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1. Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

Author

Abdurashidova, THCZ, Adams, T, Aguirre, JE, Alexander, P, Ali, ZS, Baartman, R, Balfour, Y, Barkana, R, Beardsley, AP, Bernardi, G, Billings, TS, Bowman, JD, Bradley, RF, Breitman, D, Bull, P, Burba, J, Carey, S, Carilli, CL, Cheng, C, Choudhuri, S, DeBoer, DR, De Lera Acedo, E, Dexter, M, Dillon, JS, Ely, J, Ewall-Wice, A, Fagnoni, N, Fialkov, A, Fritz, R, Furlanetto, Gale-Sides, K, Garsden, H, Glendenning, B, Gorce, A, Gorthi, D, Greig, B, Grobbelaar, J, Halday, Z, Hazelton, BJ, Heimersheim, S, Hewitt, JN, Hickish, J, Jacobs, DC, Julius, A, Kern, NS, Kerrigan, J, Kittiwisit, P, Kohn, SA, Kolopanis, M, Lanman, A, La Plante, P, Lewis, D, Liu, A, Loots, A, Ma, YZ, MacMahon, DHE, Malan, L, Malgas, K, Malgas, C, Maree, M, Marero, B, Martinot, ZE, McBride, L, Mesinger, A, Mirocha, J, Molewa, M, Morales, MF, Mosiane, T, Muñoz, JB, Murray, SG, Nagpal, V, Neben, AR, Nikolic, B, Nunhokee, CD, Nuwegeld, H, Parsons, AR, Pascua, R, Patra, N, Pieterse, S, Qin, Y, Razavi-Ghods, N, Robnett, J, Rosie, K, Santos, MG, Sims, P, Singh, S, Smith, C, Swarts, H, Tan, J, Thyagarajan, N, Wilensky, MJ, Williams, PKG, Van Wyngaarden, P, Zheng, H, Aguirre, JE [0000-0002-4810-666X], Barkana, R [0000-0002-1557-693X], Beardsley, AP [0000-0001-9428-8233], Bernardi, G [0000-0002-0916-7443], Bowman, JD [0000-0002-8475-2036], Bradley, RF [0000-0003-1172-8331], Breitman, D [0000-0002-2349-3341], Bull, P [0000-0001-5668-3101], Carilli, CL [0000-0001-6647-3861], Choudhuri, S [0000-0002-2338-935X], DeBoer, DR [0000-0003-3197-2294], de Lera Acedo, E [0000-0001-8530-6989], Dillon, JS [0000-0003-3336-9958], Ewall-Wice, A [0000-0002-0086-7363], Fagnoni, N [0000-0001-5300-3166], Fialkov, A [0000-0002-1369-633X], Furlanetto, SR [0000-0002-0658-1243], Gorce, A [0000-0002-1712-737X], Gorthi, D [0000-0002-0829-167X], Greig, B [0000-0002-4085-2094], Hazelton, BJ [0000-0001-7532-645X], Heimersheim, S [0000-0001-9631-4212], Hewitt, JN [0000-0002-4117-570X], Jacobs, DC [0000-0002-0917-2269], Kern, NS [0000-0002-8211-1892], Kerrigan, J [0000-0002-1876-272X], Kittiwisit, P [0000-0003-0953-313X], Kohn, SA [0000-0001-6744-5328], Kolopanis, M [0000-0002-2950-2974], Lanman, A [0000-0003-2116-3573], La Plante, P [0000-0002-4693-0102], Liu, A [0000-0001-6876-0928], Ma, YZ [0000-0001-8108-0986], Mesinger, A [0000-0003-3374-1772], Mirocha, J [0000-0002-8802-5581], Morales, MF [0000-0001-7694-4030], Muñoz, JB [0000-0002-8984-0465], Murray, SG [0000-0003-3059-3823], Nagpal, V [0000-0001-5909-4433], Neben, AR [0000-0001-7776-7240], Nikolic, B [0000-0001-7168-2705], Nunhokee, CD [0000-0002-5445-6586], Parsons, AR [0000-0002-5400-8097], Pascua, R [0000-0003-0073-5528], Patra, N [0000-0002-9457-1941], Qin, Y [0000-0002-4314-1810], Razavi-Ghods, N [0000-0003-2930-5396], Rosie, K [0000-0003-3611-8804], Santos, MG [0000-0003-3892-3073], Sims, P [0000-0002-2871-0413], Singh, S [0000-0001-7755-902X], Tan, J [0000-0001-6161-7037], Thyagarajan, N [0000-0003-1602-7868], Wilensky, MJ [0000-0001-7716-9312], Williams, PKG [0000-0003-3734-3587], Zheng, H [0000-0001-8267-3425], and Apollo - University of Cambridge Repository

