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相关论文: The vertical structure of galactic discs: nonlocal…

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Modified gravity theories such as Modified Newtonian Dynamics (MOND) and Scalar-Tensor-Vector Gravity (STVG) have been proposed as alternatives to dark matter, but decisive tests have been hindered by degeneracies between baryonic structure…

星系天体物理 · 物理学 2026-05-12 Zheng-long Wang , Yue-Lin Sming Tsai , Lan Zhang , Yin Wu , Haining Li , Xiang-Xiang Xue , Hongsheng Zhao , Yi-Zhong Fan

The presence of nuclear discs in barred disc galaxies has been demonstrated in studies on stellar structures and kinematics. It is thus imperative to establish their fundamental properties and scaling relations, which can help understanding…

星系天体物理 · 物理学 2025-09-19 Dimitri A. Gadotti , Camila de Sá-Freitas

I show that the predicted densities of the inner dark matter halos in LCDM models of structure formation appear to be higher than estimates from real galaxies and constraints from dynamical friction on bars. This inconsistency would not be…

天体物理学 · 物理学 2015-05-13 J. A. Sellwood

The spiral galaxy NGC 6503 exhibits a regular kinematical structure except for a remarkable drop of the stellar velocity dispersion values in the central region. To investigate the dynamics of the disc a theoretical framework has been…

天体物理学 · 物理学 2015-06-24 Roelof Bottema , Jeroen P. E. Gerritsen

We use $N$-body simulations to investigate the excitation of bending waves in a Milky Way-like disc-bulge-halo system. The dark matter halo consists of a smooth component and a population of subhaloes while the disc is composed of thin and…

星系天体物理 · 物理学 2018-08-15 Matthew H. Chequers , Lawrence M. Widrow , Keir Darling

We examine the vertical structure of Galactic disk kinematics over a Galactocentric radial distance range of $R=5-15$ $\rm{kpc}$ and up to $3$ $\rm{kpc}$ away from the Galactic plane, using the K-type giants surveyed by LAMOST. Based on…

星系天体物理 · 物理学 2021-08-25 Ping-Jie Ding , Xiang-Xiang Xue , Chengqun Yang , Gang Zhao , Lan Zhang , Zi Zhu

A typical galactic disc has a finite thickness and in addition to stars it also contains a finite amount of interstellar gas. Here, we investigate the physical impact of the finite thickness of a galactic disc on the disc stability against…

星系天体物理 · 物理学 2022-03-14 Soumavo Ghosh , Chanda J. Jog

Molecular gas disks are generally Toomre stable ($Q_T>$1) and yet clearly gravitationally unstable to structure formation as evidenced by the existence of molecular clouds and ongoing star formation. This paper adopts a 3D perspective to…

星系天体物理 · 物理学 2022-10-12 Sharon E. Meidt

A substantial fraction of the warps in spiral galaxies may result from bending instabilities if the disks are essentially self-gravitating. With N-body simulations, we show that galaxies with self-gravitating disks as thick as HI disks are…

天体物理学 · 物理学 2009-11-10 Yves Revaz , Daniel Pfenniger

We present numerical simulations of misaligned discs around a spinning black hole covering a range of parameters. Previous simulations have shown that discs that are strongly warped by a forced precession -- in this case the Lense-Thirring…

高能天体物理现象 · 物理学 2021-03-24 Anagha Raj , Chris Nixon , Suzan Dogan

We present a study of the vertical structure of the gaseous and stellar disks in a sample of edge-on galaxies (NGC 4157, 4565, and 5907) using BIMA/CARMA 12CO (J = 1 --> 0), VLA H I, and Spitzer 3.6 micron data. In order to take into…

Warped accretion discs of low viscosity are prone to hydrodynamic instability due to parametric resonance of inertial waves as confirmed by local simulations. Global simulations of warped discs, using either smoothed particle hydrodynamics…

地球与行星天体物理 · 物理学 2020-11-18 Hongping Deng , Gordon I. Ogilvie , Lucio Mayer

The vertical density distribution of stars in a galactic disc is traditionally obtained by assuming an isothermal vertical velocity dispersion of stars. Recent observations from SDSS, LAMOST, RAVE, Gaia etc show that this dispersion…

星系天体物理 · 物理学 2020-12-04 Suchira Sarkar , Chanda J. Jog

We investigate the connection between the morphology and internal kinematics of the stellar component of central galaxies with mass $M_\star > {10}^{9.5} {\rm M}_\odot$ in the EAGLE simulations. We compare several kinematic diagnostics…

Debris discs provide valuable insights into the formation and evolution of exoplanetary systems. Their structures are commonly attributed to planetary perturbations, serving as probes of as-yet-undetected planets. However, most studies of…

The colour and metallicity gradients observed in spiral galaxies suggest that the mass-to-light ratio (M*/L) of the stellar disc is a function of radius. This is indeed predicted by chemo-photometric models of galactic discs. We investigate…

宇宙学与河外天体物理 · 物理学 2015-05-13 Laura Portinari , Paolo Salucci

Astrophysical discs which are sufficiently massive and cool are linearly unstable to the formation of axisymmetric structures. In practice, linearly stable discs of surface density slightly below the threshold needed for this instability…

地球与行星天体物理 · 物理学 2025-01-22 Joshua J. Brown , Gordon I. Ogilvie

The stability of spiral galaxies is compared in modified Newtonian Dynamics (MOND) and Newtonian dynamics with dark matter (DM). We extend our previous simulations that involved pure stellar discs without gas, to deal with the effects of…

天体物理学 · 物理学 2009-11-13 O. Tiret , F. Combes

Using three-dimensional stellar kinematic data from simulated galaxies, we examine the efficacy of a Jeans equation analysis in reconstructing the total disk surface density, including the dark matter, at the "Solar" radius. Our simulation…

星系天体物理 · 物理学 2016-01-18 G. N. Candlish , R. Smith , C. Moni Bidin , B. K. Gibson

We present results of numerical modeling made for the galactic stellar disk embedded in the spherical halo. The non-linear dynamics of bending instabilities developed in the disk is studied. The axisymmetrical bending mode is considered as…

天体物理学 · 物理学 2007-05-23 D. Bizyaev , A. Khoperskov , N. Tiurina