128 research outputs found
CMB component separation in the pixel domain
We show that the popular ILC approach is unstable in respect to the division
of the sample of map pixels to the set of ``homogeneous'' subsamples. For
suitable choice of such subsamples we can obtain the restored CMB signal with
amplitudes ranged from zero to the amplitudes of the observed signal. We
propose approach which allows us to obtain reasonable estimates of at
and similar to WMAP for larger . With this
approach we reduce some anomalies of the WMAP results. In particular, our
estimate of the quadrupole is well consistent to theoretical one, the effect of
the ``axis of evil'' is suppressed and the symmetry of the north and south
galactic hemispheres increases. This results can change estimates of quadrupole
polarization and the redshift of reionization of the Universe. We propose also
new simple approach which can improve WMAP estimates of high power
spectrum.Comment: 7 pages, 5 figure
Catalog of Radio Galaxies with z>0.3. III: Angular Sizes and Flux Density According to the NVSS Data
We describe the procedure of the construction of a sample of distant
() radio galaxies using the NED, CATS and SDSS databases for further use
in various statistical tests. We believe the sample to be free of objects with
quasar properties. This paper is the third part of the description of the radio
galaxies catalog that we plan to use for cosmological tests. We report the
results of the sample of angular sizes for the NVSS survey list objects, and
its preliminary statistical analysis. Three-parameter diagrams "angular
size-redshift-flux density" and "angular size-redshift-spectral index", and
their two-parameter projections are constructed. Three subsamples of radio
galaxies are separated in the "source size--flux density" diagram.Comment: 6 pages, 4 figures, 1 tabl
On the Spectral Index of Distant Radio Galaxies
The problems of using the spectral index of radio galaxies in various tests,
in particular, in selecting distant radio sources are considered. The history
of the question of choosing a criterion of searching for distant radio galaxies
based on the spectral index is presented. For a new catalog of 2442 radio
galaxies constructed from NED, SDSS, and CATS data, an analytical form of the
sp ectral index.redshift relation has been determined for the first time. The
spectral index.angular size and spectral index.flux density diagrams have also
been constructed. Peculiarities of the distribution of sources on these
diagrams are discussed.Comment: 7 pages,5 figure
The estimation of black-hole masses in distant radio galaxies
We have estimated the masses of the central supermassive black holes of 2442
radio galaxies froma catalog compiled using data from the NED, SDSS, and CATS
databases. Mass estimates based on optical photometry and radio data are
compared. Relationships between the mass of the central black hole
and the redshift are constructed for both wavelength ranges. The
distribution of the galaxies in these diagrams and systematic effects
influencing estimation of the black-hole parameters are discussed.
Upperenvelope cubic regression fits are obtained using the maximum estimates of
the black-hole masses. The optical and radio upper envelopes show similar
behavior, and have very similar peaks in position, , and
amplitude, = 9.4. This is consistent with a model in which the
growth of the supermassive black holes is self-regulating, with this redshift
corresponding to the epoch when the accretion-flow phase begins to end and the
nuclear activity falls off.Comment: 8 pages, 6 figure
- …