HLX-1 may be an SS433 system

Abstract

We show that the hyperluminous source HLX--1 may be a stellar--mass binary system like SS433, but seen along its X--ray beams. The precession of these beams gives the $\sim 1$~yr characteristic timescale of the light curve, while the significant X--ray duty cycle means that the precession angle must be comparable with the beam opening angle, which is of order $1.6^{\circ }$. The X--ray light curve appears to result from geometric collimation and scattering as the beam moves through the line of sight. Encouragingly, the distance $\sim 95$~Mpc suggested for HLX--1 is only a few times larger than the minimum distance at which we can expect to view such a highly--beamed system along its axis. This picture allows a simple interpretation of HLX--1 as the most extreme known member of the ULX population.

accepted for publication in MNRAS

References in corpus (3)

• X-ray Properties of Black-Hole Binaries
• The Nature of SS433 and the Ultraluminous X-ray Sources
• Masses, Beaming and Eddington Ratios in Ultraluminous X-ray Sources

Cited by in corpus (7)

• NuSTAR and XMM-Newton observations of the extreme ultraluminous X-ray source NGC 5907 ULX1: A Vanishing Act
• On the radio properties of the intermediate-mass black hole candidate ESO 243-49 HLX-1
• Implications of the delayed 2013 outburst of the ESO 243-49 HLX-1
• The universal "heartbeat" oscillations in black hole systems accross the mass-scale
• The hyperluminous X-ray source candidate in IC 4320: another HLX bites the dust
• ESO 243-49 HLX-1: scaling of X-ray spectral properties and black hole mass determination
• Detection of Very Low-Frequency Quasi-Periodic Oscillations in the 2015 Outburst of V404 Cygni