The Expected Mass Function for Low Mass Galaxies in a CDM Cosmology: Is There a Problem?
نویسندگان
چکیده
It is well known that the mass function for halos in CDM cosmology is a relatively steep power law (n(M) ∝ M) for low masses, possibly too steep to be consistent with observations. But how steep is the galaxy mass function? We have analyzed the stellar and gas mass functions of the first massive luminous objects formed in a ΛCDM universe, as calculated in the numerical simulation described in Gnedin (2000ab). Our analysis indicates that, as suspected, the relationship between luminous or gaseous matter and total (primarily dark matter) mass is present address: U.S. Environmental Protection Agency, Mail Code 6608J, 1200 Pennsylvania Ave. NW, Washington, DC 20460
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