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Articles de revues sur le sujet « Bar formation, galaxy evolution »

Auteur : Grafiati

Publié le 9 mars 2023

Mis à jour le 31 juillet 2025

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1

Combes, Francoise. "Galaxy Dynamics: Secular Evolution and Accretion." Proceedings of the International Astronomical Union 6, S271 (2010): 119–26. http://dx.doi.org/10.1017/s1743921311017522.

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AbstractRecent results are reviewed on galaxy dynamics, bar evolution, destruction and re-formation, cold gas accretion, gas radial flows and AGN fueling, minor mergers. Some problems of galaxy evolution are discussed in particular, exchange of angular momentum, radial migration through resonant scattering, and consequences on abundance gradients, the frequency of bulgeless galaxies, and the relative role of secular evolution and hierarchical formation.

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Łokas, Ewa L. "An interesting case of the formation and evolution of a barred galaxy in the cosmological context." Astronomy & Astrophysics 642 (October 2020): L12. http://dx.doi.org/10.1051/0004-6361/202039425.

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Elongated, bar-like galaxies without a significant disk component, with little rotation support and no gas, often form as a result of tidal interactions with a galaxy cluster, as was recently demonstrated using the IllustrisTNG-100 simulation. Galaxies that exhibit similar properties are, however, also found to be infalling into the cluster for the first time. We use the same simulation to study in detail the history of such a galaxy over cosmic time in order to determine its origin. The bar appears to be triggered at t = 6.8 Gyr by the combined effect of the last significant merger with a sub

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Combes, Françoise. "Ring and Lens Formation." International Astronomical Union Colloquium 157 (1996): 286–98. http://dx.doi.org/10.1017/s0252921100049927.

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AbstractThe dynamical mechanism to form rings at Lindblad resonances in a barred galaxy is now well-known: due to its dissipative character, the gas is forced in a spiral structure, and experiences torques from the bar potential. Angular momentum is transferred until gas accumulates in the resonant rings. Some problems remain however to account for all observations, such as the very different time-scales for nuclear, inner and outer ring formation, while the three are frequently observed in the same galaxy; the shapes, orientations and thickness of the rings, etc... The adequacy of the present

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Athanassoula, E. "Evolution of Bars in Isolated and in Interacting Disk Galaxies." International Astronomical Union Colloquium 157 (1996): 309–20. http://dx.doi.org/10.1017/s0252921100049940.

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AbstractI use N-body simulations to follow the evolution of bars in both isolated and interacting disk galaxies. The pattern speeds of bars evolving in isolated galaxies decline gradually with time, due to transfer of angular momentum from the bar to other components in the galaxy. Both the form and amount of this decline depend on the model used. The fate of a bar in an interacting disk galaxy depends on the mass, central concentration and orbit of the perturber. The pattern speed, form and amplitude of the bar may change, the bar can become off-centered, or, more drastically, it can disappea

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Géron, Tobias, R. J. Smethurst, Chris Lintott, et al. "The Effects of Bar Strength and Kinematics on Galaxy Evolution: Slow Strong Bars Affect Their Hosts the Most." Astrophysical Journal 973, no. 2 (2024): 129. http://dx.doi.org/10.3847/1538-4357/ad66b7.

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Abstract We study how bar strength and bar kinematics affect star formation in different regions of the bar by creating radial profiles of EW[Hα] and Dn4000 using data from Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory (MaNGA). Bars in galaxies are classified as strong or weak using Galaxy Zoo DESI, and they are classified as fast and slow bars using the Tremaine–Weinberg method on stellar kinematic data from the MaNGA survey. In agreement with previous studies, we find that strong bars in star-forming (SF) galaxies have enhanced star formation in their center

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Neumann, Justus, Francesca Fragkoudi, Isabel Pérez, et al. "Stellar populations across galaxy bars in the MUSE TIMER project." Astronomy & Astrophysics 637 (May 2020): A56. http://dx.doi.org/10.1051/0004-6361/202037604.

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Stellar populations in barred galaxies save an imprint of the influence of the bar on the host galaxy’s evolution. We present a detailed analysis of star formation histories (SFHs) and chemical enrichment of stellar populations in nine nearby barred galaxies from the TIMER project. We used integral field observations with the MUSE instrument to derive unprecedented spatially resolved maps of stellar ages, metallicities, [Mg/Fe] abundances, and SFHs, as well as Hα as a tracer of ongoing star formation. We find a characteristic V-shaped signature in the SFH that is perpendicular to the bar major

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Géron, Tobias, R. J. Smethurst, Hugh Dickinson, et al. "Galaxy Zoo CEERS: Bar Fractions Up to z ∼ 4.0." Astrophysical Journal 987, no. 1 (2025): 74. https://doi.org/10.3847/1538-4357/add7d0.

