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We present radio through X-ray results of a bright (10^{40} erg/s in the 0.5 to 8.0 keV band) ultraluminous X-ray source (ULX), CXOU J153434.9+151149, in the starburst, interacting pair of galaxies NGC 5953/5954. Chandra image of this ULX shows that it is elongated. From HST/WFPC2/F606W data we have detected a counterpart of the ULX system with M_{F606W} ~-7.1 pm 0.7 mag. This optical counterpart may be either an O-type supergiant star or a young star cluster. From our Fabry-Perot interferometric observations, we have detected Halpha and [NII](6584 A) diffuse emission, with velocity gradients up to 60 km/s at the astrometric corrected Chandra position of the ULX. Different scenarios have been invoked as to explain the possible nature of CXOU J153434.9+151149. Based on the observed X-ray morphology of the ULX, we determine that the inclination angle to the elongated emission will be ~53 deg. Beaming with this geometry from a stellar-mass black hole system will be inadequate to explain the observed X-ray luminosity of this ULX. Finally, we suggest that mild-beaming from a binary black hole with mass more than 50 solar masses, associated with a young star cluster, is the most favorable scenario that describes the multiwavelength properties of this ULX. Future observations are highly essential to determine the nature of this rare object.
Ultraluminous X-ray Sources (ULXs) provide a unique opportunities to probe the geometry and energetics of super-Eddington accretion. The radiative processes involved in super-Eddington accretion are not well understood, and so studying correlated var
We present a multi-mission X-ray analysis of a bright (peak observed 0.3-10 keV luminosity of ~ 6x10^{40} erg s^{-1}), but relatively highly absorbed ULX in the edge-on spiral galaxy NGC 5907. The ULX is spectrally hard in X-rays (Gamma ~ 1.2-1.7, wh
Some ultraluminous X-ray sources (ULXs) are surrounded by collisionally ionized bubbles, larger and more energetic than supernova remnants: they are evidence of the powerful outflows associated with super-Eddington X-ray sources. We illustrate the mo
Majority of ultraluminous X-ray sources (ULXs) are believed to be super-Eddington objects, providing a nearby prototype for studying an accretion in super-critical regime. In this work, we present the study of time-lag spectra of the ULX NGC 5408 X-1
We report on the discovery of a new, transient ultraluminous X-ray source (ULX) in the galaxy NGC 7090. This new ULX, which we refer to as NGC 7090 ULX3, was discovered via monitoring with $Swift$ during 2019-20, and to date has exhibited a peak lumi