The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory (SARAO) Square Kilometer Array (SKA) site in South Africa. Each of the 6~m, f/0.23 dishes will be instrumented with dual-polarisation feeds operating over a frequency range of 400-800 MHz. Through intensity mapping of the 21 cm emission line of neutral hydrogen, HIRAX will provide a cosmological survey of the distribution of large-scale structure over the redshift range of 0.775<z<2.55 over ∼15,000 square degrees of the southern sky. The statistical power of such a survey is sufficient to produce ∼7 percent constraints on the dark energy equation of state parameter when combined with measurements from the Planck satellite. Additionally, HIRAX will provide a highly competitive platform for radio transient and HI absorber science while enabling a multitude of cross-correlation studies. In these proceedings, we describe the science goals of the experiment, overview of the design and status of the sub-components of the telescope system, and describe the expected performance of the initial 256-element array as well as the planned future expansion to the final, 1024-element array.
The Hydrogen Intensity and Real-time Analysis eXperiment: 256-Element Array Status and Overview, Devin Crichton, Moumita Aich, Adam Amara, Kevin Bandura, Bruce A. Bassett, Carlos Bengaly, Pascale Berner, Shruti Bhatporia, Martin Bucher, Tzu-Ching Chang, H. Cynthia Chiang, Jean-Francois Cliche, Carolyn Crichton, Romeel Dave, Dirk I. L. de Villiers, Matt A. Dobbs, Aaron M. Ewall-Wice, Scott Eyono, Christopher Finlay, Sindhu Gaddam, Ken Ganga, Kevin G. Gayley, Kit Gerodias, Tim Gibbon, Austin Gumba, Neeraj Gupta, Maile Harris, Heiko Heilgendorf, Matt Hilton, Adam D. Hincks, Pascal Hitz, Mona Jalilvand, Roufurd Julie, Zahra Kader, Joseph Kania, Dionysios Karagiannis, Aris Karastergiou, Kabelo Kesebonye, Piyanat Kittiwisit, Jean-Paul Kneib, Kenda Knowles, Emily R. Kuhn, Martin Kunz, Roy Maartens, Vincent MacKay, Stuart MacPherson, Christian Monstein, Kavilan Moodley, V. Mugundhan, Warren Naidoo, Arun Naidu, Laura B. Newburgh, Viraj Nistane, Amanda Di Nitto, Deniz Ölçek, Xinyu Pan, Sourabh Paul, Jeffrey B. Peterson, Elizabeth Pieters, Carla Pieterse, Aritha Pillay, Anna R. Polish, Liantsoa Randrianjanahary, Alexandre Refregier, Andre Renard, Edwin Retana-Montenegro, Ian H. Rout, Cyndie Russeeawon, Alireza Vafaei Sadr, Benjamin R.B. Saliwanchik, Ajith Sampath, Pranav Sanghavi, Mario G. Santos, Onkabetse Sengate, J. Richard Shaw, Jonathan L. Sievers, Oleg M. Smirnov, Kendrick M. Smith, Ulrich Armel Mbou Sob, Raghunathan Srianand, Pieter Stronkhorst, Dhaneshwar D. Sunder, Simon Tartakovsky, Russ Taylor, Peter Timbie, Emma E. Tolley, Junaid Townsend, Will Tyndall, Cornelius Ungerer, Jacques van Dyk, Gary van Vuuren, Keith Vanderlinde, Thierry Viant, Anthony Walters, Jingying Wang, Amanda Weltman, Patrick Woudt, Dallas Wulf, Anatoly Zavyalov, Zheng Zhang, Submitted to the Journal of Astronomical Telescopes, Instruments, and Systems (JATIS), SKA Observatory special section, arXiv:2109.13755