Overdispersed radio source counts and excess radio dipole detection
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866909897451372544 |
|---|---|
| author | Böhme, Lukas Schwarz, Dominik J. Tiwari, Prabhakar Pashapour-Ahmadabadi, Morteza Bahr-Kalus, Benedict Bilicki, Maciej Hale, Catherine L. Heneka, Caroline S. Siewert, Thilo M. |
| author_facet | Böhme, Lukas Schwarz, Dominik J. Tiwari, Prabhakar Pashapour-Ahmadabadi, Morteza Bahr-Kalus, Benedict Bilicki, Maciej Hale, Catherine L. Heneka, Caroline S. Siewert, Thilo M. |
| contents | The source count dipole from wide-area radio continuum surveys allows us to test the cosmological standard model. Many radio sources have multiple components, which can cause an overdispersion of the source counts distribution. We account for this effect via a new Bayesian estimator, based on the negative binomial distribution. Combining the two best understood wide-area surveys, NVSS and RACS-low, and the deepest wide-area survey, LoTSS-DR2, we find that the source count dipole exceeds its expected value as the kinematic dipole amplitude from standard cosmology by a factor of $3.67 \pm 0.49$ -- a $5.4σ$ discrepancy. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_16732 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Overdispersed radio source counts and excess radio dipole detection Böhme, Lukas Schwarz, Dominik J. Tiwari, Prabhakar Pashapour-Ahmadabadi, Morteza Bahr-Kalus, Benedict Bilicki, Maciej Hale, Catherine L. Heneka, Caroline S. Siewert, Thilo M. Cosmology and Nongalactic Astrophysics The source count dipole from wide-area radio continuum surveys allows us to test the cosmological standard model. Many radio sources have multiple components, which can cause an overdispersion of the source counts distribution. We account for this effect via a new Bayesian estimator, based on the negative binomial distribution. Combining the two best understood wide-area surveys, NVSS and RACS-low, and the deepest wide-area survey, LoTSS-DR2, we find that the source count dipole exceeds its expected value as the kinematic dipole amplitude from standard cosmology by a factor of $3.67 \pm 0.49$ -- a $5.4σ$ discrepancy. |
| title | Overdispersed radio source counts and excess radio dipole detection |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2509.16732 |