A guided map to the Spiral arms in the galactic disk of the Milky Way

TL;DR

This paper provides a comprehensive overview of the Milky Way's spiral arms, combining observational data and theoretical models to serve as a detailed guide to the galaxy's structure and formation mechanisms.

Contribution

It offers an integrated review of recent observational results and compares them with theoretical predictions, enhancing understanding of galactic spiral arm structure and dynamics.

Findings

Detailed mapping of the Milky Way's spiral arms and their geometry

Comparison of observations with numerical simulations and analytical models

Insights into the role of magnetic fields and dark matter in spiral arm formation

Abstract

An up-to-date overview of the recent history is given, aiming to present a helpful working guide to the literature and at the same time introduce key systems and observational results, starting from the Sun and going towards the Galactic Center and parts of the Zona Galactica Incognita, and beyond. We start by presenting an observational view of the Milky Way's disk plane (cartographic. dynamical, chemical cross-cut, magnetic). This included the four long spiral arms in the disk of the Milky Way (fig.1), their geometry (fig.2), component, velocity (fig.3), their widths and internal layers as well as onion-like ordered offsets (fig.4), the central galactic bars, arm tangents, arm pitch and arm shape, arm origins near the Galactic Center (fig.5), and other possible players in the spiral arms, such as the magnetic field (fig.6) and the dark matter content. After, we present a basic analysis of some theoretical predictions from galactic arm formation: numerical simulations or analytical theories, and observations are checked against predictions from various numerical simulations and analytical (theoretical) models.