Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
Closing In On Omega(M): The Amplitude Of Mass Fluctuations From Galaxy Clusters And The Ly Alpha Forest, Dh Weinberg, Rac Croft, L Hernquist, N Katz, M Pettini
Closing In On Omega(M): The Amplitude Of Mass Fluctuations From Galaxy Clusters And The Ly Alpha Forest, Dh Weinberg, Rac Croft, L Hernquist, N Katz, M Pettini
Astronomy Department Faculty Publication Series
We estimate the present-day value of the matter density parameter ΩM by combining constraints from the galaxy cluster mass function with Croft et al.'s recent measurement of the mass power spectrum, P(k), from Lyα forest data. The key assumption of the method is that cosmic structure formed by gravitational instability from Gaussian primordial fluctuations. For a specified value of ΩM, matching the observed cluster mass function then fixes the value of σ8, the rms amplitude of mass fluctuations in 8 h-1 Mpc spheres, and it thus determines the normalization of P …
The Clustering Of High-Redshift Galaxies In The Cold Dark Matter Scenario, N Katz, L Hernquist, Dh Weinberg
The Clustering Of High-Redshift Galaxies In The Cold Dark Matter Scenario, N Katz, L Hernquist, Dh Weinberg
Astronomy Department Faculty Publication Series
We investigate the clustering of high-redshift galaxies in five variants of the cold dark matter (CDM) scenario, using hydrodynamic cosmological simulations that resolve the formation of systems with circular velocities vc ≥ 100 km s-1 (Ω = 1) or vc ≥ 70 km s-1 (Ω = 0.4). Although the five models differ in their cosmological parameters and in the shapes and amplitudes of their mass power spectra, they predict remarkably similar galaxy clustering at z = 2, 3, and 4. The galaxy correlation functions show almost no evolution over this redshift range, even though the mass …