Journal article

Interpreting LOFAR 21-cm signal upper limits at z approximate to 9.1 in the context of high-z galaxy and reionization observations

Bradley Greig, Andrei Mesinger, Leon VE Koopmans, Benedetta Ciardi, Garrelt Mellema, Saleem Zaroubi, Sambit K Giri, Raghunath Ghara, Abhik Ghosh, Ilian T Iliev, Florent G Mertens, Rajesh Mondal, Andre R Offringa, Vishambhar N Pandey



Using the latest upper limits on the 21-cm power spectrum at z ≈ 9.1 from the Low Frequency Array (LOFAR), we explore the regions of parameter space which are inconsistent with the data. We use 21cmmc, a Monte Carlo Markov chain sampler of 21cmfast which directly forward models the three dimensional (3D) cosmic 21-cm signal in a fully Bayesian framework. We use the astrophysical parametrization from 21cmfast, which includes mass-dependent star formation rates and ionizing escape fractions as well as soft-band X-ray luminosities to place limits on the properties of the high-z galaxies. Further, we connect the disfavoured regions of parameter space with existing observational constraints on th..

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University of Melbourne Researchers


Awarded by Australian Research Council Centre of Excellence for All SkyAstrophysics in Three Dimensions (ASTRO3D)

Awarded by European Research Council (ERC) under the European Union

Awarded by Swedish Research Council

Awarded by Israeli Science Foundation

Awarded by Science and Technology Facilities Council

Funding Acknowledgements

We thank the anonymous referee for their constructive feedback which has improved this manuscript. Parts of this research were supported by the Australian Research Council Centre of Excellence for All SkyAstrophysics in Three Dimensions (ASTRO3D), through project number CE170100013. AM acknowledges funding support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 638809 - AIDA-PI: AM). FGM and LVEK would like to acknowledge support from an SKA-NL Roadmap grant from the Dutch Ministry of Education, Culture and Science. GM is thankful for support by Swedish Research Council grant 201603581. SZ acknowledges support from the Israeli Science Foundation (grant no. 255/18). ITI was supported by the Science and Technology Facilities Council [grant numbers ST/I000976/1 and ST/T000473/1] and the Southeast Physics Network (SEP-Net). AG would like to acknowledge IUCAA, Pune for providing support through the associateship programme. RM is grateful for financial support from the Wenner-Gren Foundations.