This is the astro-ph blog of the Theoretical Modelling of Cosmic Structures group (TMoX) at the Max-Planck-Institute for Extraterrestrial Physics. We are an independent Max-Planck Research Group focusing on the various aspects in the formation and evolution of galaxies. Part of our focus is on the formation and evolution of early-type galaxies, super-massive black holes, the formation of the first structures in the universe and the enrichment history of the Universe. We are theoreticians using analytic modelling as well as numerical simulations in our work.

The CosmologyCake blog is dedicated to the discussion of research papers and current developments. We will regularly post interesting papers and comment on them. Feel free to leave your comments as well. We encourage authors of discussed papers to post replies if they wish to. Our aim is to provide a platform to discuss recent astro-ph papers within a wider audience. Please feel free to send papers you would like to be discussed to us at

27 January 2011

Title: Dynamical Delays Between Starburst and AGN Activity in Galaxy Nuclei

Author: Philip F. Hopkins
Link to paper:

The author investigates the observed (possible) delay between the onset of AGN activity and the peak of star formation in star-burst galaxies. He shows that the delay can be reproduced in simulations of merging galaxies, and give a physical explanation of it. He argues of implications for the role of the AGN feedback in suppressing star formation.

On Lyman-limit Systems

On Lyman-limit Systems and the Evolution of the Intergalactic Ionizing Background
Authors: Matthew McQuinn, S. Peng Oh, Claude-Andre Faucher-Giguere

The authors use cosmological simulations to study the properties of Lyman-limit systems at 3 < z < 6 and the relation between the ionising emissivity of galaxies and the amplitude of the intergalactic ionising background. This could explain the rapid decrease in the Ly-alpha forest transmission observed around z=6 without invoking reionisation.

19 January 2011

Conformal Cyclic Cosmology in WMAP data?

Authors: V.G.Gurzadyan, R.Penrose
Link to Paper:

The Conformal Cyclic Cosmology model. A dynamic and controversial model (R. Penrose) that argues for various aeons preceding and following our current universe. The authors also explain that the validity of this model can be tested via observations (CMB anisotropies) and even claim to have found proof for the same!

An Actively Accreting Massive Black Hole in the Dwarf Starburst Galaxy Henize 2-10

Authors: Reines et al.
Link to the paper: arXiv:1101.1309

The authors report observations strongly suggesting the presence of a central black hole in a blue compact dwarf galaxy. The mass of the black hole is estimated to be ~10^6 MSun, which is intriguing given that the galaxy itself has no bulge, nucleus, or nuclear stellar cluster. In turn, the authors suggest that in the early universe black holes may have formed before the stellar components of the first dwarf galaxies.