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Related papers: Galactic Bar Resonances Inferred from Kinematicall…

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We explore the chemodynamical properties of the Galaxy in the azimuthal velocity $V_\phi$ and metallicity [Fe/H] space using red giant stars from Gaia Data Release 3. The row-normalized $V_\phi$-[Fe/H] maps form a coherent sequence from the…

Astrophysics of Galaxies · Physics 2024-03-28 Xiaojie Liao , Zhaoyu Li , Iulia Simion , Juntai Shen , Robert Grand , Francesca Fragkoudi , Federico Marinacci

We compare distance resolved, absolute proper motions in the Milky Way bar/bulge region to a grid of made-to-measure dynamical models with well defined pattern speeds. The data are obtained by combining the relative VVV Infrared Astrometric…

Astrophysics of Galaxies · Physics 2022-04-29 Jonathan Clarke , Ortwin Gerhard

Theoretical works have shown that off-plane motions of bars can heat stars in the vertical direction during buckling but is not clear how do they affect the rest of components of the Stellar Velocity Ellipsoid (SVE). We study the 2D spatial…

Diffuse interstellar bands (DIBs) are absorption features seen in optical and infrared spectra of stars that are probably caused by large and complex molecules in the ISM. Here we investigate the Galactic distribution and properties of two…

When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the ratio…

Astrophysics of Galaxies · Physics 2021-03-30 Mahmood Roshan , Indranil Banik , Neda Ghafourian , Ingo Thies , Benoit Famaey , Elena Asencio , Pavel Kroupa

We risk reaching false scientific conclusions if we test our physical theories against subsets of the Gaia catalogue without correcting for the biased process by which stars make it into our sample. In this paper we produce selection…

Astrophysics of Galaxies · Physics 2021-11-24 Andrew Everall , Douglas Boubert

There are few warp kinematic models of the Galaxy able to characterise structure and kinematics. These models are necessary to study the lopsidedness of the warp and the twisting of the line-of-nodes of the stellar warp, already seen in gas…

Astrophysics of Galaxies · Physics 2019-07-17 M. Romero-Gómez , C. Mateu , L. Aguilar , F. Figueras , A. Castro-Ginard

We measure the Sun's velocity with respect to the Galactic halo using Gaia Early Data Release 3 (EDR3) observations of stellar streams. Our method relies on the fact that, in low-mass streams, the proper motion of stars should be directed…

Astrophysics of Galaxies · Physics 2020-12-11 Khyati Malhan , Rodrigo A. Ibata , Nicolas F. Martin

Constraints on the Galactic bulge/bar structure and formation history from stellar kinematics and metallicities mainly come from relatively high-latitude fields (|b|>4) where a complex mix of stellar population is seen. We aim here to…

Action-based dynamical modelling, using stars as dynamical tracers, is an excellent diagnostic to estimate the underlying axisymmetric matter distribution of the Milky Way. However, the Milky Way's bar causes non-axisymmetric resonance…

Astrophysics of Galaxies · Physics 2023-06-27 Soumavo Ghosh , Wilma H. Trick , Gregory M. Green

In the present work we have developed a three-dimensional gravitational model of barred galaxies, in order to study orbital and escape dynamics of the stars inside their central barred region. Our gravitational model is composed of four…

Astrophysics of Galaxies · Physics 2021-09-29 Debasish Mondal , Tanuka Chattopadhyay

Stellar bars are a common feature in massive disc galaxies. On a theoretical ground, the response of gas to a bar is generally thought to cause nuclear starbursts and, possibly, AGN activity once the perturbed gas reaches the central…

Astrophysics of Galaxies · Physics 2015-10-28 R. Fanali , M. Dotti , D. Fiacconi , F. Haardt

We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and Gaia EDR3 data. Our inner Galactic sample has more than 26,000 stars within $|X_{\rm Gal}| <5$ kpc, $|Y_{\rm Gal}|…

Isolated barred galaxies evolve by redistributing their angular momentum, which, emitted by material in the inner disc at resonance with the bar, can be absorbed by resonant material in the outer disc, or in the halo. The amount of angular…

Astrophysics · Physics 2009-11-07 E. Athanassoula

We study the regeneration of stellar bars triggered by a tidal interaction, using numerical simulations of either purely stellar or stellar+gas disc galaxies. We find that interactions which are sufficiently strong to regenerate the bar in…

Astrophysics · Physics 2009-11-10 I. Berentzen , E. Athanassoula , C. H. Heller , K. J. Fricke

Galaxy disks in rotation are sometimes the site of radial flows, especially in their gas component. It is important to estimate the outflows, due to AGN or supernovae feedback, or inflows due to bar gravity torques. However, these radial…

Astrophysics of Galaxies · Physics 2026-03-18 E. Salibur , A. Hallé , F. Combes

Context: In our Paper I, by using statistical deconvolution methods, extended kinematics maps of Gaia-DR2 data have been produced in a range of heliocentric distances that are a factor of two to three larger than those analyzed previously…

Astrophysics of Galaxies · Physics 2020-02-12 M. Lopez-Corredoira , F. Garzon , H. -F. Wang , F. Sylos Labini , R. Nagy , Z. Chrobakova , J. Chang , B. Villarroel

Galactic bars are important drivers of galactic evolution, and yet how they impact the interstellar medium and correspondingly star formation, remains unclear. We present simulation results for two barred galaxies with different formation…

Astrophysics of Galaxies · Physics 2021-11-29 Elizabeth J. Iles , Alex R. Pettitt , Takashi Okamoto

Bars are common galactic structures in the local universe that play an important role in the secular evolution of galaxies, including the Milky Way. In particular, the velocity distribution of individual stars in our galaxy is useful to…

Gaia Data Release 3 (Gaia DR3) contains the second release of the combined radial velocities. It is based on the spectra collected during the first 34 months of the nominal mission. The longer time baseline and the improvements of the…