Subjects
Space and Planetary Science, 5101 Astronomical Sciences, Astronomy and Astrophysics, 51 Physical Sciences
Abstract

We report the most sensitive upper limits to date on the 21 cm epoch of reionization power spectrum using 94 nights of observing with Phase I of the Hydrogen Epoch of Reionization Array (HERA). Using similar analysis techniques as in previously reported limits, we find at 95% confidence that Δ2(k = 0.34 h Mpc−1) ≤ 457 mK2 at z = 7.9 and that Δ2(k = 0.36 h Mpc−1) ≤ 3496 mK2 at z = 10.4, an improvement by a factor of 2.1 and 2.6, respectively. These limits are mostly consistent with thermal noise over a wide range of k after our data quality cuts, despite performing a relatively conservative analysis designed to minimize signal loss. Our results are validated with both statistical tests on the data and end-to-end pipeline simulations. We also report updated constraints on the astrophysics of reionization and the cosmic dawn. Using multiple independent modeling and inference techniques previously employed by HERA Collaboration, we find that the intergalactic medium must have been heated above the adiabatic cooling limit at least as early as z = 10.4, ruling out a broad set of so-called “cold reionization” scenarios. If this heating is due to high-mass X-ray binaries during the cosmic dawn, as is generally believed, our result’s 99% credible interval excludes the local relationship between soft X-ray luminosity and star formation and thus requires heating driven by evolved low-metallicity stars.

