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We present a framework for dark matter (DM) halo formation based on a kinetic theory of self-gravitating fermions together with a solid connection to thermodynamics. Based on maximum entropy arguments, this approach predicts a most likely…

Astrophysics of Galaxies · Physics 2026-01-09 A. Krut , C. R. Argüelles , P. -H. Chavanis

The cold dark matter halo mass function is much steeper than the galaxy stellar mass function on galactic and subgalactic scales. This difference is usually reconciled by assuming that the galaxy formation efficiency drops sharply with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Ismael Ferrero , Mario G. Abadi , Julio F. Navarro , Laura V. Sales , Sebastian Gurovich

In this paper, we use the outer-galactic HI scale height data as well as the observed rotation curve as constraints to determine the halo density distribution of the Andromeda galaxy (M31). We model the galaxy as a gravitationally-coupled…

Astrophysics · Physics 2009-11-13 Arunima Banerjee , Chanda J. Jog

This work explores dynamical models of the Milky Way (MW) by analyzing a sample of 86,109 K giant stars selected through cross-matching the LAMOST DR8 and Gaia EDR3 surveys. Our earlier torus models in Wang et al. (2017) did not include…

Astrophysics of Galaxies · Physics 2025-05-26 Guang-Chen Sun , Qiao Wang , Shude Mao , Yichao Li , Richard J. Long , Ping-Jie Ding , Yougang Wang , Xin Zhang , Xuelei Chen

Context. Gas within a galaxy is forced to establish pressure balance against gravitational forces. The shape of an unperturbed gaseous disk can be used to constrain dark matter models. Aims. We derive the 3-D HI volume density distribution…

Astrophysics · Physics 2009-11-13 P. M. W. Kalberla , L. Dedes , J. Kerp , U. Haud

We show that the mass of a dark matter halo can be inferred from the dynamical status of its satellite galaxies. Using 9 dark-matter simulations of halos like the Milky Way (MW), we find that the present-day substructures in each halo…

Astrophysics of Galaxies · Physics 2017-12-06 Zhao-Zhou Li , Y. P. Jing , Yong-Zhong Qian , Zhen Yuan , Dong-Hai Zhao

We search for evidence of dark matter in the Milky Way by utilizing the stellar number density distribution and kinematics measured by the Sloan Digital Sky Survey (SDSS) to heliocentric distances exceeding ~10 kpc. We employ the…

We measure the angular correlation function, w(theta), from 0.5 to 30 arcminutes of detected sources in two wide fields of the Herschel Multi-tiered Extragalactic Survey (HerMES). Our measurements are consistent with the expected clustering…

We present the 21-cm rotation curve of the nearby galaxy M33 out to a galactocentric distance of 16 kpc (13 disk scale-lengths). The rotation curve keeps rising out to the last measured point and implies a dark halo mass larger than 5…

Astrophysics · Physics 2009-10-31 Edvige Corbelli , Paolo Salucci

The halo of the Milky-Way circumgalactic gas extends up to the virial radius of the Galaxy, ~250 kpc. The halo properties may be deduced from X-ray spectroscopic observations and from studies of the ram-pressure stripping of satellite dwarf…

Astrophysics of Galaxies · Physics 2017-03-07 Sergey Troitsky

We present a novel, data-driven analysis of Galactic dynamics, using unsupervised machine learning -- in the form of density estimation with normalizing flows -- to learn the underlying phase space distribution of 6 million nearby stars…

Astrophysics of Galaxies · Physics 2025-12-05 Sung Hak Lim , Eric Putney , Matthew R. Buckley , David Shih

The halo stars on highly radial orbits should inevitably pass the center regions of the Milky Way. Under the assumption that the stellar halo is in dynamical equilibrium and axisymmetric, we integrate the orbits of $\sim 10,000$ halo…

Astrophysics of Galaxies · Physics 2022-11-16 Chengqun Yang , Ling Zhu , Behzad Tahmasebzadeh , Xiang-Xiang Xue , Chao Liu

We present the results of a study of the average mass profile around galaxies using weak gravitational lensing. We use 45.5 deg^2 of R_C band imaging data from the Red-Sequence Cluster Survey (RCS) and define a sample of 1.2\times 10^5…

Astrophysics · Physics 2007-05-23 Henk Hoekstra , Howard K. C. Yee , Michael D. Gladders

We perform a series of simulations of a Galactic mass dark matter halo at different resolutions, our largest uses over three billion particles and has a mass resolution of 1000 M_sun. We quantify the structural properties of the inner dark…

We explore the cosmological halo-to-halo scatter of the distribution of mass within dark matter halos utilizing a well-resolved statistical sample of clusters from the cosmological Millennium simulation. We find that at any radius, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Darren S. Reed , Savvas M. Koushiappas , Liang Gao

It has been recently claimed that the confined structure of the debris from the Sagittarius dwarf implies that the dark-matter halo of our Galaxy should be nearly spherical, in strong contrast with predictions from cold dark-matter (CDM)…

Astrophysics · Physics 2009-11-10 Amina Helmi

The shape and orientation of dark matter (DM) halos are sensitive to the micro-physics of the DM particle, yet in many mass models, the symmetry axes of the Milky Way's DM halo are often assumed to be aligned with the symmetry axes of the…

We explore the stellar metallicity distribution function of the Galactic halo based on SDSS ugriz photometry. A set of stellar isochrones is calibrated using observations of several star clusters and validated by comparisons with…

Observations of the lengthy tidal streams produced by the destruction of the Sagittarius dwarf spheroidal (Sgr dSph) are capable of providing strong constraints on the shape of the Galactic gravitational potential. However, previous work,…

Astrophysics of Galaxies · Physics 2015-05-14 David R. Law , Steven R. Majewski , Kathryn V. Johnston

We discuss a sample of over 3000 candidate RR Lyrae stars selected by various methods using Sloan Digital Sky Survey data for about 1000 deg^2 of sky. These stars probe the halo structure out to ~100 kpc from the Galactic center. Their…