Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data
The separation of the faint cosmological background signal from bright astrophysical foregrounds remains one of the most daunting challenges of mapping the high-redshift intergalactic medium with the redshifted 21 cm line of neutral hydrogen. Advances in mapping and modeling of diffuse and point sou...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Published: |
American Physical Society
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/41105 |
| _version_ | 1848756052278902784 |
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| author | Dillon, J. Neben, A. Hewitt, J. Tegmark, M. Barry, N. Beardsley, A. Bowman, J. Briggs, F. Carroll, P. De Oliveira-Costa, A. Ewall-Wice, A. Feng, L. Greenhill, L. Hazelton, B. Hernquist, L. Hurley-Walker, N. Jacobs, D. Kim, H. Kittiwisit, P. Lenc, E. Line, J. Loeb, A. McKinley, B. Mitchell, D. Morales, M. Offringa, A. Paul, S. Pindor, B. Pober, J. Procopio, P. Riding, J. Sethi, S. Shankar, N. Subrahmanyan, R. Sullivan, I. Thyagarajan, N. Tingay, Steven Trott, C. Wayth, Randall Webster, R. Wyithe, S. Bernardi, G. Cappallo, R. Deshpande, A. Johnston-Hollitt, M. Kaplan, D. Lonsdale, C. McWhirter, S. Morgan, E. Oberoi, D. Ord, S. Prabu, T. Srivani, K. Williams, A. Williams, C. |
| author_facet | Dillon, J. Neben, A. Hewitt, J. Tegmark, M. Barry, N. Beardsley, A. Bowman, J. Briggs, F. Carroll, P. De Oliveira-Costa, A. Ewall-Wice, A. Feng, L. Greenhill, L. Hazelton, B. Hernquist, L. Hurley-Walker, N. Jacobs, D. Kim, H. Kittiwisit, P. Lenc, E. Line, J. Loeb, A. McKinley, B. Mitchell, D. Morales, M. Offringa, A. Paul, S. Pindor, B. Pober, J. Procopio, P. Riding, J. Sethi, S. Shankar, N. Subrahmanyan, R. Sullivan, I. Thyagarajan, N. Tingay, Steven Trott, C. Wayth, Randall Webster, R. Wyithe, S. Bernardi, G. Cappallo, R. Deshpande, A. Johnston-Hollitt, M. Kaplan, D. Lonsdale, C. McWhirter, S. Morgan, E. Oberoi, D. Ord, S. Prabu, T. Srivani, K. Williams, A. Williams, C. |
| author_sort | Dillon, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The separation of the faint cosmological background signal from bright astrophysical foregrounds remains one of the most daunting challenges of mapping the high-redshift intergalactic medium with the redshifted 21 cm line of neutral hydrogen. Advances in mapping and modeling of diffuse and point source foregrounds have improved subtraction accuracy, but no subtraction scheme is perfect. Precisely quantifying the errors and error correlations due to missubtracted foregrounds allows for both the rigorous analysis of the 21 cm power spectrum and for the maximal isolation of the "EoR window" from foreground contamination. We present a method to infer the covariance of foreground residuals from the data itself in contrast to previous attempts at a priori modeling. We demonstrate our method by setting limits on the power spectrum using a 3 h integration from the 128-tile Murchison Widefield Array. Observing between 167 and 198 MHz, we find at 95% confidence a best limit of ?2(k)<3.7×104mK2 at comoving scale k=0.18hMpc-1 and at z=6.8, consistent with existing limits. |
| first_indexed | 2025-11-14T09:06:04Z |
| format | Journal Article |
| id | curtin-20.500.11937-41105 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:06:04Z |
| publishDate | 2015 |
| publisher | American Physical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-411052018-03-29T09:06:49Z Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data Dillon, J. Neben, A. Hewitt, J. Tegmark, M. Barry, N. Beardsley, A. Bowman, J. Briggs, F. Carroll, P. De Oliveira-Costa, A. Ewall-Wice, A. Feng, L. Greenhill, L. Hazelton, B. Hernquist, L. Hurley-Walker, N. Jacobs, D. Kim, H. Kittiwisit, P. Lenc, E. Line, J. Loeb, A. McKinley, B. Mitchell, D. Morales, M. Offringa, A. Paul, S. Pindor, B. Pober, J. Procopio, P. Riding, J. Sethi, S. Shankar, N. Subrahmanyan, R. Sullivan, I. Thyagarajan, N. Tingay, Steven Trott, C. Wayth, Randall Webster, R. Wyithe, S. Bernardi, G. Cappallo, R. Deshpande, A. Johnston-Hollitt, M. Kaplan, D. Lonsdale, C. McWhirter, S. Morgan, E. Oberoi, D. Ord, S. Prabu, T. Srivani, K. Williams, A. Williams, C. The separation of the faint cosmological background signal from bright astrophysical foregrounds remains one of the most daunting challenges of mapping the high-redshift intergalactic medium with the redshifted 21 cm line of neutral hydrogen. Advances in mapping and modeling of diffuse and point source foregrounds have improved subtraction accuracy, but no subtraction scheme is perfect. Precisely quantifying the errors and error correlations due to missubtracted foregrounds allows for both the rigorous analysis of the 21 cm power spectrum and for the maximal isolation of the "EoR window" from foreground contamination. We present a method to infer the covariance of foreground residuals from the data itself in contrast to previous attempts at a priori modeling. We demonstrate our method by setting limits on the power spectrum using a 3 h integration from the 128-tile Murchison Widefield Array. Observing between 167 and 198 MHz, we find at 95% confidence a best limit of ?2(k)<3.7×104mK2 at comoving scale k=0.18hMpc-1 and at z=6.8, consistent with existing limits. 2015 Journal Article http://hdl.handle.net/20.500.11937/41105 10.1103/PhysRevD.91.123011 American Physical Society restricted |
| spellingShingle | Dillon, J. Neben, A. Hewitt, J. Tegmark, M. Barry, N. Beardsley, A. Bowman, J. Briggs, F. Carroll, P. De Oliveira-Costa, A. Ewall-Wice, A. Feng, L. Greenhill, L. Hazelton, B. Hernquist, L. Hurley-Walker, N. Jacobs, D. Kim, H. Kittiwisit, P. Lenc, E. Line, J. Loeb, A. McKinley, B. Mitchell, D. Morales, M. Offringa, A. Paul, S. Pindor, B. Pober, J. Procopio, P. Riding, J. Sethi, S. Shankar, N. Subrahmanyan, R. Sullivan, I. Thyagarajan, N. Tingay, Steven Trott, C. Wayth, Randall Webster, R. Wyithe, S. Bernardi, G. Cappallo, R. Deshpande, A. Johnston-Hollitt, M. Kaplan, D. Lonsdale, C. McWhirter, S. Morgan, E. Oberoi, D. Ord, S. Prabu, T. Srivani, K. Williams, A. Williams, C. Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data |
| title | Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data |
| title_full | Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data |
| title_fullStr | Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data |
| title_full_unstemmed | Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data |
| title_short | Empirical covariance modeling for 21 cm power spectrum estimation: A method demonstration and new limits from early Murchison Widefield Array 128-tile data |
| title_sort | empirical covariance modeling for 21 cm power spectrum estimation: a method demonstration and new limits from early murchison widefield array 128-tile data |
| url | http://hdl.handle.net/20.500.11937/41105 |