|
The First Stars and Galaxies: Challenges for the Next Decade Participants
Contact: |
Talk
Title: Probing the IMF with the Hamburg/ESO and SEGUE Surveys Author(s): Timothy Beers Abstract: The nature of the First Star IMF reveals (or potentially reveals) itself in the chemical fingerprints that such stars may have left on subsequent generations of lower-mass stars, some of which are so iron-poor that they must have formed close to the first-star era. In the past few decades, dedicated surveys to identify the most interesting low-metallicity stars for this application have succeeded in identifying on the order of 30,000 stars in the Milky Way with [Fe/H] $< -2.0$. We have also learned that the most metal-poor stars may be associated with a distinct outer-halo component of the Galaxy, a recognition that will inform more refined searches in the near future. I discuss efforts to demonstrate that the halo metallicity distribution function (MDF) of stars with [Fe/H] < -2.0 may in fact not be a single function, but may contain separable components associated with the inner- and outer-halo populations. Predictions of the expected MDF in the post first-stars era will need to be compared with the appropriate MDF from the lowest metallicity halo stars.
|