Systematics and foregrounds cloud the Epoch of Reionisation (EoR) measurement, and thus the EoR team focuses on building, developing, and publishing mitigation methods. A lot of recent effort into decreasing these systematics has been pushed into simulations like WODEN by Jack Line, calibration pipelines like hyperdrive by Chris Jordan, and smooth kernel implementations in FHD by Nichole...
As spectral calibration precision is the greatest limiting factor for EoR science, understanding individual antenna behavior is crucial. The new MWAX correlator provides a unique opportunity to examine antenna spectral shape without the nonlinearities and other digital artifacts present in Legacy correlator data. By removing coarse channel polyphase filter shapes and cable reflections we...
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 achieve...
I am happy to report some progress from Shanghai Astronomical Observatory, which is contineously in deep collaboration with the MWA observatory. With the archival MWA-VCS data and the computational platform of China SKA regional prototype in SHAO, we got preliminary results of the discovery of new pulsars in dense stellar environment, which is considered to be difficult in low-frequency radio...
We present the [pulsar_spectra][1] software repository, an open-source pulsar flux density catalogue and automated spectral fitting software that finds the best spectral model and produces publication-quality plots. The Python-based software includes features that enable users in the astronomical community to add newly published spectral measurements to the catalogue as they become available....
We announce the independent discovery of PSR J0027-1956 with the Murchison Widefield Array (MWA) in the ongoing Southern-sky MWA Rapid Two-meter (SMART) pulsar survey. J0027-1956 is an intermittent pulsar, with a nulling fraction of ~77%. This pulsar highlights the advantages of the survey's long dwell times (~80 min), which, when fully searched, will be sensitive to the expected population of...
With their broad range of applications from performing exquisite tests of strong-field gravity to detecting ultra-low-frequency gravitational waves, pulsars are a key science driver for the Square Kilometre Array (SKA). Pulsar radio emission properties in the low-frequency band of the SKA (50-350 MHz) remain underexplored, yet are important for furthering our understanding of the detectable...
Making precise measurements of pulsar dispersion measures (DMs) and applying suitable corrections for them is one of the major challenges in pulsar timing arrays (PTAs). While the advent of wide-band pulsar instrumentation can enable more precise DM measurements and thence improved timing precision, it also necessitates careful assessments of frequency-dependent (chromatic) DMs that was...
Type II solar radio bursts are believed to be caused by magnetohydrodynamics (MHD) shock-accelerated electrons in the solar corona. Often type IIs exhibit fine structures in their dynamic spectra. For example, both fundamental and harmonic bands of type II bursts are split into two sub-bands. This is generally believed to be coming from upstream and downstream regions of the shock; however,...
We present the recently published full Stopes map of galactic diffuse emission across 11k square degrees of the Southern galactic cap. While observed and processed under the auspices of the MWA EoR collaboration, we think this map might be of scientific interest to the wider MWA astrophysics community. Features include deep removal of extra-galactic sources, complete coverage on 1-9 degree...
Determining the origins of low-frequency (~MHz) variability of extragalactic sources has, until recently, largely been limited to small populations and/or single frequencies. Variability offers a unique opportunity to study both intrinsic properties of sources as well as the intervening media between source and observer. However, large population studies with significant spectral and temporal...