Published
2023

2. Direct Optimal Mapping for 21cm Cosmology: A Demonstration with the Hydrogen Epoch of Reionization Array

Author

Xu, Z, Hewitt, JN, Chen, KF, Kim, H, Dillon, JS, Kern, NS, Morales, MF, Hazelton, BJ, Byrne, R, Fagnoni, N, Acedo, EDL, Abdurashidova, Z, Adams, T, Aguirre, JE, Alexander, P, Ali, ZS, Baartman, R, Balfour, Y, Beardsley, AP, Bernardi, G, Billings, TS, Bowman, JD, Bradley, RF, Bull, P, Burba, J, Carey, S, Carilli, CL, Cheng, C, DeBoer, DR, Dexter, M, Eksteen, N, Ely, J, Ewall-Wice, A, Fritz, R, Furlanetto, Gale-Sides, K, Glendenning, B, Gorthi, D, Greig, B, Grobbelaar, J, Halday, Z, Hickish, J, Jacobs, DC, Julius, A, Kariseb, M, Kerrigan, J, Kittiwisit, P, Kohn, SA, Kolopanis, M, Lanman, A, Plante, PL, Liu, A, Loots, A, Ma, YZ, Edward MacMahon, DH, Malan, L, Malgas, C, Malgas, K, Marero, B, Martinot, ZE, Mesinger, A, Molewa, M, Mosiane, T, Murray, SG, Neben, AR, Nikolic, B, Nuwegeld, H, Parsons, AR, Patra, N, Pieterse, S, Pober, JC, Razavi-Ghods, N, Robnett, J, Rosie, K, Sims, P, Smith, C, Swarts, H, Thyagarajan, N, Wyngaarden, PVV, Williams, PKG, Zheng, H, Xu, Z [0000-0001-5112-2567], Hewitt, JN [0000-0002-4117-570X], Chen, KF [0000-0002-3839-0230], Dillon, JS [0000-0003-3336-9958], Kern, NS [0000-0002-8211-1892], Morales, MF [0000-0001-7694-4030], Hazelton, BJ [0000-0001-7532-645X], Byrne, R [0000-0003-4980-2736], Aguirre, JE [0000-0002-4810-666X], Beardsley, AP [0000-0001-9428-8233], Bernardi, G [0000-0002-0916-7443], Bowman, JD [0000-0002-8475-2036], Bradley, RF [0000-0003-1172-8331], Bull, P [0000-0001-5668-3101], Carilli, CL [0000-0001-6647-3861], DeBoer, DR [0000-0003-3197-2294], Ewall-Wice, A [0000-0002-0086-7363], Furlanetto, SR [0000-0002-0658-1243], Gorthi, D [0000-0002-0829-167X], Greig, B [0000-0002-4085-2094], Jacobs, DC [0000-0002-0917-2269], Kerrigan, J [0000-0002-1876-272X], Kittiwisit, P [0000-0003-0953-313X], Kohn, SA [0000-0001-6744-5328], Kolopanis, M [0000-0002-2950-2974], Lanman, A [0000-0003-2116-3573], Plante, PL [0000-0002-4693-0102], Liu, A [0000-0001-6876-0928], Ma, YZ [0000-0001-8108-0986], Mesinger, A [0000-0003-3374-1772], Murray, SG [0000-0003-3059-3823], Neben, AR [0000-0001-7776-7240], Parsons, AR [0000-0002-5400-8097], Patra, N [0000-0002-9457-1941], Pober, JC [0000-0002-3492-0433], Sims, P [0000-0002-2871-0413], Thyagarajan, N [0000-0003-1602-7868], Williams, PKG [0000-0003-3734-3587], Apollo - University of Cambridge Repository, Xu, Zhilei, Hewitt, Jacqueline N., Chen, Kai-Feng, Kim, Honggeun, Dillon, Joshua S., Kern, Nicholas S., Morales, Miguel F., Hazelton, Bryna J., Byrne, Ruby, Fagnoni, Nicola, de Lera Acedo, Eloy, Abdurashidova, Zara, Adams, Tyrone, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Baartman, Rushelle, Balfour, Yanga, Beardsley, Adam P., Bernardi, Gianni, Billings, Tashalee S., Bowman, Judd D., Bradley, Richard F., Bull, Philip, Burba, Jacob, Carey, Steven, Carilli, Chris L., Cheng, Carina, Deboer, David R., Dexter, Matt, Eksteen, Nico, Ely, John, Ewall-Wice, Aaron, Fritz, Randall, Furlanetto, Steven R., Gale-Sides, Kingsley, Glendenning, Brian, Gorthi, Deepthi, Greig, Bradley, Grobbelaar, Jasper, Halday, Ziyaad, Hickish, Jack, Jacobs, Daniel C., Julius, Austin, Kariseb, Maccalvin, Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Liu, Adrian, Loots, Anita, Ma, Yin-Zhe, Harold Edward MacMahon, David, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Martinot, Zachary E., Mesinger, ANDREI ALBERT, Molewa, Mathakane, Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nikolic, Bojan, Nuwegeld, Han, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Robnett, Jame, Rosie, Kathryn, Sims, Peter, Smith, Craig, Swarts, Hilton, Thyagarajan, Nithyanandan, Van Van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), model, maps, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galactic radio-emission, 5109 Space Sciences, power spectrum, calibration, 10 mhz, Settore FIS/05 - Astronomia e Astrofisica, 5101 Astronomical Sciences, Space and Planetary Science, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), upper limit, 51 Physical Sciences, 5107 Particle and High Energy Physics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Motivated by the desire for wide-field images with well-defined statistical properties for 21cm cosmology, we implement an optimal mapping pipeline that computes a maximum likelihood estimator for the sky using the interferometric measurement equation. We demonstrate this direct optimal mapping with data from the Hydrogen Epoch of Reionization (HERA) Phase I observations. After validating the pipeline with simulated data, we develop a maximum likelihood figure-of-merit for comparing four sky models at 166MHz with a bandwidth of 100kHz. The HERA data agree with the GLEAM catalogs to, 16 pages, 10 figures, 2 tables, published on ApJ

Published
2022

3. HERA Phase I Limits on the Cosmic 21 cm Signal: Constraints on Astrophysics and Cosmology during the Epoch of Reionization

