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 tmoxgroup@googlemail.com.

22 October 2010

Lyman 'bump' galaxies - II. A possible signature of massive extremely metal-poor or metal-free stars in z = 3.1 Lya emitters

Authors: Inoue, et al.
Link to article: arXiv:1010.2582

Observations of both Lya emission and Lyman continuum emission (the Lyman 'bump') are presented for a sample of galaxies at z = 3.1.  Besides exhibiting the Lyman 'bump' (blueward of Lya), which could be a sign of a population of metal-poor stars which have hard spectra, some of the galaxies also show a spatial offset between the Lya emission and the Lyman continuum emission.  The authors argue that the observed properties of the galaxies may be best explained by the presence of massive, metal-free stars.  Interestingly, it is the same galaxies which show the spatial offset which also appear to require the largest fractions of Pop III stars.  Indeed, this would be consistent with a scenario in which Pop III star formation may take place at relatively low redshift, albeit only at the outskirts of metal-enriched regions.

2 comments:

  1. While there are still uncertainties that must be overcome, the observations and their interpretation are intriguing. It is especially interesting that there is a spatial offset, as this would be broadly consistent with recent theoretical predictions for where Pop III stars could be found at low redshift (e.g. Tornatore et al. 2007; Johnson 2010). Perhaps similar studies can be carried out on galaxies at higher redshift, the expectation being that stronger evidence for Pop III star formation could be uncovered.

    ReplyDelete