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Abstract We study the evolution of the bar fraction in disk galaxies between 0.5 < z < 4.0 using multiband colored images from JWST Cosmic Evolution Early Release Science Survey (CEERS). These images were classified by citizen scientists in a new phase of the Galaxy Zoo (GZ) project called GZ CEERS. Citizen scientists were asked whether a strong or weak bar was visible in the host galaxy. After considering multiple corrections for observational biases, we find that the bar fraction decreases with redshift in our volume-limited sample (n = 398); from 2 5 − 4 + 6 % at 0.5 < z < 1.0 t

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López Gómez, Alejandro, Ruslan Gabbasov, and Isaura Luisa Fuentes-Carrera. "Numerical Study of Bar Suppression in Galaxy Models Due to Disc Heating." Galaxies 13, no. 2 (2025): 45. https://doi.org/10.3390/galaxies13020045.

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The process of bar formation, evolution and destruction is still a controversial topic regarding galaxy dynamics. Numerical simulations show that these phenomena strongly depend on physical and numerical parameters. In this work, we study the combined influence of the softening parameter, ϵ and disc mass fraction, md, on the formation and evolution of bars in isolated disc-halo models via N-body simulations with different particle resolutions. Previous studies indicate that the bar strength depends on md as ∝md−1, which is seen as a delay in bar formation. However, the distorsion parameter, η,

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Fraser-McKelvie, Amelia, Alfonso Aragón-Salamanca, Michael Merrifield, et al. "SDSS-IV MaNGA: spatially resolved star formation in barred galaxies." Monthly Notices of the Royal Astronomical Society 495, no. 4 (2020): 4158–69. http://dx.doi.org/10.1093/mnras/staa1416.

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ABSTRACT Bars inhabit the majority of local-Universe disc galaxies and may be important drivers of galaxy evolution through the redistribution of gas and angular momentum within discs. We investigate the star formation and gas properties of bars in galaxies spanning a wide range of masses, environments, and star formation rates using the Mapping Nearby Galaxies at APO galaxy survey. Using a robustly defined sample of 684 barred galaxies, we find that fractional (or scaled) bar length correlates with the host’s offset from the star formation main sequence. Considering the morphology of the Hα e

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Kataria, Sandeep Kumar, and Juntai Shen. "Importance of Initial Condition on Bar Secular Evolution: Role of Halo Angular Momentum Distribution Discontinuity." Astrophysical Journal 970, no. 1 (2024): 45. http://dx.doi.org/10.3847/1538-4357/ad5b58.

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Abstract The dark matter halo properties, for example, mass, spin, and concentration, play a significant role in the formation and evolution of bars in disk galaxies. This study highlights the importance of a new parameter: the dark matter halo angular momentum distribution in the disk’s central region. We experiment with N-body galaxy models having a disk and dark matter similar to Milky Way–type galaxies. In these models, we vary the discontinuity of the angular momentum distribution of the halo (the total spin is the same for all models). Our N-body experiments suggest that bar forms in all

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Fraser-McKelvie, Amelia, Michael Merrifield, Alfonso Aragón-Salamanca, and Karen Masters. "Properties of barred galaxies in the MaNGA galaxy survey." Proceedings of the International Astronomical Union 14, S353 (2019): 226–30. http://dx.doi.org/10.1017/s1743921319008081.

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AbstractWe present the initial results of a census of 684 barred galaxies in the MaNGA galaxy survey. This large sample contains galaxies with a wide range of physical properties, and we attempt to link bar properties to key observables for the whole galaxy. We find the length of the bar, when normalised for galaxy size, is correlated with the distance of the galaxy from the star formation main sequence, with more passive galaxies hosting larger-scale bars. Ionised gas is observed along the bars of low-mass galaxies only, and these galaxies are generally star-forming and host short bars. Highe

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Athanassoula, E. "Boxy/peanut and discy bulges: formation, evolution and properties." Proceedings of the International Astronomical Union 3, S245 (2007): 93–102. http://dx.doi.org/10.1017/s1743921308017389.

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AbstractThe class ‘bulges’ contains objects with very different formation and evolution paths and very different properties. I review two types of ‘bulges’, the boxy/peanut bulges (B/Ps) and the discy bulges. The former are parts of bars seen edge-on, have their origin in vertical instabilities of the disc and are somewhat shorter in extent than bars. Their stellar population is similar to that of the inner part of the disc from which they formed. Discy bulges have a disc-like outline, i.e., seen face-on they are circular or oval and seen edge-on they are thin. Their extent is of the order of

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Weinberg, Martin D. "Investigating the long-term evolution of galaxies: Noise, cuspy halos and bars." Symposium - International Astronomical Union 208 (2003): 215–26. http://dx.doi.org/10.1017/s0074180900207171.

