科研之友
微信
新浪微博
Facebook
分享链接
摘要
We study the nature of the globular cluster (GC) candidates FSR 1603 and FSR 1755 selected from the catalogue of Froebrich, Scholz & Raftery. Their properties are investigated with Two-Micron All-Sky Survey field-star decontaminated photometry, which is used to build colour-magnitude diagrams (CMDs) and stellar radial density profiles. FSR 1603 has the open cluster Ruprecht 101 as optical counterpart, and we show it to be a massive intermediate-age cluster. Relevant parameters of FSR 1603 are the age approximate to 1 Gyr, distance from the Sun d(circle dot) approximate to 2.7 kpc, Galactocentric distance R-GC approximate to 6.4 kpc, core radius R-C approximate to 1.1 pc, mass function slope chi approximate to 1.8, observed stellar mass (for stars with mass in the range 1.27 <= m <= 2.03 M-circle dot) M-obs approximate to 500 M-circle dot and a total (extrapolated to m = 0.08 M-circle dot) stellar mass M-tot approximate to 2300 M-circle dot. FSR 1755, on the other hand, is not a populous cluster. It may be a sparse young cluster embedded in the H II region Sh 2-3, subject to an absorption A(V) approximate to 4.1, located at d(circle dot) approximate to 1.3 kpc. Important field-star contamination, spatially variable heavy dust obscuration, even in K-s, and gas emission characterize its field. A nearly vertical, sparse blue stellar sequence shows up in the CMDs.
- 出版日期2008-3-11
