Related papers: A Possible Extension of the Scutum-Centaurus Arm i…
The spiral arm tangencies are ideal lines of sight in which to determine the distribution of interstellar gas components in the spiral arms and study the influence of spiral density waves on the interarm gas in the Milky Way. We present a…
We present high-resolution (~ 4") 12CO (J = 1 - 0) mapping observations with high - velocity resolution (~ 2.6 km s^{-1}) toward the disk of flocculent galaxy NGC 5055, using the Nobeyama Millimeter Array in order to study the physical…
The Galactic global magnetic field is thought to play a vital role in shaping Galactic structures such as spiral arms and giant molecular clouds. However, our knowledge of magnetic field structures in the Galactic plane at different…
We use the largest open clusters catalogue in the post-Gaia era to provide the observational view of the Galactic disk. By compiling the physical parameters like age, distance, and kinematic information, we investigate the spatial…
We report measurements of parallaxes and proper motions of ten high-mass star-forming regions in the Sagittarius spiral arm of the Milky Way as part of the BeSSeL Survey with the VLBA. Combining these results with eight others from the…
Striking regularities are found in the northwestern arm of the M31 galaxy. Star complexes located in this arm are all spaced 1.2 kpc apart and have similar sizes of about 0.6 kpc. Within the same arm region Beck et al. (1989) detected a…
The advent of more precise measurements of distance estimates for some objects (bayesian estimates for filaments, trigonometric estimates for masers) permits a better comparison of their relative locations, and a comparison with a most…
The ubiquity of filamentary structure at various scales through out the Galaxy has triggered a renewed interest in their formation, evolution, and role in star formation. The largest filaments can reach up to Galactic scale as part of the…
Some galactic theories of spiral arms predict an offset between different tracers of star formation. Our goal here is to find such an offset between the observed location of radio masers and the location of the arms, using a recent 4-arm…
In spite of much work, the overall spiral structure morphology of the Milky Way remains somewhat uncertain. In the last two decades, accurate distance measurements have provided us with an opportunity to solve this issue. Using the precise…
We consider the problem of determining the geometric parameters of a Galactic spiral arm from its segment by including the distance to the spiral pole, i.e., the distance to the Galactic center ($R_0$). The question about the number of…
An updated catalog of 205 observed tangents to the spiral arms (in Galactic longitudes) since 1980 is presented. This represents an addition of 80 arm tangents in 6 years (since 2016). Most arm tangents are observed at telescopes in the…
We have made an unbiased survey for molecular clouds in the Galactic Warp. This survey, covering an area of 56 square degrees at l = 252 deg to 266 deg and b = -5 deg to -1 deg, has revealed 70 molecular clouds, while only 6 clouds were…
The spiral structure of our Milky Way Galaxy is not yet known. HII regions and giant molecular clouds are the most prominent spiral tracers. We collected the spiral tracer data of our Milky Way from the literature, namely, HII regions and…
In the J, H, and Ks bands survey of the the Galactic Center region over an area of 2deg x 5deg, we have found many dark clouds, among which a distinguished chain of dark clouds can be identified with a quiescent CO cloud. The distances of…
As part of the BeSSeL Survey, we report trigonometric parallaxes and proper motions of molecular maser sources associated with 13 distant high mass star forming regions in the Sagittarius spiral arm of the Milky Way. In particular, we…
To estimate the parameters of the Galactic spiral structure - namely, the pitch angle i and the number of spiral arms,- data on Galactic masers with known trigonometric parallaxes were used. We applied the well-known method based on…
We present trigonometric parallax and proper motion measurements toward 22 GHz water and 6.7 GHz methanol masers in 16 high-mass star-forming regions. These sources are all located in the Scutum spiral arm of the Milky Way. The observations…
We present a new face-on map of dense neutral atomic hydrogen (HI) gas in the outer Galaxy. Our map has been produced from the Leiden/Argentine/Bonn (LAB) HI 21-cm line all-sky survey by finding intensity maxima along every line of sight…
A new model for the luminosity distribution in the inner Milky Way is found, using a non-parametric penalized maximum-likelihood algorithm to deproject a dereddened COBE/DIRBE L-band map of the inner Galaxy. The model is also constrained by…