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Related papers: Galactic echoes

200 papers

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 2007-05-23 Amina Helmi , Simon D. M. White

One major problem of current theoretical models of galaxy formation is given by their inability to reproduce the apparently `anti-hierarchical' evolution of galaxy assembly: massive galaxies appear to be in place since $z\sim 3$, while a…

Astrophysics of Galaxies · Physics 2016-06-15 Michaela Hirschmann , Gabriella De Lucia , Fabio Fontanot

In the simplest scenario, disk galaxies form predominantly in halos with high angular momentum and quiet recent assembly history, whereas spheroids are the slowly-rotating remnants of repeated merging events. We explore these assumptions…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-13 Laura V. Sales , Julio F. Navarro , Tom Theuns , Joop Schaye , Simon D. M. White , Carlos S. Frenk , Robert A. Crain , Claudio Dalla Vecchia

We investigate the spatially-resolved morphology of galaxies in the early Universe. We consider a typical redshift z = 6 Lyman Break galaxy, "Althaea" from the SERRA hydrodynamical simulations. We create mock rest-frame ultraviolet,…

Astrophysics of Galaxies · Physics 2020-11-18 A. Zanella , A. Pallottini , A. Ferrara , S. Gallerani , S. Carniani , M. Kohandel , C. Behrens

The perturbation mechanism of the Galactic disk has puzzled us for a long time. The imprints from perturbations provide important diagnostics on the disk formation and evolution. Here we try to constrain when the vertical perturbation took…

Astrophysics of Galaxies · Physics 2018-10-10 Hai-Jun Tian , Chao Liu , Yue Wu , Mao-Sheng Xiang , Yong Zhang

Using data from the Gaia satellite's Radial Velocity Spectrometer Data Release 3 (RVS, DR3), we find a new and robust feature in the phase space distribution of halo stars. It is a prominent ridge at constant energy and with angular…

Astrophysics of Galaxies · Physics 2023-07-21 Adam M. Dillamore , Vasily Belokurov , N. Wyn Evans , Elliot Y. Davies

A fundamental question regarding the evolution of dwarf spheroidal galaxies is the identification of the key physical mechanisms responsible for gas depletion. Here, we focus on the study of stellar feedback in isolated dwarf spheroidal…

Astrophysics of Galaxies · Physics 2024-05-08 Roberto Hazenfratz , Paramita Barai , Gustavo A. Lanfranchi , Anderson Caproni

In this work we present two new $\sim10^9$ particle self-consistent simulations of the merger of a Sagittarius-like dwarf galaxy with a Milky Way-like disc galaxy. One model is a violent merger creating a thick disc, and a…

Disc stars from the Gaia DR3 RVS catalogue are selected to explore the phase spiral as a function of position in the Galaxy. The data reveal a two-armed phase spiral pattern in the local $z-v_z$ plane inside the solar radius, which appears…

Astrophysics of Galaxies · Physics 2023-08-02 Chengdong Li , Arnaud Siebert , Giacomo Monari , Benoit Famaey , Simon Rozier

The vertical phase-space spirals in the Milky Way are clear evidence of disequilibrium. However, they are challenging to study because phase mixing signals evolve under the influence of many different dynamical processes and can be driven…

Gaia recently revealed a two-armed spiral pattern in the vertical phase-space distribution of the inner Galactic disk (guiding radius $R_\textrm{g} \sim 6.2$ kpc), indicating that some non-adiabatic perturbation symmetric about the…

Astrophysics of Galaxies · Physics 2025-10-22 Rimpei Chiba , Neige Frankel , Chris Hamilton

Gaia DR2 has provided an unprecedented wealth of information about the kinematics of stars in the Solar neighbourhood, and has highlighted the degree of features in the Galactic disc. We confront the data with a range of bar and spiral…

Astrophysics of Galaxies · Physics 2019-10-02 Jason A. S. Hunt , Mathew W. Bub , Jo Bovy , J. Ted Mackereth , Wilma H. Trick , Daisuke Kawata

The Milky Way stellar halo contains relics of ancient mergers that tell the story of our Galaxy's formation. Some of them are identified due to their similarity in energy, actions and chemistry, referred to as the "chemodynamical space",…

We develop a linear perturbative formalism to compute the response of an inhomogeneous stellar disk embedded in a non-responsive dark matter halo to perturbations like bars, spiral arms and satellite galaxy encounters. Without self-gravity…

Astrophysics of Galaxies · Physics 2023-07-26 Uddipan Banik , Frank C. van den Bosch , Martin D. Weinberg

We investigate what the proposed ESA astrometric satellite GAIA will reveal by observing the halo of the Milky Way. Specifically, we look for halo streams which are the signatures left by the merging/accretion events experienced by a…

Astrophysics · Physics 2007-05-23 Amina Helmi , HongSheng Zhao , P. Tim de Zeeuw

We examine the tidal disruption of satellite galaxies in a cosmological simulation of the formation of a disk galaxy in the $\Lambda$CDM scenario. We find that the disruption of satellite galaxies in orbits roughly coplanar with the disk…

Astrophysics · Physics 2009-11-07 Amina Helmi , Julio F. Navarro , Andres Meza , Matthias Steinmetz , Vincent R. Eke

We use hydrodynamical simulations to investigate the response of geometrically thin, self-gravitating, singular isothermal disks of gas to imposed rigidly rotating spiral potentials. By minimizing reflection-induced feedback from…

Astrophysics · Physics 2009-11-10 S. Chakrabarti , G. Laughlin , F. H. Shu

Decoding the key dynamical processes that shape the Galactic disk structure is crucial for reconstructing the Milky Way's evolution history. The second Gaia data release unveils a novel wave pattern in the $L_Z-\langle V_R\rangle$ space,…

Astrophysics of Galaxies · Physics 2024-11-19 Chengye Cao , Zhao-Yu Li , Ralph Schönrich , Teresa Antoja

We explore the predictive power of cosmological, hydrodynamical simulations for stellar phase space substructure and velocity correlations with the Auriga simulations and Aurigaia mock-Gaia catalogues. We show that at the solar circle the…

We aim to study the phase spiral in the Milky Way (MW) with Gaia DR3. We used an edge detection algorithm to find the border of the phase spiral, allowing us to robustly quantify its shape at different positions and for different…

Astrophysics of Galaxies · Physics 2023-05-26 T. Antoja , P. Ramos , B. García-Conde , M. Bernet , C. F. P. Laporte , D. Katz