TY - JOUR
T1 - Open cluster birth analysis and multiple spiral arm sets in the Milky Way
AU - Naoz, Smadar
AU - Shaviv, Nir J.
PY - 2007/7
Y1 - 2007/7
N2 - The Milky Way spiral arm kinematics is studied using the birth place of open clusters. We separately study the nearby spiral arms, and find evidence for multiple spiral sets. In particular, the Sagittarius-Carina arm appears to be a superposition of two sets. The first has a pattern speed of ΩP,Carina, 1 = 16.5- 1.4 sys+ 1.2 ± 1.1stat km s- 1 kpc- 1, while the second has ΩP,Carina, 2 = 29.8- 1.3 sys+ 0.6 ± 1.3stat km s- 1 kpc- 1. The Perseus arm located at larger galactic radii exhibits only one clear set with ΩP,Perseus = 20.0- 1.2 sys+ 1.7 ± 1.6stat km s- 1 kpc- 1. The Perseus and "slower" Carina arms are most probably part of an m = 4 set. The Orion "armlet" appears to have a pattern speed of ΩP,Orion = 28.9- 1.2 sys+ 1.3 ± 0.8stat km s- 1 kpc- 1. In other words, both the "faster" Carina arm and the Orion arm are nearly corotating with the solar system.
AB - The Milky Way spiral arm kinematics is studied using the birth place of open clusters. We separately study the nearby spiral arms, and find evidence for multiple spiral sets. In particular, the Sagittarius-Carina arm appears to be a superposition of two sets. The first has a pattern speed of ΩP,Carina, 1 = 16.5- 1.4 sys+ 1.2 ± 1.1stat km s- 1 kpc- 1, while the second has ΩP,Carina, 2 = 29.8- 1.3 sys+ 0.6 ± 1.3stat km s- 1 kpc- 1. The Perseus arm located at larger galactic radii exhibits only one clear set with ΩP,Perseus = 20.0- 1.2 sys+ 1.7 ± 1.6stat km s- 1 kpc- 1. The Perseus and "slower" Carina arms are most probably part of an m = 4 set. The Orion "armlet" appears to have a pattern speed of ΩP,Orion = 28.9- 1.2 sys+ 1.3 ± 0.8stat km s- 1 kpc- 1. In other words, both the "faster" Carina arm and the Orion arm are nearly corotating with the solar system.
KW - Galaxy: kinematics
KW - Open clusters and associations:general
UR - http://www.scopus.com/inward/record.url?scp=33847038325&partnerID=8YFLogxK
U2 - 10.1016/j.newast.2006.12.001
DO - 10.1016/j.newast.2006.12.001
M3 - Article
AN - SCOPUS:33847038325
SN - 1384-1076
VL - 12
SP - 410
EP - 421
JO - New Astronomy
JF - New Astronomy
IS - 5
ER -