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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 that simulations with large numbers of particles (N ≳ 106) are required to resolve the dynamics. Finally, I will describe some new results which demonstrates that a disk bar can produce cores in a cuspy CDM dark-matter profile within a gigayear. An inner Lindblad-like resonance couples the rotating bar to halo orbits at all radii through the cusp, rapidly fla

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Pérez, I., I. Martínez-Valpuesta, T. Ruiz-Lara, et al. "Observational constraints to boxy/peanut bulge formation time." Monthly Notices of the Royal Astronomical Society: Letters 470, no. 1 (2017): L122—L126. http://dx.doi.org/10.1093/mnrasl/slx087.

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Abstract Boxy/peanut bulges are considered to be part of the same stellar structure as bars and both could be linked through the buckling instability. The Milky Way is our closest example. The goal of this Letter is to determine if the mass assembly of the different components leaves an imprint in their stellar populations allowing the estimation the time of bar formation and its evolution. To this aim, we use integral field spectroscopy to derive the stellar age distributions, SADs, along the bar and disc of NGC 6032. The analysis clearly shows different SADs for the different bar areas. Ther

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Zurita, A., E. Florido, I. Pérez, P. Coelho, and D. A. Gadotti. "Bar effects on ionized gas properties and dust content in galaxy centers." Proceedings of the International Astronomical Union 10, S309 (2014): 356. http://dx.doi.org/10.1017/s1743921314010473.

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AbstractObservations and simulations indicate that bars are important agents to transfer material towards galaxy centers. However, observational studies devoted to investigate the effects of bars in galaxy centers are not yet conclusive. We have used a sample (Coelho & Gadotti 2011) of nearby face–on galaxies with available spectra (SDSS database) to investigate the footprints of bars in galaxy centers by analysing the central ionized gas properties of barred and unbarred galaxies separately. We find statistically significant differences in the Hβ Balmer extinction, star formation rate per

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Rosas-Guevara, Yetli, Silvia Bonoli, Massimo Dotti, et al. "The evolution of the barred galaxy population in the TNG50 simulation." Monthly Notices of the Royal Astronomical Society 512, no. 4 (2022): 5339–57. http://dx.doi.org/10.1093/mnras/stac816.

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ABSTRACT We use the magnetic-hydrodynamical simulation TNG50 to study the evolution of barred massive disc galaxies. Massive spiral galaxies are already present as early as z = 4, and bar formation takes place already at those early times. The bars grow longer and stronger as the host galaxies evolve, with the bar sizes increasing at a pace similar to that of the disc scalelengths. The bar fraction mildly evolves with redshift for galaxies with $M_{*}\ge 10^{10}\rm M_{\odot }$, being greater than $\sim 40{{\ \rm per\ cent}}$ at 0.5 &lt; z &lt; 3 and $\sim 30{{\ \rm per\ cent}}$ at z =

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Norman, C. A., H. Hasan, and J. A. Sellwood. "Bar dissolution and bulge formation." Symposium - International Astronomical Union 171 (1996): 427. http://dx.doi.org/10.1017/s0074180900233457.

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We discuss the general classification of secular evolution in galaxies into terms of stellar dynamics. We present two-dimensional N-body simulations of a disk galaxy in which a central mass concentration is imposed after the formation of a strong bar. We show that the bar dissolves almost completely if the central mass concentration exceeds approximately 5% of the combined disk and bulge mass. This behavior can be understood in terms of previous work on single particle orbits (Hasan & Norman 1990, Hasan et al. 1993); the sustaining orbits aligned with the bar become stochastic as the Inner

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Tawfeek, Amira A., Bernardo Cervantes Sodi, Jacopo Fritz, et al. "Morphology Driven Evolution of Barred Galaxies in OMEGAWINGS Clusters." Astrophysical Journal 940, no. 1 (2022): 1. http://dx.doi.org/10.3847/1538-4357/ac9976.

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Abstract We present a study of barred galaxies in the cluster environment, exploiting a sample of galaxies drawn from the extended WIde-field Nearby Galaxy-cluster Survey (OmegaWINGS) that covers up to the outer regions of 32 local X-ray selected clusters. Barred galaxies are identified through a semiautomatic analysis of ellipticity and position angle profiles. We find, in agreement with previous studies, a strong codependence of the bar fraction with the galaxy stellar mass and morphological type, being maximum for massive late-type galaxies. The fraction of barred galaxies decreases with in

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Semczuk, Marcin, Walter Dehnen, Ralph Schönrich, and E. Athanassoula. "Pattern speed evolution of barred galaxies in TNG50." Astronomy & Astrophysics 692 (December 2024): A159. https://doi.org/10.1051/0004-6361/202451521.

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Context. Galactic bars are found in the majority of disc galaxies. They rotate nearly rigidly with an angular frequency called pattern speed. In idealised simulations, the bar pattern speed generally decreases with time due to dynamical friction exerted by the dark-matter halo, while cold gas can reduce or even reverse this trend. Aims. We want to understand how different galaxy properties affect the evolution of the bar pattern speed in more realistic situations, including ongoing star formation, mass infall, active galactic nucleus (AGN) feedback, and galaxy interactions. Methods. We traced

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Freeman, K. C. "The Evolutionary History of the Milky Way." Symposium - International Astronomical Union 171 (1996): 3–10. http://dx.doi.org/10.1017/s0074180900232087.

