Gas and dust in the inner disk of the Herbig Ae star MWC 758

We investigate the origin of the near-infrared emission of the Herbig Ae star MWC 758 on sub-astronomical unit (AU) scales using spectrally dispersed low resolution (R = 35) AMBER/VLTI interferometric observations in the H (1.7 µm) and K (2.2 µm) bands. We find that the K band visibilities and closure phases are consistent with the presence of a dusty disk inner rim located at the dust evaporation distance (0.4 AU) while the bulk of the H band emission arises within 0.1 AU from the central star. Comparing the observational results with theoretical model predictions, we suggest that the H band emission is dominated by an hot gaseous accretion disk.

[1]  The shape of the inner rim in proto-planetary disks , 2005, astro-ph/0503635.

[2]  K. Rice,et al.  Protostars and Planets V , 2005 .

[3]  Large dust grains in the inner region of circumstellar disks , 2006, astro-ph/0601438.

[4]  J. Pollack,et al.  Composition and radiative properties of grains in molecular clouds and accretion disks , 1994 .

[5]  et al,et al.  Disk and wind interaction in the young stellar object MWC 297 spatially resolved with VLTI/AMBER , 2005, astro-ph/0510350.

[6]  E. Tatulli,et al.  AMBER : Instrument description and first astrophysical results Special feature Interferometric data reduction with AMBER / VLTI . Principle , estimators , and illustration , 2007 .

[7]  Hiroyuki Mito,et al.  The IRSA 2MASS all-sky point source catalog , 2008 .

[8]  S. Covino,et al.  Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition -Comments and statistics , 1981 .

[9]  J. A. Eisner,et al.  Water vapour and hydrogen in the terrestrial-planet-forming region of a protoplanetary disk , 2007, Nature.

[10]  R. Millan-Gabet,et al.  Keck Interferometer Observations of Classical and Weak-line T Tauri Stars , 2005 .

[11]  C. Dominik,et al.  Passive Irradiated Circumstellar Disks with an Inner Hole , 2001, astro-ph/0106470.

[12]  J. Najita,et al.  Warm Gas in the Inner Disks around Young Intermediate-Mass Stars , 2006, astro-ph/0612201.

[13]  L. Hillenbrand,et al.  Resolved Inner Disks around Herbig Ae/Be Stars , 2004, astro-ph/0406356.

[14]  L. Testi,et al.  Accretion Rates in Herbig Ae stars , 2006 .

[15]  F. P. Schloerb,et al.  Few Skewed Disks Found in First Closure-Phase Survey of Herbig Ae/Be Stars , 2006, astro-ph/0606052.

[16]  R. L. Akeson,et al.  Spectrally Dispersed K-Band Interferometric Observations of Herbig Ae/Be Sources: Inner Disk Temperature Profiles , 2006, astro-ph/0611447.

[17]  L. Hartmann,et al.  Magnetospheres and Disk Accretion in Herbig Ae/Be Stars , 2004, astro-ph/0409008.