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Related papers: Proper Motion of the Leo II Dwarf Galaxy Based On …

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The High Resolution Echelle Spectrometer on the Keck I telescope has been used to measure nine radial velocities having a median precision of 2 km/s for seven red giants belonging to the isolated dwarf spheroidal galaxy Andromeda II. We…

Astrophysics · Physics 2009-10-31 Patrick Cote , Mario Mateo , Edward Olszewski , Kem Cook

We present evidence for a ring of stars in the plane of the Milky Way, extending at least from l = 180 deg to l = 227 deg with turnoff magnitude $g \sim 19.5$; the ring could encircle the Galaxy. We infer that the low Galactic latitude…

This article presents a measurement of the proper motion of the Ursa Minor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope in two distinct fields.

Astrophysics · Physics 2009-11-10 S. Piatek , C. Pryor , P. Bristow , E. Olszewski , H. Harris , M. Mateo , D. Minniti , C. Tinney

We investigate whether the subhalos of Lambda-CDM galaxy halos have potentials consistent with the observed properties of Milky Way satellites, particularly those with high-quality photometric and kinematic data: Fornax, Leo I, Sculptor,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Louis E. Strigari , Carlos S. Frenk , Simon D. M. White

We measure proper motions with the Hubble Space Telescope for 16 extreme radial velocity stars, mostly unbound B stars in the Milky Way halo. Twelve of these stars have proper motions statistically consistent with zero, and thus have radial…

Solar and Stellar Astrophysics · Physics 2015-06-23 Warren R. Brown , Jay Anderson , Oleg Y. Gnedin , Howard E. Bond , Margaret J. Geller , Scott J. Kenyon

We have measured the absolute proper motion of the Draco dwarf spheroidal galaxy using Subaru Suprime-Cam images taken at three epochs, with time baselines of 4.4 and 7 years. The magnitude limit of the proper-motion study is i=25, thus…

Astrophysics of Galaxies · Physics 2016-06-15 Dana I. Casetti-Dinescu , Terrence M. Girard

We combine Gaia EDR3 astrometry with accurate photometry and utilize a probabilistic mixture model to measure the systemic proper motion of 52 dwarf spheroidal (dSph) satellite galaxies of the Milky Way (MW). For the 46 dSphs with…

Astrophysics of Galaxies · Physics 2022-12-07 Andrew B. Pace , Denis Erkal , Ting S. Li

We analyze subhalos in the Via Lactea II (VL2) cosmological simulation to look for correlations among their infall times and z = 0 dynamical properties. We find that the present day orbital energy is tightly correlated with the time at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Miguel Rocha , Annika H. G. Peter , James S. Bullock

The goal of this paper is to demonstrate the outstanding quality of the second data release of the Gaia mission and its power for constraining many different aspects of the dynamics of the satellites of the Milky Way. We focus here on…

We use a particle tagging technique to dynamically populate the N-body Via Lactea II high-resolution simulation with stars. The method is calibrated using the observed luminosity function of Milky Way satellites and the concentration of…

Astrophysics of Galaxies · Physics 2015-05-28 Valery Rashkov , Piero Madau , Michael Kuhlen , Jurg Diemand

The measured proper motion of Fornax, expressed in the equatorial coordinate system, is $(\mu_{\alpha},\mu_{\delta})=(47.6\pm 4.6,-36.0\pm 4.1)$ mas century$^{-1}$. This proper motion is a weighted mean of four independent measurements for…

We use simulations of Milky Way-sized dark matter haloes from the Aquarius Project to investigate the orbits of substructure haloes likely, according to a semi-analytic galaxy formation model, to host luminous satellites. These tend to…

Astrophysics of Galaxies · Physics 2015-06-17 Christopher Barber , Else Starkenburg , Julio Navarro , Alan McConnachie , Azadeh Fattahi

In this Letter, we announce the discovery of a new dwarf galaxy, Leo T, in the Local Group. It was found as a stellar overdensity in the Sloan Digital Sky Survey Data Release 5 (SDSS DR5). The color-magnitude diagram of Leo T shows two…

Recent results of microlensing surveys, show that 10-20% of the dark halo mass of the Milky Way consists of compact objects. The masses of these compact objects range from 0.1 to 1 solar mass. New theoretical cooling models for white…

Astrophysics · Physics 2007-05-23 Jelte de Jong , Konrad Kuijken , Mark Neeser

Using SDSS I data, we have analysed the stellar distribution of the Leo II dwarf spheroidal galaxy (distance of 233 kpc) to search for evidence of tidal deformation. The existing SDSS photometric catalogue contains gaps in regions of high…

Astrophysics · Physics 2009-06-23 Matthew G. Coleman , Katrin Jordi , Hans-Walter Rix , Eva K. Grebel , Andreas Koch

We have performed a search for halo white dwarfs as high proper motion objects in a second epoch WFPC2 image of the Groth-Westphal strip. We identify 24 high proper motion objects with mu > 0.014 ''/yr. Five of these high proper motion…

Astrophysics · Physics 2009-11-07 Cailin A. Nelson , Kem H. Cook , Tim S. Axelrod , Jeremy R. Mould , Charles Alcock

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 photometry data base of the second phase of the OGLE microlensing experiment, OGLE-II, is a rich source of information about the kinematics and structure of the Galaxy. In this work we use the OGLE-II proper motion catalogue to identify…

Astrophysics · Physics 2009-11-13 Nicholas J. Rattenbury , Shude Mao

We report the discovery of two ultra-faint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way. Using Hubble Space Telescope imaging of the resolved stars, we create color-magnitude diagrams reaching the old main…