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相关论文: The pattern speed of the Milky Way bar from transv…

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We compare distance resolved, absolute proper motions in the Milky Way bar/bulge region to a grid of made-to-measure dynamical models with well defined pattern speeds. The data are obtained by combining the relative VVV Infrared Astrometric…

星系天体物理 · 物理学 2022-04-29 Jonathan Clarke , Ortwin Gerhard

We present gas flow models for the Milky Way based on high-resolution grid-based hydrodynamical simulations. The basic galactic potential we use is from a N-body model constrained by the density of red clump giants in the Galactic bulge. We…

星系天体物理 · 物理学 2016-06-15 Zhi Li , Ortwin Gerhard , Juntai Shen , Matthieu Portail , Christopher Wegg

We construct a large set of dynamical models of the galactic bulge, bar and inner disk using the Made-to-Measure method. Our models are constrained to match the red clump giant density from a combination of the VVV, UKIDSS and 2MASS…

星系天体物理 · 物理学 2016-12-21 Matthieu Portail , Ortwin Gerhard , Christopher Wegg , Melissa Ness

We have derived absolute proper motions of the entire Galactic bulge region from VIRAC and Gaia. We present these as both integrated on-sky maps and, after isolating standard candle red clump (RC) stars, as a function of distance using RC…

星系天体物理 · 物理学 2019-12-06 Jonathan P. Clarke , Christopher Wegg , Ortwin Gerhard , Leigh C. Smith , Phil W. Lucas , Shola M. Wylie

We use Schwarzschild's orbit-superposition technique to construct self-consistent models of the Galactic bar. Using $\chi^2$ minimisation, we find that the best-fit Galactic bar model has a pattern speed $\Omega_{\rm p}=60 \rm{km s^{-1}…

星系天体物理 · 物理学 2015-06-11 Yougang Wang , Hongsheng Zhao , Shude Mao , R. M. Rich

We show how the continuity equation can be used to determine pattern speeds in the Milky Way Galaxy (MWG). This method, first discussed by Tremaine & Weinberg in the context of external galaxies, requires projected positions, $(l,b)$, and…

天体物理学 · 物理学 2009-11-07 Victor P. Debattista , Ortwin Gerhard , Maartje N. Sevenster

The Milky Way (MW) hosts a central bar whose pattern speed, orientation, and length remain uncertain, largely due to observational biases and selection effects, despite the transformative data provided by the Gaia mission. We aim to…

Our goal is to calculate the circular velocity curve of the Milky Way, along with corresponding uncertainties that quantify various sources of systematic uncertainty in a self-consistent manner. The observed rotational velocities are…

Previous work has related the Galactic bar to structure in the local stellar velocity distribution. Here we show that the bar also influences the spatial gradients of the velocity vector via the Oort constants. By numerical integration of…

星系天体物理 · 物理学 2010-02-10 Ivan Minchev , Jason Nordhaus , Alice Quillen

We provide a purely dynamical global map of the non-axisymmetric structure of the Milky Way disk. For this, we exploit the information contained within the in-plane motions of disk stars from Gaia DR3 to adjust a model of the Galactic…

星系天体物理 · 物理学 2025-07-16 Y. R. Khalil , B. Famaey , G. Monari , M. Bernet , A. Siebert , R. Ibata , G. F. Thomas , P. Ramos , T. Antoja , C. Li , S. Rozier , M. Romero-Gómez

The distribution of moving groups in the solar neighborhood has been used to constrain dynamical properties of the Milky Way for decades. The kinematic bimodality between the main mode (Hyades, Pleiades, Coma Berenices, and Sirius) and…

星系天体物理 · 物理学 2024-04-09 Scott Lucchini , Elena D'Onghia , J. Alfonso L. Aguerri

A brief review is given of different methods used to determine the pattern speeds of the Galactic bar and spiral arms. The Galactic bar rotates rapidly, with corotation about halfway between the Galactic center and the Sun, and outer…

星系天体物理 · 物理学 2010-03-15 Ortwin Gerhard

Non-axisymmetries in the Galactic potential (spiral arms and bar) induce kinematic groups such as the Hercules stream. Assuming that Hercules is caused by the effects of the Outer Lindblad Resonance of the Galactic bar, we model…

Our recent studies of axial-symmetry breaking in the nearby ($d <3 \,{\rm kpc}$) star counts are sensitive to the distortions of stellar orbits perpendicular and parallel to the orientation of the bar just within and beyond the outer…

星系天体物理 · 物理学 2020-08-20 Austin Hinkel , Susan Gardner , Brian Yanny

We measure the circular velocity curve $v_{\rm c}(R)$ of the Milky Way with the highest precision to date across Galactocentric distances of $5\leq R \leq 25$ kpc. Our analysis draws on the $6$-dimensional phase-space coordinates of…

星系天体物理 · 物理学 2019-03-06 Anna-Christina Eilers , David W. Hogg , Hans-Walter Rix , Melissa Ness

Recently the commissioning APOGEE observations of the Galactic bulge reported that a significant fraction of stars ($\sim10%$) are in a cold ($\sigma_{\rm V} \approx 30$ km/s) high velocity peak (Galactocentric radial velocity $\approx 200$…

星系天体物理 · 物理学 2015-06-18 Zhao-Yu Li , Juntai Shen , R. Michael Rich , Andrea Kunder , Shude Mao

The length and pattern speed of the Milky Way bar are still controversial. Photometric and spectroscopic surveys of the inner Galaxy, as well as gas kinematics, favour a long and slowly rotating bar, with corotation around a Galactocentric…

星系天体物理 · 物理学 2017-01-18 Giacomo Monari , Daisuke Kawata , Jason A. S. Hunt , Benoit Famaey

Using the potential from N-body simulations, we construct the Galactic bar models with the Schwarzschild method. By varying the pattern speed and the position angle of the bar, we find that the best-fit bar model has pattern speed…

星系天体物理 · 物理学 2015-06-16 Yougang Wang , Shude Mao , Richard J. Long , Juntai Shen

The circular speed curve of the Milky Way provides a key constraint on its mass distribution, reflecting the axisymmetric component of the gravitational potential. This is especially critical in the inner Galaxy ($R \lesssim 4$ kpc), where…

星系天体物理 · 物理学 2025-07-18 Junichi Baba

The distance to the Galactic center $R_0$ is a fundamental parameter for understanding the Milky Way, because all observations of our Galaxy are made from our heliocentric reference point. The uncertainty in $R_0$ limits our knowledge of…

星系天体物理 · 物理学 2022-12-14 Henry W. Leung , Jo Bovy , J. Ted Mackereth , Jason A. S. Hunt , Richard R. Lane , John C. Wilson
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