TY - JOUR
T1 - Dipole anisotropy in integrated linearly polarized flux density in NVSS data
AU - Tiwari, Prabhakar
AU - Jain, Pankaj
N1 - Publisher Copyright:
© 2015 The Authors.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - We study the dipole anisotropy in integrated linearly polarized flux density in NRAO VLA Sky Survey. We extract the anisotropy in the number counts of significantly polarized sources. These are identified by imposing the cut on polarized flux (P), 1.0 < P < 100 mJy, and independently on the degree of polarization (p), 0.03 < p < 1. We also study the anisotropy in observables, PI and pI, defined as the number counts weighted by P and p, respectively. We consider data with several different cuts on the flux density, S > 20, 30, 40, 50, 75 mJy. We find a very significant signal of dipole, both in number counts and P- or p-weighted number counts. We identify and remove a polar angle, θ, dependent bias, centred at the detector array location. We find that the dipole parameters for the case of PI are relatively independent of the cut on S and study it in greater detail. The amplitude of the observed anisotropy is found to be much larger in comparison to the CMBR expectations. The direction is found to be in rough agreement with the CMBR dipole.
AB - We study the dipole anisotropy in integrated linearly polarized flux density in NRAO VLA Sky Survey. We extract the anisotropy in the number counts of significantly polarized sources. These are identified by imposing the cut on polarized flux (P), 1.0 < P < 100 mJy, and independently on the degree of polarization (p), 0.03 < p < 1. We also study the anisotropy in observables, PI and pI, defined as the number counts weighted by P and p, respectively. We consider data with several different cuts on the flux density, S > 20, 30, 40, 50, 75 mJy. We find a very significant signal of dipole, both in number counts and P- or p-weighted number counts. We identify and remove a polar angle, θ, dependent bias, centred at the detector array location. We find that the dipole parameters for the case of PI are relatively independent of the cut on S and study it in greater detail. The amplitude of the observed anisotropy is found to be much larger in comparison to the CMBR expectations. The direction is found to be in rough agreement with the CMBR dipole.
KW - Cosmology: miscellaneous
KW - Galaxies: active
KW - Galaxies: high-redshift
KW - Polarization
UR - http://www.scopus.com/inward/record.url?scp=84921715289&partnerID=8YFLogxK
U2 - 10.1093/mnras/stu2535
DO - 10.1093/mnras/stu2535
M3 - 文章
AN - SCOPUS:84921715289
SN - 0035-8711
VL - 447
SP - 2658
EP - 2670
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -