Prabhakar Tiwari

Dipole Anisotropy in Integrated Linearly Polarized Flux Density in NVSS Data

We study the dipole anisotropy in integrated linearly polarized flux density in NRAO VLA Sky Survey (NVSS). We extract the anisotropy parameters in the number counts, number counts weighted by polarization observables, i.e. polarized flux (P) and degree of polarization (p). We consider data with several different cuts on the flux density, S > 10,20,30,40,50,75 mJy. For studies with polarized flux we impose the additional cut 0.5 < P < 100 mJy. Similarly for degree of polarization we impose the cut, 0.01 < p < 1. We find a very significant signal of dipole, both in number counts and P or p weighted number counts. The polar angle, �, of the extracted dipole axis, for the case of number counts, shows a significant dependence on the flux density cut. This dependence indicates the presence of significant bias in the data. We find that the dipole parameters for the case of number counts weighted by polarized flux density are relatively stable. We argue that this parameter is relatively free of bias and study it in greater detail. The observed anisotropy is found to be much larger in comparison to the CMBR expectations. We find that polarization observables show a much higher level of anisotropy in comparison to pure number counts or sky brightness.

Revisiting the NVSS number count dipole

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

POLARIZATION ALIGNMENT IN JVAS/CLASS FLAT SPECTRUM RADIO SURVEYS

\Lambda

THE CLUSTERING OF RADIO GALAXIES: BIASING AND EVOLUTION VERSUS STELLAR MASS

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

A complete 3D numerical study of the effects of pseudoscalar-photon mixing on quasar polarizations

z\lesssim0.1

Constraining axionlike particles using the distance-duality relation

. The amplitude of the model signal depends on the bias factor

Probing Statistical Isotropy of Cosmological Radio Sources using Square Kilometre Array

b

New Limit on Pseudoscalar-Photon Mixing from WMAP Observations

of the NVSS mock galaxies. For sources with flux density,

Extracting the spectral index of the intergalactic magnetic field from radio polarizations

S> 15 \; \rm mJy

Dipole anisotropy in sky brightness and source count distribution in radio NVSS data

, the bias recipe inferred from higher order moments is consistent with the observed dipole signal at