A new MWA limit on the 21 cm power spectrum at redshifts similar to 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 Show all
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | OXFORD UNIV PRESS | Published : 2021
ABSTRACT Observations in the lowest Murchison Widefield Array (MWA) band between 75 and 100 MHz have the potential to constrain the distribution of neutral hydrogen in the intergalactic medium at redshift ∼13–17. Using 15 h of MWA data, we analyse systematics in this band such as radio-frequency interference (RFI), ionospheric and wide field effects. By updating the position of point sources, we mitigate the direction-independent calibration error due to ionospheric offsets. Our calibration strategy is optimized for the lowest frequency bands by reducing the number of direction-dependent calibrators and taking into account radio sources within a wider field of view. We remove ..View full abstract
Awarded by Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)
Awarded by JSPS KAKENHI
Awarded by ARC Future Fellowship
We would like to thank to anonymous referee for his/her useful comments. We also thank to Dr. Padmanabhan for her comments on early version of this paper. This research was supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. SY is supported by JSPS Overseas Research Fellowships and this work was supported in part by JSPS KAKENHI, grants: 16H05999 (SY) and 21J00416 (SY). CMT is supported by an ARC Future Fellowship through project number FT180100321. Computational resources used were awarded under Astronomy Australia Ltd's ASTAC merit allocation scheme on the OzSTAR national facility at Swinburne University of Technology. The OzSTAR program receives funding in part from the Astronomy National Collaborative Research Infrastructure Strategy (NCRIS) allocation provided by the Australian Government. We acknowledge the Pawsey Supercomputing Centre which is supported by the Western Australian and Australian Governments. This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis (LAMBDA), part of the High Energy Astrophysics Science Archive Center (HEASARC). HEASARC/LAMBDA is a service of the Astrophysics Science Division at the NASA Goddard Space Flight Center.