Unveiling the Inner Disk Structure of T Tauri Stars

By J. Muzerolle, N. Calvet, L. Hartmann, P. D’Alessio. 2003

200 citations recorded by the source corpus.

We present near-infrared spectra of the excess continuum emission from the innermost regions of classical T Tauri disks. In almost all cases, the shape of the excess is consistent with that of a single-temperature blackbody with T ~ 1400 K, similar to the expected dust sublimation temperature for typical dust compositions. The amount of excess flux roughly correlates with the accretion luminosity in objects with similar stellar properties. We compare our observations with the predictions of simple disk models having an inner rim located at the dust sublimation radius, including irradiation heating of the dust from both the stellar and accretion luminosities. The models yield inner rim radii in the range 0.07-0.54 AU, increasing with higher stellar and accretion luminosities. Using typical parameters that fit our observed sample, we predict a rim radius ~0.2 AU for the T Tauri star DG Tau, which agrees with recent Keck near-infrared interferometric measurements. For large mass accretion rates, the inner rim lies beyond the corotation radius at (or within) which magnetospheric accretion flows are launched, which implies that pure gaseous disks must extend inside the dust rim. Thus, for a significant fraction of young stars, dust cannot exist in the innermost disk, calling into question theories in which solid particles are ejected by a wind originating at the magnetospheric radius.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/29a9ec7597815d406eab55c4066624efe912aa4f

How researchers see this paper

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In Astronomy and Astrophysics

1. K. Luhman
2. S. Andrews
3. L. Hartmann
4. N. Calvet
5. Jonathan P. Williams
6. N. Evans II
7. P. Myers
8. D. Wilner

In Instrumentation

1. S. Andrews
2. Jonathan P. Williams
3. N. Evans II
4. K. Luhman
5. L. Hartmann
6. N. Calvet
7. L. Hillenbrand
8. A. Natta

Citations in the corpus

• High-Resolution Submillimeter Constraints on Circumstellar Disk Structure (2006, methodology): “Long-baseline near-infrared interferometry (Akeson et al. 2005; Eisner et al. 2005) and models of the infrared SED (Muzerolle et al. 2003a) can provide independent estimates of the inner radius and inclination.”
• On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga (2004, background): “The frequency may be even less, as none of the recently identified accreting T Tauri brown dwarfs (e.g., Muzerolle et al. 2003b) are known to power HH flows.”
• Outflows and Jets from Collapsing Magnetized Cloud Cores (2005, background): “Comparison of disk models with observational data show that a typical disk will have an inner rim that extends to ∼ 0.2 AU due to dust sublimation by stellar and accretion heating (Muzerolle et al. 2003).”
• UNVEILING THE STRUCTURE OF PRE-TRANSITIONAL DISKS (2010, background): “This behavior can be explained by an optically thick wall located at the dust sublimation radius, as is seen in full disks (Muzerolle et al. 2003).”
• The shape of the inner rim in proto-planetary disks (2005, methodology): “(1) can be rewritten in terms of the two layer approximation, proposed in CG97, in which the interior of the disk (with τd ≫ 1) is heated to the temperature Ti by half of the stellar flux, while the other half of the stellar flux is reemitted by the superficial layer heated at the optically thin tem”
• The Inner Regions of Protoplanetary Disks (2010, background): “But through a careful subtraction of the stellar spectrum, Muzerolle et al. (2003) show that also T Tauri stars consistently have such a NIR bump, though perhaps weaker in relative sense than the Herbig stars.”
• The Truncated Disk of CoKu Tau/4 (2004, methodology): “…distribution of the wall is calculated using the procedure described by Calvet et al. (1991, hereafter CPMD; 1992), which has been successfully applied to calculate the radial structure of the wall at the dust sublimation radius in disks around Classical T Tauri Stars by Muzerolle et al. (2003).”
• Our astrochemical heritage (2012, background): “[311]; [277]; [414]; [184]), H2 ([36]; [156]), as well as near-infrared lines of CO, H2O, OH ([386]; [77]; [358]) and simple organic molecules ([278]).”
• Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy (2006, background): “This emission excess is well characterized by a single temperature black body with T ∼ 1400 K and has been successfully modelled as arising in a raised dusty rim at the dust sublimation radius in the disk (Muzerolle et al. 2003).”
• A Survey and Analysis of Spitzer Infrared Spectrograph Spectra of T Tauri Stars in Taurus (2006, methodology): “…width of their H emission line (EW[H ]): CTTSs have broad and asymmetric H line profiles, which are generated in the magnetospheric accretion flows (Muzerolle et al. 2003b), resulting in an EW[H ] larger than 10 8, while WTTSs have an EW[H ] of less than 10 8; in WTTSs, strong surface magnetic…”
• Infrared Array Camera (IRAC) Colors of Young Stellar Objects (2004, background): “In addition, the increase in Lacc results in more energy irradiating the wall; as a result, the dust-sublimation radius moves outward, and the wall emitting area increases (Muzerolle et al. 2003).”
• Few Skewed Disks Found in First Closure-Phase Survey of Herbig Ae/Be Stars (2006, background): “Dullemond, Dominik, & Natta (2001, DDN) established the current paradigm for Herbig disks (and by extension, even new T Tauri disk models; Muzerolle et al. 2003).”
• Herbig Ae/Be Stars in nearby OB Associations (2004, background): “…energy distributions (SEDs), which has been attributed to emission from an optically thick ‘‘wall’’ at the dust destruction radius, which is directly heated by the star (Natta et al. 2001; Maheswar et al. 2002; Dullemond et al. 2001; Dullemond & Dominik 2004b; Muzerolle et al. 2004, 2003b).”
• The Spitzer c2d Survey of Weak-Line T Tauri Stars. II. New Constraints on the Timescale for Planet Building (2007, background): “Systems with λturn−off ≤ 2.0 µm show some excess in the near-IR JHK bands and are probably actively accreting (see e.g. Hartmann et al. 2005 and Muzerolle et al. 2003).”
• Bright X-Ray Flares in Orion Young Stars from COUP: Evidence for Star-Disk Magnetic Fields? (2005, background): “As discussed by Muzerolle et al. (2003), for sufficiently large accretion rates, the inner rim lies beyond the corotation radius, so pure gaseous disks must extend inside the dust rim.”
• Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective (2005, background): “2 The inner and outer disk radii are typical values based roughly on the dust sublimation temperature (e.g., Dullemond, Dominik, & Natta 2001; Muzerolle et al. 2003) and direct disk size measurements (e.g., Dutrey et al. 1996; Kitamura et al. 2002; Akeson et al. 2005).”