Extended Non-Thermal Emission Possibly Associated with Cyg OB2 #5

Gisela N. Ortiz-Leon(1), Luis F. Rodriguez(1,2), and Mauricio Tapia(3)

1 - Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Campus Morelia; 2 - Astronomy Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia; 3 - Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ensenada

Cyg OB2 #5 is a contact binary system (O6.5-7+O5.5-6) with associated radio continuum emission. Two compact (<=0.3") radio continuum components have been reported previously: the primary one is associated with the contact binary and the secondary one is an arc-like source 0.8" to the NE of the primary. This arc-like source results from the interaction of the winds of the contact binary and a B-type star in the region.In this paper we report the detection of an extended (about 30"), non-thermal component to the NE of the compact components. We propose that this extended emission could be an unresolved background source (i. e. a radio galaxy), extended galactic emission, or non-thermal emission related with relativistic electrons that are produced in the shock between the contact binary and the B-type star and that are carried away to large distances by the wind from the contact binary.

Reference: Revista Mexicana de Astronomia y Astrofisica, in press.
Status: Manuscript has been accepted

Weblink: http://arxiv.org/abs/1111.6486


Email: l.rodriguez@crya.unam.mx