Outputs (7)

Lense-Thirring precession in ULXs as a possible means to constrain the neutron star equation-of-state (2017)
Journal Article
Middleton, M., Fragile, P., Bachetti, M., Brightman, M., Jiang, Y., Ho, W., …Gehrels, N. (2018). Lense-Thirring precession in ULXs as a possible means to constrain the neutron star equation-of-state. Monthly Notices of the Royal Astronomical Society, 475(1), 154-166. https://doi.org/10.1093/mnras/stx2986

The presence of neutron stars in at least three ultraluminous X-ray sources is now firmly established and offers an unambiguous view of super-critical accretion. All three systems show long-timescale periods (60-80 days) in the X-rays and/or optical,... Read More about Lense-Thirring precession in ULXs as a possible means to constrain the neutron star equation-of-state.

Ultraluminous X-Ray Sources (2017)
Journal Article
Kaaret, P., Feng, H., & Roberts, T. P. (2017). Ultraluminous X-Ray Sources. Annual Review of Astronomy and Astrophysics, 55(1), 303-341. https://doi.org/10.1146/annurev-astro-091916-055259

We review observations of ultraluminous X-ray sources (ULXs). X-ray spectroscopic and timing studies of ULXs suggest a new accretion state distinct from those seen in Galactic stellar-mass black hole binaries. Optical and X-ray line profiles and the... Read More about Ultraluminous X-Ray Sources.

Optical and X-ray luminosity of expanding nebulae around ultraluminous X-ray sources (2017)
Journal Article
Siwek, M., Sadowski, A., Narayan, R., Roberts, T., & Soria, R. (2017). Optical and X-ray luminosity of expanding nebulae around ultraluminous X-ray sources. Monthly Notices of the Royal Astronomical Society, 470(1), 361-371. https://doi.org/10.1093/mnras/stx1185

We have performed a set of simulations of expanding, spherically symmetric nebulae inflated by winds from accreting black holes in ultraluminous X-ray sources (ULXs). We implemented a realistic cooling function to account for free-free and bound-free... Read More about Optical and X-ray luminosity of expanding nebulae around ultraluminous X-ray sources.

A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II) (2017)
Journal Article
López, K., Heida, M., Jonker, P., Torres, M., Roberts, T., Walton, D., …Harrison, F. (2017). A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II). Monthly Notices of the Royal Astronomical Society, 469(1), 671-682. https://doi.org/10.1093/mnras/stx857

We present the results of our continued systematic search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within 10 Mpc. We observed 42 ULXs in 24 nearby galaxies and detected NIR candidate counterparts to 15 ULXs... Read More about A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II).

From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link (2017)
Journal Article
Pinto, C., Alston, W., Soria, R., Middleton, M., Walton, D., Sutton, A., …Roberts, T. (2017). From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link. Monthly Notices of the Royal Astronomical Society, 468(3), 2865-2883. https://doi.org/10.1093/mnras/stx641

In recent work with high-resolution grating spectrometers (RGS) aboard XMM-Newton Pinto et al. (2016) have discovered that two bright and archetypal ultraluminous X-ray sources (ULXs) have strong relativistic winds in agreement with theoretical predi... Read More about From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link.

Crossing the Eddington Limit: Examining Disk Spectra at High Accretion Rates (2017)
Journal Article
Sutton, A., Swartz, D., Roberts, T., Middleton, M., Soria, R., & Done, C. (2017). Crossing the Eddington Limit: Examining Disk Spectra at High Accretion Rates. Astrophysical Journal, 836(1), Article 48. https://doi.org/10.3847/1538-4357/836/1/48

The faintest ultraluminous X-ray sources (ULXs), those with 0.3-10 keV luminosities 1 < L_X/10^39 < 3 erg s^-1, tend to have X-ray spectra that are disk-like but broader than expected for thin accretion disks. These `broadened disk' spectra are thoug... Read More about Crossing the Eddington Limit: Examining Disk Spectra at High Accretion Rates.

Soft Extragalactic X-Ray Binaries at the Eddington Threshold (2017)
Journal Article
Earnshaw, H., & Roberts, T. (2017). Soft Extragalactic X-Ray Binaries at the Eddington Threshold. Monthly Notices of the Royal Astronomical Society, 467(3), 2690-2705. https://doi.org/10.1093/mnras/stx308

The luminosity range at and just below the 1039 erg s−1 cut-off for defining ultraluminous X-ray sources (ULXs) is a little-explored regime. It none-the-less hosts a large number of X-ray sources, and has great potential for improving our understandi... Read More about Soft Extragalactic X-Ray Binaries at the Eddington Threshold.