ACP Seminar (Astronomy - Cosmology - Particle Physics)

Speaker: Simon Glover (ITA, Heidelberg University)
Title: The stellar initial mass function in low metallicity gas
Date (JST): Wed, Mar 04, 2009, 15:30 - 16:30
Place: Seminar Room at IPMU Prefab. B
Related File: 12.pdf
Abstract: There is growing evidence that stars that formed in metal-free gas -- the so-called population III stars -- had characteristic masses that were substantially larger than the masses of present-day stars. On the other hand, we know from observations of halo stars that it is possible to form low-mass stars with metallicities as small as [Fe/H] ~ -5. This implies that the presence of even a small amount of metals and/or dust causes the stellar initial mass function (IMF) to change significantly. Two main theories have been put forward to explain this, one centering on the role of atomic fine structure cooling at low densities, and the other on dust cooling at much higher densities. In this talk, I will discuss both of these theories and show how they can be combined to yield a single coherent picture for the origin of the IMF in low metallicity gas.