Author

The HERA Collaboration, Abdurashidova, Zara, Aguirre, James E., Alexander, Paul, Ali, Zaki, Balfour, Yanga, Barkana, Rennan, Beardsley, Adam, Bernardi, Gianni, Billings, Tashalee, Bowman, Judd, Bradley, Richard, Bull, Phillip, Burba, Jacob, Carey, Steven, Carilli, Christopher, Cheng, Carina, DeBoer, David, Dexter, Matthew, Acedo, Eloy de Lera, Dillon, Joshua, Ely, John, Ewall-Wice, Aaron, Fagnoni, Nicolas, Fialkov, Anastasia, Fritz, Randall, Furlanetto, Steven, Gale-Sides, Kingsley, Glendenning, Brian, Gorthi, Deepthi, Greig, Bradley, Grobbelaar, Jasper, Halday, Ziyaad, Hazelton, Bryna, Heimersheim, Stefan, Hewitt, Jacqueline, Hickish, Jack, Jacobs, Daniel, Julius, Austin, Kern, Nicholas, Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul, Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Lekalake, Telalo, Lewis, David, Liu, Adrian, Ma, Yin-Zhe, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthys, Martinot, Zachary, Matsetela, Eunice, Mesinger, Andrei, Mirocha, Jordan, Molewa, Mathakane, Morales, Miguel, Mosiane, Tshegofalang, Munoz, Julian, Murray, Steven, Neben, Abraham, Nikolic, Bojan, Nunhokee, Chuneeta Devi, Parsons, Aaron, Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan, Qin, Yuxiang, Razavi-Ghods, N., Reis, Itamar, Ringuette, Jon, Robnett, James, Rosie, Kathryn, Santos, Mario, Sikder, Sudipta, Sims, Peter, Smith, Craig, Syce, Angelo, Thyagarajan, Nithyanandan, Williams, Peter, Zheng, Haoxuan, Abdurashidova, Z., Aguirre, J. E., Alexander, P., Ali, Z. S., Balfour, Y., Barkana, R., Beardsley, A. P., Bernardi, G., Billings, T. S., Bowman, J. D., Bradley, R. F., Bull, P., Burba, J., Carey, S., Carilli, C. L., Cheng, C., Deboer, D. R., Dexter, M., De Lera Acedo, E., Dillon, J. S., Ely, J., Ewall-Wice, A., Fagnoni, N., Fialkov, A., Fritz, R., Furlanetto, S. R., Gale-Sides, K., Glendenning, B., Gorthi, D., Greig, B., Grobbelaar, J., Halday, Z., Hazelton, B. J., Heimersheim, S., Hewitt, J. N., Hickish, J., Jacobs, D. C., Julius, A., Kern, N. S., Kerrigan, J., Kittiwisit, P., Kohn, S. A., Kolopanis, M., Lanman, A., La Plante, P., Lekalake, T., Lewis, D., Liu, A., Ma, Y. -Z., Macmahon, D., Malan, L., Malgas, C., Maree, M., Martinot, Z. E., Matsetela, E., Mesinger, A., Mirocha, J., Molewa, M., Morales, M. F., Mosiane, T., Munoz, J. B., Murray, S. G., Neben, A. R., Nikolic, B., Nunhokee, C. D., Parsons, A. R., Patra, N., Pieterse, S., Pober, J. C., Qin, Y., Razavi-Ghods, N., Reis, I., Ringuette, J., Robnett, J., Rosie, K., Santos, M. G., Sikder, S., Sims, P., Smith, C., Syce, A., Thyagarajan, N., Williams, P. K. G., Zheng, H., USA, GBR, ZAF, Aguirre, JE [0000-0002-4810-666X], Barkana, R [0000-0002-1557-693X], Beardsley, AP [0000-0001-9428-8233], Bernardi, G [0000-0002-0916-7443], Bowman, JD [0000-0002-8475-2036], Bradley, RF [0000-0003-1172-8331], Bull, P [0000-0001-5668-3101], Carilli, CL [0000-0001-6647-3861], Deboer, DR [0000-0003-3197-2294], Dillon, JS [0000-0003-3336-9958], Ewall-Wice, A [0000-0002-0086-7363], Fialkov, A [0000-0002-1369-633X], Furlanetto, SR [0000-0002-0658-1243], Gorthi, D [0000-0002-0829-167X], Greig, B [0000-0002-4085-2094], Hazelton, BJ [0000-0001-7532-645X], Heimersheim, S [0000-0001-9631-4212], Hewitt, JN [0000-0002-4117-570X], Jacobs, DC [0000-0002-0917-2269], Kern, NS [0000-0002-8211-1892], Kerrigan, J [0000-0002-1876-272X], Kittiwisit, P [0000-0003-0953-313X], Kohn, SA [0000-0001-6744-5328], Kolopanis, M [0000-0002-2950-2974], La Plante, P [0000-0002-4693-0102], Liu, A [0000-0001-6876-0928], Ma, YZ [0000-0001-8108-0986], Mesinger, A [0000-0003-3374-1772], Mirocha, J [0000-0002-8802-5581], Morales, MF [0000-0001-7694-4030], Munoz, JB [0000-0002-8984-0465], Neben, AR [0000-0001-7776-7240], Nunhokee, CD [0000-0002-5445-6586], Patra, N [0000-0002-9457-1941], Pober, JC [0000-0002-3492-0433], Qin, Y [0000-0002-4314-1810], Reis, I [0000-0002-6203-7496], Santos, MG [0000-0003-3892-3073], Sims, P [0000-0002-2871-0413], Thyagarajan, N [0000-0003-1602-7868], and Apollo - University of Cambridge Repository

