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4,092 results on '"Smith,Craig"'

2. Bayesian estimation of cross-coupling and reflection systematics in 21cm array visibility data

Author

Murphy, Geoff G., Bull, Philip, Santos, Mario G., Abdurashidova, Zara, Adams, Tyrone, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Baartman, Rushelle, Balfour, Yanga, Beardsley, Adam P., Bernardi, Gianni, Billings, Tashalee, Bowman, Judd D., Bradley, Richard F., Burba, Jacob, Cain, Christopher, Carey, Steven, Carilli, Chris L., Cheng, Carina, DeBoer, David R., Acedo, Eloy de Lera, Dexter, Matt, Dillon, Joshua S., Eksteen, Nico, 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, Kariseb, MacCalvin, Kern, Nicholas S., Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Liu, Adrian, Loots, Anita, MacMahon, David Harold Edward, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Martinot, Zachary E., Mesinger, Andrei, Molewa, Mathakane, Morales, Miguel F., Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nikolic, Bojan, Nuwegeld, Hans, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Sims, Peter, Sipple, Jackson, Smith, Craig, Swarts, Hilton, Thyagarajan, Nithyanandan, van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Observations with radio arrays that target the 21-cm signal originating from the early Universe suffer from a variety of systematic effects. An important class of these are reflections and spurious couplings between antennas. We apply a Hamiltonian Monte Carlo sampler to the modelling and mitigation of these systematics in simulated Hydrogen Epoch of Reionisation Array (HERA) data. This method allows us to form statistical uncertainty estimates for both our models and the recovered visibilities, which is an important ingredient in establishing robust upper limits on the Epoch of Reionisation (EoR) power spectrum. In cases where the noise is large compared to the EoR signal, this approach can constrain the systematics well enough to mitigate them down to the noise level for both systematics studied. Where the noise is smaller than the EoR, our modelling can mitigate the majority of the reflections with there being only a minor level of residual systematics, while cross-coupling sees essentially complete mitigation. Our approach performs similarly to existing filtering/fitting techniques used in the HERA pipeline, but with the added benefit of rigorously propagating uncertainties. In all cases it does not significantly attenuate the underlying signal., Comment: 19 pages, 14 figures, submitted to MNRAS

Published
2023

3. Direct Optimal Mapping Image Power Spectrum and its Window Functions

Author

Xu, Zhilei, Kim, Honggeun, Hewitt, Jacqueline N., Chen, Kai-Feng, Kern, Nicholas S., Rath, Eleanor, Byrne, Ruby, Gorce, Adélie, Pascua, Robert, Martinot, Zachary E., Dillon, Joshua S., Hazelton, Bryna J., Liu, Adrian, Morales, Miguel F., 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., Acedo, Eloy de Lera, Dexter, Matt, Eksteen, Nico, 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, Hickish, Jack, Jacobs, Daniel C., Julius, Austin, Kariseb, MacCalvin, Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Loots, Anita, MacMahon, David Harold Edward, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Mesinger, Andrei, Molewa, Mathakane, Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nikolic, Bojan, Nuwegeld, Hans, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Sims, Peter, Smith, Craig, Swarts, Hilton, Thyagarajan, Nithyanandan, van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The key to detecting neutral hydrogen during the epoch of reionization (EoR) is to separate the cosmological signal from the dominating foreground radiation. We developed direct optimal mapping (DOM) to map interferometric visibilities; it contains only linear operations, with full knowledge of point spread functions from visibilities to images. Here, we demonstrate a fast Fourier transform-based image power spectrum and its window functions computed from the DOM images. We use noiseless simulation, based on the Hydrogen Epoch of Reionization Array Phase I configuration, to study the image power spectrum properties. The window functions show $<10^{-11}$ of the integrated power leaks from the foreground-dominated region into the EoR window; the 2D and 1D power spectra also verify the separation between the foregrounds and the EoR., Comment: Published in ApJ

