Constraints on accretion in Ultraluminous X-ray Sources from Spitzer IRS observations of NGC 4485/90: Infrared diagnostic diagrams

Gerardo A. Vazquez, Ann E. Hornschemeier, Edward Colbert +3

Constraining the astrophysical nature of Ultra-Luminous X-ray (ULX) sources, which have X-ray luminosities exceeding 10^39 erg/s, has been elusive due to the optical faintness of a…