A PUZZLE INVOLVING GALACTIC BULGE MICROLENSING EVENTS

• Type: Article in International Scientific Journal
• Date: 2010

Authors

J.G. Cohen (Author) Other; A. Gould (Author) FCUP; I.B. Thompson (Author) Other; S. Feltzing (Author) FCUP; T. Bensby (Author) FCUP; J.A. Johnson (Author) FCUP; W. Huang (Author) Other; J. Melendez (Author) FCUP; S. Lucatello (Author) FCUP; M. Asplund (Author) FCUP

Journal

Title: Astrophysical Journal Letters

Vol. 711 No. 1

Pages: L48-L52

ISSN: 2041-8205

Publisher: American Astronomical Society

Indexing

ISI Web of Science

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Abstract (EN): 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.

Language: English

Type (Professor's evaluation): Scientific