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Related papers: Velocity Variations in the Phoenix-Hermus Star Str…

200 papers

Using cosmological N-body simulations we study the radial velocity distribution in dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis. We determine the properties of ten massive haloes in the simulation…

Astrophysics · Physics 2009-11-10 Radoslaw Wojtak , Ewa L. Lokas , Stefan Gottloeber , Gary A. Mamon

We use Canada-France-Hawaii Telescope Legacy Survey data for 170 deg^2, recalibrated and transformed to the Sloan Digital Sky Survey ugri photometric system, to study the distribution of near-turnoff main-sequence stars in the Galactic halo…

Astrophysics of Galaxies · Physics 2015-05-20 Branimir Sesar , Mario Juric , Zeljko Ivezic

We examine the properties of dark matter halos within a rich galaxy cluster using a high resolution simulation that captures the cosmological context of a cold dark matter universe. The mass and force resolution permit the resolution of 150…

Astrophysics · Physics 2009-10-30 Sebastiano Ghigna , Ben Moore , Fabio Governato , George Lake , Thomas Quinn , Joachim Stadel

We study how the indirect observation of dark matter substructures in the Milky Way, using recent stellar stream studies, translates into constraints for different dark matter models. Particularly, we use the measured number of dark…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-05 María Benito , Juan Carlos Criado , Gert Hütsi , Martti Raidal , Hardi Veermäe

We present a simple model that accurately describes various statistical properties of peculiar velocities of dark matter halos. We pay particular attention to the following two effects; first, the evolution of the halo peculiar velocity…

Astrophysics · Physics 2009-11-07 Takashi Hamana , Issha Kayo , Naoki Yoshida , Yasushi Suto , Y. P. Jing

We use the recently completed one billion particle Via Lactea II LambdaCDM simulation to investigate local properties like density, mean velocity, velocity dispersion, anisotropy, orientation and shape of the velocity dispersion ellipsoid,…

We have analyzed the phase space distribution of a sample of about 900 non--kinematically selected low metallicity stars in the solar vicinity. The stars primarily represent the thick disk and halo populations of the Milky Way. We aim to…

Astrophysics · Physics 2009-11-13 C. Dettbarn , B. Fuchs , C. Flynn , M. Williams

We use ESA/Gaia astrometry together with SEGUE and LAMOST measurements of the GD-1 stellar stream to explore the improvement on the Galactic gravitational potential that these new data provide. Assuming a realistic universal model for the…

Astrophysics of Galaxies · Physics 2019-04-24 Khyati Malhan , Rodrigo A. Ibata

We explore the phase-space structure of nearby halo stars identified kinematically from Gaia DR2 data. We focus on their distribution in velocity and in "integrals of motion" space as well as on their photometric properties. Our sample of…

Astrophysics of Galaxies · Physics 2018-06-27 Helmer H. Koppelman , Amina Helmi , Jovan Veljanoski

The Via Lactea simulation of the dark matter halo of the Milky Way predicts the existence of many thousands of bound subhalos distributed approximately with equal mass per decade of mass. Here we show that: a) a similar steeply rising…

Astrophysics · Physics 2009-11-13 Piero Madau , Juerg Diemand , Michael Kuhlen

In order to test the reliability of determinations of the shapes of galaxies' dark matter halos, we have made such measurements for the Milky Way by two independent methods, which make use of the stellar kinematics in the solar…

Astrophysics · Physics 2017-01-04 R. P. Olling , M. R. Merrifield

Halo stars orbit within the potential of the Milky Way and hence their kinematics can be used to understand the underlying mass distribution. However, the inferred mass distribution depends sensitively upon assumptions made on the density…

Astrophysics of Galaxies · Physics 2015-06-22 Prajwal R. Kafle , Sanjib Sharma , Geraint F. Lewis , Joss Bland-Hawthorn

The C-19 star stream has the abundance characteristics of an unusually metal poor globular cluster but kinematically is uncharacteristically hot and wide for a cluster stream, having a line of sight velocity dispersion of 7 +/- 2 km/s and a…

Turbulence plays a critical role in regulating star formation in molecular clouds and is also observed in simulations of primordial halos that host Population III (Pop III) stars. The relative velocity between baryons and dark matter at the…

We confirm, quantify, and provide a table of the coherent velocity substructure of the Milky Way disk within 2 kpc of the Sun towards the Galactic anticenter, with 0.2 kpc resolution. We use the radial velocities of ~340,000 F-type stars…

Astrophysics of Galaxies · Physics 2017-10-11 Alan N. Pearl , Heidi Jo Newberg , Jeffrey L. Carlin , R. Fiona Smith

RR Lyr stars are ideal massless tracers that can be used to study the total mass and dark matter content of the outer halo of the Milky Way. This is because they are easy to find in the light curve databases of large stellar surveys and…

We explore constraints on the Milky Way dark matter halo oblateness using three stellar streams from globular clusters NGC 3201, M68, and Palomar 5. Previous constraints on the gravitational potential from dynamical equilibrium of stellar…

Astrophysics of Galaxies · Physics 2023-08-08 Carles G. Palau , Jordi Miralda-Escudé

We perform the first self-consistent measurement of the rate of interactions between stellar tidal streams created by disrupting satellites and dark subhalos in a cosmological simulation of a Milky-Way-mass galaxy. Using a retagged version…

Astrophysics of Galaxies · Physics 2016-08-22 Robyn E. Sanderson , Carlos Vera-Ciro , Amina Helmi , Joren Heit

In a serie of three papers, the dynamical interplay between environments and dark matter haloes is investigated, while focussing on the dynamical flows through their virial sphere. Our method relies on both cosmological simulations, to…

Astrophysics · Physics 2008-11-26 Dominique Aubert , Christophe Pichon

Dynamically cold stellar streams are ideal probes of the gravitational field of the Milky Way. This paper re-examines the question of how such streams might be used to test for the presence of "missing satellites" -the many thousands of…

Astrophysics of Galaxies · Physics 2015-05-20 Joo Heon Yoon , Kathryn V. Johnston , David W. Hogg