Speaker
Elena Ambrosi
(Istituto Nazionale di Astrofisica (INAF))
Description
The Swift satellite, thanks to its fast slew capability, has provided the opportunity to monitor extragalactic X-ray transients with a high cadence. This has been especially crucial in understanding that Ultra-luminous X-ray Sources (ULXs) exhibit long-term variability, the origin of which remains unclear.
In this talk, I will present the analysis of a poorly studied region of the galaxy NGC 4559. By cross-matching Swift/XRT data with Chandra images, we identified that this region contains four ULXs which have different long-term characteristics, in terms of light-curve behaviour in the broad band as well as in the hard and soft energy ranges.
Primary author
Elena Ambrosi
(Istituto Nazionale di Astrofisica (INAF))