Published
2023

5. Search for the Epoch of Reionisation with HERA: Upper Limits on the Closure Phase Delay Power Spectrum

Author

Keller, Pascal M., Nikolic, Bojan, Thyagarajan, Nithyanandan, Carilli, Chris L., Bernardi, Gianni, Charles, Ntsikelelo, Bester, Landman, Smirnov, Oleg M., Kern, Nicholas S., Dillon, Joshua S., Hazelton, Bryna J., Morales, Miguel F., Jacobs, Daniel C., Parsons, Aaron R., Abdurashidova, Zara, Adams, Tyrone, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Baartman, Rushelle, Balfour, Yanga, Beardsley, Adam P., Billings, Tashalee S., Bowman, Judd D., Bradley, Richard F., Bull, Philip, Burba, Jacob, Carey, Steven, Cheng, Carina, DeBoer, David R., Acedo, Eloy de Lera, Dexter, Matt, Eksteen, Nico, 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, Hewitt, Jacqueline N., Hickish, Jack, 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, MacMahon, David Harold Edward, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Martinot, Zachary E., Mesinger, Andrei, Molewa, Mathakane, Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nuwegeld, Hans, Pascua, Robert, Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Santos, Mario G., Sims, Peter, Smith, Craig, Swarts, Hilton, Van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to separate the weak signal from overwhelming foreground emissions. Calibration inaccuracies can compromise the sensitivity of these measurements to the effect that a detection of the EoR is precluded. An alternative to standard analysis techniques makes use of the closure phase, which allows one to bypass antenna-based direction-independent calibration. Similarly to standard approaches, we use a delay spectrum technique to search for the EoR signal. Using 94 nights of data observed with Phase I of the Hydrogen Epoch of Reionization Array (HERA), we place approximate constraints on the 21 cm power spectrum at $z=7.7$. We find at 95% confidence that the 21 cm EoR brightness temperature is $\le$(372)$^2$ "pseudo" mK$^2$ at 1.14 "pseudo" $h$ Mpc$^{-1}$, where the "pseudo" emphasises that these limits are to be interpreted as approximations to the actual distance scales and brightness temperatures. Using a fiducial EoR model, we demonstrate the feasibility of detecting the EoR with the full array. Compared to standard methods, the closure phase processing is relatively simple, thereby providing an important independent check on results derived using visibility intensities, or related., Comment: 16 pages, 14 figures, accepted for publication by MNRAS

Published
2023
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7. Characterization Of Inpaint Residuals In Interferometric Measurements of the Epoch Of Reionization

Author

Pagano, Michael, Liu, Jing, Liu, Adrian, Kern, Nicholas S., Ewall-Wice, Aaron, Bull, Philip, Pascua, Robert, Ravanbakhsh, Siamak, 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., Burba, Jacob, Carey, Steven, Carilli, Chris L., Cheng, Carina, DeBoer, David R., Acedo, Eloy de Lera, Dexter, Matt, Dillon, Joshua S., Eksteen, Nico, Ely, John, 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, Kariseb, MacCalvin, Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Loots, Anita, MacMahon, David Harold Edward, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Martinot, Zachary E., Mesinger, Andrei, Molewa, Mathakane, Morales, Miguel F., Mosiane, Tshegofalang, Neben, Abraham R., Nikolic, Bojan, Nuwegeld, Hans, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Sims, Peter, Smith, Craig, Swarts, Hilton, Thyagarajan, Nithyanandan, van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Radio Frequency Interference (RFI) is one of the systematic challenges preventing 21cm interferometric instruments from detecting the Epoch of Reionization. To mitigate the effects of RFI on data analysis pipelines, numerous inpaint techniques have been developed to restore RFI corrupted data. We examine the qualitative and quantitative errors introduced into the visibilities and power spectrum due to inpainting. We perform our analysis on simulated data as well as real data from the Hydrogen Epoch of Reionization Array (HERA) Phase 1 upper limits. We also introduce a convolutional neural network that capable of inpainting RFI corrupted data in interferometric instruments. We train our network on simulated data and show that our network is capable at inpainting real data without requiring to be retrained. We find that techniques that incorporate high wavenumbers in delay space in their modeling are best suited for inpainting over narrowband RFI. We also show that with our fiducial parameters Discrete Prolate Spheroidal Sequences (DPSS) and CLEAN provide the best performance for intermittent ``narrowband'' RFI while Gaussian Progress Regression (GPR) and Least Squares Spectral Analysis (LSSA) provide the best performance for larger RFI gaps. However we caution that these qualitative conclusions are sensitive to the chosen hyperparameters of each inpainting technique. We find these results to be consistent in both simulated and real visibilities. We show that all inpainting techniques reliably reproduce foreground dominated modes in the power spectrum. Since the inpainting techniques should not be capable of reproducing noise realizations, we find that the largest errors occur in the noise dominated delay modes. We show that in the future, as the noise level of the data comes down, CLEAN and DPSS are most capable of reproducing the fine frequency structure in the visibilities of HERA data., Comment: 21 pages, 13 figures

Published
2022
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8. Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

