BROADBAND ESO/VISIR-SPITZER INFRARED SPECTROSCOPY OF THE OBSCURED SUPERGIANT X-RAY BINARY IGR J16318-4848

Journal Article · Fri Jun 01 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/751/2/150· OSTI ID:22037133

Chaty, S; Rahoui, F ^[1]

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1. AIM (UMR-E 9005 CEA/DSM-CNRS-Universite Paris Diderot) Irfu/Service d'Astrophysique, Centre de Saclay, FR-91191 Gif-sur-Yvette Cedex (France)

A new class of X-ray binaries has recently been discovered by the high-energy observatory INTEGRAL. It is composed of intrinsically obscured supergiant high-mass X-ray binaries, unveiled by means of multi-wavelength X-ray, optical, near- and mid-infrared observations, in particular, photometric and spectroscopic observations using ESO facilities. However, the fundamental questions about these intriguing sources, namely, their formation, evolution, and the nature of their environment, are still unsolved. Among them, IGR J16318-4848, a compact object orbiting around a supergiant B[e] star, seems to be one of the most extraordinary celestial sources of our Galaxy. We present here new ESO/Very Large Telescope (VLT) VISIR mid-infrared (MIR) spectroscopic observations of this source. First, line diagnostics allow us to confirm the presence of absorbing material (dust and cold gas) enshrouding the whole binary system, and to characterize the nature of this material. Second, by fitting broadband near- to mid-infrared spectral energy distribution, including ESO NTT/SofI, VLT/VISIR, and Spitzer data, with a phenomenological model for sgB[e] stars, we show that the star is surrounded by an irradiated rim heated to a temperature of {approx}3800-5500 K, along with a viscous disk component at an inner temperature of {approx}750 K. VISIR data allow us to exclude the spherical geometry for the dust component. This detailed study will allow us in the future to get better constraints on the formation and evolution of such rare and short-living high-mass X-ray binary systems in our Galaxy.

• OSTI ID: 22037133
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 751; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTROSCOPY
ASTROPHYSICS
BINARY STARS
COSMIC DUST
ENERGY SPECTRA
GALAXIES
GAMMA ASTRONOMY
INFRARED SPECTRA
MASS
PHOTON EMISSION
STAR EVOLUTION
STELLAR WINDS
SUPERMASSIVE STARS
TELESCOPES
X RADIATION