Is the silicate emission feature only influenced by grain size?

Abstract

The flattening of the 10mu silicate emission feature observed in the spectra of T Tauri and Herbig Ae/Be stars is usually interpreted as an indicator of grain growth. We show in this paper that a similar behaviour of the feature shape occurs when the porosity of composite grains varies. The fluffy aggregates, having inclusions of different sizes, were modeled by multi-layered spheres consisting of amorphous carbon, amorphous silicate and vacuum. It is also found that the inclusion of crystalline silicates in composite porous particles can lead to a shift of the known resonances and production of new ones.

accepted by Astronomy & Astrophysics Letters; small revision after referee report

References in corpus (9)

• The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• Dust coagulation in protoplanetary disks: porosity matters
• The formation and evolution of planetary systems: Grain growth and chemical processing of dust in T Tauri systems
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• Modeling Porous Dust Grains with Ballistic Aggregates I: Geometry and Optical Properties
• The evolution of stars in the Taurus-Auriga T association
• Dust Processing in Disks around T Tauri Stars
• Silicate Dust in Evolved Protoplanetary Disks: Growth, Sedimentation, and Accretion
• Analysis of the dust evolution in the circumstellar disks of TTauri stars

Cited by in corpus (26)

• Probing dust grain evolution in IM Lupi's circumstellar disc. Multi-wavelength observations and modelling of the dust disc
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• Giants in the globular cluster omega Centauri: dust production, mass loss and distance
• Very Low-Mass Objects in the Coronet Cluster: The Realm of the Transition Disks
• Transient dust in warm debris disks - Detection of Fe-rich olivine grains
• Large grains in disks around young stars: ATCA observations of WW Cha, RU Lup, and CS Cha
• The Composition of Dust in Jupiter-Family Comets as Inferred from Infrared Spectroscopy
• Rusty old stars: a source of the missing interstellar iron?
• Disordered Silicates in Space: a Study of Laboratory Spectra of "Amorphous" Silicates
• Multi-wavelength modeling of the spatially resolved debris disk of HD 107146
• Sculpting the disk around T Cha: an interferometric view
• Radiation pressure mixing of large dust grains in protoplanetary disks
• Effect of dust grain porosity on the appearance of protoplanetary disks
• Spitzer observations of a gravitationally lensed quasar, QSO 2237+0305
• Is there more than meets the eye? Presence and role of submicron grains in debris discs
• On the Carriers of the 21 Micron Emission Feature in Post-Asymptotic Giant Branch Stars
• Shadows, gaps, and ring-like structures in protoplanetary disks
• Interstellar dust along the line of sight of GX 3+1
• On the Anomalous Silicate Emission Features of AGNs: A Possible Interpretation Based on Porous Dust
• Novalike Cataclysmic Variables in the Infrared
• Optical properties of cosmic dust analogs: A review
• ISM Dust Grains and N-band Spectral Variability in the Spatially Resolved Subarcsecond Binary UY Aur
• Infrared Emission from the Composite Grains: Effects of Inclusions and Porosities on the 10 and 18 $\mu m$ Features
• Dust mass in protoplanetary disks with porous dust opacities
• Composite Circumstellar Dust Grains
• Global Spectral Energy Distributions of the Large Magellanic Cloud with Interstellar Dust