Author

The HERA Collaboration, Abdurashidova, Zara, Adams, Tyrone, Aguirre, James E., Alexander, Paul, Ali, Zaki S., Baartman, Rushelle, Balfour, Yanga, Barkana, Rennan, Beardsley, Adam P., Bernardi, Gianni, Billings, Tashalee S., Bowman, Judd D., Bradley, Richard F., Breitman, Daniela, Bull, Philip, Burba, Jacob, Carey, Steve, Carilli, Chris L., Cheng, Carina, Choudhuri, Samir, DeBoer, David R., Acedo, Eloy de Lera, Dexter, Matt, Dillon, Joshua S., Ely, John, Ewall-Wice, Aaron, Fagnoni, Nicolas, Fialkov, Anastasia, Fritz, Randall, Furlanetto, Steven R., Gale-Sides, Kingsley, Garsden, Hugh, Glendenning, Brian, Gorce, Adélie, Gorthi, Deepthi, Greig, Bradley, Grobbelaar, Jasper, Halday, Ziyaad, Hazelton, Bryna J., Heimersheim, Stefan, 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, Lewis, David, Liu, Adrian, Loots, Anita, Ma, Yin-Zhe, MacMahon, David H. E., Malan, Lourence, Malgas, Keith, Malgas, Cresshim, Maree, Matthys, Marero, Bradley, Martinot, Zachary E., McBride, Lisa, Mesinger, Andrei, Mirocha, Jordan, Molewa, Mathakane, Morales, Miguel F., Mosiane, Tshegofalang, Muñoz, Julian B., Murray, Steven G., Nagpal, Vighnesh, Neben, Abraham R., Nikolic, Bojan, Nunhokee, Chuneeta D., Nuwegeld, Hans, Parsons, Aaron R., Pascua, Robert, Patra, Nipanjana, Pieterse, Samantha, Qin, Yuxiang, Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Santos, Mario G., Sims, Peter, Singh, Saurabh, Smith, Craig, Swarts, Hilton, Tan, Jianrong, Thyagarajan, Nithyanandan, Wilensky, Michael J., Williams, Peter K. G., van Wyngaarden, Pieter, and Zheng, Haoxuan

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
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 (HERA Collaboration 2022a), we find at 95% confidence that $\Delta^2(k = 0.34$ $h$ Mpc$^{-1}$) $\leq 457$ mK$^2$ at $z = 7.9$ and that $\Delta^2 (k = 0.36$ $h$ Mpc$^{-1}) \leq 3,496$ mK$^2$ 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 (2022b), 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., Comment: 57 pages, 37 figures. Updated to match the accepted ApJ version. Corresponding author: Joshua S. Dillon

Published
2022
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9. Impact of instrument and data characteristics in the interferometric reconstruction of the 21 cm power spectrum

Author

Gorce, Adélie, Ganjam, Samskruthi, Liu, Adrian, Murray, Steven G., 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., Acedo, Eloy de Lera, Dexter, Matt, Dillon, Joshua S., Eksteen, Nico, 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, Kariseb, MacCalvin, Kern, Nicholas S., Kerrigan, Joshua, Kittiwisit, Piyanat, Kohn, Saul A., Kolopanis, Matthew, Lanman, Adam, La Plante, Paul, Loots, Anita, MacMahon, David Harold Edward, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Martinot, Zachary E., Mesinger, Andrei, Molewa, Mathakane, Morales, Miguel F., Mosiane, Tshegofalang, Neben, Abraham R., Nikolic, Bojan, Nuwegeld, Hans, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Sims, Peter, Smith, Craig, Swarts, Hilton, Thyagarajan, Nithyanandan, van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Combining the visibilities measured by an interferometer to form a cosmological power spectrum is a complicated process. In a delay-based analysis, the mapping between instrumental and cosmological space is not a one-to-one relation. Instead, neighbouring modes contribute to the power measured at one point, with their respective contributions encoded in the window functions. To better understand the power measured by an interferometer, we assess the impact of instrument characteristics and analysis choices on these window functions. Focusing on the Hydrogen Epoch of Reionization Array (HERA) as a case study, we find that long-baseline observations correspond to enhanced low-k tails of the window functions, which facilitate foreground leakage, whilst an informed choice of bandwidth and frequency taper can reduce said tails. With simple test cases and realistic simulations, we show that, apart from tracing mode mixing, the window functions help accurately reconstruct the power spectrum estimator of simulated visibilities. The window functions depend strongly on the beam chromaticity, and less on its spatial structure - a Gaussian approximation, ignoring side lobes, is sufficient. Finally, we investigate the potential of asymmetric window functions, down-weighting the contribution of low-k power to avoid foreground leakage. The window functions presented here correspond to the latest HERA upper limits for the full Phase I data. They allow an accurate reconstruction of the power spectrum measured by the instrument and will be used in future analyses to confront theoretical models and data directly in cylindrical space., Comment: 18 pages, 19 figures, accepted for publication in MNRAS

Published
2022
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10. Severity of and Recovery From Anemia After Transcatheter Aortic Valve Replacement: An Analysis of the PARTNER Trials and Registries.

