STRUCTURE AND EVOLUTION OF PRE-MAIN-SEQUENCE CIRCUMSTELLAR DISKS

By Andrea Isella, J. Carpenter, A. Sargent. 2009

223 citations recorded by the source corpus.

We present new subarcsecond (∼0.″7) Combined Array for Research in Millimeter-wave Astronomy (CARMA) observations of the 1.3 mm continuum emission from circumstellar disks around 11 low- and intermediate-mass pre-main-sequence stars. High-resolution observations for three additional sources were obtained from the literature. In all cases the disk emission is spatially resolved. We adopt a self-consistent accretion disk model based on the similarity solution for the disk surface density and constrain the dust radial density distribution on spatial scales of about 40 AU. Disk surface densities appear to be correlated with the stellar ages where the characteristic disk radius increases from ∼20 AU to ∼100 AU over about 5 Myr. This disk expansion is accompanied by a decrease in the mass accretion rate, suggesting that our sample disks form an evolutionary sequence. Interpreting our results in terms of the temporal evolution of a viscous α-disk, we estimate (1) that at the beginning of the disk evolution about 60% of the circumstellar material was located inside radii of 25–40 AU, (2) that disks formed with masses from 0.05 to 0.4 M☉, and (3) that the viscous timescale at the disk initial radius is about 0.1–0.3 Myr. Viscous disk models tightly link the surface density Σ(R) with the radial profile of the disk viscosity ν(R) ∝ Rγ. We find values of γ ranging from −0.8 to 0.8, suggesting that the viscosity dependence on the orbital radius can be very different in the observed disks. Adopting the α parameterization for the viscosity, we argue that α must decrease with the orbital radius and that it may vary between 0.5 and 10−4. From the inferred disk initial radii we derive specific angular momenta, j, for parent cores of (0.8 − 4) × 10−4 km s−1 pc. Comparison with the values of j in dense cores suggests that about 10% of core angular momentum and 30% of the core mass are conserved in the formation of the star/disk system. We demonstrate that the similarity solution for the surface density for γ < 0 can explain the properties of some “transitional disks” without requiring discontinuities in the disk surface density. In the case of LkCa 15, a smooth distribution of material from few stellar radii to about 240 AU can produce both the observed spectral energy distribution and the spatially resolved continuum emission at millimeter wavelengths. Finally we show that among the observed sample, TW Hya is the only object that has a disk radius comparable with the early solar nebula.

Subfields: Astronomy and Astrophysics, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/62bca1acfaedfe75475c0768e35fe380a74e5bcc

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In Astronomy and Astrophysics

1. S. Andrews
2. D. Wilner
3. T. Birnstiel
4. Anders Johansen
5. C. Dullemond
6. Jonathan P. Williams
7. A. Hughes
8. C. Qi

In Spectroscopy

1. D. Wilner
2. S. Andrews
3. T. Birnstiel
4. A. Hughes
5. C. Dullemond
6. Jonathan P. Williams
7. C. Qi
8. Anders Johansen