Subjects
High Energy Physics - Theory, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010308 nuclear & particles physics, astro-ph.GA, hep-th, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, High Energy Physics - Theory (hep-th), Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, astro-ph.CO, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Recently, the Hydrogen Epoch of Reionization Array (HERA) collaboration has produced the experiment's first upper limits on the power spectrum of 21-cm fluctuations at z~8 and 10. Here, we use several independent theoretical models to infer constraints on the intergalactic medium (IGM) and galaxies during the epoch of reionization (EoR) from these limits. We find that the IGM must have been heated above the adiabatic cooling threshold by z~8, independent of uncertainties about the IGM ionization state and the nature of the radio background. Combining HERA limits with galaxy and EoR observations constrains the spin temperature of the z~8 neutral IGM to 27 K < T_S < 630 K (2.3 K < T_S < 640 K) at 68% (95%) confidence. They therefore also place a lower bound on X-ray heating, a previously unconstrained aspects of early galaxies. For example, if the CMB dominates the z~8 radio background, the new HERA limits imply that the first galaxies produced X-rays more efficiently than local ones (with soft band X-ray luminosities per star formation rate constrained to L_X/SFR = { 10^40.2, 10^41.9 } erg/s/(M_sun/yr) at 68% confidence), consistent with expectations of X-ray binaries in low-metallicity environments. The z~10 limits require even earlier heating if dark-matter interactions (e.g., through millicharges) cool down the hydrogen gas. Using a model in which an extra radio background is produced by galaxies, we rule out (at 95% confidence) the combination of high radio and low X-ray luminosities of L_{r,ν}/SFR > 3.9 x 10^24 W/Hz/(M_sun/yr) and L_X/SFR, 40 pages, 19 figures, accepted to ApJ

Published
2022
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4. First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum