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The accretion of small satellite galaxies appears to have been important in the formation of the metal-poor halo of the Galaxy. The disrupting Sgr dwarf galaxy and the recent discovery of a young, metal-poor component of the halo indicate that this is a continuing process. The evolution of the galactic disk, and some consequences of the bar-like nature of the galactic bulge are briefly discussed.

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Lingard, Timothy, Karen L. Masters, Coleman Krawczyk, et al. "Galaxy zoo builder: Morphological dependence of spiral galaxy pitch angle." Monthly Notices of the Royal Astronomical Society 504, no. 3 (2021): 3364–74. http://dx.doi.org/10.1093/mnras/stab1072.

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ABSTRACT Spiral structure is ubiquitous in the Universe, and the pitch angle of arms in spiral galaxies provide an important observable in efforts to discriminate between different mechanisms of spiral arm formation and evolution. In this paper, we present a hierarchical Bayesian approach to galaxy pitch angle determination, using spiral arm data obtained through the Galaxy Builder citizen science project. We present a new approach to deal with the large variations in pitch angle between different arms in a single galaxy, which obtains full posterior distributions on parameters. We make use of

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Nogueira-Cavalcante, J. P., R. Dupke, P. Coelho, et al. "J-PLUS: Impact of bars on quenching timescales in nearby green valley disc galaxies." Astronomy & Astrophysics 630 (September 25, 2019): A88. http://dx.doi.org/10.1051/0004-6361/201935138.

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Context. Between the blue cloud and the red sequence peaks on the galaxy colour–magnitude diagram there is a region sparsely populated by galaxies called the green valley. In a framework where galaxies mostly migrate on the colour–magnitude diagram from star forming to quiescent, the green valley is considered a transitional galaxy stage. The details of the processes that drive galaxies from star-forming to passive systems still remain unknown. Aims. We aim to measure the transitional timescales of nearby galaxies across the green valley, through the analysis of Galaxy Evolution Explorer and J

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Fraser-McKelvie, Amelia, Michael Merrifield, Alfonso Aragón-Salamanca, et al. "SDSS-IV MaNGA: The link between bars and the early cessation of star formation in spiral galaxies." Monthly Notices of the Royal Astronomical Society 499, no. 1 (2020): 1116–25. http://dx.doi.org/10.1093/mnras/staa2866.

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ABSTRACT Bars are common in low-redshift disc galaxies, and hence quantifying their influence on their host is of importance to the field of galaxy evolution. We determine the stellar populations and star formation histories of 245 barred galaxies from the Mapping Nearby Galaxies at APO (MaNGA) galaxy survey, and compare them to a mass- and morphology-matched comparison sample of unbarred galaxies. At fixed stellar mass and morphology, barred galaxies are optically redder than their unbarred counterparts. From stellar population analysis using the full spectral fitting code starlight, we attri

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Fujimoto, Yusuke, Fumiya Maeda, Asao Habe, and Kouji Ohta. "Fast cloud–cloud collisions in a strongly barred galaxy: suppression of massive star formation." Monthly Notices of the Royal Astronomical Society 494, no. 2 (2020): 2131–46. http://dx.doi.org/10.1093/mnras/staa840.

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ABSTRACT Recent galaxy observations show that star formation activity changes depending on galactic environments. In order to understand the diversity of galactic-scale star formation, it is crucial to understand the formation and evolution of giant molecular clouds in an extreme environment. We focus on observational evidence that bars in strongly barred galaxies lack massive stars even though quantities of molecular gas are sufficient to form stars. In this paper, we present a hydrodynamical simulation of a strongly barred galaxy, using a stellar potential which is taken from observational r

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Mundell, C. G., A. Pedlar, D. L. Shone, D. J. Axon, J. Meaburn, and S. W. Unger. "NGC 3227 - An Interacting Barred Spiral with an Active Nucleus." International Astronomical Union Colloquium 157 (1996): 473–75. http://dx.doi.org/10.1017/s0252921100050259.

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Recently, bars have become a favored mechanism for transporting material at larger radii towards the nuclei of active galaxies, with the possibility of inflowing gas (on kiloparsec scales) accumulating in circumnuclear rings, bar-like features or structures reminiscent of spiral arms. In addition, it seems clear that interactions play some role in the triggering and fuelling of nuclear activity, as well as in the formation and evolution of galactic bars. NGC 3227 is a barred Seyfert galaxy which appears to be interacting with the nearby elliptical galaxy NGC 3226. The NGC 3227 system thus appe

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Zee, Woong-Bae G., Sanjaya Paudel, Jun-Sung Moon, and Suk-Jin Yoon. "Unraveling Joint Evolution of Bars, Star Formation, and Active Galactic Nuclei of Disk Galaxies." Astrophysical Journal 949, no. 2 (2023): 91. http://dx.doi.org/10.3847/1538-4357/acc79a.

