论文标题
Wiyn开放群集研究LXXIX。 M48（NGC 2548）I。开放群集M48（NGC 2548）中星星的径向速度，旋转速度和金属度
WIYN Open Cluster Study LXXIX. M48 (NGC 2548) I. Radial Velocities, Rotational Velocities, and Metallicities of Stars in the Open Cluster M48 (NGC 2548)
论文作者
论文摘要
WIYN/Hydra spectra (R $\sim$ 13,500, signal-to-noise pixel$^{-1}$ = 50-1000) of a 400 $\unicode{x212B}$ region around Li 6708 $\unicode{x212B}$ are used to determine radial and rotational velocities for 287 photometrically selected candidate members of the open cluster M48。样本范围从恒星到后期的矮人和八个巨人。我们将$ v _ {\ rm {rad}} $测量和功率谱分析与视差分析以及GAIA DR2的正确运动数据相结合，以评估成员资格和多重性。我们将152颗恒星归类为单个群集成员，11个二进制成员，16个恒星为不确定的多样性成员，56个单个非会员，28个成员，28个恒星为单个“可能的”非会员，两个作为单个“可能的”成员，一个是二进制的“可能”成员，5名作为二进制的非成员，10个非成员，10作为“不确定的不确定的多样性”，而不是确定的多样性，而是不确定的多样性，而是不确定的，则是不确定的。从95个单个成员的子样本中，我们得出$ v _ {\ rm {rad}} $ = 8.512 $ \ pm $ 0.087 km s $ s $^{ - 1} $（$σ_μ$，和$σ$ = 0.848 km s $ s $^{ - 1} $）。使用16个隔离的Fe I线，用于99个单个成员的子样本（具有$σ_{t _ {\ rm {fef}}}} $ $ $ <$ 75 k（来自$ ubvri $的10颜色），$ v $ sin $ $ $ $ $ $ $ $ $ <$ <$ <$ 25 km s $ s $ s $ [fe/h] $ _ {\ rm {m48}} $ = -0.063 $ \ pm $ 0.007 dex（$σ_μ$）。 [fe/h]在前所未有的2500 k范围内独立于$ t _ {\ rm {eff}} $。最小群集二进制分数为11％-21％。 M48表现出明确但适度的扩展，对主要序列的转口扩大，颜色与$ v $ sin $ i $之间没有相关性。
WIYN/Hydra spectra (R $\sim$ 13,500, signal-to-noise pixel$^{-1}$ = 50-1000) of a 400 $\unicode{x212B}$ region around Li 6708 $\unicode{x212B}$ are used to determine radial and rotational velocities for 287 photometrically selected candidate members of the open cluster M48. The sample ranges from turnoff A stars to late-K dwarfs and eight giants. We combine our $V_{\rm{RAD}}$ measurements and power spectrum analysis with parallax and proper motion data from Gaia DR2 to evaluate membership and multiplicity. We classify 152 stars as single cluster members, 11 as binary members, 16 as members of uncertain multiplicity, 56 as single nonmembers, 28 as single "likely" nonmembers, two as single "likely" members, one as a binary "likely" member, five as binary nonmembers, 10 as "likely" members of uncertain multiplicity, three as nonmembers of uncertain multiplicity, and three as "likely" nonmembers of uncertain multiplicity. From a subsample of 95 single members, we derive $V_{\rm{RAD}}$ = 8.512 $\pm$ 0.087 km s$^{-1}$ ($σ_μ$, and $σ$ = 0.848 km s$^{-1}$). Using 16 isolated Fe I lines for a subsample of 99 single members (that have $σ_{T_{\rm{eff}}}$ $<$ 75 K (from 10 colors from $UBVRI$), $v$ sin $i$ $<$ 25 km s$^{-1}$, and well-behaved Fe I lines), [Fe/H]$_{\rm{M48}}$ = -0.063 $\pm$ 0.007 dex ($σ_μ$). [Fe/H] is independent of $T_{\rm{eff}}$ over an unprecedentedly large range of 2500 K. The minimum cluster binary fraction is 11%-21%. M48 exhibits a clear but modest broadening of the main-sequence turnoff, and there is no correlation between color and $v$ sin $i$.
