hyperdrive is a spiritual successor to the Real-Time System (RTS) calibration software commonly employed by the MWA EoR team, but with a focus on usability, testing and efficiency. It currently operates similar to André Offringa's calibrate program, but is 2-3x faster and supports many more input and output formats. At the time of writing, comparisons with the RTS are forthcoming,...
One of the major priorities of international radio astronomy is to study the early
universe through the detection of the 21 cm HI line from the Epoch of Reionisation
(EoR). Due to the weak nature of the 21 cm signal, an important part in the detection of the EoR is removing contaminating foregrounds from our observations as they are multiple orders of magnitude brighter. One method to...
The Epoch of Reionisation (EoR) is the period within which the neutral universe transitioned to an ionised one. This period remains unobserved using low-frequency radio interferometers which target the 21 cm signal of neutral hydrogen emitted in this era. The Murchison Widefield Array (MWA) radio telescope was built with the detection of this signal as one of its major science goals. One of...
One of the principal systematic constraints on the Epoch of Reionisation (EoR) experiment is the accuracy of the foreground calibration model. Recent results have shown that highly accurate models of extended foreground sources, and including models for sources in both the primary beam and its
sidelobes are necessary for reducing foreground power. To improve the source models in the EoR...
In this talk, we will show recent science updates from MWA Japan. In particular, we first highlight the MWA ultralow (75-100 MHz) data analysis. In this work, using 15 hours of MWA Phase I data, we analyzed the systematics related to the ultra-low frequency observation such as the ionosphere and RFI. Based on the careful investigation, we selected 6 hours of clean datasets, and the best upper...
The successor to the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, GLEAM-eXtended uses the Phase II extended configuration of the MWA to survey the GLEAM sky at twice the resolution and up to an order of magnitude higher sensitivity. In 2020 we completed observations across the entire southern sky. The team is finalising the first data release, covering 2,000 square degrees, down to...
High-redshift radio galaxies are vital laboratories for studying massive galaxy formation and evolution in the early Universe (review by Miley & De Breuck 2008). We have developed a new selection technique for finding these rare, powerful systems, making use of spectral curvature in the Murchison Widefield Array (MWA) 72-231 MHz GLEAM survey (Hurley-Walker et al. 2017; Franzen et al. 2021). In...
For this talk I will present synchrofit (synchrotron fitter), which implements a reduced dimensionality parameterisation of standard synchrotron spectrum models, and provides fitting routines applicable for active galactic nuclei and supernova remnants. The Python code includes the Jaffe-Parola model (JP), Kardashev-Pacholczyk model (KP), and continuous injection models (CI/KGJP) for both...
The growing number of Low Earth Orbit (LEO) objects has been an increasing concern for the Space Domain Awareness (SDA) community and the astronomy community. While the rapidly increasing number of satellites demands the development of a wide field-of-view SDA sensors that is capable of performing simultaneous detections, many recent studies have also highlighted the importance of...
The Search for Extraterrestrial Intelligence (SETI) kicked off in 1960, when Frank Drake turned the Tatel telescope toward nearby stars to search for 'technosignatures' that would indicate intelligent life beyond Earth. While SETI searches have been running ever since -- including several searches of archival MWA image cubes -- the low-frequency radio sky remains under-explored. In this talk,...
Pulsars are highly linearly polarised sources whose polarimetry contains a wealth of information about the poorly-understood pulsar radio emission mechanism and the dynamics of the turbulent, relativistic plasma that gives rise to it. However, in order to leverage this information for scientific gain, the polarimetric response of the telescope must be precisely understood. While much fruitful...
One of the unsolved problems of pulsar physics is the discrepancy between the neutron star birth rate derived from core-collapse supernova rates, and that derived from the observed radio pulsar populations. One method to increase the accuracy of our pulsar population simulations is to improve our understanding of the relatively unexplored low-frequency parameter space.
The Southern-sky MWA...
I will present a brief overview of the recent work by MWA Solar group. The aspects covered will range from work on developing the next version solar imaging pipeline which will have the capability to make full Stokes images on the tools and technique development front, to sharing the current status of our ongoing investigations on characterizing the Weak Impulsive Narrowband Quiet Sun...
We present a high fidelity snapshot spectroscopic radio imaging study of a weak type I solar noise storm which took place during an otherwise exceptionally quiet time. Using high fidelity images from the Murchison Widefield Array, we track the observed morphology of the burst source for 70 minutes and identify multiple instances where its integrated flux density and area are strongly...
Energetically weak bursts contribute most to the solar plasma heating. However, they are difficult to image accurately due to the thermal background from the active region. Broadly, we can distinguish the emission from radio bursts consisting of slowly varying components and transient burst components. To characterise the burst component, we must take out the slowly varying components by...
