THE THICKENING OF THE THIN DISK IN THE THIRD GALACTIC QUADRANT

• Published in: The Astronomical journal Vol. 149; no. 1; pp. 1 - 17
• Main Authors: Carraro, Giovanni, Vazquez, Ruben A, Costa, Edgardo, Ahumada, Javier A, Giorgi, Edgar E
• Format: Journal Article
• Language: English
• Published: United States 01.01.2015
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BENDING; Clusters; Constellations; Disks; DISTANCE; EXCEPTIONS; GALAXIES; MILKY WAY; Milky Way Galaxy; Open clusters; PHOTOMETRY; Quadrants; STAR CLUSTERS; SUN
• ISSN: 1538-3881; 0004-6256; 1538-3881
• DOI: 10.1088/0004-6256/149/1/12

In the third Galactic quadrant (180[degrees] [< or =, slant] l [< or =, slant] 270[degrees]) of the Milky Way, the Galactic thin disk exhibits a significant warp-shown both by gas and young stars-bending down a few kiloparsecs below the formal Galactic plane (b = 0[degrees]). This warp shows its maximum at l ~ 240[degrees], in the direction of the Canis Major constellation. In a series of papers, we have traced the detailed structure of this region using open star clusters, putting particular emphasis on the spiral structure of the outer disk. We noted a conspicuous accumulation of young star clusters within 2-3 kpc from the Sun and close to b = 0[degrees], which we interpreted as the continuation of the Local (Orion) arm toward the outer disk. Here, we report on a search for clusters that share the same properties as Haffner 18 and 19, and investigate the possible reasons for such an unexpected occurrence.