Influence from cosmological uncertainties on galaxy number count at faint limit

Counting galaxy number density with wide range sky surveys has been well adopted in researches focusing on revealing evolution pattern of different types of galaxies. As understood intuitively the astrophysics environment physics is intimately affected by cosmology priors with theoretical estimation or vice versa, or simply stating that the astrophysics effect couples the corresponding cosmology observations or the way backwards. In this paper, we try to quantify the influence on galaxy number density prediction at faint luminosity limit from the uncertainties in cosmology, and how much the uncertainties blur the detection of galaxy evolution, with the hope that this trying may indeed help for precise and physical cosmology study in near future or vice versa.

The Galactic Evolution of Beryllium

The abundance of beryllium has been determined in unevolved stars over a range metal abundances in order to enhance our understanding of the chemical evolution of our Galaxy, cosmic-ray theory, and cosmology. Observations of 27 stars have been made with Keck I with HIRES at high spectral resolution (45,000) and high signal-to-noise ratios (60 - 110 typically). We find a remarkably linear relationship between log N(Be/H) and [Fe/H] with a slope of 0.96 (±0.04). Similarly, the relationship between log N(Be/H) and [O/H] is linear with a slope of 1.45 (±0.04). Beryllium increases at the same rate as Fe, but much faster than O. This provides constraints for and insights into models of Galactic chemical evolution. There is some evidence for an intrinsic spread in Be at a given [O/H] or [Fe/H]. There is no evidence of a plateau in Be at the lowest metallicities down to log N(Be/H) = —13.5.