Related papers: Two-component outer ring and the Galactic spiral s…
Recent observations have revealed that several cosmic ray (CR) sources themselves exhibit pronounced double power-law features in their radiation spectra. Combined with the phenomenon of two-component structure in the observed CR energy…
Many barred galaxies, including the Large Magellanic Cloud (LMC), display strong lopsidedness and off-centre bars. The dynamical connection between bar-disc misalignments, internal mass asymmetries, and arm morphology is not yet fully…
OB associations are the prime star forming sites in galaxies. However the detailed formation process of such stellar systems still remains a mystery. In this context, identifying the presence of substructures may help tracing the footprints…
We present a dynamical study of the effect of the bar and spiral arms on the simulated orbits of open clusters in the Galaxy. Specifically, this work is devoted to the puzzling presence of high-altitude open clusters in the Galaxy. For this…
The kinematics within the Solar vicinity have revealed interesting features relevant to both stellar and Galactic structures. This study examines three stellar associations in the Upper Scorpius and Ophiuchus regions, along with their…
Planetary rings are not only ubiquitous around the giant planets in the outer Solar System, but have also been discovered around several small distant bodies. In contrast, no rings have been observed around any inner Solar System objects.…
In this paper we study the morphological properties of spiral galaxies, including measurements of spiral arm number and pitch angle. Using Galaxy Zoo 2, a stellar mass-complete sample of 6,222 SDSS spiral galaxies is selected. We use the…
In this paper, we look to analyse the spiral features of grand-design, multiarmed, and flocculent spiral galaxies using deep optical imaging from DESI Legacy Imaging Surveys. We explore the resulting distributions of various characteristics…
The geometry and physics of the spiral structure of the giant Hubble type Sc galaxy NGC 309 is studied. A schematic of two patterns with three arms in each is suggested for the blue spiral. The red and blue patterns form together a grand…
A model of the Galaxy with the outer ring R1R2 can explain the observed distribution of the radial, VR, and azimuthal, VT, velocity components along the Galactocentric distance, R, derived from the Gaia EDR3 data. We selected stars from the…
Over the last decade a series of results have lent support to the hypothesis of the existence of a long thin bar in the Milky Way with a half-length of 4.5 kpc and a position angle of around 45 deg. This is apparently a very different…
We created a three-dimensional distribution map of molecular gas throughout the Milky Way Galaxy using the latest $^{12}$CO($J=$1--0) survey data cube and rotation curve based on the kinematic distance. The radial distribution of the…
While the galactic density wave theory is over 50 years old and well known in science, whether it fits our own Milky Way disk has been difficult to say. Here we show a substructure inside the spiral arms. This substructure is reversing with…
The Sagittarius dwarf spheroidal (Sgr) and a few paculiar Galactic Globular Clusters (GGC) can be considered as building blocks of theGalactic Halo. We present a series of results based on a wide field photometry of the Sgr system and the…
With the discovery of the Sagittarius dwarf spheroidal (Ibata et al. 1994), a galaxy caught in the process of merging with the Milky Way, the hunt for other such accretion events has become a very active field of astrophysical research. The…
In this work we revisit the issue of the rotation speed of the spiral arms and the location of the corotation radius of our Galaxy. This research was performed using homogeneous data set of young open clusters (age < 50 Myr) determined from…
We use Gaia DR2 data to show that the globular cluster NGC5634 is physically associated with an arm of the Sagittarius Stream, the huge system of tidal tails created by the ongoing disruption of the Sagittarius dwarf spheroidal galaxy (Sgr…
We develop diagnostics based on gas kinematics to identify the presence of a bar in an edge-on spiral galaxy and determine its orientation. We use position-velocity diagrams (PVDs) obtained by projecting edge-on two-dimensional…
We present a proper motion survey over about 200 square degrees towards the NGP, based on the material used for the construction of the GSC-II, that we are using to study the vertical structure and kinematics of the Galaxy. In particular,…
We describe simulations of the response of a gaseous disc to an active spiral potential. The potential is derived from an N-body calculation and leads to a multi-armed time-evolving pattern. The gas forms long spiral arms typical of grand…