Second Announcement

Workshop on using the [α/Fe] abundance ratio
as a tracer of formation and evolution of the Galaxy


in celebration of
Prof. Poul Erik Nissen's 70th birthday


28 - 30 Sept. 2009, Beijing, China


The workshop has been successfully held in National Astronomical Observatories, Chinese Academy of Sciences.

 A workshop on using the [α/Fe] abundance ratio as a tracer of  formation and evolution of the Galaxy has been successfully held in Beijing on Sept. 28-30, 2009 by reporting and discussing recent discoveries and developments in stellar abundance studies and related fields.

Understanding how the Galaxy forms and evolves is one of the main objectives of Galactic astrophysics and cosmology. The [α/Fe] abundance ratios (where α refers to the abundance of typical α-capture elements like Mg, Si, Ca and Ti) of stellar populations in the Galaxy and their kinematic properties supply important information about the Galaxy's formation process.One of the most important results is the detection of a few low [α/Fe] stars in the halo. Actually, the chemical signatures of stars in the Milky Way's dwarf galaxies also point to lower values of [α/Fe] than in the majority of Galactic halo, thick-disk and bulge stars. But the number of low [α/Fe] halo stars seems relatively small, which indicates that the main components of our Galaxy have not been formed through the merging of dwarf galaxies similar to present-day dSphs. This could be seen as an argument against hierarchical structure formation as predicted in Cold Dark Matter cosmologies.



  • Left:Spectra of two stars with nearly the same atmospheric parameters Teff, logg and [Fe/H]. The spectrum of the "low-α" star CD-45 3283 is shown with a thick (red) line, and that of the "high-α" star G159-50 with a lighter (green) line.
  • Right: [Mg/Fe] vs. [Fe/H] for 26 halo stars and 13 thick-disk stars (see arXiv:0807.3831).
 NOTE: The Registration is closed.


Scientific Organizing Committee

  • Poul Erik Nissen (Department of Physics and Astronomy, University of Aarhus, Denmark) chair
  • Gang Zhao (National Astronomical Observatories, China) co-chair
  • W. Schuster (Observatorio Astronómico Nacional, UNAM, México)
  • Zhanwen Han (Yunnan Astronomical Observatory, China)
  • Martin Asplund (Max Planck Institute for Astrophysics, Germany )
  • Norbert Christlieb (University of Heidelberg, Germany)
  • W. Aoki (National Astronomical Observatory of Japan)


Local Organizing Committee

  • Yuqin Chen (National Astronomical Observatories, China)
  • Bing Zhao (National Astronomical Observatories, China)
  • Yujuan Liu (National Astronomical Observatories, China)
  • Jingkun Zhao (National Astronomical Observatories, China)


Contact: Yuqin CHEN    ✉    ☏ +86-10-64863224

Supported by China-VO