Related papers: A Dynamical Model of the Local Group
Masers found in massive star-forming regions can be located precisely in six-dimensional phase space and therefore serve as a tool for studying Milky Way dynamics. The non-random orbital phases at which the masers are found and the…
The peculiar velocity of the Local Group of galaxies manifested in the Cosmic Microwave Background dipole is found to decompose into three dominant components. The three components are clearly separated because they arise on distinct…
Based on accurate measurements of distances to nearby galaxies made with Hubble Space Telescope, we determined the radii of the zero-velocity surface: R_0 = 0.96+-0.03 Mpc for the Local Group and R_0 = 0.89+-0.05 Mpc for the group of…
The kinematical and spatial properties of the metal-rich globular clusters in the Galaxy ([Fe/H] > -0.8) indicates that these objects do not comprise a homogeneous population. Three subsystems are identified. The highest-mass clusters…
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…
Measuring stellar motions at the Milky Way's Galactic center (GC) provides unique insight into the dynamical processes within galactic nuclei. We present proper motion measurements for 23 SiO-maser emitting stars within 45'' of SgrA*,…
We review the recent theoretical and observational developments concerning the interaction of the Large Magellanic Cloud (LMC) with the Milky Way and its neighbourhood. An emerging picture is that the LMC is a fairly massive companion…
The meaning of "linear expansion" is explained. Particularly accurate relative distances are compiled and homogenized a) for 246 SNe Ia and 35 clusters with v<30,000 km/s, and b) for relatively nearby galaxies with 176 TRGB and 30 Cepheid…
NGC 6822 is the closest isolated dwarf irregular galaxy to the Milky Way. Its proximity and stellar mass ($10^8 M_\odot$, large for a dwarf galaxy) allow for a detailed study of its kinematic properties. The red giant branch (RGB) stars at…
The hot gaseous halos of galaxies likely contain a large amount of mass and are an integral part of galaxy formation and evolution. The Milky Way has a 2e6 K halo that is detected in emission and by absorption in the OVII resonance line…
We present a sample of 212 early-type galaxies (ETGs) at redshifts $0.25 < z < 0.75$. We combine deep integral-field spectroscopy from the MUSE-DEEP survey with high-resolution HST imaging to study the structure, kinematics, and stellar…
Star counts, obtained from a 2 x 2 degree area centered on NGC 6822 have revealed an optical image of this galaxy composed of two components: in addition to the well-known HI disk with its young stellar component, there is a spheroidal…
We review our understanding of the kinematics of the LMC and the SMC, and their orbit around the Milky Way. The line-of-sight velocity fields of both the LMC and SMC have been mapped with high accuracy using thousands of discrete traces, as…
JHKs photometry is presented from a 3.5 year survey of the central regions of the irregular galaxy NGC6822. The morphology of the colour-magnitude and colour-colour diagrams is discussed with particular reference to M, S and C-type AGB…
We consider global HI and optical properties of about three hundred nearby galaxies with V$_0 < 500$ km/s. The majority of them have individual photometric distance estimates. The galaxy sample parameters, e.g. their linear diameters, their…
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…
We present a sample of 1148 ab-type RR Lyrae (RRLab) variables identified from Catalina Surveys Data Release 1, combined with SDSS DR8 and LAMOST DR4 spectral data. We firstly use a large sample of 860 Galactic halo RRLab stars and derive…
We measure the escape speed curve of the Milky Way based on the analysis of the velocity distribution of $\sim 2850$ counter-rotating halo stars from the Gaia DR2. The distances were estimated through the StarHorse code, and only stars with…
We present the first detailed assessment of the large-scale rotation of any galaxy based on full three-dimensional velocity measurements. We do this for the LMC by combining our HST average proper motion (PM) measurements for stars in 22…
We consider a sample of 412 galaxies with radial velocities $V_{\rm LG} < 2500$ km s$^{-1}$ situated in the sky region of ${\rm RA}=13^h\hspace{-0.4em}.\,0$ ... $19^h\hspace{-0.4em}.\,0$, ${\rm Dec}=+10^{\circ}$ ... $+40^{\circ}$ between…