LS I +61 303: microquasar or not microquasar?

G.E. ROMERO; A.T. OKAZAKI; M. ORELLANA; S.P. OWOCKI

Dublin, Ireland

Workshop; High energy phenomena in relativistic outflows (HEPRO I); 2007

Dublin Institute for Advanced Studies

LS I +61 303 is a puzzling object detected from radio up to very high-energy gamma-rays.  Variability has recently been observed in its high-energy emission.  The object is a binary system, with a compact object and a Be star as primary.  The nature of the secondary and the origin of the gamma-ray emission are not clearly established at present.  Recent VLBA radio data have been used to claim that the system is a Be/neutron star colliding wind binary, instead of amicroquasar.  We review the main views on the nature of LS I +61 303 and present results of 3D SPH simulations that can shed some light on the nature of the system.  Our results support anaccretion powered source, compatible with a microquasar interpretation.