(No) dynamical constraints on the mass of the black hole in two ULXs

Abstract

We present the preliminary results of two Gemini campaigns to constrain the mass of the black hole in an ultraluminous X-ray source (ULX) via optical spectroscopy. Pilot studies of the optical counterparts of a number of ULXs revealed two candidates for further detailed study, based on the presence of a broad He II 4686 Angstrom emission line. A sequence of 10 long-slit spectra were obtained for each object, and the velocity shift of the ULX counterpart measured. Although radial velocity variations are observed, they are not sinusoidal, and no mass function is obtained. However, the broad He II line is highly variable on timescales shorter than a day. If associated with the reprocessing of X-rays in the accretion disc, its breadth implies that the disc must be close to face-on.

5 pages, 4 figures. Accepted for publication in Astronomische Nachrichten, 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 (19)

• Super-critically accreting stellar-mass black holes as ultraluminous X-ray sources
• XMM-Newton observations of the brightest Ultraluminous X-ray sources
• The Nature of SS433 and the Ultraluminous X-ray Sources
• A 15.65 solar mass black hole in an eclipsing binary in the nearby spiral galaxy Messier 33
• X-ray observations of ultraluminous X-ray sources
• Low metallicity natal environments and black hole masses in Ultraluminous X-ray Sources
• On IC 10 X-1, the Most Massive Known Stellar-Mass Black Hole
• The Orbital Period of the Wolf-Rayet Binary IC 10 X-1; Dynamic Evidence that the Compact Object is a Black Hole
• Challenging times: a re-analysis of NGC 5408 X-1
• Evidence for an Intermediate Mass Black Hole in NGC 5408 X-1
• Irradiation models for ULXs and fits to optical data
• Models for the Observable System Parameters of Ultraluminous X-ray Sources
• The long-term evolution of the accreting millisecond X-ray pulsar Swift J1756.9-2508
• New Hubble Space Telescope imaging of the counterparts to six ultraluminous X-ray sources
• X-ray reflection in a sample of X-ray bright Ultraluminous X-ray sources
• Optical Counterparts of Ultra Luminous X-ray Sources
• Ultraluminous X-ray Sources: Bubbles and Optical Counterparts
• The black hole in NGC 1313 X-2: constraints on the mass from optical observations
• The ULX NGC 1313 X-2 : an optical study revealing an interesting behavior

Cited by in corpus (38)

• Ultraluminous X-Ray Sources
• Ultraluminous X-ray Sources in the Chandra and XMM-Newton Era
• Mass Measurements of Stellar and Intermediate Mass Black-Holes
• Puzzling accretion onto a black hole in the ultraluminous X-ray source M101 ULX-1
• The discovery of weak coherent pulsations in the ultraluminous X-ray source NGC 1313 X-2
• Ultraluminous X-ray sources
• Supercritical Accretion Discs in Ultraluminous X-ray Sources and SS 433
• Ultraluminous X-Ray Sources
• Optical emission of the ultraluminous X-ray source NGC 5408 X-1: donor star or irradiated accretion disk?
• Discovery of a red supergiant donor star in SN2010da/NGC 300 ULX-1
• Keck/MOSFIRE spectroscopy of five ULX counterparts
• The X-ray spectral evolution of the ultraluminous X-ray source Holmberg IX X-1
• Near-infrared counterparts of ultraluminous X-ray sources
• Discovery of a red supergiant counterpart to RX~J004722.4-252051, a ULX in NGC 253
• Revisiting the ultraluminous supersoft source in M101: an optically thick outflow model
• SDSS1133: An Unusually Persistent Transient in a Nearby Dwarf Galaxy
• The Lense-Thirring timing-accretion plane for ULXs
• Milliarcsec-scale radio emission of ultraluminous X-ray sources: steady jet emission from an intermediate-mass black hole?
• Irradiated, colour-temperature-corrected accretion discs in ultraluminous X-ray sources
• Roche-lobe overflow systems powered by black holes in young star clusters: the importance of dynamical exchanges
• The Nature of the UV/optical Emission of the Ultraluminous X-Ray Source in Holmberg II
• Uncovering Red and Dusty Ultraluminous X-ray Sources with Spitzer
• NIR Counterparts to ULXs (III): Completing the photometric survey and selected spectroscopic results
• Evolution of the spectral curvature in the ULX Holmberg II X-1
• A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II)
• Scaling of the photon index vs mass accretion rate correlation and estimate of black hole mass in M101 ULX-1
• XMM-Newton Observations of NGC 247: X-ray Population and a Supersoft Ultraluminous X-ray Source
• Searching for the Donor Stars of ULX Pulsars
• Towards a dynamical mass of the ultraluminous X-ray source NGC 5408 X-1
• A Wind-Disk Self-Irradiation Model For Supercritical Accretion
• Dynamical mass constraints on the ultraluminous X-ray Source NGC 1313 X-2
• The Local Environment of Ultraluminous X-ray Sources Viewed by XMM Newton's Optical Monitor
• A New Transient Ultraluminous X-ray Source in NGC 7090
• Searching for the orbital period of the ultraluminous X-ray source NGC 1313 X-2
• A multi-wavelength view of distinct accretion regimes in the pulsating ultraluminous X-ray source NGC 1313 X-2
• Identification of a Helium Donor Star in NGC 247 ULX-1
• The largest bright ULX population in a galaxy: X-ray variability and Luminosity Function in the Cartwheel ring Galaxy
• New Transient ULX Candidate in NGC 4254: Evidence of Circumbinary Disk?