A PUZZLE INVOLVING GALACTIC BULGE MICROLENSING EVENTS

作者:Cohen Judith G*; Gould Andrew; Thompson Ian B; Feltzing Sofia; Ben**y Thomas; Johnson Jennifer A; Huang Wenjin; Melendez Jorge; Lucatello Sara; Asplund Martin
来源:Astrophysical Journal Letters, 2010, 711(1): L48-L52.
DOI:10.1088/2041-8205/711/1/L48

摘要

We study a sample of 16 microlensed Galactic bulge main-sequence turnoff region stars for which high-dispersion spectra have been obtained with detailed abundance analyses. We demonstrate that there is a very strong and highly statistically significant correlation between the maximum magnification of the microlensed bulge star and the value of the [Fe/H] deduced from the high resolution spectrum of each object. Physics demands that this correlation, assuming it to be real, be the result of some sample bias. We suggest several possible explanations, but are forced to reject them all, and are left puzzled. To obtain a reliable metallicity distribution in the Galactic bulge based on microlensed dwarf stars, it will be necessary to resolve this issue through the course of additional observations.

  • 出版日期2010-3-1