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Related papers: The Splash without a merger

200 papers

The Milky Way stellar disk has both a thin and a thick component. The thin disk is composed mostly of younger stars ($\lesssim$8 Gyr) with a lower abundance of $\alpha$ elements, while the thick disk contains predominantly older stars…

The hierarchical structure formation model predicts that stellar halos should form, at least partly, via mergers. If this was a predominant formation channel for the Milky Way's halo, imprints of this merger history in the form of moving…

Astrophysics of Galaxies · Physics 2017-02-01 Amina Helmi , Jovan Veljanoski , Maarten A. Breddels , Hao Tian , Laura V. Sales

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

Observations of the Milky Way's stellar halo find that it is predominantly comprised of a radially biased population of stars, dubbed the Gaia Sausage--Enceladus, or GSE. These stars are thought to be debris from dwarf galaxy accretion…

Astrophysics of Galaxies · Physics 2026-04-08 Dylan Folsom , Mariangela Lisanti , Lina Necib , Danny Horta , Mark Vogelsberger , Lars Hernquist

Stellar populations and their distribution differ widely across the Galaxy, which is likely to affect planet demographics. Our local neighbourhood is dominated by young, metal-rich stars in the galactic thin disc, while the stellar halo and…

Earth and Planetary Astrophysics · Physics 2024-06-12 C. Boettner , P. Dayal , M. Trebitsch , N. Libeskind , K. Rice , C. Cockell , B. I. Tieleman

We analyse the phase-space structure of simulated thick discs that are the result of a significant merger between a disc galaxy and a satellite. Our main goal is to establish what would be the characteristic imprints of a merger origin for…

Astrophysics of Galaxies · Physics 2015-05-13 Álvaro Villalobos , Amina Helmi

We identify a simulated Milky Way analog in the EAGLE suite of cosmological hydrodynamical simulations. This galaxy not only shares similar global properties as the Milky Way, but was specifically selected because its merger history…

Astrophysics of Galaxies · Physics 2019-09-25 Lucas A. Bignone , Amina Helmi , Patricia B. Tissera

We study the chemical properties of the stellar populations in eight simulations of the formation of Milky-Way mass galaxies in a LCDM Universe. Our simulations include metal-dependent cooling and an explicitly multiphase treatment of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Patricia B. Tissera , Simon D. M. White , Cecilia Scannapieco

We analyse from an observational perspective the formation history and kinematics of a Milky Way-like galaxy from a high-resolution zoom-in cosmological simulation that we compare to those of our Galaxy as seen by Gaia DR2 to better…

Astrophysics of Galaxies · Physics 2021-02-05 M. Giammaria , A. Spagna , M. G. Lattanzi , G. Murante , P. Re Fiorentin , M. Valentini

The present day chemical and dynamical properties of the Milky Way bear the imprint of the Galaxy's formation and evolutionary history. One of the most enduring and critical debates surrounding Galactic evolution is that regarding the…

Astrophysics · Physics 2009-11-07 Chris B. Brook , Daisuke Kawata , Brad K. Gibson , Chris Flynn

The Milky Way is a unique laboratory, where stellar properties can be measured and analyzed in detail. In particular, stars in the older populations encode information on the mechanisms that led to the formation of our Galaxy. In this…

The Milky Way halo was predominantly formed by the merging of numerous progenitor galaxies. However, our knowledge of this process is still incomplete, especially in regard to the total number of mergers, their global dynamical properties…

We study numerical simulations of satellite galaxy disruption in a potential resembling that of the Milky Way. Our goal is to assess whether a merger origin for the stellar halo would leave observable fossil structure in the phase-space…

Astrophysics · Physics 2009-05-11 Amina Helmi , Simon D. M. White

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

In the first billion years after its formation, the Galaxy underwent several mergers with dwarf satellites of various masses. The debris of Gaia-Sausage/Enceladus (GSE), the galaxy responsible for the last significant merger of the Milky…

The stellar populations of the stellar halo and of the thick disk of the Milky Way reveal much about the merging history that our Galaxy, a typical large disk galaxy, has experienced. Our current understanding, described here, implies a…

Astrophysics · Physics 2007-05-23 Rosemary F. G. Wyse

We characterize the Gaia-Enceladus-Sausage kinematic structure recently discovered in the Galactic halo using photometric metallicities from the SkyMapper survey, and kinematics from Gaia radial velocities measurements. By examining the…

Astrophysics of Galaxies · Physics 2020-07-08 Diane K Feuillet , Sofia Feltzing , Christian Sahlholdt , Luca Casagrande

We develop a new method to account for the finite lifetimes of stars and trace individual abundances within a semi-analytic model of galaxy formation. At variance with previous methods, based on the storage of the (binned) past star…

Astrophysics of Galaxies · Physics 2015-06-22 Gabriella De Lucia , Luca Tornatore , Carlos S. Frenk , Amina Helmi , Julio F. Navarro , Simon D. M. White

We employ our Bayesian Machine Learning framework BINGO (Bayesian INference for Galactic archaeOlogy) to obtain high-quality stellar age estimates for 68,360 red giant and red clump stars present in the 17th data release of the Sloan…

It is now known that minor mergers are capable of creating structure in the phase-space distribution of their host galaxy's disc. In order to search for such imprints in the Milky Way, we analyse the SEGUE F/G-dwarf and the Schuster et al.…