BY: Y. Xu, et all.
https://arxiv.org/pdf/2304.10690.pdf
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 locations of very young objects, for the first time, we propose
that our Galaxy has a multiple-arm morphology that consists of two-arm symmetry (the Perseus and Norma Arms) in the inner parts and that extends to the outer parts, where there are several long,
irregular arms (the Centaurus, Sagittarius, Carina, Outer, and Local Arms).
Figure 4. Density map of the O–B2-type stars and contours of the YOCs, which are over plotted with the MW’s spiral arms (the
black lines) obtained by fitting for the positions of the O–B2-type stars. The red Sun symbol is the position of the Sun. For
the original projected distributions of O–B2 stars and YOCs onto the Galactic disk, please see Figure A1 in Appendix A.
H I emission as a function of LSR radial velocity and Galactic longitude. The colored dots are HMSFR masers with parallax measurements: Norma Arm (orange), Sagittarius Arm (cyan), Carina Arm (green), Local Arm (blue), Perseus Arm (magenta), and Outer Arm (red). The white dots indicate spurs or sources for which the arm assignment is unclear. The H I emission is from the HI4PI survey (HI4PI Collaboration et al. 2016). The subfigure presents a zoomed-in view of the red box, in which the masers are assigned to the Norma Arm (orange crosses) and the Scutum Arm (orange triangles) by R19, respectively, while here they are assigned to the same arm, i.e., the Norma Arm.
Below: The multiple secondary Galaxy Arms suggested to be remnants of former galaxy mergers, by the the Q-FFF Model are only partly visible in the picture 5.see below:
Below see: Large Magellanic Cluster Galaxy Black Hole based irregular GABHs. (probably created by the external GABHs of the Milky Way)
Below: see the small Black Hole network around the Andromeda Galaxy.
