Photophoretic Structuring of Circumstellar Dust Disks

We study dust accumulation by photophoresis in optically thin gas disks. Using formulae for the photophoretic force that are applicable for the free molecular regime and for the slip-flow regime, we calculate dust accumulation distances as a function of particle size. It is found that photophoresis pushes particles (smaller than 10 cm) outward. For a Sun-like star, these particles are transported to 0.1-100 AU, depending on their size, and form an inner disk. Radiation pressure pushes small particles (1 mm) out further to form an extended outer disk. Consequently, an inner hole opens inside ~0.1 AU. The radius of the inner hole is determined by the condition that the mean free path of the gas molecules equal the maximum size of the particles that photophoresis effectively works on (100 μm-10 cm, depending on the dust properties). The dust disk structure formed by photophoresis can be distinguished from the structure of model gas-free dust disks, because the particle sizes in the outer disk are larger, and the inner hole radius depends on the gas density.

[1]  J. Greaves.  Dense gas discs around T Tauri stars , 2004 .

[2]  J. Greaves,et al.  The absence of CO from the dust peak around ε Eri , 2004 .

[3]  K. Miyake,et al.  Effects of Particle Size Distribution on Opacity Curves of Protoplanetary Disks around T Tauri Stars , 1993 .

[4]  R. Rich,et al.  Stellar Companions and the Age of HD 141569 and Its Circumstellar Disk , 2000, astro-ph/0007170.

[5]  J. R. Brock.  Photophoresis and the Descent of Particles into the Lower Stratosphere G. M. HDY National Centeror Atmospheric Research, Boulder, Colorado , 1967 .

[6]  T. Löhne,et al.  Dust distributions in debris disks: effects of gravity, radiation pressure and collisions , 2006 .

[7]  Andrew Steele,et al.  Comet 81P/Wild 2 Under a Microscope , 2006, Science.

[8]  Yann Alibert,et al.  Astronomy Astrophysics Letter to the Editor Photophoresis as a source of hot minerals in comets , 2022 .

[9]  C. Hayashi,et al.  Settling and growth of dust particles in a laminar phase of a low-mass solar nebula , 1986 .

[10]  Oliver Krauss,et al.  Concentration and sorting of chondrules and CAIs in the late Solar Nebula , 2006 .

[11]  L. Hartmann,et al.  Accretion and the Evolution of T Tauri Disks , 1998 .

[12]  T. Forveille,et al.  Inhibition of giant-planet formation by rapid gas depletion around young stars , 1995, Nature.

[13]  C. Clarke,et al.  Photoevaporation of protoplanetary discs – I. Hydrodynamic models , 2006 .

[14]  S. Ida,et al.  Dust Growth and Settling in Protoplanetary Disks and Disk Spectral Energy Distributions. I. Laminar Disks , 2005, astro-ph/0502287.

[15]  T. G. Cowling,et al.  The mathematical theory of non-uniform gases , 1939 .

[16]  C. Dominik,et al.  Dust coagulation in protoplanetary disks: A rapid depletion of small grains , 2004, astro-ph/0412117.

[17]  Subaru Telescope,et al.  Inner Rim of a Molecular Disk Spatially Resolved in Infrared CO Emission Lines , 2006, astro-ph/0606362.

[18]  Frank H. Shu,et al.  Photoevaporation of Disks around Massive Stars and Application to Ultracompact H II Regions , 1994 .

[19]  R. Knacke,et al.  Detection of Extended Thermal Infrared Emission around the Vega-like Source HD 141569 , 2000, The Astrophysical journal.

[20]  G. Wurm,et al.  Photophoresis and the Pile-up of Dust in Young Circumstellar Disks , 2005 .

[21]  Philip R. Christensen,et al.  Thermal conductivity measurements of particulate materials 1. A review , 1997 .

[22]  Dust Migration and Morphology in Optically Thin Circumstellar Gas Disks , 2000, astro-ph/0012464.

[23]  C. Clarke,et al.  Photoevaporation of protoplanetary discs - II. Evolutionary models and observable properties , 2006 .

[24]  M. Wyatt.  Dust in Resonant Extrasolar Kuiper Belts: Grain Size and Wavelength Dependence of Disk Structure , 2005, astro-ph/0511219.

[25]  V. Mannings,et al.  The Dust and Gas Content of a Disk around the Young Star HR 4796A , 2000 .

[26]  DUST DYNAMICS, SURFACE BRIGHTNESS PROFILES, AND THERMAL SPECTRA OF DEBRIS DISKS: THE CASE OF AU MICROSCOPII , 2005, astro-ph/0510527.

[27]  CO emission from discs around isolated HAeBe and Vega-excess stars , 2005, astro-ph/0502544.

[28]  E. Becklin,et al.  Mid-Infrared Images of the Debris Disk around HD 141569 , 2002 .

[29]  S. A. Beresnev,et al.  Photophoresis of a spherical particle in a rarefied gas , 1993 .

[30]  M. Franx,et al.  A dynamical simulation of the debris disk around HD 141569A , 2005 .

[31]  M. Franx,et al.  Hubble Space Telescope ACS Coronagraphic Imaging of the Circumstellar Disk around HD 141569A , 2003 .

[32]  David R. Alexander,et al.  Low-Temperature Rosseland Opacities , 1975 .

[33]  David R. Alexander,et al.  Low-Temperature Opacities , 2005, astro-ph/0502045.

[34]  J. Cuzzi,et al.  Size-selective Concentration of Chondrules and Other Small Particles in Protoplanetary Nebula Turbulence , 2000, astro-ph/0009210.

[35]  D. Mouillet,et al.  Asymmetries in the HD 141569 circumstellar disk , 2001 .

[36]  C. Clarke,et al.  The dispersal of circumstellar discs: the role of the ultraviolet switch , 2001 .

[37]  D. Mackowski.  Photophoresis of aerosol particles in the free molecular and slip-flow regimes , 1989 .

[38]  Dust in the Photospheric Environment: Unified Cloudy Models of M, L, and T Dwarfs , 2002, astro-ph/0204401.

[39]  C. J. Clarke,et al.  The differential lifetimes of protostellar gas and dust disks , 2005 .

[40]  R. Rosenfeld.  Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[41]  Weinberger,et al.  The Circumstellar Disk of HD 141569 Imaged with NICMOS. , 1999, The Astrophysical journal.

[42]  I. Kamp,et al.  Are Giant Planets Forming around HR 4796A? , 2003 .

[43]  Y. Nakagawa,et al.  Dust Size Growth and Settling in a Protoplanetary Disk , 2006, astro-ph/0601013.

[44]  J. Burns,et al.  Radiation forces on small particles in the solar system , 1979 .

[45]  S. Weidenschilling.  Evolution of Grains in a Turbulent Solar Nebula: a Reappraisal , 1984 .

[46]  Y. Alibert,et al.  The photophoretic sweeping of dust in transient protoplanetary disks , 2012 .