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Abstract We aim to unravel the interplay between bars, star formation (SF), and active galactic nuclei (AGNs) in barred galaxies. To this end, we utilize the SDSS DR12 to select a sample of nearby (0.02 < z < 0.06) disk galaxies that are suitable for bar examination (M r < −20.12 and inclination ≲53°). We identify 3662 barred galaxies and measure the length and axis ratio of each bar. We invent new bar parameters that mitigate the stellar and bulge mass biases and show, for the first time, that the evolution of non-AGN and AGN-hosting barred galaxies should be tracked using different

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Chantavat, T., S. Yuma, P. Malelohit, and T. Worrakitpoonpon. "Morphological Evolution of Disk Galaxies and Their Concentration, Asymmetry, and Clumpiness (CAS) Properties in Simulations across Toomre’s Q Parameter." Astrophysical Journal 965, no. 1 (2024): 77. http://dx.doi.org/10.3847/1538-4357/ad3218.

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Abstract We investigate the morphological and structural evolution of disk galaxies in simulations for a wide range of Toomre’s Q parameters. In addition to the inspection of conventional bar modes, we compute the concentration, asymmetry, and clumpiness (CAS) parameters to enlarge the understanding of the galaxy evolution. These parameters are widely employed to analyze the light distribution of the observed galaxies, but the adaptation to numerical simulations is not much considered. While the bar formation takes place in a considerable range of Q around 1, barred galaxies originating from Q

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Combes, Françoise. "The role of external gas accretion on galaxy transformations, and evidence of such accretion." Proceedings of the International Astronomical Union 10, H16 (2012): 366. http://dx.doi.org/10.1017/s1743921314011387.

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AbstractContinuously accreting matter from cosmic filaments is one of the main way to assemble mass for galaxies (Keres et al.2005, Dekel et al.2009). This external accretion accelerates secular processes, and maintain star formation, but also bar and spiral formation (Bournaud & Combes 2002), and consequent radial migration. Secular evolution may alleviate the problem of too massive bulge formation in the standard LCDM hierarchical scenario. Inside out formation of galaxies may account for the evolution of the size-mass relation and evolution with redshift. I will show how gas accretion f

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Zana, Tommaso, Pedro R. Capelo, Massimo Dotti, et al. "Barred galaxies in cosmological zoom-in simulations: the importance of feedback." Monthly Notices of the Royal Astronomical Society 488, no. 2 (2019): 1864–77. http://dx.doi.org/10.1093/mnras/stz1834.

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Abstract Bars are a key factor in the long-term evolution of spiral galaxies, in their unique role in redistributing angular momentum and transporting gas and stars on large scales. The Eris-suite simulations are cosmological zoom-in, N-body, smoothed-particle hydrodynamic simulations built to follow the formation and evolution of a Milky-Way-sized galaxy across the build-up of the large-scale structure. Here we analyse and describe the outcome of two particular simulations taken from the Eris suite – ErisBH and Eris2k – which mainly differ in the prescriptions employed for gas cooling, star f

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Athanassoula, E. "Isolated and Interacting Galaxies: Simulations with GRAPE." Symposium - International Astronomical Union 208 (2003): 177–88. http://dx.doi.org/10.1017/s0074180900207134.

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I present N-body simulations of isolated and interacting galaxies, made on GRAPE machines. In particular I discuss the formation and evolution of N-body bars and compare their properties to those of bars in early-type and late-type galactic discs. I argue that the halo can help the bar grow, contrary to previous beliefs, by taking positive angular momentum from it via its resonant stars. I then focus on the interaction and subsequent merging of a barred disc galaxy with a spheroidal satellite. The evolution depends strongly on the mass (density) of the satellite and may lead to its destruction

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Peterken, Thomas, Amelia Fraser-McKelvie, Alfonso Aragón-Salamanca, et al. "Time-slicing spiral galaxies with SDSS-IV MaNGA." Monthly Notices of the Royal Astronomical Society 489, no. 1 (2019): 1338–43. http://dx.doi.org/10.1093/mnras/stz2204.

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ABSTRACT Spectra of galaxies contain a wealth of information about the stellar populations from which they are made. With integral field unit (IFU) surveys, such data can be used to map out stellar population properties across the face of a galaxy, allowing one to go beyond simple radial profiles and study details of non-axisymmetric structure. To-date, however, such studies have been limited by the quality of available data and the power of spectral analysis tools. We now take the next step and study the barred spiral galaxy MCG + 07-28-064 from observations obtained as part of the SDSS-IV Ma

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Łokas, Ewa L. "Anatomy of a buckling galactic bar." Astronomy & Astrophysics 629 (September 2019): A52. http://dx.doi.org/10.1051/0004-6361/201936056.

