TY - JOUR
T1 - Can the gamma-ray source 3EG J2033+4118 be produced by the stellarsystem Cygnus OB2 No. 5?
AU - Benaglia, P
AU - Romero, GE
AU - Stevens, Ian
AU - Torres, DF
PY - 2001/2/1
Y1 - 2001/2/1
N2 - We discuss the possibility that the stellar system Cyg OB2 No.5 can be a gamma-ray source in the light of recent EGRET and radio data. This system is formed by an O7 Ia + Ofpc/WN9 contact binary. A third star, probably a B0 V star also associated with the system, is located at similar to 1700 AU from the primary. We estimate the expected gamma-ray luminosity from the colliding winds region, the terminal shock of the wind, and the unstable zone at the base of the wind, and conclude that, undervery reasonable assumptions, Cyg OB2 No.5 can generate about a half of the gamma-ray flux detected from the positionally coincident source 3EG J2033+4118. We suggest, then, that other O stars belonging to the association, also placed within the 95% probability EGRET location contour, could contribute to the observed gamma-ray flux.
AB - We discuss the possibility that the stellar system Cyg OB2 No.5 can be a gamma-ray source in the light of recent EGRET and radio data. This system is formed by an O7 Ia + Ofpc/WN9 contact binary. A third star, probably a B0 V star also associated with the system, is located at similar to 1700 AU from the primary. We estimate the expected gamma-ray luminosity from the colliding winds region, the terminal shock of the wind, and the unstable zone at the base of the wind, and conclude that, undervery reasonable assumptions, Cyg OB2 No.5 can generate about a half of the gamma-ray flux detected from the positionally coincident source 3EG J2033+4118. We suggest, then, that other O stars belonging to the association, also placed within the 95% probability EGRET location contour, could contribute to the observed gamma-ray flux.
KW - gamma-rays : observations
KW - stars : early-type
KW - gamma-rays : theory
KW - stars : winds, outflows
U2 - 10.1051/0004-6361:20000261
DO - 10.1051/0004-6361:20000261
M3 - Article
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
VL - 366
SP - 665
EP - 671
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 2
ER -