2007/11/30 by Stefan Kraus, T. Preibisch, Thomas Preibisch +2 · 2 citations
Chemistry · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Atmospheric radiative transfer codes #Circumstellar dust #Debris disk #Infrared #Interferometry #K band #Optics #Physics #Planetary system #Radiative transfer #Scale height #Spectral energy distribution #Spectroscopy and Laser Applications #Stars #Stellar, planetary, and galactic studies #Sublimation (psychology) #Wavelength #astro-ph
paper · pdf · doi:10.1086/527427
44 pages, 15 figures, accepted for publication in The Astrophysical Journal. The quality of the figures was slightly reduced in order to comply with the astro-ph file-size restrictions. You can find a high-quality version of the paper at http://www.mpifr-bonn.mpg.de/staff/skraus/papers/mwc147.pdf
arxiv created 2007/11/30 · openalex publication_date 2008/03/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the geometry and the physical conditions in the inner (AU-scale) circumstellar region around the young Herbig Be star MWC 147 using long-baseline spectrointerferometry in the near-infrared (NIR) K -band, VLTI/AMBER observations, and PTI archive data, as well as the mid-infrared (MIR) N -band, VLTI/MIDI observations. The emission from MWC 147 is clearly resolved and has a characteristic physical size of ~1.3 and ~9 AU at 2.2 and 11 μm, respectively (Gaussian diameter). The MIR emission reveals asymmetry consistent with a disk structure seen under intermediate inclination. The spectrally dispersed AMBER and MIDI interferograms both show a strong increase in the characteristic size toward longer wavelengths, much steeper than predicted by analytic disk models assuming power-law radial temperature distributions. We model the interferometric data and the spectral energy distribution of MWC 147 with two-dimensional, frequency-dependent radiation transfer simulations. This analysis shows that models of spherical envelopes or passive irradiated Keplerian disks (with vertical or curved puffed-up inner rim) can easily fit the SED, but predict much lower visibilities than observed; the angular size predicted by such models is 2-4 times larger than the size derived from the interferometric data, so these models can clearly be ruled out. Models of a Keplerian disk with optically thick gas emission from an active gaseous disk (inside the dust sublimation zone), however, yield a good fit of the SED and simultaneously reproduce the absolute level and the spectral dependence of the NIR and MIR visibilities. We conclude that the NIR continuum emission from MWC 147 is dominated by accretion luminosity emerging from an optically thick inner gaseous disk, while the MIR emission also contains contributions from the outer, irradiated dust disk.