OGLE Bulge区域的Mira变量星
摘要
(abridged) OGLE-II调查在银河系中心方向检测到的222000颗I带变星光度曲线被拟合，并与DENIS和2MASS数据库相关联。报告2691个I带半幅面积大于0.45幅度的天体，这些天体对应经典Mira变量星。6个在类似赤道度但纬度从-1.2到-5.8度的区域的Mira周期分布在统计上不可区分，表明这些区域具有相似的星系，初始质量为1.5-2 \msol（对应年龄为1-3 Gyr）。一个在类似赤道度、纬度为-0.05度的区域（Glass等人，2001）显示出显著不同的周期分布，表明存在2.5-3 \msol、年龄小于1 Gyr的年轻星系。 presented for the whole sample and for sub-fields. The zero point depends on Galactic longitude. Simulations are carried out to show that the observed dependence of the zero point with , and the number of stars per field are naturally explained using the model of disk and bulge stars of Binney et al. (1997), for a viewing angle of 43 +/- 17 degrees. A comparison is made with similar objects in the Magellanic Clouds, studied in a previous paper. The slope of the PL-relation in the Bulge and the MCs agree within the errorbars. A distance to the Galactic Centre between 8.6 and 9.0 kpc is derived (for an assumed DM of 18.50 to the LMC).
引用
@article{arxiv.astro-ph/0506337,
title = {Emission line variability of RS Ophiuchi},
author = {R. K. Zamanov and M. F. Bode and N. A. Tomov and J. Porter},
journal= {arXiv preprint arXiv:astro-ph/0506337},
year = {2009}
}
备注
accepted in MNRAS (letters)