The Spectral Energy Distribution of HH 30 IRS: Constraining the Circumstellar Dust Size Distribution

By Kenneth Wood, Michael J. Wolff, J. Bjorkman, B. Whitney. 2001

137 citations recorded by the source corpus.

We present spectral energy distribution (SED) models for the edge-on classical T Tauri star HH 30 IRS that indicate that dust grains have grown to larger than 50 μm within its circumstellar disk. The disk geometry and inclination are known from previous modeling of multiwavelength Hubble Space Telescope images, and we use the SED (0.5 μm ≤ λ ≤ 3 mm) to constrain the dust size distribution. Model spectra are shown for different circumstellar dust models: a standard interstellar medium (ISM) mixture and larger grain models. As compared to ISM grains, the larger dust grain models have a shallower wavelength-dependent opacity: smaller at short wavelengths and larger at long wavelengths. Models with the larger dust grains provide a good match to the observed SED of HH 30 IRS. Although the currently available SED is poorly sampled, we estimate L* ≈ 0.2 L☉, Mdisk ≈ 1.5 × 10-3 M☉, and a power law with exponential cutoff dust grain size distribution. This model provides a good fit to the currently available data, but mid- and far-IR observations are required to more tightly constrain the size distribution. The accretion luminosity in our models is Lacc ≲ 0.2L*, corresponding to an accretion rate Ṁ ≲ 4 × 10-9 M☉ yr-1. Dust size distributions that are simple power-law extensions (i.e., no exponential cutoff) yield acceptable fits to the optical/near-IR but too much emission at millimeter wavelengths, and require larger disk masses up to Mdisk ~ 0.5 M☉. Such a simple size distribution would not be expected in an environment such as the disk of HH 30 IRS (i.e., where coagulation and accretion processes are occurring in addition to grain shattering), particularly over such a large range in grain sizes. Its ability to adequately characterize the grain populations, however, may be determined from more complete observational sampling of the SED in the mid- to far-IR.

Subfields: Astronomy and Astrophysics, Atmospheric Science

View Paper: https://www.semanticscholar.org/paper/58f611ed3953cb0d37737bc59ef8079a18808f2c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Atmospheric Science

Citations in the corpus

Two-dimensional Radiative Transfer in Protostellar Envelopes. I. Effects of Geometry on Class I Sources (2003, methodology): “We include accretion in our disk, following Wood et al. (2002a).”
Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets (2006, methodology): “The solid c© 0000 RAS, MNRAS 000, 000–000 curve is the SED resulting from a dust model with a grain size distribution of n(r) ∝ r−3 with minimum and maximum grain sizes of 0.005µm and 1 mm respectively (see Wood et al. (2002), Table 1 and Figure 3).”
Two-dimensional Radiative Transfer in Protostellar Envelopes. II. An Evolutionary Sequence (2003, methodology): “For the dense regions of the disk (nH2 > 10 8 cm−3), we use the large grain model that Wood et al. (2002a) used to fit the HH30 disk SED.”
DUST FILTRATION BY PLANET-INDUCED GAP EDGES: IMPLICATIONS FOR TRANSITIONAL DISKS (2012, methodology): “We use the standard ISM dust model for the small-dust (Kim et al. 1994), and use Model 3 in Wood et al. (2002) for the largedust (β”
On the formation of Hα line emission around classical T Tauri stars (2006, methodology): “This corresponds to Model 1 of the dust model used by Wood et al. (2002).”
Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A Grid of 200,000 YSO Model SEDs (2006, background): “This is in agreement with the results from Wood et al. (2002a).”