Author

The HERA Collaboration, Abdurashidova, Zara, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Balfour, Yanga, Beardsley, Adam P., Bernardi, Gianni, Billings, Tashalee S., Bowman, Judd D., Bradley, Richard F., Bull, Philip, Burba, Jacob, Carey, Steve, Carilli, Chris L., Cheng, Carina, DeBoer, David R., Dexter, Matt, Acedo, Eloy de Lera, Dibblee-Barkman, Taylor, Dillon, Joshua S., Ely, John, Ewall-Wice, Aaron, Fagnoni, Nicolas, Fritz, Randall, Furlanetto, Steven R., Gale-Sides, Kingsley, Glendenning, Brian, Gorthi, Deepthi, Greig, Bradley, Grobbelaar, Jasper, Halday, Ziyaad, Hazelton, Bryna J., Hewitt, Jacqueline N., Hickish, Jack, Jacobs, Daniel C., Julius, Austin, Kern, Nicholas S., Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Lekalake, Telalo, Lewis, David, Liu, Adrian, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthys, Martinot, Zachary E., Matsetela, Eunice, Mesinger, Andrei, Molewa, Mathakane, Morales, Miguel F., Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nikolic, Bojan, Nunhokee, Chuneeta D., Parsons, Aaron R., Patra, Nipanjana, Pascua, Robert, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Ringuette, Jon, Robnett, James, Rosie, Kathryn, Sims, Peter, Singh, Saurabh, Smith, Craig, Syce, Angelo, Thyagarajan, Nithyanandan, Williams, Peter K. G., Zheng, Haoxuan, USA, GBR, ZAF, Abdurashidova, Z., Aguirre, J. E., Alexander, P., Ali, Z. S., Balfour, Y., Beardsley, A. P., Bernardi, G., Billings, T. S., Bowman, J. D., Bradley, R. F., Bull, P., Burba, J., Carey, S., Carilli, C. L., Cheng, C., Deboer, D. R., Dexter, M., De Lera Acedo, E., Dibblee-Barkman, T., Dillon, J. S., Ely, J., Ewall-Wice, A., Fagnoni, N., Fritz, R., Furlanetto, S. R., Gale-Sides, K., Glendenning, B., Gorthi, D., Greig, B., Grobbelaar, J., Halday, Z., Hazelton, B. J., Hewitt, J. N., Hickish, J., Jacobs, D. C., Julius, A., Kern, N. S., Kerrigan, J., Kittiwisit, P., Kohn, S. A., Kolopanis, M., Lanman, A., La Plante, P., Lekalake, T., Lewis, D., Liu, A., Macmahon, D., Malan, L., Malgas, C., Maree, M., Martinot, Z. E., Matsetela, E., Mesinger, A., Molewa, M., Morales, M. F., Mosiane, T., Murray, S. G., Neben, A. R., Nikolic, B., Nunhokee, C. D., Parsons, A. R., Patra, N., Pascua, R., Pieterse, S., Pober, J. C., Razavi-Ghods, N., Ringuette, J., Robnett, J., Rosie, K., Sims, P., Singh, S., Smith, C., Syce, A., Thyagarajan, N., Williams, P. K. G., Zheng, H., Aguirre, JE [0000-0002-4810-666X], Beardsley, AP [0000-0001-9428-8233], Bernardi, G [0000-0002-0916-7443], Bowman, JD [0000-0002-8475-2036], Bull, P [0000-0001-5668-3101], Carilli, CL [0000-0001-6647-3861], Deboer, DR [0000-0003-3197-2294], Dillon, JS [0000-0003-3336-9958], Ewall-Wice, A [0000-0002-0086-7363], Furlanetto, SR [0000-0002-0658-1243], Gorthi, D [0000-0002-0829-167X], Greig, B [0000-0002-4085-2094], Hazelton, BJ [0000-0001-7532-645X], Jacobs, DC [0000-0002-0917-2269], Kern, NS [0000-0002-8211-1892], Kerrigan, J [0000-0002-1876-272X], Kittiwisit, P [0000-0003-0953-313X], Kohn, SA [0000-0001-6744-5328], Kolopanis, M [0000-0002-2950-2974], Liu, A [0000-0001-6876-0928], Mesinger, A [0000-0003-3374-1772], Morales, MF [0000-0001-7694-4030], Murray, SG [0000-0003-3059-3823], Neben, AR [0000-0001-7776-7240], Nunhokee, CD [0000-0002-5445-6586], Patra, N [0000-0002-9457-1941], Pober, JC [0000-0002-3492-0433], Sims, P [0000-0002-2871-0413], Singh, S [0000-0001-7755-902X], Thyagarajan, N [0000-0003-1602-7868], Williams, PKG [0000-0003-3734-3587], and Apollo - University of Cambridge Repository