Citations in the corpus

• REVEALING A UNIVERSAL PLANET–METALLICITY CORRELATION FOR PLANETS OF DIFFERENT SIZES AROUND SOLAR-TYPE STARS (2013, background): “Observations of transition disks demonstrate that the central region of the circumstellar disk clears before the outer regions (e.g., Isella et al. 2009), and imaging surveys of the brightest disks in the nearby Ophiuchus star forming region demonstrate that central clearings are very common in…”
• CHARACTERIZING THE COOL KOIs. IV. KEPLER-32 AS A PROTOTYPE FOR THE FORMATION OF COMPACT PLANETARY SYSTEMS THROUGHOUT THE GALAXY (2012, methodology): “…constrain the surface density profile in Kepler 32b the outer disk (& 40AU) to be on average shallower than this, γ ≈ 0.4–1.0 (Andrews & Williams 2007; Isella et al. 2009; Andrews et al. 2009), while the form of the surface density profile in the inner disk remains largely unconstrained.”
• Observational Signatures of Planets in Protoplanetary Disks I: Gaps Opened by Single and Multiple Young Planets in Disks (2014, background): “…Submillimeter Array (e.g. Brown et al. 2009; Andrews et al. 2009, 2010, 2011), the Combined Array for Research in Millimeter-wave Astronomy (e.g. Isella et al. 2009, 2010; Ricci et al. 2013), the Plateau de Bure Interferometer (e.g. Piétu et al. 2006; Guilloteau et al. 2011), and the newly…”
• The Birth Environment of the Solar System (2010, background): “For example, one study finds that disks in the Rho Ophiuchus star forming region have surface densities of the approximate form Σ ∼ r−p exp[−r/r0], where the scale r0 = 20 – 200 AU (Andrews et al. 2009; see also Isella et al. 2009).”
• Trapping dust particles in the outer regions of protoplanetary disks (2011, unknown): “…& Sargent (1991); Wilner et al. (2000, 2005); Testi et al. (2001, 2003); Andrews & Williams (2005); Rodmann et al. (2006); Natta et al. (2007); Isella et al. (2009); Lommen et al. (2009); Ricci et al. (2010a, 2011); Guilloteau et al. (2011)) that suggests a mechanism operating that prevents…”
• RESOLVED IMAGES OF LARGE CAVITIES IN PROTOPLANETARY TRANSITION DISKS (2011, background): “…on viscous evolution, based on tracking the decline of accretion rates with age (e.g., Sicilia-Aguilar et al. 2010) and characterizing disk sizes and surface density profiles with resolved millimeter observations (Kitamura et al. 2002; Andrews et al. 2009, 2010b; Isella et al. 2009, 2010a).”
• CONSTRAINTS ON THE RADIAL VARIATION OF GRAIN GROWTH IN THE AS 209 CIRCUMSTELLAR DISK (2012, methodology): “The χ2 probability distribution is sampled by varying the free parameters, generating a model state and comparing this state to the data in Fourier space, following the Markov Chain Monte Carlo (MCMC) method described in Isella et al. (2009).”
• THE MASS DEPENDENCE BETWEEN PROTOPLANETARY DISKS AND THEIR STELLAR HOSTS (2013, unknown): “– 36 – 2005, 2007b; Rodmann et al. 2006; Cabrit et al. 2006; Bouy et al. 2008; Hughes et al. 2008, 2009; Schaefer et al. 2009; Isella et al. 2009, 2010, 2012; Hamidouche 2010; Öberg et al. 2010; Ricci et al. 2010, 2012, 2013; Andrews et al. 2011; Phan-Bao et al. 2011; Sandell et al. 2011; Cieza et…”
• A STEEPER THAN LINEAR DISK MASS–STELLAR MASS SCALING RELATION (2016, background): “Previous work has pointed out that dust disk radii correlate positively with millimeter fluxes for TTauri stars (Isella et al. 2009; Andrews et al. 2010; Guilloteau et al. 2011), but the scatter is large and what is really needed is to demonstrate a correlation with stellar mass.”
• Multiwavelength analysis for interferometric (sub-)mm observations of protoplanetary disks - Radial constraints on the dust properties and the disk structure (2015, methodology): “The amax(R) radial profiles derived for the three disks tend towards similar values amax(R) ' 2 cm in the innermost spatially resolved region 10 AU R 20 AU, but display apparent differences in the slope with AS 209, FT Tau, and DR Tau showing respectively an increasing steepness.”
• THE TW Hya DISK AT 870 μm: COMPARISON OF CO AND DUST RADIAL STRUCTURES (2011, background): “Some recent studies have made progress in extracting the radial (surface) density profiles in these disks from high angular resolution measurements of their millimeterwave continuum emission (Andrews et al. 2009, 2010b; Isella et al. 2009; Guilloteau et al. 2011).”
• A dual-frequency sub-arcsecond study of proto-planetary disks at mm wavelengths: first evidence for radial variations of the dust properties (2011, methodology): “In the strict framework of a viscous disk model, we find values of γ that are somewhat larger (and with higher dispersion) than those derived in the previous studies by Isella et al. (2009) and Andrews et al. (2009).”
• Dust Evolution and the Formation of Planetesimals (2016, methodology): “The profile has been widely used to reproduce the resolved images of the dust emission or the CO rotational line emission of disks (Andrews et al. 2009; Isella et al. 2009; Andrews et al. 2011, 2012).”
• The Disk Substructures at High Angular Resolution Project (DSHARP). I. Motivation, Sample, Calibration, and Overview (2018, background): “…framework that takes a set of measured disk properties (e.g., the spatial distribution of densities and temperatures; Andrews et al. 2009, 2010; Isella et al. 2009, 2010) and predicts the key characteristics of the exoplanet population (e.g., masses, orbital architectures, atmosphere…”
• PROTOPLANETARY DISK STRUCTURES IN OPHIUCHUS. II. EXTENSION TO FAINTER SOURCES (2010, methodology): “Isella et al. (2009) claim a significant correlation between their parameterization of Rc and stellar age in a sample of Taurus disks.”
• EMPIRICAL CONSTRAINTS ON TURBULENCE IN PROTOPLANETARY ACCRETION DISKS (2010, background): “…well-studied using spatially-resolved observations at millimeter wavelengths, so that excellent models of the temperature and density structure of the gas and dust disks are already available (Calvet et al. 2002; Isella et al. 2007, 2009; Hughes et al. 2008; Qi et al. 2004, 2006, 2008).”
• Forming the cores of giant planets from the radial pebble flux in protoplanetary discs (2014, background): “Such large radii are not inconsistent with those inferred from protoplanetary discs (Isella et al. 2009; Williams & Cieza 2011) and debris discs (Wyatt 2008).”
• A millimeter Continuum Size–Luminosity Relationship for Protoplanetary Disks (2017, background): “…relationship is nearly perpendicular to the direction expected for viscously evolving disks that conserve angular momentum, and because of that they speculated that it may point to the underlying spread in the specific angular momenta in molecular cloud cores (see also Isella et al. 2009).”
• Dust properties of protoplanetary disks in the Taurus-Auriga star forming region from millimeter wavelengths (2009, methodology): “I09: Isella et al. (2009). spectral index < β > between unmapped and resolved disks (see discussion below).”