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Related papers: Dark Galactic subhalos and the Gaia snail

200 papers

Data from the Gaia satellite show that the solar neighbourhood of the Milky Way's stellar halo is imprinted with substructure from several accretion events. Evidence of these events is found in "the Shards", stars clustering with high…

Astrophysics of Galaxies · Physics 2020-01-15 Ciaran A. J. O'Hare , N. Wyn Evans , Christopher McCabe , GyuChul Myeong , Vasily Belokurov

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

One of the main challenges facing standard hierarchical structure formation models is that the predicted abundance of galactic subhalos with circular velocities of 10-30 km/s is an order of magnitude higher than the number of satellites…

Astrophysics · Physics 2009-10-31 James S. Bullock , Andrey V. Kravtsov , David H. Weinberg

We analyse the dynamical properties of substructures in a high-resolution dark matter simulation of the formation of a Milky Way-like halo in a $\Lambda$CDM cosmology. Our goal is to shed light on the dynamical peculiarities of the Milky…

Astrophysics · Physics 2008-03-11 Yang-Shyang Li , Amina Helmi

Stellar streams from disrupted globular clusters are dynamically cold structures that are sensitive to perturbations from dark matter subhalos, allowing them in principle to trace the dark matter substructure in the Milky Way. We model,…

Astrophysics of Galaxies · Physics 2026-05-13 Duncan K. Adams , Aditya Parikh , Oren Slone , Rouven Essig , Manoj Kaplinghat , Adrian M. Price-Whelan

Signatures of vertical disequilibrium have been observed across the Milky Way's disk. These signatures manifest locally as unmixed phase-spirals in $z$--$v_z$ space ("snails-in-phase") and globally as nonzero mean $z$ and $v_z$ which wraps…

We discuss the physical mechanism by which pure vertical bending waves in a stellar disc evolve to form phase space spirals similar to those discovered by Antoja et al. ( arXiv:1804.10196) in Gaia Data Release 2. These spirals were found by…

Astrophysics of Galaxies · Physics 2019-01-01 Keir Darling , Lawrence M. Widrow

Context: With the data releases from the astrometric space mission Gaia, the exploration of the structure of the Milky Way has developed in unprecedented detail and unveiled many previously unknown structures in the Galactic disc and halo.…

Astrophysics of Galaxies · Physics 2024-07-08 S. Alinder , P. J. McMillan , T. Bensby

We characterize substructure in the simulated stellar halos of Cooper et al. (2010) which were formed by the disruption of satellite galaxies within the cosmological N-body simulations of galactic halos of the Aquarius Project. These…

Astrophysics of Galaxies · Physics 2015-05-27 Amina Helmi , A. P. Cooper , S. D. M. White , S. Cole , C. S. Frenk , J. F. Navarro

The Milky Way contains several distinct old stellar components that provide a fossil record of its formation. We can understand their spatial distribution and kinematics in a hierarchical formation scenario by associating the proto-galactic…

Astrophysics · Physics 2009-11-11 Ben Moore , Juerg Diemand , Piero Madau , Marcel Zemp , Joachim Stadel , .

We present evidence to support an earlier indication that the Galaxy is embedded in an extended, highly inclined, triaxial halo outlined by the spatial distribution of companion galaxies to the Milky Way. Signatures of this spatial…

Astrophysics · Physics 2009-10-31 F. D. A. Hartwick

The dwarf galaxies orbiting a main galaxy suffer strong tidal forces produced by its dark halo. As a consequence, substructures and tidal tails could appear in the satellites. These structures could give us information about the dark matter…

Astrophysics · Physics 2007-05-23 M. A. Gómez-Flechoso

It is now generally believed that galaxies were built up through gravitational amplification of primordial fluctuations and the subsequent merging of smaller precursor structures. The stars of the structures that assembled to form the Milky…

Astrophysics · Physics 2012-08-27 Amina Helmi , Simon D. M. White , P. Tim de Zeeuw , and HongSheng Zhao

We study the vertical perturbations in the galactic disc of the Milky Way-size high-resolution hydrodynamical cosmological simulation named GARROTXA. We detect phase spirals in the vertical projection $Z- V_{Z}$ of disc's stellar particles…

Astrophysics of Galaxies · Physics 2022-06-24 Begoña García-Conde , Santi Roca-Fàbrega , Teresa Antoja , Pau Ramos , Octavio Valenzuela

Galactic spiral shocks are dominant morphological features and believed to be responsible for substructure formation within spiral arms in disk galaxies. They can also contribute a substantial amount of kinetic energy to the interstellar…

Astrophysics of Galaxies · Physics 2015-05-19 Chang-Goo Kim , Woong-Tae Kim , Eve C. Ostriker

Motivated by a recently found interesting property of the dark halo surface density within a radius, $r_{\rm max}$, giving the maximum circular velocity, $V_{\rm max}$, we investigate it for dark halos of the Milky Way's and Andromeda's…

Astrophysics of Galaxies · Physics 2017-07-26 Kohei Hayashi , Tomoaki Ishiyama , Go Ogiya , Masashi Chiba , Shigeki Inoue , Masao Mori

(Abbreviated) We investigate the dynamical mechanisms responsible for producing tidal tails from dwarf satellites using N-body simulations. We identify two important dynamical co-conspirators: 1) the points where the attractive force of the…

Astrophysics · Physics 2009-11-13 Jun-Hwan Choi , Martin D. Weinberg , Neal Katz

The Gaia mission has triggered major developments in the field of Galactic dynamics in recent years, which we discuss in this review. The structure and kinematics of all Galactic components - disc, bar/bulge and halo - are now mapped in…

Astrophysics of Galaxies · Physics 2025-02-17 Jason A. S. Hunt , Eugene Vasiliev

The planar arrangement of nearly half the satellite galaxies of M31 has been a source of mystery and speculation since it was discovered. With a growing number of other host galaxies showing these satellite galaxy planes, their stability…

Astrophysics of Galaxies · Physics 2017-11-15 Nuwanthika Fernando , Veronica Arias , Geraint F. Lewis , Rodrigo A. Ibata , Chris Power

While recent sky surveys have uncovered large numbers of ever fainter Milky Way satellites, their classification as star clusters, low-luminosity galaxies, or tidal overdensities remains often unclear. Likewise, their contributions to the…

Astrophysics of Galaxies · Physics 2016-08-14 Andreas Koch , Sebastien Lépine , Seyma Çalışkan