Classical Cepheids and the spiral structure of the milky way
Date Issued
2015
Author(s)
Dambis, A. K.
Berdnikov, L. N.
Efremov, Yu. N.
Kniazev, A. Yu.
Rastorguev, A. S.
Glushkova, E. V.
Kravtsov, V. V.
Turner, D. G.
Majaess, D. J.
Sefako, R.
DOI
http://dx.doi.org/10.1134/S1063773715090017
Abstract
We use data on space distribution of the currently most complete sample of Cepheids with reliable distances (565 stars), located within similar to 5 kpc from the Sun, to study the spiral pattern of the Milky Way galaxy. We estimate the pitch angle as 9A degrees-10A degrees; the most accurate estimate, i = 9.5A degrees +/- 0.1A degrees, was obtained assuming the existence of a global four-armed spiral pattern; the solar phase angle in the spiral pattern is chi(aS (TM)) = -121A degrees +/- 3A degrees. Comparing positions of the spiral arms delineated by classical Cepheids and galactic masers, with the age difference of these objects in mind, we estimate the rotation angular speed of the spiral pattern to be Omega (P) = 25.2 +/- 0.5 km s(-1)kpc(-1).


