TY - JOUR
T1 - Detection of x-ray elongated emission from an ultraluminous x-ray source in the interacting pair of galaxies NGC 5953/5954
AU - Rosado, Margarita
AU - Ghosh, Kajal K.
AU - Fuentes-Carrera, Isaura
PY - 2008/7/1
Y1 - 2008/7/1
N2 - We present radio through X-ray observations of a bright (>10 40 erg s-1 in the 0.5-8.0 keV band) ultraluminous X-ray source (ULX), CXOU J153434.9+151149, in the starburst, interacting pair of galaxies NGC 5953/5954. A 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 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 Hα and [N II] (6584 ) diffuse emission, with velocity gradients up to 60 km s-1 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 estimate that the inclination between the line of sight to the observer and the direction of a possibly beamed outflow is 53°. 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 M associated with a young star cluster, is the most favorable scenario that describes the multiwavelength properties of this ULX. Future observations are definitely needed to determine the nature of this rare object.
AB - We present radio through X-ray observations of a bright (>10 40 erg s-1 in the 0.5-8.0 keV band) ultraluminous X-ray source (ULX), CXOU J153434.9+151149, in the starburst, interacting pair of galaxies NGC 5953/5954. A 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 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 Hα and [N II] (6584 ) diffuse emission, with velocity gradients up to 60 km s-1 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 estimate that the inclination between the line of sight to the observer and the direction of a possibly beamed outflow is 53°. 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 M associated with a young star cluster, is the most favorable scenario that describes the multiwavelength properties of this ULX. Future observations are definitely needed to determine the nature of this rare object.
KW - Galaxies: individual (NGC 5953, NGC 5954)
KW - Galaxies: interactions
KW - X-rays: galaxies
KW - X-rays: individual (CXOU J153434.9+151149)
UR - http://www.scopus.com/inward/record.url?scp=56449092859&partnerID=8YFLogxK
U2 - 10.1088/0004-6256/136/1/212
DO - 10.1088/0004-6256/136/1/212
M3 - Artículo
SN - 0004-6256
VL - 136
SP - 212
EP - 220
JO - Astronomical Journal
JF - Astronomical Journal
IS - 1
ER -