Title: Accretion at Eddington rates: the curious case of IGR J17091-3624 and GRS 1915+105   　　  

　　Speaker: Diego Altamirano (Univ. of Southampton) 　　  

　　Time: Thursday, 3:00pm, May 22nd 　　  

　　Location: Lecture Hall, 3rd floor 　　  

　　Abstract: IGR J17091-3624 and GRS 1915+105 are two Galactic black-hole systems which have attracted particular interest in the scientific community as they are the only sources known to show bizarre, high-amplitude, highly-structured X-ray variability. These sources are thought to be of particular importance for our understanding of accretion disk physics, as they have been observed to accrete at Eddington rates for longer periods of time than any other known Galactic system. In this talk I will present results based on RXTE, Swift, INTEGRAL and XMM-Newton observations and review what we have learn so far from the comparison between IGR J17091-3624 and GRS 1915+105. I will argue that current observations indicate that all models requiring near Eddington luminosities for the highly-structured X-ray variability might fail