1. The hydrogen epoch of reionization array dish III: measuring chromaticity of prototype element with reflectometry
- Author
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Aaron R. Parsons, Adam P. Beardsley, Cherie Day, Haoxuan Zheng, Joshua S. Dillon, Gcobisa Fadana, Bradley Greig, Jacqueline N. Hewitt, Craig Smith, Daniel C. Jacobs, Anna Lebedeva, Richard F. Bradley, Cresshim Malgas, Brian Glendenning, Carina Cheng, Peter K. G. Williams, Jonathan C. Pober, Andrei Mesinger, Abraham R. Neben, Nima Razavi-Ghods, Randall Fritz, Nipanjana Patra, Jasper Grobbelaar, Paul Alexander, Nithyanandan Thyagarajan, David DeBoer, Gilbert Hsyu, Steve R. Furlanetto, Kathryn Rosie, Max Tegmark, Nicolas Fagnoni, Lourence Malan, Angelo Syce, Zachary E. Martinot, David MacMahon, Jon Ringuette, Adrian Liu, Saul A. Kohn, James Robnett, Chris Carilli, Eloy de Lera Acedo, Nathan Mathison, Austin Julius, Judd D. Bowman, Samantha Pieterse, Anita Loots, Tsz Kuk Leung, Raddwine Sell, Eunice Matsetela, Miguel F. Morales, Bryna J. Hazelton, Zaki S. Ali, MacCalvin Kariseb, Aaron Ewall-Wice, James E. Aguirre, Matthys Maree, Telalo Lekalake, Patra, Nipanjana, Parsons, Aaron R., Deboer, David R., Thyagarajan, Nithyanandan, Ewall-Wice, Aaron, Hsyu, Gilbert, Leung, Tsz Kuk, Day, Cherie K., de Lera Acedo, Eloy, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Beardsley, Adam P., Bowman, Judd D., Bradley, Richard F., Carilli, Chris L., Cheng, Carina, Dillon, Joshua S., Fadana, Gcobisa, Fagnoni, Nicola, Fritz, Randall, Furlanetto, Steve R., Glendenning, Brian, Greig, Bradley, Grobbelaar, Jasper, Hazelton, Bryna J., Jacobs, Daniel C., Julius, Austin, Kariseb, Mac. Calvin., Kohn, Saul A., Lebedeva, Anna, Lekalake, Telalo, Liu, Adrian, Loots, Anita, Macmahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthy, Martinot, Zachary, Mathison, Nathan, Matsetela, Eunice, Mesinger, Andrei, Morales, Miguel F., Neben, Abraham R., Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Ringuette, Jon, Robnett, Jame, Rosie, Kathryn, Sell, Raddwine, Smith, Craig, Syce, Angelo, Tegmark, Max, Williams, Peter K. G., and Zheng, Haoxuan
- Subjects
Frequency response ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astronomy & Astrophysics ,01 natural sciences ,Astronomical instrumentation ,Methods and techniques-wideband radio interferometry ,Optics ,0103 physical sciences ,cm cosmology ,010306 general physics ,Reflectometry ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Reionization ,Physics ,Delay spectrum technique-EoR power spectrum ,business.industry ,Attenuation ,Astrophysics::Instrumentation and Methods for Astrophysics ,Delay spectrum technique–EoR power spectrum ,Spectral density ,Astronomy and Astrophysics ,HERA ,Astronomy and Astrophysic ,Methods and technique ,Redshift ,wideband radio interferometry ,Space and Planetary Science ,21 cm cosmology ,Antenna (radio) ,Astrophysics - Instrumentation and Methods for Astrophysics ,business ,Astronomical and Space Sciences ,astro-ph.IM - Abstract
The experimental efforts to detect the redshifted 21 cm signal from the Epoch of Reionization (EoR) are limited predominantly by the chromatic instrumental systematic effect. The delay spectrum methodology for 21 cm power spectrum measurements brought new attention to the critical impact of an antenna's chromaticity on the viability of making this measurement. This methodology established a straightforward relationship between time-domain response of an instrument and the power spectrum modes accessible to a 21 cm EoR experiment. We examine the performance of a prototype of the Hydrogen Epoch of Reionization Array (HERA) array element that is currently observing in Karoo desert, South Africa. We present a mathematical framework to derive the beam integrated frequency response of a HERA prototype element in reception from the return loss measurements between 100-200 MHz and determined the extent of additional foreground contamination in the delay space. The measurement reveals excess spectral structures in comparison to the simulation studies of the HERA element. Combined with the HERA data analysis pipeline that incorporates inverse covariance weighting in optimal quadratic estimation of power spectrum, we find that in spite of its departure from the simulated response, HERA prototype element satisfies the necessary criteria posed by the foreground attenuation limits and potentially can measure the power spectrum at spatial modes as low as $k_{\parallel} > 0.1h$~Mpc$^{-1}$. The work highlights a straightforward method for directly measuring an instrument response and assessing its impact on 21 cm EoR power spectrum measurements for future experiments that will use reflector-type antenna., 13 pages, 10 figures, Submitted to APJ
- Published
- 2018