BATC 13 Band Photometry of the Open Cluster NGC 7789
BATC 13 Band Photometry of the Open Cluster NGC 7789
复制标题
疏散星团 NGC 7789 的 BATC 13 波段光度测量
DOI：
10.1086/512189
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发表时间：
2007-01
影响因子：
5.3
通讯作者：
Wu, Z.
中科院分区：
文献类型：
--
作者：
Wu, Z.
我们提出了13波段CCD中间波段分光光度计的领域为中心的疏散星团NGC 7789从400到近1000 nm，采取了北京-亚利桑那州-台湾-康涅狄格州（BATC）多色测光系统。通过对NGC 7789恒星光谱能量分布的观测与理论计算的比较，得到了该星团的基本参数：年龄为1.4 ± 0.1 Gyr，距离模（m-M）0 = 11.27 ± 0.04，红化E（B - V）= 0.28 ± 0.02，太阳成分Z = 0.019的金属丰度。当用King模型拟合BATC e波段极限星等为19.0的成员星（λeff = 4925 Å）的表面密度轮廓时，推导出NGC 7789的核心半径Rc = 7.52 '和潮汐半径Rt = 28.84'。对质量在0.95 ~ 1.85 M <$m之间的NGC 7789主序星的观测质量函数（MF）进行了幂律拟合，得到斜率α = -0.96。NGC 7789的强烈质量分离反映在不同质量范围内成员星的浓度参数C 0 = log（Rt/Rc）的显著变化上：最大质量恒星的C 0 = 1.02，最小质量MS星的C 0 = 0.37。NGC 7789的质量分离也表现在星系团不同空间区域的斜率α的显著变化上：核心区域内恒星的MF α =-0.71，远比星系团外部区域的恒星的MF α = -1.20要平坦。
We present 13 band CCD intermediate-band spectrophotometry of a field centered on the open cluster NGC 7789 from 400 to nearly 1000 nm, taken with the Beijing-Arizona-Taiwan-Connecticut (BATC) Multi-Color Survey photometric system. By comparing observed spectral energy distributions of NGC 7789 stars with theoretical ones, the fundamental parameters of this cluster are derived: an age of 1.4 ± 0.1 Gyr, a distance modulus (m - M)0 = 11.27 ± 0.04, a reddening E(B - V) = 0.28 ± 0.02, and a metallicity with the solar composition Z = 0.019. When the surface density profile for member stars with limiting magnitudes of 19.0 in the BATC e band (λeff = 4925 Å) is fitted by a King model, a core radius Rc = 7.52′ and a tidal radius Rt = 28.84′ are derived for NGC 7789. The observed mass function (MF) for main-sequence (MS) stars of NGC 7789 with masses from 0.95 to 1.85 M⊙ is fitted with a power-law function ϕ(m) ∝ mα, and a slope α = -0.96 is derived. Strong mass segregation in NGC 7789 is reflected in the significant variation of the concentration parameters C0 = log(Rt/Rc) for member stars of NGC 7789 within different mass ranges: C0 = 1.02 for the most massive stars and C0 = 0.37 for the lowest mass MS stars. Strong mass segregation in NGC 7789 is also indicated in the significant variation of the slopes α in different spatial regions of the cluster: the MF for stars within the core region has α = -0.71, much flatter than that for stars in external regions of the cluster (α = -1.20).
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DOI：
10.1086/112004
发表时间：
1977
期刊：
The Astronomical Journal
影响因子：
--
作者：
K. Janes
通讯作者：
K. Janes
影响因子：
6.5
作者：
D. Schönberner;S. Andrievsky;J. Drilling
通讯作者：
D. Schönberner;S. Andrievsky;J. Drilling
DOI：
10.1046/j.1365-8711.2001.04022.x
发表时间：
2000-09
影响因子：
4.8
作者：
P. Kroupa
通讯作者：
P. Kroupa
DOI：
10.1111/j.1365-2966.2005.09448.x
发表时间：
2005-07
影响因子：
4.8
作者：
J. Hurley;O. Pols;S. Aarseth;C. Tout
通讯作者：
J. Hurley;O. Pols;S. Aarseth;C. Tout
DOI：
10.1086/146535
发表时间：
1958-09
期刊：
The Astrophysical Journal
影响因子：
--
作者：
E. Burbidge;A. Sandage
通讯作者：
E. Burbidge;A. Sandage