Hydrodynamic Simulations of Galaxy Formation. I. Dissipation and the Maximum Mass of Galaxies

We describe an accurate, one-dimensional, spherically symmetric, Lagrangian hydrodynamics/gravity code, designed to study the effects of radiative cooling and photo-ionization on the formation of protogalaxies. The code can treat an arbitrary number of fluid shells (representing baryons) and collisionless shells (representing cold dark matter). As a test of the code, we reproduce analytic solutions for the pulsation behavior of a polytrope and for the self-similar collapse of a spherically symmetric, cosmological perturbation. In this paper, we concentrate on the effects of radiative cooling, examining the ability of collapsing perturbations to cool within the age of the universe. In contrast to some studies based on order-of- magnitude estimates, we find that cooling arguments alone cannot explain the sharp upper cutoff observed in the galaxy luminosity function.Comment: 33 pages, uuencoded compressed postscript with figures, Ap.J. (in press), corrections to axes in Fig

Accounting for corporate behavior

Corporate governance ; Financial institutions - Law and legislation

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Technology ; Labor market

Opinion : How many kinds of unemployment?

Unemployment

Selling Federal Reserve payment services: one price fits all?

Federal Reserve banks ; Payment systems

Tie-in sales and banks

Antitrust law ; Banks and banking

Competition among bank regulators

Banks and banking ; Competition

Opinion : More theory, please

We can question whether the economics profession adequately rewards speaking to the public but that public communication will be most valuable if it reflects recent advances in economic theory and quantitative analysis.Economics - Study and teaching ; Economics

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Banks and banking, Central

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