相关论文: Detection of a slow HI bar in the dwarf irregular …

The central part of a dark matter halo reacts to the presence and evolution of a bar. Not only does the halo absorb angular momentum from the disk, it can also be compressed and have its shape modified. We study these issues in a series of…

In this paper we analyse the methodology to derive the bar pattern speed from dynamical simulations. The results are robust to the changes in the vertical-scale height and in the mass-to-light (M/L) ratios. There is a small range of…

The non-circular streaming motions in barred galaxies are sensitive to the mass of the bar and can be used to lift the degeneracy between disk and dark matter halo encountered when fitting axisymmetric rotation curves of disk galaxies. In…

We measured the bar pattern speed in a sample of 7 SB0 galaxies using the Tremaine-Weinberg method. This represents the largest sample of galaxies for which bar pattern speed has been measured this way. All the observed bars are as rapidly…

Elongated bar-like features are ubiquitous in galaxies, occurring at the centers of approximately two-thirds of spiral disks in the nearby Universe. Due to gravitational interactions between the bar and the other components of galaxies, it…

Co-moving groups of stars (streams) are well known in the velocity space of the disc near the Sun. Many are thought to arise from resonances with the Galactic bar or spiral arms. In this work, we search for similar moving groups in the…

Does the environment of a galaxy directly influence the kinematics of its bar? We present observational evidence that bars in high-density environments exhibit significantly slower rotation rates than bars in low-density environments.…

Theories that attempt to explain the dynamical relationship between bar and spiral patterns in galactic disks make different predictions about the radial profile of the pattern speed. These are tested for the H-alpha bar and spiral patterns…

`Conspiracy' between the dark and the baryonic mater prohibits an unambiguous decomposition of disc galaxy rotation curves into the corresponding components. Several methods have been proposed to counter this difficulty, but their results…

We present radio interferometric observations of two irregular galaxies that were candidates for having unusually extended HI emission. The galaxies, UGC 199 and DDO 26, otherwise appeared to be normal, low-luminosity systems with modest…

We study the bar pattern speeds and corotation radii of 225 barred galaxies, using IFU data from MaNGA and the Tremaine-Weinberg method. Our sample, which is divided between strongly and weakly barred galaxies identified via Galaxy Zoo, is…

The discovery of a previously unknown 21cm HI line source identified as an ultra-compact high velocity cloud in the ALFALFA survey is reported. The HI detection is barely resolved by the Arecibo 305m telescope ~4' beam and has a narrow HI…

We aim at investigating the formation process of weak bars by measuring their properties in a sample of 29 nearby SAB galaxies, spanning a wide range of morphological types and luminosities. The sample galaxies were selected to have an…

We present resolved HI observations of six dwarf galaxies drawn from a sample of baryon-dominated dwarf galaxy (BDDG) candidates previously identified using global HI spectra from ALFALFA and optical inclinations from SDSS, both of which…

The dynamic evolution of galactic bars in standard $\Lambda$CDM models is dominated by angular momentum loss to the dark matter haloes via dynamical friction. Traditional approximations to dynamical friction are formulated using the…

We model the distribution of the observed profiles of 21 cm line emission from neutral hydrogen (HI) in central galaxies selected from a statistically representative mock catalog of the local Universe in the Lambda-cold dark matter…

We examine the amplitude of the rotation velocity that can be attributed to the dark matter halos of disk galaxies, focusing on well measured intermediate radii. The data for 60 galaxies spanning a large range of mass and Hubble types,…

We present new, high sensitivity VLA observations of HI in four dwarf galaxies (UGCA 292, GR8, DDO 210, and DDO 216) and we use these data to study interactions between star formation and the interstellar medium. HI velocity dispersions and…

A bar rotating in a pressure-supported halo generally loses angular momentum and slows down due to dynamical friction. Valenzuela & Klypin report a counter-example of a bar that rotates in a dense halo with little friction for several Gyr,…

A strong bar rotating within a massive halo should lose angular momentum to the halo through dynamical friction, as predicted by Weinberg. We have conducted fully self-consistent, numerical simulations of barred galaxy models with a live…