Consistent Dust and Gas Models for Protoplanetary Disks. III. Models for Selected Objects from the FP7 DIANA Project*

Abstract

The European FP7 project DIANA has performed a coherent analysis of a large set of observational data of protoplanetary disks by means of thermo-chemical disk models. The collected data include extinction-corrected stellar UV and X-ray input spectra (as seen by the disk), photometric fluxes, low and high resolution spectra, interferometric data, emission line fluxes, line velocity profiles and line maps, which probe the dust, polycyclic aromatic hydrocarbons (PAHs) and the gas in these objects. We define and apply a standardized modeling procedure to fit these data by state-of-the-art modeling codes (ProDiMo, MCFOST, MCMax), solving continuum and line radiative transfer (RT), disk chemistry, and the heating and cooling balance for both the gas and the dust. 3D diagnostic RT tools (e.g., FLiTs) are eventually used to predict all available observations from the same disk model, the DIANA-standard model. Our aim is to determine the physical parameters of the disks, such as total gas and dust masses, the dust properties, the disk shape, and the chemical structure in these disks. We allow for up to two radial disk zones to obtain our best-fitting models that have about 20 free parameters. This approach is novel and unique in its completeness and level of consistency. It allows us to break some of the degeneracies arising from pure Spectral Energy Distribution (SED) modeling. In this paper, we present the results from pure SED fitting for 27 objects and from the all inclusive DIANA-standard models for 14 objects. Our analysis shows a number of Herbig Ae and T Tauri stars with very cold and massive outer disks which are situated at least partly in the shadow of a tall and gas-rich inner disk. The disk masses derived are often in excess to previously published values, since these disks are partially optically thick even at millimeter wavelength and so cold that they emit less than in the Rayleigh–Jeans limit. We fit most infrared to millimeter emission line fluxes within a factor better than 3, simultaneously with SED, PAH features and radial brightness profiles extracted from images at various wavelengths. However, some line fluxes may deviate by a larger factor, and sometimes we find puzzling data which the models cannot reproduce. Some of these issues are probably caused by foreground cloud absorption or object variability. Our data collection, the fitted physical disk parameters as well as the full model output are available to the community through an online database (http://www.univie.ac.at/diana).

The First Detection of 13C17O in a Protoplanetary Disk: A Robust Tracer of Disk Gas Mass

“…The HD 163296 disk has been well studied and there are many mass measurements in the literature. In general, our estimate is the highest by a factor of 2 to 6 compared to previous studies using 12 (Woitke et al 2019). The inconsistencies in these mass measurements and g/d from different models may be explained by trying to recover the gas density structure with optically thick lines.…”

Model exploration of near-IR ro-vibrational CO emission as a tracer of inner cavities in protoplanetary disks

“…8 and 9, Fig. 20 and 12 of Woitke et al (2019), and HD135344B, red hexagon, from Carmona et al (2014) in Fig. 3 bottom right).…”

Mass constraints for 15 protoplanetary discs from HD 1–0

“…Fitting of CO and 850 µm continuum emission, observed by ALMA, with a tapered surface density powerlaw yielded γ = 0.9 and R c = 125 au (Tilling et al 2012;de Gregorio-Monsalvo et al 2013). We model HD 163296 with the stellar spectrum from the ProDiMo project (Woitke et al 2019), fixing the shape of the dust surface density profile to the above parameters and varying the gas mass. To satisfy the radial profile of CO 3 -2 emission simultenaously with the spectral energy distribution, we find the density profile flaring index in Eq.…”

“…Most previous estimates of the HD 163296 gas mass relied on low-J emission lines of CO isotopologs, and used a range of modelling approaches from generic model grids to tailored modelling with physical-chemical codes. Those M gas estimates range from 8×10 −3 to 5.8×10 −1 M (Isella et al 2007;Williams & Best 2014;Boneberg et al 2016;Miotello et al 2016;Williams & McPartland 2016;Powell et al 2019;Woitke et al 2019;Booth et al 2019). The mass obtained from the most optically thin isotopolog among these, 13 C 17 O, was 2.1 × 10 −1 M (Booth et al 2019).…”