10 research outputs found
Spatial Periodicity of Galaxy Number Counts, CMB Anisotropy, and SNIa Hubble Diagram Based on the Universe Accompanied by a Non-Minimally Coupled Scalar Field
We have succeeded in establishing a cosmological model with a non-minimally
coupled scalar field that can account not only for the spatial
periodicity or the {\it picket-fence structure} exhibited by the galaxy -
relation of the 2dF survey but also for the spatial power spectrum of the
cosmic microwave background radiation (CMB) temperature anisotropy observed by
the WMAP satellite. The Hubble diagram of our model also compares well with the
observation of Type Ia supernovae. The scalar field of our model universe
starts from an extremely small value at around the nucleosynthesis epoch,
remains in that state for sufficiently long periods, allowing sufficient time
for the CMB temperature anisotropy to form, and then starts to grow in
magnitude at the redshift of , followed by a damping oscillation
which is required to reproduce the observed picket-fence structure of the
- relation. To realize such behavior of the scalar field, we have found
it necessary to introduce a new form of potential , with being a constant. Through this parameter ,
we can control the epoch at which the scalar field starts growing.Comment: 19 pages, 18 figures, Accepted for publication in Astrophysics &
Space Scienc
The Spatial Clustering of Faint Galaxies
We estimate the spatial clustering of faint galaxies in an extensive new redshift survey performed using the automatic fibre positioner (Autofib) on the Anglo-Australian Telescope. The survey comprises 1100 galaxies within a magnitude range of 17 < B < 22 selected from 33 deep pencil beams. The redshift distribution extends to z~0.5 and has a median redshift of z = 0.16, making the survey the most extensive and deepest of its kind for which the spatial clustering has been estimated. Over the apparent magnitude range of the survey, the galaxy number counts exceed the no-evolution prediction by a factor similar to the proportion of galaxies observed with strong [O II] emission. Adopting the hypothesis that the strong [O II] emitters can be statistically identified with the blue star-forming excess population, we investigate variation in the galaxy correlation functions between strong and weak O II populations, as well as with redshift. All the data are adequately described by a correlation function {xi}(r)=(r/r_0_)^-1.7 with r_0_ = 6.5+/-0.4 h^-1^ Mpc. We find no evidence for evolution of the comoving correlation length with redshift: r_0_(z)= r_0_(0)(1 +z)^{epsilon}^, with {epsilon} = 0.411.6. The correlation lengths for strong and weak [O II] emitters are compatible with the global value, albeit with moderately large uncertainties. A better constraint is provided by cross-correlation of the two populations which yields r_0_ = 6.2+/-0.5 h^-1^ Mpc. To B = 22, there is no evidence that the star-forming blue galaxies represent a new unclustered population. On the contrary, the physical association of blue galaxies with the normal population is as expected in the merger hypothesis put forward to explain the excess galaxy counts
