Physical Sciences and Mathematics Commons^™

Cooling Radiation And The Ly Alpha Luminosity Of Forming Galaxies, Ma Fardal, N Katz, Jp Gardner, L Hernquist, Dh Weinberg, R Dave

Astronomy Department Faculty Publication Series

We examine the cooling radiation from forming galaxies in hydrodynamic simulations of the LCDM model (cold dark matter with a cosmological constant), focusing on the Lyα line luminosities of high-redshift systems. Primordial composition gas condenses within dark matter potential wells, forming objects with masses and sizes comparable to the luminous regions of observed galaxies. As expected, the energy radiated in this process is comparable to the gravitational binding energy of the baryons, and the total cooling luminosity of the galaxy population peaks at z 2. However, in contrast to the classical picture of gas cooling from the ~10⁶ K …