The black hole in NGC 1313 X-2

Abstract

The amount of data available for NGC 1313 X-2 make it a cornerstone for the study of ultraluminous X-ray sources (ULXs). We modelled the optical and X-ray data of this ULX with a binary evolution code that takes into account X-ray irradiation. We restricted the candidate binary system to be either a 50-100 Msun black hole (BH) accreting from a 12-15 Msun main sequence star or a 20 Msun BH with a 12-15 Msun giant donor. If the orbital period of the system is ~6 days, a 20 Msun BH model becomes unlikely and we are left with the only possibility that the compact accretor in NGC1313 X-2 is a massive BH of 50-100 Msun. We briefly discuss these results within the framework of an alternative scenario for the formation of ULXs, in which a portion of them may contain BHs of >~30-40 Msun formed from very massive stars in a low metallicity environment.

4 pages, 2 figures. Accepted for publication in the Astronomische Nachrichten (Astronomical Notes), to appear in the proceedings of the conference "Ultra-Luminous X-ray sources and Middle Weight Black Holes" (Madrid, May 24-26, 2010)

References in corpus (24)

• On The Maximum Mass of Stellar Black Holes
• The Ultraluminous State
• Tip of the Red Giant Branch Distances. II. Zero-Point Calibration
• XMM-Newton observations of the brightest Ultraluminous X-ray sources
• Low metallicity natal environments and black hole masses in Ultraluminous X-ray Sources
• Ultra-luminous X-ray sources and remnants of massive metal-poor stars
• Quasi-Periodic Variability in NGC 5408 X-1
• Low metallicity and ultra-luminous X-ray sources in the Cartwheel galaxy
• A Systematic Study of Variability in a Sample of Ultraluminous X-ray Sources
• Spectral State Transitions of the Ultraluminous X-ray Sources X-1 and X-2 in NGC 1313
• An Optical Study of Stellar and Interstellar Environments of Seven Luminous and Ultraluminous X-Ray Sources
• The ultraluminous X-ray source NGC 1313 X-2 - Its optical counterpart and environment
• Optical emission from massive donors in ULX binary systems
• The linear rms-flux relation in an Ultraluminous X-ray Source
• A survey of the Wolf-Rayet population of the barred, spiral galaxy NGC 1313
• Discovery of mHz X-ray Oscillations in a Transient Ultraluminous X-ray Source in M82
• The long-term evolution of the accreting millisecond X-ray pulsar Swift J1756.9-2508
• Optical studies of the ultraluminous X-ray source NGC1313 X-2
• Discovery of a 115 Day Orbital Period in the Ultraluminous X-ray Source NGC 5408 X-1
• X-ray and optical variability of the ultraluminous X-ray source NGC 1313 X-2
• The Orbital Period of the Ultraluminous X-ray Source in M82
• VLT Observations of the Ultraluminous X-ray Source NGC 1313 X-2
• The black hole in NGC 1313 X-2: constraints on the mass from optical observations
• Interpretation of the 115 Day Periodic Modulation in the X-ray Flux of NGC 5408 X-1