Results 41 to 50 of about 154,367 (172)
Molecular Bars in Spiral Galaxies [PDF]
International Astronomical Union Colloquium, 1996 Images of molecular gas in spiral galaxies show two types of bar structure: large-scale bars, which are correlated with the presence of stellar bars, and generally follow the spiral structure, and nuclear “bars” of a few hundred parsecs in size, which show no direct correlation with the presence of a stellar bar.
openaire +2 more sources
Spiral arm formation mechanisms: Spiral Structure in Barred galaxies. Observational constraints to spiral arm formation mechanisms [PDF]
MNRAS, 2019, 482, 5362, 2019 A method which we have developed for determining corotation radii, has allowed us to map in detail the radial resonant structures of barred spiral galaxies. Here we have combined this information with new determinations of the bar strength and the pitch angle of the innermost segment of the spiral arms to find relationships between these parameters of ...
arxiv +1 more source
Stellar Bars in Isolated Gas-rich Spiral Galaxies Do Not Slow Down
The Astrophysical Journal, 2023 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 is expected ...
Angus Beane +8 more
doaj +1 more source
A Technique for Separating the Gravitational Torques of Bars and Spirals in Disk Galaxies [PDF]
Astron.J. 126 (2003) 1148, 2003 We describe a Fourier-based method of separating bars from spirals in near-infrared images. The method takes advantage of the fact that a bar is typically a feature with a relatively fixed position angle, and uses the simple assumption that the relative Fourier amplitudes due to the bar decline with radius past a maximum in the same or a similar manner
arxiv +1 more source
J0107a: A Barred Spiral Dusty Star-forming Galaxy at z = 2.467
The Astrophysical Journal Letters, 2023 Dusty star-forming galaxies (DSFGs) are among the most massive and active star-forming galaxies during the cosmic noon. Theoretical studies have proposed various formation mechanisms of DSFGs, including major merger-driven starbursts and secular star ...
Shuo Huang +9 more
doaj +1 more source
The shapes of spiral arms in the S$^4$G survey and their connection with stellar bars [PDF]
A&A 631, A94 (2019), 2019 Spiral galaxies are common in the local Universe, but their formation, evolution, and interplay with bars remain poorly understood. We use a sample of 391 nearby galaxies from the S$^4$G survey to characterise the winding angle and amplitude of spiral arms as a function of disc properties, such as bar strength, in all kinds of spirals (grand-design ...
arxiv +1 more source
Diffusion in barred-spiral galaxies
, 2010 We characterize the radial migration of stars in the disk plane by calculating the diffusion coefficient and the diffusion time-scale for a bulge-disk N-body self-consistent system with a marginally-stable Toomre-Q parameter. We find that diffusion is not constant in time, but follows the evolution of the bar, and becomes maximum near the corotation ...
Brunetti, Maura +2 more
openaire +3 more sources
Short-term dynamical evolution of grand-design spirals in barred galaxies [PDF]
, 2015 We investigate the short-term dynamical evolution of stellar grand-design spiral arms in barred spiral galaxies using a three-dimensional (3D) $N$-body/hydrodynamic simulation. Similar to previous numerical simulations of unbarred, multiple-arm spirals, we find that grand-design spiral arms in barred galaxies are not stationary, but rather dynamic ...
arxiv +1 more source
Gravitational bar and spiral arm torques from K_s-band observations and implications for the pattern speeds [PDF]
, 2004 We have obtained deep near-infrared K_s-band William Herschel Telescope observations of a sample of 15 nearby spiral galaxies having a range of Hubble types and apparent bar strengths. The near-infrared light distributions are converted into gravitational potentials, and the maximum relative gravitational torques due to the bars and the spirals are ...
arxiv +1 more source
The Astrophysical Journal, 2023 The dependence of the star formation efficiency (SFE) on galactic structures—especially whether the SFE in the bar region is lower than those in other regions—has recently been debated. We report the SFEs of 18 nearby gas-rich massive star-forming barred
Fumiya Maeda +4 more
doaj +1 more source