A substructure inside spiral arms, and a mirror image across the Galactic Meridian

Abstract

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 respect to the Galactic Meridian (longitude zero), and crosscuts of the arms at negative longitudes appear as mirror images of crosscuts of the arms at positive longitudes. Four lanes are delineated: mid-arm (extended 12CO gas at mid arm, HI atoms), in-between offset by about 100 pc (synchrotron, radio recombination lines), in between offset by about 200 pc (masers, colder dust), and inner edge (hotter dust seen in Mid-IR and Near-IR).

arXiv comment25 pages, 2 figures, 10 tables, 1 appendix, accepted 13 February 2016 by Astrophysical Journal (in press)

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Cited by in corpus (21)

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• The role of spiral arms in Milky Way star formation
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• Microlensing optical depth and event rate in the OGLE-IV Galactic plane fields
• Local Spiral Structure Traced by Red Clump Stars
• Spiral arm kinematics for Milky Way stellar populations
• Meta-analysis from different tracers of the small Local Arm around the Sun - extent, shape, pitch, origin
• The Norma spiral arm: large-scale pitch angle
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• Catalog of spiral arm Tangents (Galactic Longitudes) in the Milky Way, and the Age Gradient based on various arm tangents
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• A New Multi-Tracer Approach to Defining the Spiral arm width in the Milky Way
• Spatial and velocity offsets of Galactic masers from the centers of spiral arms
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• Superposing the Magnetic spiral structure of the Milky Way, on the stellar spiral arms -- Matching the unique galactic magnetic field reversal Zone with two galactic spiral arm Segments
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