric instrumentation remains an ongoing challenge. We present the results of a lab-bench assessment of the viability of…

Instrumentation and Methods for Astrophysics · Physics 2021-08-24 Sasha Brownsberger , Lige Zhang , David Andrade , Christopher Stubbs

A flexible apparatus for calibration of the absolute flux at the focal plane of the X-ray Source of a Powder Diffractometer, based on a fast scintillator counter, is presented. The measured fluxes, depending on the high voltage on the X-ray…

Instrumentation and Detectors · Physics 2020-08-27 Emmanuel Fokitis , Theodoros Geralis , Stavros Maltezos , Nikolaos Vodinas

The science cases for incorporating high time resolution capabilities into modern radio telescopes are as numerous as they are compelling. Science targets range from exotic sources such as pulsars, to our Sun, to recently detected possible…