Rachel Webster

A new MWA limit on the 21 cm power spectrum at redshifts ∼13–17

S Yoshiura, B Pindor, JLB Line, N Barry, CM Trott, A Beardsley, J Bowman, R Byrne, A Chokshi, BJ Hazelton, K Hasegawa, E Howard, B Greig, D Jacobs, CH Jordan, R Joseph, M Kolopanis, C Lynch, B McKinley, DA Mitchell, et al.

Journal article  |  2021  |  Monthly Notices of the Royal Astronomical Society

ABSTRACT Observations in the lowest Murchison Widefield Array (MWA) band between 75 and 100 MHz have the potential ..

Dual polarization measurements of MWA beampatterns at 137 MHz

A Chokshi, JLB Line, N Barry, D Ung, D Kenney, A McPhail, A Williams, RL Webster

Journal article  |  2021  |  MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

ABSTRACT The wide adoption of low-frequency radio interferometers as a tool for deeper and higher resolution astron..

Evidence for an intermediate-mass black hole from a gravitationally lensed gamma-ray burst

James Paynter, Rachel Webster, Eric Thrane

Journal article  |  2021  |  NATURE ASTRONOMY

If gamma-ray bursts are at cosmological distances, they must be gravitationally lensed occasionally1,2. The detection of lensed im..

Exploring reionization and high-z galaxy observables with recent multiredshift MWA upper limits on the 21-cm signal

Bradley Greig, Cathryn M Trott, Nichole Barry, Simon J Mutch, Bart Pindor, Rachel L Webster, J Stuart B Wyithe

Journal article  |  2021  |  MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

We use the latest multiredshift (z = 6.5-8.7) upper limits on the 21-cm signal from the Murchison Widefield Array (MWA) to explore..

The impact of tandem redundant/sky-based calibration in MWA Phase II data analysis

Zheng Zhang, Jonathan C Pober, Wenyang Li, Bryna J Hazelton, Miguel F Morales, Cathryn M Trott, Christopher H Jordan, Ronniy C Joseph, Adam Beardsley, Nichole Barry, Ruby Byrne, Steven J Tingay, Aman Chokshi, Kenji Hasegawa, Daniel C Jacobs, Adam Lanman, Jack LB Line, Christene Lynch, Benjamin McKinley, Daniel A Mitchell, et al.

Journal article  |  2020  |  Publications of the Astronomical Society of Australia

Precise instrumental calibration is of crucial importance to 21-cm cosmology experiments. The Murchison Widefield Array’s (MWA) Ph..

Changing look active galactic nuclei in the MaNGA survey

Wei Jeat Hon, Rachel Webster, Christian Wolf

Journal article  |  2020  |  Monthly Notices of the Royal Astronomical Society

Changing look active galactic nuclei (CLAGNs) are rare cases of AGNs, where the continuum flux increases/decreases and the broad e..

Deep multiredshift limits on Epoch of Reionization 21 cm power spectra from four seasons of Murchison Widefield Array observations

Cathryn M Trott, CH Jordan, S Midgley, N Barry, B Greig, B Pindor, JH Cook, G Sleap, SJ Tingay, D Ung, P Hancock, A Williams, J Bowman, R Byrne, A Chokshi, BJ Hazelton, K Hasegawa, D Jacobs, RC Joseph, W Li, et al.

Journal article  |  2020  |  MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

We compute the spherically averaged power spectrum from four seasons of data obtained for the Epoch of Reionization (EoR) project ..

Determining quasar orientation

Suk Yee Yong, Rachel L Webster, Anthea L King, Nicholas F Bate, Kathleen Labrie, Matthew J O'Dowd

Journal article  |  2020  |  MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Since the discovery of active galactic nuclei (AGN) and their subclasses, a unification scheme of AGN has been long sought. Orient..

Modelling and peeling extended sources with shapelets: A Fornax A case study

JLB Line, DA Mitchell, B Pindor, JL Riding, B McKinley, RL Webster, CM Trott, N Hurley-Walker, AR Offringa

Journal article  |  2020  |  Publications of the Astronomical Society of Australia

To make a power spectrum (PS) detection of the 21-cm signal from the Epoch of Reionisation (EoR), one must avoid/subtract bright f..

First Season MWA Phase II Epoch of Reionization Power Spectrum Results at Redshift 7

W Li, JC Pober, N Barry, BJ Hazelton, MF Morales, CM Trott, A Lanman, M Wilensky, I Sullivan, AP Beardsley, T Booler, JD Bowman, R Byrne, B Crosse, D Emrich, TMO Franzen, K Hasegawa, L Horsley, M Johnston-Hollitt, DC Jacobs, et al.

Journal article  |  2019  |  ASTROPHYSICAL JOURNAL

The compact configuration of Phase II of the Murchison Widefield Array (MWA) consists of both a redundant subarray and pseudo-rand..