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200 papers

We use the Stripe 82 proper motion catalogue of Bramich et al. (2008) to study the kinematics of Galactic disk stars in the solar neighborhood. We select samples of dwarf stars with reliable spectra and proper motions. They have cylindrical…

Astrophysics of Galaxies · Physics 2012-02-08 Martin C. Smith , S. Hannah Whiteoak , N. W. Evans

We suggest a new component of the Milky Way that can account for both the optical depth and event durations implied by microlensing searches targeting the Large Magellanic Cloud. This component, which represents less than 4% of the total…

Astrophysics · Physics 2007-05-23 Evalyn Gates , Geza Gyuk

The Gaia map of the Milky Way reveals a pair of triangular features at nearly symmetric locations on opposite sides of the Galactic Center. In this paper we explore the implications of these features assuming they are manifestations of a…

Astrophysics of Galaxies · Physics 2021-06-10 Sankha S. Chakrabarty , Yaqi Han , Anthony H. Gonzalez , Pierre Sikivie

For almost twenty years models of the Galaxy have included a dark halo responsible for supporting a substantial fraction of the local rotation velocity and a flat rotation curve at large distances. Estimates of the local halo density range…

Astrophysics · Physics 2011-09-29 E. Gates , G. Gyuk , M. Turner

Caustic rings of dark matter with $\textit{tricusp}$ cross-section were predicted to lie in the galactic disk. Their radii increase on cosmological time scales at a rate of order $1$ kpc/Gyr. When a caustic ring passes through the orbit of…

Astrophysics of Galaxies · Physics 2018-11-21 Sankha S. Chakrabarty , Pierre Sikivie

Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…

Astrophysics of Galaxies · Physics 2016-10-19 Allison Merritt , Pieter van Dokkum , Roberto Abraham , Jielai Zhang

We present the first and so far the only simulations to follow the fine-grained phase-space structure of galaxy haloes formed from generic LCDM initial conditions. We integrate the geodesic deviation equation in tandem with the N-body…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Mark Vogelsberger , Simon D. M. White

We use the Jaffe model as a global mass distribution for the Galaxy and determine the circular velocity $v_c$ and the Jaffe radius $r_j$ using the satellites of the Galaxy, estimates of the local escape velocity of stars, the constraints…

Astrophysics · Physics 2009-10-28 Christopher S. Kochanek

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…

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

The caustic skeleton is a parameter-free and mathematically rigorous formalism for tracing the hierarchical formation history of the multiscale cosmic web from the singularities in the underlying dark matter flow. In the present study, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-21 Benjamin Hertzsch , Job Feldbrugge , Rien van de Weygaert

We present the result of an unbiased CO survey in Galactic range of 34.75$^{\circ}\leq$l$\leq$ 45.25$^{\circ}$ and -5.25$^{\circ}\leq$b$\leq$ 5.25$^{\circ}$, and velocity range beyond the Outer arm. A total of 168 molecular clouds (MCs) are…

Astrophysics of Galaxies · Physics 2017-06-21 Yan Sun , Yang Su , Shao-Bo Zhang , Ye Xu , Xue-Peng Chen , Ji Yang , Zhi-Bo Jiang , Min Fang

We use extensive gravity-sensitive DDO 51 photometry over 5100 square degrees, combined with SDSS broadband photometry, to select a catalog of $\sim 4,000$ giant stars covering a large fraction of the high Galactic latitude sky and reaching…

Astrophysics of Galaxies · Physics 2016-12-14 Colin T. Slater , David L. Nidever , Jeffrey A. Munn , Eric F. Bell , Steven R. Majewski

Edge Cloud 2 (EC2) is a molecular cloud, about 35 pc in size, with one of the largest galactocentric distances known to exist in the Milky Way. We present observations of a peak CO emission region in the cloud and use these to determine its…

Astrophysics · Physics 2009-11-13 P. M. E. Ruffle , T. J. Millar , H. Roberts , D. A. Lubowich , C. Henkel , J. M. Pasachoff , G. Brammer , .

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

Deep observations of galaxy outskirts reveal faint extended stellar components (ESCs) of streams, shells, and halos, which are ghostly remnants of the tidal disruption of satellite galaxies. We use cosmological galaxy formation simulations…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Chris Power

Caustics are high-density structures that form frequently in collisionless media. Under self-gravity, cold dark matter flows focus onto caustics which are yet to be resolved in numerical simulations and or observed in the real world. If…

Astrophysics · Physics 2008-11-26 Raphael Gavazzi , Roya Mohayaee , Bernard Fort

Stellar mass is the most fundamental property of a galaxy. While it has been robustly measured for millions of external galaxies, it remains poorly constrained for the Milky Way because of the strong selection effect from our inside…

Astrophysics of Galaxies · Physics 2025-08-20 Jianhui Lian , Tao Wang , Qikang Feng , Yang Huang , Helong Guo

We analyze recent observations of the spiral arm width in the Milky Way, as a function of the galactic radius, and we compare this relation with the prediction from the density wave theory. We use the following method: in each spiral arm,…

Astrophysics of Galaxies · Physics 2020-06-11 Jacques P Vallée

Caustic rings of dark matter were predicted to exist in the plane of the Galaxy at radii $a_n \simeq 40 {\rm kpc}/n$ for $n = 1,2,3 ..$. The recently discovered Monoceros Ring of stars is located near the $n=2$ caustic, prompting us to…

Astrophysics · Physics 2008-12-18 Aravind Natarajan , Pierre Sikivie