Candidate Milky Way satellites in the Galactic halo

¹ National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China e-mail: chaoliu@lamost.org
² Graduate University of Chinese Academy of Sciences, Beijing 100049, PR China
³ Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA

Received: 1 August 2007
Accepted: 28 September 2007

Abstract

Aims.Sloan Digital Sky Survey (SDSS) DR5 photometric data with , were searched for new Milky Way companions or substructures in the Galactic halo.

Methods. Five candidates are identified as overdense faint stellar sources that have color-magnitude diagrams similar to those of known globular clusters, or dwarf spheroidal galaxies. The distance to each candidate is estimated by fitting suitable stellar isochrones to the color-magnitude diagrams. Geometric properties and absolute magnitudes are roughly measured and used to determine whether the candidates are likely dwarf spheroidal galaxies, stellar clusters, or tidal debris.

Results.SDSSJ1000+5730 and SDSSJ1329+2841 are probably faint dwarf galaxy candidates while SDSSJ0814+5105, SDSSJ0821+5608, and SDSSJ1058+2843 are very likely extremely faint globular clusters.

Conclusions.Follow-up study is needed to confirm these candidates.