Journal article

Stacking redshifted 21 cm images of H II regions around high-redshift galaxies as a probe of early reionization

James E Davies, Rupert AC Croft, Tiziana Di-Matteo, Bradley Greig, Yu Feng, J Stuart B Wyithe



A number of current and future experiments aim to detect the reionization of neutral hydrogen by the first stars and galaxies in the Universe via the redshifted 21 cm line. Using the bluetides simulation, we investigate the measurement of an average ionized region towards the beginning of reionization by stacking redshifted 21 cm images around optically identified bright galaxies using mock observations. We find that with an SKA 1000 h observation, assuming perfect foreground subtraction, a 5σ detection of a stacked H ii region can be made with 30 images around some of the brightest galaxies in bluetides (brighter than MUV 1σ detection will be possible. However, partial foreground subtractio..

View full abstract


Awarded by Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)

Awarded by NASA

Awarded by NSF

Funding Acknowledgements

JD is supported by the University of Melbourne under the Melbourne Research Scholarship (MRS). This research was also supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. This work was performed on the OzSTAR national facility at Swinburne University of Technology. OzSTAR is funded by Swinburne University of Technology and the National Collaborative Research Infrastructure Strategy (NCRIS). The BLUETIDES simulation was run on the BlueWaters facility at the National Center for SupercomputingApplications. TDMand RAC are grateful for the hospitality of the Physics Department of theUniversity of Melbourne, and for the support of a Shimmins Fellowship (TDM) and Lyle Fellowships (TDM and RAC). TDM and RAC acknowledge support fromNASA NNX17AK56G, NASAATP 80NSSC18K101, andNSF AST-1614853. RAC was also supported by NSF AST-1615940 and NSF AST-1909193.