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, astro-ph.GA, Astrophysics of Galaxies (astro-ph.GA), astro-ph.CO, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We report upper-limits on the Epoch of Reionization (EoR) 21 cm power spectrum at redshifts 7.9 and 10.4 with 18 nights of data ($\sim36$ hours of integration) from Phase I of the Hydrogen Epoch of Reionization Array (HERA). The Phase I data show evidence for systematics that can be largely suppressed with systematic models down to a dynamic range of $\sim10^9$ with respect to the peak foreground power. This yields a 95% confidence upper limit on the 21 cm power spectrum of $\Delta^2_{21} \le (30.76)^2\ {\rm mK}^2$ at $k=0.192\ h\ {\rm Mpc}^{-1}$ at $z=7.9$, and also $\Delta^2_{21} \le (95.74)^2\ {\rm mK}^2$ at $k=0.256\ h\ {\rm Mpc}^{-1}$ at $z=10.4$. At $z=7.9$, these limits are the most sensitive to-date by over an order of magnitude. While we find evidence for residual systematics at low line-of-sight Fourier $k_\parallel$ modes, at high $k_\parallel$ modes we find our data to be largely consistent with thermal noise, an indicator that the system could benefit from deeper integrations. The observed systematics could be due to radio frequency interference, cable sub-reflections, or residual instrumental cross-coupling, and warrant further study. This analysis emphasizes algorithms that have minimal inherent signal loss, although we do perform a careful accounting in a companion paper of the small forms of loss or bias associated with the pipeline. Overall, these results are a promising first step in the development of a tuned, instrument-specific analysis pipeline for HERA, particularly as Phase II construction is completed en route to reaching the full sensitivity of the experiment., Comment: Accepted to ApJ. https://reionization.org/science/public-data-release-1/

Published
2021
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5. Validation of the HERA Phase I Epoch of Reionization 21 cm Power Spectrum Software Pipeline

Author

Aguirre, James E., Murray, Steven G., Pascua, Robert, Martinot, Zachary E., Burba, Jacob, Dillon, Joshua S., Jacobs, Daniel C., Kern, Nicholas S., Kittiwisit, Piyanat, Kolopanis, Matthew, Lanman, Adam, Liu, Adrian, Whitler, Lily, Abdurashidova, Zara, Alexander, Paul, Ali, Zaki S., Balfour, Yanga, Beardsley, Adam P., BERNARDI, GIANNI, Billings, Tashalee S., Bowman, Judd D., Bradley, Richard F., BULL, PHILIP, Carey, Steve, Carilli, Chris L., Cheng, Carina, DeBoer, David R., Dexter, Matt, de Lera Acedo, Eloy, Ely, John, Ewall-Wice, Aaron, Fagnoni, Nicolas, Fritz, Randall, Furlanetto, Steven R., Gale-Sides, Kingsley, Glendenning, Brian, Gorthi, Deepthi, Greig, Bradley, Grobbelaar, Jasper, Halday, Ziyaad, Hazelton, Bryna J., Hewitt, Jacqueline N., Hickish, Jack, Julius, Austin, Kerrigan, Joshua, Kohn, Saul A., La Plante, Paul, Lekalake, Telalo, Lewis, David, MacMahon, David, Malan, Lourence, Malgas, Cresshim, Maree, Matthys, Matsetela, Eunice, Mesinger, Andrei, Molewa, Mathakane, Morales, Miguel F., Mosiane, Tshegofalang, Neben, Abraham R., Nikolic, Bojan, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Ringuette, Jon, Robnett, James, Rosie, Kathryn, Santos, Mario G., Sims, Peter, Singh, Saurabh, Smith, Craig, Syce, Angelo, Thyagarajan, Nithyanandan, Williams, Peter K. G., Zheng, Haoxuan, HERA Collaboration, Aguirre, J. E., Murray, S. G., Pascua, R., Martinot, Z. E., Burba, J., Dillon, J. S., Jacobs, D. C., Kern, N. S., Kittiwisit, P., Kolopanis, M., Lanman, A., Liu, A., Whitler, L., Abdurashidova, Z., Alexander, P., Ali, Z. S., Balfour, Y., Beardsley, A. P., Bernardi, G., Billings, T. S., Bowman, J. D., Bradley, R. F., Bull, P., Carey, S., Carilli, C. L., Cheng, C., Deboer, D. R., Dexter, M., De Lera Acedo, E., Ely, J., Ewall-Wice, A., Fagnoni, N., Fritz, R., Furlanetto, S. R., Gale-Sides, K., Glendenning, B., Gorthi, D., Greig, B., Grobbelaar, J., Halday, Z., Hazelton, B. J., Hewitt, J. N., Hickish, J., Julius, A., Kerrigan, J., Kohn, S. A., La Plante, P., Lekalake, T., Lewis, D., Macmahon, D., Malan, L., Malgas, C., Maree, M., Matsetela, E., Mesinger, A., Molewa, M., Morales, M. F., Mosiane, T., Neben, A. R., Nikolic, B., Parsons, A. R., Patra, N., Pieterse, S., Pober, J. C., Razavi-Ghods, N., Ringuette, J., Robnett, J., Rosie, K., Santos, M. G., Sims, P., Singh, S., Smith, C., Syce, A., Thyagarajan, N., Williams, P. K. G., Zheng, H., USA, GBR, ZAF, Aguirre, JE [0000-0002-4810-666X], Murray, SG [0000-0003-3059-3823], Dillon, JS [0000-0003-3336-9958], Jacobs, DC [0000-0002-0917-2269], Kern, NS [0000-0002-8211-1892], Kittiwisit, P [0000-0003-0953-313X], Kolopanis, M [0000-0002-2950-2974], Lanman, A [0000-0003-2116-3573], Liu, A [0000-0001-6876-0928], Beardsley, AP [0000-0001-9428-8233], Bernardi, G [0000-0002-0916-7443], Bowman, JD [0000-0002-8475-2036], Bradley, RF [0000-0003-1172-8331], Bull, P [0000-0001-5668-3101], Carilli, CL [0000-0001-6647-3861], Deboer, DR [0000-0003-3197-2294], Ewall-Wice, A [0000-0002-0086-7363], Furlanetto, SR [0000-0002-0658-1243], Gorthi, D [0000-0002-0829-167X], Greig, B [0000-0002-4085-2094], Hazelton, BJ [0000-0001-7532-645X], Hewitt, JN [0000-0002-4117-570X], Kerrigan, J [0000-0002-1876-272X], Kohn, SA [0000-0001-6744-5328], Mesinger, A [0000-0003-3374-1772], Morales, MF [0000-0001-7694-4030], Neben, AR [0000-0001-7776-7240], Patra, N [0000-0002-9457-1941], Pober, JC [0000-0002-3492-0433], Santos, MG [0000-0003-3892-3073], Sims, P [0000-0002-2871-0413], Singh, S [0000-0001-7755-902X], and Apollo - University of Cambridge Repository