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Using N-body simulations we study the buckling instability in a galactic bar forming in a Milky Way-like galaxy. The galaxy is initially composed of an axisymmetric, exponential stellar disk embedded in a spherical dark matter halo. The parameters of the model are chosen so that the galaxy is mildly unstable to bar formation and the evolution is followed for 10 Gyr. A strong bar forms slowly over the first few gigayears and buckles after 4.5 Gyr from the start of the simulation becoming much weaker and developing a pronounced boxy/peanut shape. We measure the properties of the bar at the time

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Gadotti, Dimitri A., Adrian Bittner, Jesus Falcón-Barroso, and Jairo Méndez-Abreu. "Kinematical signatures of disc instabilities and secular evolution in the MUSE TIMER Survey." Proceedings of the International Astronomical Union 14, S353 (2019): 135–39. http://dx.doi.org/10.1017/s1743921319008585.

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AbstractThe MUSE TIMER Survey has obtained high signal and high spatial resolution integral-field spectroscopy data of the inner ~ 6×6 kpc of 21 nearby massive disc galaxies. This allows studies of the stellar kinematics of the central regions of massive disc galaxies that are unprecedented in spatial resolution. We confirm previous predictions from numerical and hydrodynamical simulations of the effects of bars and inner bars on stellar and gaseous kinematics, and also identify box/peanuts via kinematical signatures in mildly and moderately inclined galaxies, including a box/peanut in a face-

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Jang, Dajeong, and Woong-Tae Kim. "Effects of the Central Mass Concentration on Bar Formation in Disk Galaxies." Astrophysical Journal 942, no. 2 (2023): 106. http://dx.doi.org/10.3847/1538-4357/aca7bc.

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Abstract While bars are common in disk galaxies, their formation conditions are not well understood. We use N-body simulations to study the formation and evolution of a bar in isolated galaxies consisting of a stellar disk, a classical bulge, and a dark halo. We consider 24 galaxy models that are similar to the Milky Way but differ in the mass and compactness of the classical bulge and halo concentration. We find that the bar formation requires ( Q T , min / 1.2 ) 2 + ( CMC / 0.05 ) 2 ≲ 1 , where Q T , min and CMC refer to the minimum value of the Toomre stability parameter and the central mas

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Ansar, Sioree, and Mousumi Das. "The Stellar Bar–Dark Matter Halo Connection in the TNG50 Simulations." Astrophysical Journal 975, no. 2 (2024): 243. http://dx.doi.org/10.3847/1538-4357/ad7a6b.

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Abstract Stellar bars in disk galaxies grow as stars in near-circular orbits lose angular momentum to their environments, including their dark matter (DM) halo, and transform into elongated bar orbits. This angular momentum exchange during galaxy evolution hints at a connection between bar properties and the DM halo spin λ, the dimensionless form of DM angular momentum. We investigate the connection between halo spin λ and galaxy properties in the presence/absence of stellar bars, using the cosmological magnetohydrodynamic TNG50 simulations at multiple redshifts (0 < z r < 1). We determi

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Staveley-Smith, L. "Michigan 160: a precursor to the LMC?" Symposium - International Astronomical Union 148 (1991): 376–77. http://dx.doi.org/10.1017/s0074180900200910.

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The tidal interaction between the Magellanic Clouds and the Galaxy is an important factor in influencing the physical and dynamical evolution of the Clouds (e.g. the Magellanic Stream) as well as the genesis and evolution of their respective stellar populations. However, how important is the influence of the Galaxy? This is a key question since we know that relatively isolated, magellanic-type galaxies do exist (e.g. NGC 3109 and NGC 4449) and have been just as efficient at star-formation as the LMC. It is possible in fact that the star formation in the clouds is primarily stochastic in nature

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Wozniak, Hervé. "Diffusion of radial action in a galactic disc." Astronomy & Astrophysics 642 (October 2020): A207. http://dx.doi.org/10.1051/0004-6361/202038959.

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Context. The stellar migration of the galactic disc stars has been invoked to explain the dispersion of stellar metallicity observed in the solar neighbourhood. Aims. We seek to identify the dynamical mechanisms underlying stellar migration in an isolated galaxy disc under the influence of a bar. Our approach is to analyse the diffusion of dynamical quantities. Methods. We extend our previous work by exploring Chirikov’s diffusion rate (and derived timescale) of the radial action JR in an idealised N-body simulation of an isolated disc galaxy. We limit our study to the evolution of the disc re

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Fortune-Bashee, Xena, Jiayi 嘉懿 Sun 孙, and Jonathan C. Tan. "The Impact of Shear on Disk Galaxy Star Formation Rates." Astrophysical Journal Letters 977, no. 1 (2024): L6. https://doi.org/10.3847/2041-8213/ad91a3.

