Very large telescope/X-shooter spectroscopy of the candidate black hole X-ray binary maxi J1659-152 in outburst

Ramanpreet Kaur, Lex Kaper, Lucas E. Ellerbroek, David M. Russell, Diego Altamirano, Rudy Wijnands, Yi Jung Yang, Paolo D'Avanzo, Antonio De Ugarte Postigo, Hector Flores, Johan P.U. Fynbo, Paolo Goldoni, Christina C. Thöne, Alexander Van Der Horst, Michiel Van Der Klis, Chryssa Kouveliotou, Klaas Wiersema, Erik Kuulkers

Research output: Contribution to journalArticlepeer-review


We present the optical to near-infrared spectrum of MAXI J1659-152 during the onset of its 2010 X-ray outburst. The spectrum was obtained with X-shooter on the ESO Very Large Telescope early in the outburst simultaneous with high-quality observations at both shorter and longer wavelengths. At the time of the observations, the source was in the low-hard state. The X-shooter spectrum includes many broad (∼2000kms-1), double-peaked emission profiles of H, He I, and He II, characteristic signatures of a low-mass X-ray binary during outburst. We detect no spectral signatures of the low-mass companion star. The strength of the diffuse interstellar bands results in a lower limit to the total interstellar extinction of AV ≃ 0.4mag. Using the neutral hydrogen column density obtained from the X-ray spectrum we estimate AV ≃ 1mag. The radial velocity structure of the interstellar Na I D and Ca II H&K lines results in a lower limit to the distance of ∼4± 1kpc, consistent with previous estimates. With this distance and AV, the dereddened spectral energy distribution represents a flat disk spectrum. The two 10 minute X-shooter spectra show significant variability in the red wing of the emission-line profiles, indicating a global change in the density structure of the disk, though on a timescale much shorter than the typical viscous timescale of the disk.

Original languageEnglish (US)
Article numberL23
JournalAstrophysical Journal Letters
Issue number2
StatePublished - Feb 20 2012


  • X-rays: binaries
  • accretion, accretion disks
  • binaries: close
  • black hole physics

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Very large telescope/X-shooter spectroscopy of the candidate black hole X-ray binary maxi J1659-152 in outburst'. Together they form a unique fingerprint.

Cite this