Related papers: A high pitch angle structure in the Sagittarius Ar…
We investigated the high-mass star formation activity in a subregion of the Sagittarius E star-forming complex, centered at (l,b) = (358.69 deg, 0.03 deg), where infrared and radio sources trace a prominent U-shaped structure that has not…
We present the first all-sky view of the Sagittarius (Sgr) dwarf galaxy mapped by M giant star tracers detected in the complete Two Micron All-Sky Survey (2MASS). The main body is fit with a King profile of 30 deg limiting radius, but with…
Recent JWST observations have revealed the prevalence of spiral structures at $z > 1$. Unlike in the local Universe, the origin and the consequence of spirals at this epoch remain unexplored. We use public JWST/NIRCam data from the…
We propose a new, more realistic, description of the perturbed gravitational potential of spiral galaxies, with spiral arms having Gaussian-shaped groove profiles. We investigate the stable stellar orbits in galactic disks, using the new…
We present a comprehensive and precise description of the Sagittarius (Sgr) stellar stream's 3D geometry as traced by its old stellar population. This analysis draws on the sample of ${\sim}44,000$ RR Lyrae (RRab) stars from the Pan-STARRS1…
We report trigonometric parallaxes and proper motions of water masers for 12 massive star forming regions in the Perseus spiral arm of the Milky Way as part of the Bar and Spiral Structure Legacy (BeSSeL) Survey. Combining our results with…
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…
We aim to measure the proper motion along the Sagittarius stream that is the missing piece to determine its full 6D phase space coordinates. We conduct a blind search of over-densities in proper motion from Gaia DR2 in a broad region around…
The Milky Way spiral arm dynamics is studied using the birth place of open clusters. We separately study the nearby spiral arms, and find evidence for multiple spiral sets. In particular, the Sagittarius-Carina arm appears to be a…
We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the…
One of the scenarios for the formation of grand-design spiral arms in disky galaxies involves their interactions with a satellite or another galaxy. Here we consider another possibility, where the perturbation is instead due to the…
Over the last decade it has become clear that there is a decoupling between the old stellar disk and young stellar disk in spiral galaxies. This has led to a scheme for classifying galaxies on the basis of their near-infrared morphology.…
The most complete sample of galactic maser sources and radio stars with trigonometric parallaxes, proper motions and radial velocities measured by the VLBI method has been compiled based on literature data. These sources are associated with…
Spiral arm properties of 46 galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G) were measured at 3.6mu, where extinction is small and the old stars dominate. The sample includes flocculent, multiple arm, and grand design…
Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models of the Galactic structure. More efforts to build dynamical…
We present a detailed study of the internal structure and kinematics of the core of the Sagittarius dwarf spheroidal galaxy (Sgr). Using machine-learning techniques, we have combined the information provided by 3300 RR Lyrae stars, more…
We bring the two color maps for the plane component magnetic field of our Galaxy in coordinates of (R;l) and (DM;l). It was shown that magnetic field has reversals of the direction in neighbor spiral arms, in agreement with known models for…
The solar neighborhood contains disc stars that have recently crossed spiral arms in the Galaxy. We propose that boundaries in local velocity distributions separate stars that have recently crossed or been perturbed by a particular arm from…
We present an analysis of Galactic halo structure and substructure traced by ~500 RR Lyrae stars in the SDSS stripe 82 region. The main result of this study is a 2D map of the Galactic halo that reaches distances of 100 kpc and traces…
We develop a new method for studying the Galactic magnetic field along the spiral arms using pulsar Faraday rotation measures (RMs). Our new technique accounts for the dot-product nature of Faraday rotation and also splits the associated…