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Abstract Determining the physical processes that control galactic-scale star formation rates is essential for an improved understanding of galaxy evolution. The role of orbital shear is currently unclear, with some models expecting reduced star formation rates and efficiencies with increasing shear, e.g., if shear stabilizes gas against gravitational collapse, while others predicting enhanced rates, e.g., if shear-driven collisions between giant molecular clouds trigger star formation. Expanding on the analysis of 16 galaxies by C. Suwannajak et al., we assess the shear dependence of star form

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Najarro, Francisco, J. S. Clark, Marcus Lohr, et al. "Infrared studies of the massive stellar population at the Galactic Center and the inner disk." Proceedings of the International Astronomical Union 18, S361 (2022): 114–15. http://dx.doi.org/10.1017/s1743921322003052.

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AbstractWe present results from our ongoing infrared spectroscopic studies of the massive stellar content at the Center of the Milky Way (GC) and across the obscured Galactic disk. Together with the full characterization of these clusters, we seek to obtain a present day metallicity 2-D map of the inner Galaxy and characterize the influence on the bar in the chemical evolution. We will also constrain the clusters IMFs, infer the presence of possible top-heavy recent star formation histories and test massive star formation channels: clusters vs isolation.

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Gadotti, Dimitri A., Adrian Bittner, Jesús Falcón-Barroso, et al. "Kinematic signatures of nuclear discs and bar-driven secular evolution in nearby galaxies of the MUSE TIMER project." Astronomy & Astrophysics 643 (October 27, 2020): A14. http://dx.doi.org/10.1051/0004-6361/202038448.

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The central regions of disc galaxies hold clues to the processes that dominate their formation and evolution. To exploit this, the TIMER project has obtained high signal-to-noise and spatial resolution integral-field spectroscopy data of the inner few kpc of 21 nearby massive barred galaxies, which allows studies of the stellar kinematics in their central regions with unprecedented spatial resolution. We confirm theoretical predictions of the effects of bars on stellar kinematics and identify box/peanuts through kinematic signatures in mildly and moderately inclined galaxies, finding a lower l

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Cavichia, Oscar, Mercedes Mollá, Roberto D. D. Costa, and Walter J. Maciel. "The star formation rate in the inner Milky Way Galaxy." Proceedings of the International Astronomical Union 8, S292 (2012): 98. http://dx.doi.org/10.1017/s1743921313000586.

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AbstractThe present star formation rate (SFR) in the inner Galaxy is puzzling for the chemical evolution models (CEM). No static CEM is able to reproduce the peak of the SFR in the 4 kpc ring. The main reason is probably a shortage of gas, which could be due to the dynamical effects produced by the galactic bar, not considered by these models. We developed a CEM that includes radial gas flows in order to mimic the effects of the galactic bar in the first 5 kpc of the galactic disk. In this model, the star formation (SF) is a two-step process: first, the diffuse gas forms molecular clouds. Then

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Nuritdinov, S. N., E. R. Gaynullia, and K. T. Mirtodjieva. "1.17. Bulge and bar: a possible way of their formation." Symposium - International Astronomical Union 184 (1998): 49–50. http://dx.doi.org/10.1017/s0074180900083960.

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Some observational data indicate that galaxy subsystems, including their central areas, first of all are the result of their global nonstationary evolution. That is why we earlier built (Nuritdinov 1992) the exact non-linearly pulsing rotating models of disklike and spherical self-gravitating systems. Unlike other authors we want to research the stability problem of nonlinear nonstationary models. In the present report we want to give only those results of the instability studied, which have a direct attitude to the subject under discussion. We put a certain question: what initial conditions h

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Cuomo, V., J. A. L. Aguerri, E. M. Corsini, and V. P. Debattista. "Relations among structural parameters in barred galaxies with a direct measurement of bar pattern speed." Astronomy & Astrophysics 641 (September 2020): A111. http://dx.doi.org/10.1051/0004-6361/202037945.

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We investigate the relations between the properties of bars and their host galaxies in a sample of 77 nearby barred galaxies, spanning a wide range of morphological types and luminosities, with 34 SB0-SBa and 43 SBab-SBc galaxies. The sample includes all the galaxies with reliable direct measurement of their bar pattern speed based on long-slit or integral-field stellar spectroscopy using the Tremaine-Weinberg method. We limited our analysis to the galaxies with a relatively small relative error on the bar pattern speed (≤50%) and that do not host an ultrafast bar. For each galaxy, we collecte

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Ansar, Sioree, Sarah Pearson, Robyn E. Sanderson, et al. "Bar Formation and Destruction in the FIRE-2 Simulations." Astrophysical Journal 978, no. 1 (2024): 37. https://doi.org/10.3847/1538-4357/ad8b45.

