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Related papers: Barless flocculent galaxies: a dynamic puzzle

200 papers

From this vast subject, I will pick out and review three specific topics, namely the formation and evolution of bars, the formation of bulges, and the evolution during multiple major mergers. Bars form naturally in galactic discs. Their…

Astrophysics · Physics 2009-11-13 E. Athanassoula

The structure of a sample of high-redshift (z=2), rotating galaxies with high star formation rates and turbulent gas velocities of sigma=40-80 km/s is investigated. Fitting the observed disk rotational velocities and radii with a Mo, Mao,…

The classical picture for the formation of stellar bars -- key dynamical drivers of the evolution of galaxies -- is through secular evolution of instability in gas poor, stellar-dominated disks. The detection with the James Webb Space…

Bars in disk galaxies slow down as they transfer their angular momentum to their dark matter halo via dynamical friction from near-resonant orbits. This bar-halo dynamical friction can become ineffective once phase mixing erases the…

Astrophysics of Galaxies · Physics 2026-03-16 Rumi Kodama , Rimpei Chiba , Tetsuro Asano , Junichi Baba , Michiko Fujii

We present a catalogue of bulgeless galaxies, which includes 19225 objects selected in four of the deepest, largest multi-wavelength datasets available -- COSMOS, AEGIS, GEMS and GOODS -- at intermediate redshift ($0.4 \leq z \leq 1.0$).…

The time evolution of barred structures is examined under the influence of the external forces exerted by a spherical halo and by prolate halos. In particular, galaxy disks are placed in the plane including the major axis of prolate halos,…

Astrophysics · Physics 2009-10-31 Makoto Ideta , Shunsuke Hozumi

We present a scenario for the formation of disks which explains not only the properties of normal galaxies, but the properties of the population of low surface brightness galaxies (LSBs) as well. We use a gravitationally self-consistent…

Astrophysics · Physics 2009-10-28 J. J. Dalcanton , D. N. Spergel , F J Summers

Having once thought that we understood how some galaxies were barred and had difficulty accounting for the absence of bars in others, it now seems that we have the opposite problem. Most real galaxies have centres dense enough to inhibit…

Astrophysics · Physics 2007-05-23 J. A. Sellwood

Dissipative dark matter, where dark matter particles interact with a massless (or very light) boson, is studied. Such dark matter can arise in simple hidden sector gauge models, including those featuring an unbroken $U(1)'$ gauge symmetry,…

Astrophysics of Galaxies · Physics 2015-06-03 R. Foot

Unhappily, there has been a maelstrom of problems for dark matter theories over the last few years and many serious difficulties still have no resolution in sight. This article reviews the evidence for dark matter in galaxies. The haloes…

Astrophysics · Physics 2016-11-03 N. W. Evans

We have analyzed the redshift-dependent fraction of galactic bars over 0.2<z<0.84 in 2,157 luminous face-on spiral galaxies from the COSMOS 2-square degree field. Our sample is an order of magnitude larger than that used in any previous…

We present data for a sample of 45 spiral galaxies over a range of Hubble types, imaged in the near-IR J and K bands. Parameters are calculated describing the bulge, disk and bar K-band light distributions, and we look for correlations…

Astrophysics · Physics 2007-05-23 M. S. Seigar , P. A. James

Galactic bars are found in the majority of disc galaxies. They rotate nearly rigidly with an angular frequency called pattern speed. Previous idealised simulations have shown that bar pattern speed decreases with time due to dynamical…

Astrophysics of Galaxies · Physics 2024-12-11 Marcin Semczuk , Walter Dehnen , Ralph Schönrich , E. Athanassoula

The presence of dark gaps, a preferential light deficit along the bar minor axis, is observationally well known. The properties of dark gaps are thought to be associated with the properties of bars, and their spatial locations are often…

Astrophysics of Galaxies · Physics 2024-07-24 Soumavo Ghosh , Dimitri A. Gadotti , Francesca Fragkoudi , Vighnesh Nagpal , Paola Di Matteo , Virginia Cuomo

Bars are important in the secular evolution of galaxies. This study is aimed at exploring the reasons why some galaxies have bars at redshift $z=0$ while others do not. We use ellipse fitting to measure the properties and evolution of bars…

Astrophysics of Galaxies · Physics 2025-05-28 Shuai Lu , Min Du , P. Victor Debattista

I review the arguments for the importance of halo structure in driving galaxy evolution and coupling a galaxy to its environment. We begin with a general discussion of the key dynamics and examples of structure dominated by modes. We find…

Astrophysics · Physics 2007-05-23 Martin D. Weinberg

High-quality observations of dark matter-dominated low surface brightness (LSB) galaxies indicate that, in contrast to the triaxial, centrally-concentrated cuspy halos formed in collisionless simulations of halo assembly, these galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Rachel Kuzio de Naray , Kristine Spekkens

We present empirical constraints on the influence of stellar bars on the fueling of active galactic nuclei (AGNs) out to z=0.84 using a sample of X-ray-selected AGNs hosted in luminous non-interacting face-on and moderately inclined disk…

Astrophysics of Galaxies · Physics 2015-06-22 Mauricio Cisternas , Kartik Sheth , Mara Salvato , Johan H. Knapen , Francesca Civano , Paola Santini

In both observed and simulated galaxies, disk morphologies become more prevalent at higher masses and lower redshifts. To elucidate the physical origin of this trend, we develop a simple analytical model in which galaxy morphology is…

Astrophysics of Galaxies · Physics 2026-02-06 Vadim A. Semenov

A simple model for the dust media describing evolution of the system like spiral galaxy is considered. In contrast to previous considerations we show that the initial density fold should be quasi-one-dimensional (bar-like) instead of…

Astrophysics · Physics 2007-05-23 A. E. Filippov , A. S. Zhedanov