Very large telescope/X-shooter spectroscopy of the candidate black hole X-ray binary maxi J1659-152 in outburst
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 ti...
| Autores: | , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/416372 |
| Acceso en línea: | http://hdl.handle.net/10261/416372 |
| Access Level: | acceso abierto |
| Palabra clave: | Accretion, accretion disks Binaries: close Black hole physics X-rays: binaries |
| Sumario: | 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. © 2012. The American Astronomical Society. All rights reserved. |
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