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Related papers: Triangulum-Andromeda overdensity: a region with a …

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We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…

Astrophysics of Galaxies · Physics 2015-06-22 Amina Helmi , Mary Williams , K. C. Freeman , J. Bland-Hawthorn , G. De Silva

We characterize the kinematic and chemical properties of 589 Galactic Anticenter Substructure Stars (GASS) with K-/M- giants in Integrals-of-Motion space. These stars likely include members of previously identified substructures such as…

Recent studies have presented evidence that the Milky Way global potential may be nonspherical. In this case, the assembling process of the Galaxy may have left long lasting stellar halo kinematic fossils due to the shape of the dark matter…

Astrophysics of Galaxies · Physics 2015-05-27 Armando Rojas-Niño , Luis A. Martínez-Medina , Barbara Pichardo , Octavio Valenzuela

Among the Milky Way satellites discovered in the past three years, Triangulum II has presented the most difficulty in revealing its dynamical status. Kirby et al. (2015a) identified it as the most dark matter-dominated galaxy known, with a…

Astrophysics of Galaxies · Physics 2017-04-04 Evan N. Kirby , Judith G. Cohen , Joshua D. Simon , Puragra Guhathakurta , Anders O. Thygesen , Gina E. Duggan

Galactic Archeology is a powerful tool for investigating the formation and evolution of the Milky Way. We use this technique to study kinematic groups of F- and G-stars in the solar neighbourhood. From correlations between orbital…

Astrophysics of Galaxies · Physics 2012-03-29 E. Stonkutė , G. Tautvaišienė , B. Nordström , R. Ženovienė

The current knowledge of the abundance structure in the Milky Way is reviewed. Special emphasis is put on recent results for stars with kinematics typical of the thin and the thick disks, respectively, and how these results can, apart from…

Astrophysics · Physics 2007-05-23 Sofia Feltzing

An outstanding question is whether the $\alpha$/Fe bimodality exists in disk galaxies other than in the Milky Way. Here we present a bimodality using our state-of-the-art galactic chemical evolution models that can explain various…

Astrophysics of Galaxies · Physics 2023-09-06 Chiaki Kobayashi , Souradeep Bhattacharya , Magda Arnaboldi , Ortwin Gerhard

Using modern published data on velocities and spectroscopic definitions of chemical elements in stellar objects of the Galaxy, we investigated the relationship of chemical composition with the kinematics of different populations. The paper…

Astrophysics of Galaxies · Physics 2020-04-22 V. A. Marsakov , V. V. Koval' , M. L. Gozha

The environmental density of galaxies within the cosmic web constrains their 3D locations in filaments, voids, groups, and clusters. It traces the distribution of baryons and the influence of dark-matter halos on galaxy evolution, and helps…

We present the discovery of an inhomogenous, low-surface brightness, extended disk-like structure around the Andromeda galaxy (M31) based on a large kinematic survey of more than 2800 stars with the Keck/DEIMOS spectrograph. The stellar…

Astrophysics · Physics 2008-11-26 R. Ibata , S. Chapman , A. M. N. Ferguson , G. Lewis , M. Irwin , N. Tanvir

We have compiled a sample of 699 stars from the recent literature with detailed chemical abundance information (spanning -4.2 < [Fe/H] < +0.3), and we compute their space velocities and Galactic orbital parameters. We identify members of…

Astrophysics · Physics 2009-11-13 Ian U. Roederer

Our Galaxy is thought to have undergone an active evolutionary history dominated by star formation, the accretion of cold gas, and, in particular, mergers up to 10 gigayear ago. The stellar halo reveals rich fossil evidence of these…

The Milky Way's stellar disk exhibits a bimodality in the [Fe/H] vs. [$\alpha$/Fe] plane, showing a distinct high-$\alpha$ and low-$\alpha$ sequence whose origin is still under debate. We examine the [Fe/H]-[$\alpha$/Fe] abundance plane in…

Astrophysics of Galaxies · Physics 2020-01-28 Tobias Buck

From correlations between orbital parameters, several new coherent groups of stars were recently identified in the Galactic disc and suggested to correspond to remnants of disrupted satellites. To reconstruct their origin at least three…

Solar and Stellar Astrophysics · Physics 2015-06-18 R. Ženovienė , G. Tautvaišienė , B. Nordström , E. Stonkutė

We present the first high-resolution chemical abundances of seven stars in the recently discovered high-energy stream Typhon. Typhon stars have apocenters >100 kpc, making this the first detailed chemical picture of the Milky Way's very…

Astrophysics of Galaxies · Physics 2022-10-05 Alexander P. Ji , Rohan P. Naidu , Kaley Brauer , Yuan-Sen Ting , Joshua D. Simon

With a luminosity similar to that of Milky Way dwarf spheroidal (dSph) systems like Sextans, but a spatial extent similar to that of ultradiffuse galaxies (UDGs), Andromeda (And) XIX is an unusual satellite of M31. To investigate the origin…

The growing number of Milky Way satellites detected in recent years has introduced a new focus for stellar abundance analysis. Abundances of stars in satellites have been used to probe the nature of these systems and their chemical…

Our Milky Way provides a unique test case for galaxy evolution models, thanks to our privileged position within the Milky Way's disc. This position also complicates comparisons between the Milky Way and external galaxies, due to our…

Context. The presence of [$\alpha$/Fe]-[Fe/H] bi-modality in the Milky Way disc has animated the Galactic archaeology community since more than two decades. Aims. Our goal is to investigate the chemical, temporal, and kinematical structure…