Related papers: A Dynamical Model of the Local Group
Observations in the IJKs wave bands covering the central 20'x20' of the Local Group galaxy NGC 6822 have been performed from the William Herschel Telescope in La Palma. They have allowed us to characterize, for the first time in the…
We have determined bulk proper motions (PMs) for 31 LMC GCs from Gaia eDR3 and Hubble Space Telescope data using multiple independent analysis techniques. Combined with literature values for distances, line-of-sight velocities and existing…
We present HST WFPC2 and ground-based images of the low surface brightness dwarf Irr/Sph galaxy KKR~25 in Draco. Its colour-magnitude diagram shows red giant branch stars with the tip at I = 22.32 mag, and the presence of some blue stars.…
We measured the angular rotation and proper motion of the Triangulum Galaxy (M33) with the Very Long Baseline Array by observing two H2O masers on opposite sides of the galaxy. By comparing the angular rotation rate with the inclination and…
Observed mass-to-light ratios (M/L) of metal-rich globular clusters (GCs) disagree with theoretical predictions. This discrepancy is of fundamental importance since stellar population models provide the stellar masses that underpin most of…
We identify nine galaxies with dynamical masses of M_dyn>10^10 M_sol as photometric point sources, but with redshifts between z=0.2 and z=0.6, in the Sloan Digital Sky Survey (SDSS) spectro-photometric database. All nine galaxies have…
The Large Magellanic Cloud is the most massive satellite galaxy of the Milky Way, with an estimated mass exceeding a tenth of the mass of the Milky Way. Just past its closest approach of about 50 kpc, and flying by the Milky Way at an…
We study Milky Way kinematics using a sample of 18.8 million main-sequence stars with r<20 and proper-motion measurements derived from SDSS and POSS astrometry, including ~170,000 stars with radial-velocity measurements from the SDSS…
The trajectories since z=4 of systems of galaxies (`halos') with cz < 8,000 km/s are found through Numerical Action reconstructions. A set of 9,719 halos from a 2MASS group catalog and Cosmicflows-3 catalogs are given attention. Present…
A magnitude limited sample of nearly 9000 early-type galaxies, in the redshift range 0.01 < z < 0.3, was selected from the Sloan Digital Sky Survey using morphological and spectral criteria. The sample was used to study how early-type…
The circular rotation speed of the Milky Way at the solar radius, Theta_o, has been estimated to be 220 km/s by fitting the maximum velocity of HI emission as a function of Galactic longitude. This result is in tension with a recent…
We present central velocity dispersions, masses, mass to light ratios ($M/L$s), and rotation strengths for 25 Galactic globular clusters. We derive radial velocities of 1951 stars in 12 globular clusters from single order spectra taken with…
By evaluating angular momentum directions of open cluster (OC) samples across various Galactocentric radii, we assessed their orbital plane inclinations. Our findings reveal that, without considering the local tilt of the Galactic disk near…
We identify 42 candidate groups lying between 1.8<z<3.0 from a sample of 3502 galaxies with spectroscopic redshifts in the zCOSMOS-deep redshift survey within the same redshift interval. These systems contain three to five spectroscopic…
Cosmologists have often considered the Milky Way as a typical spiral galaxy, and its properties have considerably influenced the current scheme of galaxy formation. Here we compare the general properties of the Milky Way disk and halo with…
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…
We perform a comprehensive determination of the systemic proper motions of 74 dwarf galaxies and dwarf galaxy candidates in the Local Group based on Gaia early data release 3. The outputs of the analysis for each galaxy, including…
We introduce a new methodology to robustly determine the mass profile, as well as the overall distribution, of Local Group satellite galaxies. Specifically we employ a statistical multilevel modelling technique, Bayesian hierarchical…
We use the Gaia data release 1 (DR1) to study the proper motion (PM) fields of the Large and Small Magellanic Clouds (LMC, SMC). This uses the Tycho-Gaia Astrometric Solution (TGAS) PMs for 29 Hipparcos stars in the LMC and 8 in the SMC.…
A ``friends-of-friends'' percolation algorithm has been used to extract a catalogue of dn/n = 80 density enhancements (groups) from the six slices of the Las Campanas Redshift Survey (LCRS). The full catalogue contains 1495 groups and…