Spectral variability in Swift and Chandra observations of the ultraluminous source NGC 55 ULX1
Spectral variability in Swift and Chandra observations of the ultraluminous source NGC 55 ULX1
NGC 55 ULX1 is a bright Ultraluminous X-ray source located 1.78 Mpc away. We analysed a sample of 20 Swift observations, taken between 2013 April and August, and two Chandra observations taken in 2001 September and 2004 June. We found only marginal hints of a limited number of dips in …