The MASSIVE Survey -- XVII. A Triaxial Orbit-based Determination of the Black Hole Mass and Intrinsic Shape of Elliptical Galaxy NGC 2693
Jacob D. Pilawa, Christopher M. Liepold, Silvana C. Delgado Andrade, Jonelle L. Walsh, Chung-Pei Ma, Matthew E. Quenneville, Jenny E. Greene, John P. Blakeslee
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18 pages, 9 figures, 2 tables, accepted to ApJ 2022/02/24
We present a stellar dynamical mass measurement of a newly detected supermassive black hole (SMBH) at the center of the fast-rotating, massive elliptical galaxy NGC 2693 as part of the MASSIVE survey. We combine high signal-to-noise integral field spectroscopy (IFS) from the Gemini Multi-Object Spectrograph (GMOS) with wide-field data from the Mitchell Spectrograph at McDonald Observatory to extract and model stellar kinematics of NGC 2693 from the central $\sim 150$ pc out to $\sim2.5$ effective radii. Observations from Hubble Space Telescope (HST) WFC3 are used to determine the stellar light distribution. We perform fully triaxial Schwarzschild orbit modeling using the latest TriOS code and a Bayesian search in 6-D galaxy model parameter space to determine NGC 2693's SMBH mass ($M_\text{BH}$), stellar mass-to-light ratio, dark matter content, and intrinsic shape. We find $M_\text{BH} = \left(1.7\pm 0.4\right)\times 10^{9}\ M_\odot$ and a triaxial intrinsic shape with axis ratios $p=b/a=0.902 \pm 0.009$ and $q=c/a=0.721^{+0.011}_{-0.010}$, triaxiality parameter $T = 0.39 \pm 0.04$. In comparison, the best-fit orbit model in the axisymmetric limit and (cylindrical) Jeans anisotropic model of NGC 2693 prefer $M_\text{BH} = \left(2.4\pm 0.6\right)\times 10^{9}\ M_\odot$ and $M_\text{BH} = \left(2.9\pm 0.3\right)\times 10^{9}\ M_\odot$, respectively. Neither model can account for the non-axisymmetric stellar velocity features present in the IFS data.
Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453
在轴对称假设下，利用轨道叠加技术得到了大部分邻近超大质量黑洞质量的恒星动力学测定。然而，很少有星系--特别是大质量的早期星系--遵守精确的轴对称。在这里，我们提出了一个修改后的轨道叠加代码和一个新的方法来动态确定的内在形状和质量参数的三轴星系的空间分辨恒星运动学数据的基础上。这里描述的三轴TriOS代码纠正了原始van den Bosch等人（2008年）代码中的一个错误，该错误导致三轴模型中大多数轨道的预测不正确，并可能显著影响参数碰撞参量。修订后的代码还包含轨道采样，质量约束和运行时间的显着改进。此外，我们引入了两个新的参数搜索策略-一组新的三轴形状参数和一种新的无网格采样技术-一起导致在定位最佳拟合模型的效率显着提高。我们将更新的代码和搜索方法应用于NGC 1453，一个快速旋转的大质量椭圆星系。完整的6D参数搜索找到固有轴比的$p=b/a=0.933^{+0.014}_{-0.015}$和$q=c/a=0.779\pm0.012$，以及三轴度参数的$T=0.33\pm0.06$。尽管偏离轴对称，最佳拟合SMBH质量，恒星质光比和NGC 1453的暗物质封闭质量与轴对称结果一致。在得出一般性结论之前，需要对轴对称和三轴模型进行更多的比较。
The Stellar IMF and Dark Matter Halo of ESO0286: Constraints from Strong Lensing and Dynamics
Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Technical University of Munich（慕尼黑工业大学）；Max-Planck-Institut für extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；Université de Genève（日内瓦大学）；Institute of Cosmology and Gravitation, University of Portsmouth（朴茨茅斯宇宙学与引力研究所）
Galaxy shapes in Magneticum. I. Connecting stellar and dark matter shapes to dynamical and morphological galaxy properties and the large-scale structure