Author

Bhardwaj, Bhaskar, Kolte, Dhaval, Zhao, Yanglu, Alu, Maria, Zahr, Firas, Passeri, Jonathan, Inglessis, Ignacio, Vlahakes, Gus, Garcia, Santiago, Cohen, David, Makkar, Raj, Kodali, Susheel, Thourani, Vinod, Kapadia, Samir, Palacios, Igor, Leon, Martin, Smith, Craig, Mack, Michael, and Elmariah, Sammy

Subjects
anemia, anemia recovery, aortic stenosis, transcatheter aortic valve implantation, transfusion
Abstract

BACKGROUND: Anemia is associated with increased mortality in patients undergoing transcatheter aortic valve replacement (TAVR); however, data on the effect of the severity of and recovery from anemia on clinical outcomes are limited. This study examined the impact of the severity of and recovery from anemia after TAVR. METHODS: Patients with symptomatic, severe aortic stenosis across all surgical risk groups from the Placement of Aortic Transcatheter Valves (PARTNER) I, II, and III trials and registries who underwent TAVR were analyzed. Baseline anemia was defined as mild (hemoglobin [Hb] level ≥11.0 g/dL and

Published
2023

13. The time is right for an Antarctic biorepository network

Author

O’Brien, Kristin M, Crockett, Elizabeth L, Adams, Byron J, Amsler, Charles D, Appiah-Madson, Hannah J, Collins, Allen, Desvignes, Thomas, Detrich, H William, Distel, Daniel L, Eppley, Sarah M, Frable, Benjamin W, Franz, Nico M, Grim, Jeffrey M, Kocot, Kevin M, Mahon, Andrew R, Mayfield-Meyer, Teresa J, Mikucki, Jill A, Moser, William E, Schmull, Michaela, Seid, Charlotte A, Smith, Craig R, Todgham, Anne E, and Watkins-Colwell, Gregory J

Subjects
Antarctic Regions
Published
2022

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

Author

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, Nicolas, Acedo, Eloy de Lera, 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, MacMahon, David Harold Edward, Malan, Lourence, Malgas, Cresshim, Malgas, Keith, Marero, Bradley, Martinot, Zachary E., Mesinger, Andrei, Molewa, Mathakane, Mosiane, Tshegofalang, Murray, Steven G., Neben, Abraham R., Nikolic, Bojan, Nuwegeld, Hans, Parsons, Aaron R., Patra, Nipanjana, Pieterse, Samantha, Pober, Jonathan C., Razavi-Ghods, Nima, Robnett, James, Rosie, Kathryn, Sims, Peter, Smith, Craig, Swarts, Hilton, Thyagarajan, Nithyanandan, Van Van Wyngaarden, Pieter, Williams, Peter K. G., and Zheng, Haoxuan

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Instrumentation and Methods for 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 <10%. After subtracting the GLEAM point sources, the HERA data discriminate between the different continuum sky models, providing most support for the model of Byrne et al. 2021. We report the computation cost for mapping the HERA Phase I data and project the computation for the HERA 320-antenna data; both are feasible with a modern server. The algorithm is broadly applicable to other interferometers and is valid for wide-field and non-coplanar arrays., Comment: 16 pages, 10 figures, 2 tables, published on ApJ

Published
2022
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33. Bibliography

Author

Smith, Craig R. and Johnson, Kevin A.

Published
2024

34. Index

Author

Smith, Craig R. and Johnson, Kevin A.

Published
2024

35. Cover

Author

Smith, Craig R. and Johnson, Kevin A.

Published
2024

36. Notes

Author

Smith, Craig R. and Johnson, Kevin A.

Published
2024

46. Utilising accessible and reproducible neurological assessments in clinical studies: Insights from use of the Neurological Impairment Scale in the multi-centre COVID-CNS study

Author

Alam, Ali M., Webb, Glynn W., Collie, Ceryce, Mariathasan, Sashini, Huang, Yun, Hilton, Orla, Shil, Rajish, Dodd, Katherine C., Lilleker, James B., Smith, Craig J., Easton, Ava, Tamborska, Arina, Thomas, Rhys H., Davies, Nicholas W.S., Jenkins, Thomas M., Zandi, Michael, Benjamin, Laura, Ellul, Mark A., Solomon, Tom, Pollak, Thomas A., Nicholson, Tim, Breen, Gerome, van Wamelen, Daniel J., Wood, Nicholas W., and Michael, Benedict D.

Published
2024
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49. Carbonate compensation depth drives abyssal biogeography in the northeast Pacific

Author

Simon-Lledó, Erik, Amon, Diva J., Bribiesca‐Contreras, Guadalupe, Cuvelier, Daphne, Durden, Jennifer M., Ramalho, Sofia P., Uhlenkott, Katja, Arbizu, Pedro Martinez, Benoist, Noëlie, Copley, Jonathan, Dahlgren, Thomas G., Glover, Adrian G., Fleming, Bethany, Horton, Tammy, Ju, Se-Jong, Mejía-Saenz, Alejandra, McQuaid, Kirsty, Pape, Ellen, Park, Chailinn, Smith, Craig R., and Jones, Daniel O. B.

Published
2023
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