Subjects
Settore FIS/05 - Astronomia e Astrofisica, 010308 nuclear & particles physics, Space and Planetary Science, 0103 physical sciences, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, 01 natural sciences, astro-ph.IM
Abstract

We describe the validation of the HERA Phase I software pipeline by a series of modular tests, building up to an end-to-end simulation. The philosophy of this approach is to validate the software and algorithms used in the Phase I upper limit analysis on wholly synthetic data satisfying the assumptions of that analysis, not addressing whether the actual data meet these assumptions. We discuss the organization of this validation approach, the specific modular tests performed, and the construction of the end-to-end simulations. We explicitly discuss the limitations in scope of the current simulation effort. With mock visibility data generated from a known analytic power spectrum and a wide range of realistic instrumental effects and foregrounds, we demonstrate that the current pipeline produces power spectrum estimates that are consistent with known analytic inputs to within thermal noise levels (at the 2 sigma level) for k > 0.2 h/Mpc for both bands and fields considered. Our input spectrum is intentionally amplified to enable a strong `detection' at k ~0.2 h/Mpc -- at the level of ~25 sigma -- with foregrounds dominating on larger scales, and thermal noise dominating at smaller scales. Our pipeline is able to detect this amplified input signal after suppressing foregrounds with a dynamic range (foreground to noise ratio) of > 10^7. Our validation test suite uncovered several sources of scale-independent signal loss throughout the pipeline, whose amplitude is well-characterized and accounted for in the final estimates. We conclude with a discussion of the steps required for the next round of data analysis., 32 pages, 20 figures. Submitted to the Astrophysical Journal

Published
2022
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