Patil_2017_ApJ_838_65.pdf (3.11 MB)
Upper limits on the 21 cm Epoch of Reionization power spectrum from one night with LOFAR
journal contribution
posted on 2023-06-09, 06:51 authored by A H Patil, Ilian IlievIlian Iliev, et alWe present the first limits on the Epoch of Reionization 21 cm H I power spectra, in the redshift range z = 7.9–10.6, using the Low-Frequency Array (LOFAR) High-Band Antenna (HBA). In total, 13.0 hr of data were used from observations centered on the North Celestial Pole. After subtraction of the sky model and the noise bias, we detect a non-zero I 56 13 mK D2 = ? 2 ( ) (1-s) excess variance and a best 2-s upper limit of 21 79.6 mK D2 < 2 ( ) at k = 0.053 h cMpc-1 in the range z = 9.6–10.6. The excess variance decreases when optimizing the smoothness of the direction- and frequency dependent gain calibration, and with increasing the completeness of the sky model. It is likely caused by (i) residual side-lobe noise on calibration baselines, (ii) leverage due to nonlinear effects, (iii) noise and ionosphere-induced gain errors, or a combination thereof. Further analyses of the excess variance will be discussed in forthcoming publications.
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Publication status
- Published
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- Published version
Journal
Astrophysical JournalISSN
0004-637XPublisher
Institute of PhysicsExternal DOI
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1Volume
838Article number
a65Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Astronomy Centre Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2017-06-22First Open Access (FOA) Date
2017-06-22First Compliant Deposit (FCD) Date
2017-06-21Usage metrics
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