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Abstract The physical mechanisms responsible for bar formation and destruction in galaxies remain a subject of debate. While we have gained valuable insight into how bars form and evolve from isolated idealized simulations, in the cosmological domain, galactic bars evolve in complex environments, with mergers and gas accretion events occurring in the presence of the turbulent interstellar medium with multiple star formation episodes, in addition to coupling with their host galaxies’ dark matter halos. We investigate the bar formation in 13 Milky Way–mass galaxies from the Feedback in Realistic

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Weinberg, Martin D. "The Dynamics of the Galactic Bar." International Astronomical Union Colloquium 157 (1996): 516–28. http://dx.doi.org/10.1017/s0252921100050363.

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The dynamics of formation and evolution of structure in barred galaxies is subtle and will require many and detailed observations to discriminate between the alternative hypotheses. Why should someone interested in such problems consider the Milky Way? In terms of data volume, our knowledge of the Milky Way is vast and the availability of detail is its major advantage. In principle, one can study morphological details such as orientations, strengths of asymmetries and kinematics details such as velocity field/pattern speeds using a wide variety of tracers. To illustrate, theorists have not con

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Kumar, Ankit, Mousumi Das, and Sandeep Kumar Kataria. "The effect of dark matter halo shape on bar buckling and boxy/peanut bulges." Monthly Notices of the Royal Astronomical Society 509, no. 1 (2021): 1262–68. http://dx.doi.org/10.1093/mnras/stab3019.

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ABSTRACT It is well established that bars evolve significantly after they form in galaxy discs, often changing shape both in and out of the disc plane. In some cases they may bend or buckle out of the disc plane resulting in the formation of boxy/peanut/x-shape bulges. In this paper we show that the dark matter halo shape affects bar formation and buckling. We have performed N-body simulations of bar buckling in non-spherical dark matter haloes and traced bar evolution for 8 Gyr. We find that bar formation is delayed in oblate haloes, resulting in delayed buckling whereas bars form earlier in

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Li, Zhi, Juntai Shen, Ortwin Gerhard, and Jonathan P. Clarke. "Gas Dynamics in the Galaxy: Total Mass Distribution and the Bar Pattern Speed." Astrophysical Journal 925, no. 1 (2022): 71. http://dx.doi.org/10.3847/1538-4357/ac3823.

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Abstract Gas morphology and kinematics in the Milky Way contain key information for understanding the formation and evolution of our Galaxy. We present hydrodynamical simulations based on realistic barred Milky Way potentials constrained by recent observations. Our model can reproduce most features in the observed longitude–velocity diagram, including the Central Molecular Zone, the Near and Far 3 kpc arms, the Molecular Ring, and the spiral arm tangents. It can also explain the noncircular motions of masers from the recent BeSSeL2 survey. The central gas kinematics are consistent with a mass

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Pfenniger, Daniel. "Delayed formation of bulges by dynamical processes." Symposium - International Astronomical Union 153 (1993): 387–90. http://dx.doi.org/10.1017/s0074180900123721.

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Two mechanisms involving purely dynamical processes can lead to the formation of a bulge after its disc: 1) small bulges (1 – 2 kpc), including box-shaped bulges and mildly triaxial bulges, can result from the formation and destruction of a bar; 2) big bulges (> 2kpc) à la Sombrero can grow following the accretion of small satellites. Fully consistent N-body simulations show that the fraction of galaxy mass accreted in this way needs to be larger than about 5%. Less accretion does not create smaller bulges, but heats the whole disc. These dynamical effects transforming Hubble types from SB

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Fragkoudi, F., R. J. J. Grand, R. Pakmor та ін. "Revisiting the tension between fast bars and the ΛCDM paradigm". Astronomy & Astrophysics 650 (червень 2021): L16. http://dx.doi.org/10.1051/0004-6361/202140320.

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The pattern speed with which galactic bars rotate is intimately linked to the amount of dark matter in the inner regions of their host galaxies. In particular, dark matter haloes act to slow down bars via torques exerted through dynamical friction. Observational studies of barred galaxies tend to find that bars rotate fast, while hydrodynamical cosmological simulations of galaxy formation and evolution in the Lambda cold dark matter (ΛCDM) framework have previously found that bars slow down excessively. This has led to a growing tension between fast bars and the ΛCDM cosmological paradigm. In

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Laurikainen, Eija, Heikki Salo, Ronald Buta, and Johan Knapen. "NIRS0S: Observations of early-type galaxy secular evolution spanning the Sa/S0/disky-E boundaries." Proceedings of the International Astronomical Union 10, H16 (2012): 331. http://dx.doi.org/10.1017/s174392131400595x.

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AbstractNIRS0S (Near-IR S0 galaxy Survey), is a K-band survey of ~ 200 early-type disk galaxies, mainly S0s, 2-3 mag deeper than the 2Micron All Sky Survey. In depth morphological analysis was done, in which multi-component structural decompositions played an important role. Possible implications to internal dynamical galaxy evolution were discussed. S0s were suggested to be former spirals in which star formation has ceased, forming a parallel sequence with spirals (see Fig. 1). If that evolution is faster among the brighter galaxies, the observed magnitude difference between the barred and no

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