Open AccessThe angular power spectrum of NVSS radio galaxies
Author(s) -
Blake Chris,
Ferreira Pedro G.,
Borrill Julian
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07831.x
Subject(s) - physics , astrophysics , radio galaxy , galaxy , astronomy , luminous infrared galaxy , disc galaxy
We measure the angular power spectrum C ℓ of radio galaxies in the NRAO VLA Sky Survey (NVSS) using two independent methods: direct spherical harmonic analysis and maximum likelihood estimation (MLE). The results are consistent and can be understood using models for the spatial matter power spectrum and for the redshift distribution of radio galaxies at mJy flux density levels. A good fit to the angular power spectrum can only be achieved if radio galaxies possess high bias with respect to mass fluctuations; by marginalizing over the other parameters of the model we derive a 68 per cent confidence interval 1.53 < b 0 ×σ 8 < 1.87 , where b 0 is the linear bias factor for radio galaxies and σ 8 describes the normalization of the matter power spectrum. Our models indicate that the majority of the signal in the NVSS C ℓ spectrum is generated at low redshifts z ≲ 0.1 . Individual redshifts for the NVSS sources are thus required to alleviate projection effects and probe directly the matter power spectrum on large scales.