• English
    • Norsk
  • English 
    • English
    • Norsk
  • Administration
View Item 
  •   Home
  • Øvrige samlinger
  • Høstingsarkiver
  • CRIStin høstingsarkiv
  • View Item
  •   Home
  • Øvrige samlinger
  • Høstingsarkiver
  • CRIStin høstingsarkiv
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Improved upper limits on the 21 cm signal power spectrum of neutral hydrogen at z ≈ 9.1 from LOFAR

Mertens, Florent G.; Mevius, M.; Koopmans, Leon V. E.; Offringa, A. R.; Mellema, Garrelt; Zaroubi, Saleem; Brentjens, M. A.; Gan, H.; Gehlot, Bharat Kumar; Pandey, V. N.; Sardarabadi, A. M.; Vedantham, Harish K.; Yatawatta, Sarod; Asad, Khan M. B.; Ciardi, B.; Chapman, Emma; Gazagnes, S.; Ghara, R.; Ghosh, Abhik; Giri, Sambit Kumar; Iliev, Ilian T.; Jelić, Vibor; Kooistra, Robin; Mondal, Rajesh; Schaye, Joop; Silva, Marta Bruno
Journal article; PublishedVersion; Peer reviewed
View/Open
staa327.pdf (9.310Mb)
Year
2020
Permanent link
http://urn.nb.no/URN:NBN:no-82429

CRIStin
1827431

Metadata
Show metadata
Appears in the following Collection
  • Institutt for teoretisk astrofysikk [722]
  • CRIStin høstingsarkiv [15977]
Original version
Monthly notices of the Royal Astronomical Society. 2020, 493 (2), 1662-1685, DOI: https://doi.org/10.1093/mnras/staa327
Abstract
A new upper limit on the 21 cm signal power spectrum at a redshift of z ≈ 9.1 is presented, based on 141 h of data obtained with the Low-Frequency Array (LOFAR). The analysis includes significant improvements in spectrally smooth gain-calibration, Gaussian Process Regression (GPR) foreground mitigation and optimally weighted power spectrum inference. Previously seen ‘excess power’ due to spectral structure in the gain solutions has markedly reduced but some excess power still remains with a spectral correlation distinct from thermal noise. This excess has a spectral coherence scale of 0.25–0.45 MHz and is partially correlated between nights, especially in the foreground wedge region. The correlation is stronger between nights covering similar local sidereal times. A best 2-σ upper limit of Δ221<(73)2mK2
 
Responsible for this website 
University of Oslo Library


Contact Us 
duo-hjelp@ub.uio.no


Privacy policy
 

 

For students / employeesSubmit master thesisAccess to restricted material

Browse

All of DUOCommunities & CollectionsBy Issue DateAuthorsTitlesThis CollectionBy Issue DateAuthorsTitles

For library staff

Login
RSS Feeds
 
Responsible for this website 
University of Oslo Library


Contact Us 
duo-hjelp@ub.uio.no


Privacy policy