Predicting Gaia's Parallax Distance to the Cygnus OB2 Association with Eclipsing Binaries
| Autor: | Michael J. Alexander, Carlos A. Vargas Álvarez, Michael J. Lundquist, Daniel C. Kiminki, Henry A. Kobulnicky |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Star formation Interstellar cloud FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies Galaxy Radial velocity Star cluster Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Protostar Cygnus OB2 Stellar evolution Solar and Stellar Astrophysics (astro-ph.SR) |
| DOI: | 10.48550/arxiv.1508.03108 |
| Popis: | The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the "Cygnus X" complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this $\ell\simeq80$ degree sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus~X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg~OB2. We find distances of $1.33\pm0.17$, $1.32\pm0.07$, $1.44\pm0.18$, and $1.32\pm0.13$ kpc toward MT91~372, MT91~696, CPR2002~A36, and Schulte~3 respectively. We adopt a weighted average distance of 1.33$\pm$0.06~kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg~OB2. We also identify Schulte 3C (O9.5V), a 4" visual companion to the 4.75 day binary Schulte~3(A+B), as a previously unrecognized Association member. Comment: 20 pages, 13 figures, accepted to the Astrophysical Journal |
| Databáze: | OpenAIRE |
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