DoAr 33: a good candidate for revealing dust growth and settling in protoplanetary disks

Liu, Y.; Madlener, David; Wolf, S.; Wang, H.; Ruge, Jan Philipp

doi:10.1051/0004-6361/201219336

Cited by 15 publications

(25 citation statements)

References 60 publications

(76 reference statements)

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“…For the star and disk parameters, we use a model which has been applied to explain various spatially-resolved multi-band observations of protostellar disks (Wolf et al 2003Schegerer et al 2008Schegerer et al , 2009Sauter et al 2009;Madlener et al 2012;Liu et al 2012;Gräfe et al 2013). The model uses parameters of a typical T Tauri system.…”

Section: Initial Conditionsmentioning

confidence: 99%

Radiation Hydrodynamical Turbulence in Protoplanetary Disks: Numerical Models and Observational Constraints

Flock

Nelson

Turner

et al. 2017

ApJ

143

152

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Planets are born in protostellar disks, which are now observed with enough resolution to address questions about internal gas flows. Candidates for driving the flows include magnetic forces, but ionization state estimates suggest much of the gas mass decouples from magnetic fields. Thus, hydrodynamical instabilities could play a major role. We investigate disk dynamics under conditions typical for a T Tauri system, using global 3D radiation hydrodynamics simulations with embedded particles and a resolution of 70 cells per scale height. Stellar irradiation heating is included with realistic dust opacities. The disk starts in joint radiative balance and hydrostatic equilibrium. The vertical shear instability (VSI) develops into turbulence that persists up to at least 1600 inner orbits (143 outer orbits). Turbulent speeds are a few percent of the local sound speed at the midplane, increasing to 20%, or 100 m/s, in the corona. These are consistent with recent upper limits on turbulent speeds from optically thin and thick molecular line observations of TW Hya and HD 163296. The predominantly vertical motions induced by the VSI efficiently lift particles upwards. Grains 0.1 and 1 mm in size achieve scale heights greater than expected in isotropic turbulence. We conclude that while kinematic constraints from molecular line emission do not directly discriminate between magnetic and nonmagnetic disk models, the small dust scale heights measured in HL Tau and HD 163296 favor turbulent magnetic models, which reach lower ratios of the vertical kinetic energy density to the accretion stress.

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Section: Initial Conditionsmentioning

confidence: 99%

Radiation Hydrodynamical Turbulence in Protoplanetary Disks: Numerical Models and Observational Constraints

Flock

Nelson

Turner

et al. 2017

ApJ

143

152

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“…A way to improve the prediction is to modify the underlying dust distribution. In particular a spatial variation of the particle size, caused by dust settling and segregation of large dust particles, has a strong influence on the local chromaticity and thus on scattered and reemitted radiation from the disk (e. g., Pinte et al 2008;Liu et al 2012;Gräfe et al 2013). Figure 9 shows the calculated temperature in the disk's midplane for the best-fit model.…”

Section: Simulated Maps and Radial Profilesmentioning

confidence: 99%

The circumstellar disc of FS Tau B – a self-consistent model based on observations in the mid-infrared withNACO

Kirchschlager¹,

Wolf²,

Madlener³

2016

Mon. Not. R. Astron. Soc.

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Protoplanetary disks are a byproduct of the star formation process. In the dense mid-plane of these disks, planetesimals and planets are expected to form. The first step in planet formation is the growth of dust particles from submicrometer-sized grains to macroscopic mm-sized aggregates. The grain growth is accompanied by radial drift and vertical segregation of the particles within the disk. To understand this essential evolutionary step, spatially resolved multi-wavelength observations as well as photometric data are necessary which reflect the properties of both disk and dust. We present the first spatially resolved image obtained with NACO at the VLT in the L p band of the near edge-on protoplanetary disk FS Tau B. Based on this new image, a previously published Hubble image in H band and the spectral energy distribution from optical to millimeter wavelengths, we derive constraints on the spatial dust distribution and the progress of grain growth. For this purpose we perform a disk modeling using the radiative transfer code MC3D. Radial drift and vertical sedimentation of the dust are not considered. We find a best-fit model which features a disk extending from 2 AU to several hundreds AU with a moderately decreasing surface density and M disk = 2.8 × 10 −2 M . The inclination amounts to i = 80• . Our findings indicate that substantial dust grain growth has taken place and that grains of a size equal to or larger than 1 mm are present in the disk. In conclusion, the parameters describing the vertical density distribution are better constrained than those describing the radial disk structure.

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“…If CEN 34 is an evolved star the circumstellar envelope is a more plausible assumption than a circumstellar disk (Fujii et al 2002). We used the simulated annealing approach described in Liu et al (2012) to model the observed SED and to estimate the mass of circumstellar material. We explored the scenario of a spherical envelope that is commonly adopted to mimic the dust shell surrounding a post-AGB star.…”

Section: Extinction and Luminositymentioning

confidence: 99%

CEN 34 – high-mass YSO in M 17 or background post-AGB star?

Chen

Nürnberger

Chini

et al. 2013

A&A

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We investigate the proposed high-mass young stellar object (YSO) candidate CEN 34, thought to be associated with the star-forming region M 17. Its optical to near-infrared (550−2500 nm) spectrum reveals several photospheric absorption features, such as Hα, the Ca ii triplet, and the CO bandhead, but lacks emission lines. The spectral features in the range 8375−8770 Å are used to constrain an effective temperature T eff = 5250 ± 250 K (early-/mid-G) and a log g = 2.0 ± 0.3 (supergiant). The spectral energy distribution (SED) displays a faint infrared excess that resembles that of a high-mass YSO or an evolved star of intermediate mass. Moreover, the observed temperature and surface gravity are identical for high-mass YSOs and evolved stars. The radial velocity of CEN 34 relative to the local standard of rest (V LSR ) as obtained from various photospheric lines is of the order of −60 km s −1 and thus distinct from the +25 km s −1 found for several OB stars in the cluster and for the associated molecular cloud. The SED modeling yields ∼10 −4 M of circumstellar material, which contributes only a tiny fraction to the total visual extinction (11 mag). The distance of CEN 34 is between 2.0 kpc and 4.5 kpc. In the case of a YSO, a dynamical ejection process is proposed to explain the V LSR difference between CEN 34 and M 17. Additionally, to match the temperature and luminosity, we speculate that CEN 34 had accumulated the bulk of its mass with an accretion rate >4 × 10 −3 M /yr over a very short time span (∼10 3 yrs), and it is currently undergoing a phase of gravitational contraction without any further mass gain. However, all the aforementioned characteristics of CEN 34 are compatible with an evolved star of 5−7 M and an age of 50−100 Myr, so it is most likely a background post-AGB star with a distance between 2.0 kpc and 4.5 kpc. We consider the latter classification as the more likely interpretation. Further discrimination of the two possible scenarios should come from the stricter confinement of CEN 34's distance.

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DoAr 33: a good candidate for revealing dust growth and settling in protoplanetary disks

Cited by 15 publications

References 60 publications

Radiation Hydrodynamical Turbulence in Protoplanetary Disks: Numerical Models and Observational Constraints

Radiation Hydrodynamical Turbulence in Protoplanetary Disks: Numerical Models and Observational Constraints

The circumstellar disc of FS Tau B – a self-consistent model based on observations in the mid-infrared withNACO

CEN 34 – high-mass YSO in M 17 or background post-AGB star?

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