论文标题
在附近星系的圆形介质中旋转成分的证据
Evidence for a Rotational Component in the Circumgalactic Medium of Nearby Galaxies
论文作者
论文摘要
我们提出了一项研究的结果，该研究比较了$ \ rmlyα$吸收器与当地宇宙中附近星系磁盘的旋转速度的相对速度（$ z \ leq 0.03 $）。我们已经通过与南部非洲大型望远镜的八个星系的长期光谱法获得了旋转曲线，并将该数据集与另外16个星系与文献数据结合在一起。每个星系出现在$ 3R _ {\ rm vir} $的$ 3R _ {\ rm vir} $中，带有档案宇宙起源光谱仪（COS）光谱。我们研究了吸收剂相对于附近星系旋转的速度方向，并与Steidel等人的结果进行了比较。 （2002）单片光环模型和一种新的圆柱navarro-frenk-frenk-frenk-white Galaxy Halo模型，可以通过1D QSO吸收线光谱法探测3D Galaxy Halos的上下文来解释这些数据。相对于这些模型，我们发现$ 59 \ pm5 \％$ $ \ rmlyα$吸收器具有与共旋转一致的速度。我们发现$ \ rmlyα$共存的分数可随着星系光度（$ l^*$）的降低，并以模型独立的方式降低了影响参数。我们报告说，抗旋转吸收剂和在发光星系附近发现（$ l \ gtrsim 0.5 l^*$）都有低多普勒$ b $ -parameters（$ b \ lyssim 50 $ km $ $ \ rm s^{ - 1} $）。与联合旋转一致的吸收器显示了多种多普勒$ b $ - 参数。最后，我们发现共旋转部分和星系倾斜度之间存在很强的反相关，这与最近的金属线运动学研究是不符的，并且表明环乳培养基的运动学和几何分布是复杂的和多相。
We present results of a study comparing the relative velocity of $\rm Lyα$ absorbers to the rotation velocity of nearby galaxy disks in the local universe ($z \leq 0.03$). We have obtained rotation curves via long-slit spectroscopy of eight galaxies with the Southern African Large Telescope, and combine this dataset with an additional 16 galaxies with data from the literature. Each galaxy appears within $3R_{\rm vir}$ of a QSO sightline with archival Cosmic Origin Spectrograph (COS) spectra. We study the velocity orientation of absorbers with respect to nearby galaxy's rotation, and compare with results from both the Steidel et al. (2002) monolithic halo model and a new cylindrical Navarro-Frenk-White galaxy halo model to interpret these data in the context of probing 3D galaxy halos via 1D QSO absorption-line spectroscopy. Relative to these models we find that up to $59\pm5\%$ of $\rm Lyα$ absorbers have velocities consistent with co-rotation. We find the $\rm Lyα$ co-rotation fraction to decrease with galaxy luminosity ($L^*$) and impact parameter in a model-independent fashion. We report that both anti-rotating absorbers and those found near luminous galaxies ($L \gtrsim 0.5 L^*$) mostly have low Doppler $b$-parameters ($b \lesssim 50$ km $\rm s^{-1}$). Absorbers consistent with co-rotation show a wide range of Doppler $b$-parameters. Finally, we find a strong anticorrelation between co-rotation fraction and galaxy inclination, which is at odds with recent metal-line kinematic studies and suggests the kinematic and geometric distribution of the circumgalactic medium is complex and multiphase.
