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arXiv · 1509.02532

Revisiting the NVSS number count dipole

Prabhakar Tiwari·Adi Nusser
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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 $Λ$CDM 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 $z\lesssim0.1$. The amplitude of the model signal depends on the bias factor $b$ of the NVSS mock galaxies. For sources with flux density, $ S> 15 \; \rm mJy$, the bias recipe inferred from higher order moments is consistent with the observed dipole signal at $2.12σ$. Flux thresholds above $20 \; \rm mJy$ yield a disagreement close to the $3σ$ level. A constant high bias, $b=3$ is needed to mitigate the tension to the $\sim 2.3σ$ level.

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Prabhakar Tiwari, Adi Nusser. 2016-04-06. Revisiting the NVSS number count dipole. https://doi.org/10.1088/1475-7516%2F2016%2F03%2F062

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