English

Revisiting the NVSS number count dipole

Cosmology and Nongalactic Astrophysics 2016-04-07 v3 Astrophysics of Galaxies

Abstract

We present a realistic modeling of the dipole component of the projected sky distribution of NVSS radio galaxies. The modeling relies on mock catalogs generated within the context of Λ\LambdaCDM cosmology, in the linear regime of structure formation. After removing the contribution from the solar motion, the mocks show that the remaining observed signal is mostly (70\%) due to structures within z0.1z\lesssim0.1. The amplitude of the model signal depends on the bias factor bb of the NVSS mock galaxies. For sources with flux density, S>15  mJy S> 15 \; \rm mJy, the bias recipe inferred from higher order moments is consistent with the observed dipole signal at 2.12σ2.12\sigma. Flux thresholds above 20  mJy20 \; \rm mJy yield a disagreement close to the 3σ3\sigma level. A constant high bias, b=3b=3 is needed to mitigate the tension to the 2.3σ\sim 2.3\sigma level.

Cite

@article{arxiv.1509.02532,
  title  = {Revisiting the NVSS number count dipole},
  author = {Prabhakar Tiwari and Adi Nusser},
  journal= {arXiv preprint arXiv:1509.02532},
  year   = {2016}
}

Comments

14 pages, 5 figures, 3 tables

R2 v1 2026-06-22T10:52:13.540Z