Cosmic radio dipole: Estimators and frequency dependence

Siewert T, Schmidt-Rubart M, Schwarz D (2021)
Astronomy and Astrophysics 653: A9.

Zeitschriftenaufsatz | Veröffentlicht | Englisch
 
Download
Es wurden keine Dateien hochgeladen. Nur Publikationsnachweis!
Abstract / Bemerkung
The cosmic radio dipole is of fundamental interest to studies of cosmology. Recent works have put forth open questions about the nature of the observed cosmic radio dipole. In the current work, we use simulated source count maps to test a linear and a quadratic estimator for possible biases in the estimated dipole amplitude with respect to the masking procedure. We find a superiority on the part of the quadratic estimator, which we used to analyse the TGSS-ADR1, WENSS, SUMSS, and NVSS radio source catalogues, spread over a decade of frequencies. We applied the same masking strategy to all four surveys to produce comparable results. In order to address the differences in the observed dipole amplitudes, we cross-matched the two surveys located at both ends of the analysed frequency range. For the linear estimator, we identified a general bias in the estimated dipole directions. The positional offsets of the quadratic estimator to the cosmic microwave background (CMB) dipole for skies with 10(7) simulated sources is found to be below one degree and the absolute accuracy of the estimated dipole amplitudes is better than 10(-3). For the four radio source catalogues, we find an increasing dipole amplitude with decreasing frequency, which is consistent with results from the literature and the results of the cross-matched catalogue. We conclude that for all analysed surveys, the observed cosmic radio dipole amplitudes exceed the expectations derived from the CMB dipole, which cannot strictly be explained by a kinematic dipole alone.
Stichworte
galaxies; statistics; galaxies; structure; galaxies; clusters; general; large-scale structure of Universe
Erscheinungsjahr
2021
Zeitschriftentitel
Astronomy and Astrophysics
Band
653
Art.-Nr.
A9
ISSN
0004-6361
eISSN
1432-0746
Page URI
https://pub.uni-bielefeld.de/record/2957348

Zitieren

Siewert T, Schmidt-Rubart M, Schwarz D. Cosmic radio dipole: Estimators and frequency dependence. Astronomy and Astrophysics. 2021;653: A9.
Siewert, T., Schmidt-Rubart, M., & Schwarz, D. (2021). Cosmic radio dipole: Estimators and frequency dependence. Astronomy and Astrophysics, 653, A9. https://doi.org/10.1051/0004-6361/202039840
Siewert, T., Schmidt-Rubart, M., and Schwarz, D. (2021). Cosmic radio dipole: Estimators and frequency dependence. Astronomy and Astrophysics 653:A9.
Siewert, T., Schmidt-Rubart, M., & Schwarz, D., 2021. Cosmic radio dipole: Estimators and frequency dependence. Astronomy and Astrophysics, 653: A9.
T. Siewert, M. Schmidt-Rubart, and D. Schwarz, “Cosmic radio dipole: Estimators and frequency dependence”, Astronomy and Astrophysics, vol. 653, 2021, : A9.
Siewert, T., Schmidt-Rubart, M., Schwarz, D.: Cosmic radio dipole: Estimators and frequency dependence. Astronomy and Astrophysics. 653, : A9 (2021).
Siewert, Thilo, Schmidt-Rubart, Matthias, and Schwarz, Dominik. “Cosmic radio dipole: Estimators and frequency dependence”. Astronomy and Astrophysics 653 (2021): A9.

Export

Markieren/ Markierung löschen
Markierte Publikationen

Open Data PUB

Web of Science

Dieser Datensatz im Web of Science®

Suchen in

Google Scholar