Mid-IR spectroscopy of T Tauri stars in Chamealeon I: evidence for processed dust at the earliest stages

Abstract

We present mid-IR spectroscopy of three T Tauri stars in the young Chamealeon I dark cloud obtained with TIMMI2 on the ESO 3.6m telescope. In these three stars, the silicate emission band at 9.7 micron is prominent. We model it with a mixture of amorphous olivine grains of different size, crystalline silicates and silica. The fractional mass of these various components change widely from star to star. While the spectrum of CR Cha is dominated by small amorphous silicates, in VW Cha (and in a lesser degree in Glass I), there is clear evidence of a large amount of processed dust in the form of crystalline silicates and large amorphous grains. This is the first time that processed dust has been detetected in very young T Tauri stars (~ 1 Myr).

5 pages, 4 Postscript figures. accepted for A&A Letters

References in corpus (4)

• Infrared Views of the TW Hya Disk
• A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales
• Detection of crystalline silicates around the T Tauri star Hen 3-600A
• Discovery of a New Companion and Evidence of a Circumprimary Disk: Adaptive Optics Imaging of the Young Multiple System VW Cha

Cited by in corpus (40)

• Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective
• Dust coagulation in protoplanetary disks: a rapid depletion of small grains
• The effect of dust settling on the appearance of protoplanetary disks
• A 10 micron spectroscopic survey of Herbig Ae star disks: grain growth and crystallization
• Dust coagulation in protoplanetary disks: porosity matters
• The Onset of Planet Formation in Brown Dwarf Disks
• Dust Growth and Settling in Protoplanetary Disks and Disk Spectral Energy Distributions. I. Laminar Disks
• Disk Evolution in the three Nearby Star-Forming Regions of Taurus, Chamaeleon, and Ophiuchus
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• Mid-Infrared Spectroscopy of Disks around Classical T Tauri Stars
• Evolution of brown dwarf disks: A Spitzer survey in Upper Scorpius
• Evolution of Young Brown Dwarf Disks in the Mid-Infrared
• 8--13 um spectroscopy of YSOs: Evolution of the silicate feature
• Dust distribution in protoplanetary disks - Vertical settling and radial migration
• Observations of Solids in Protoplanetary Disks
• Growth and migration of solids in evolving protostellar disks I: Methods and Analytical tests
• Medium-separation binaries do not affect the first steps of planet formation
• Silicate Dust in Evolved Protoplanetary Disks: Growth, Sedimentation, and Accretion
• Large dust grains in the inner region of circumstellar disks
• Spitzer Infrared Spectrograph survey of young stars in the Chamaeleon I star-forming region
• Large grains in disks around young stars: ATCA observations of WW Cha, RU Lup, and CS Cha
• XMM-Newton X-ray spectroscopy of classical T Tauri stars
• Grain growth and dust settling in a brown dwarf disk: Gemini/T-ReCS observations of CFHT-BD-Tau 4
• Structural and compositional properties of brown dwarf disks: the case of 2MASS J04442713+2512164
• The 10 $\mu$m infrared band of silicate dust: A laboratory study comparing the aerosol and KBr pellet techniques
• Analysis of the dust evolution in the circumstellar disks of TTauri stars
• Grain growth across protoplanetary discs: 10-micron silicate feature versus millimetre slope
• Crystalline Silicate Feature of the Vega-like star HD145263
• Dust properties and disk structure of evolved protoplanetary disks in Cep OB2: Grain growth, settling, gas and dust mass, and inside-out evolution
• Do we really know the dust? Systematics and uncertainties of the mid-infrared spectral analysis methods
• Dust amorphization in protoplanetary disks
• Variations of the 10 um Silicate Features in the Actively Accreting T Tauri Stars: DG Tau and XZ Tau
• Crystalline Silicate Emission in the Protostellar Binary Serpens--SVS20
• Interstellar Silicate Dust in the z=0.89 Absorber Towards PKS 1830-211: Crystalline Silicates at High Redshift?
• A mid-infrared study of very low mass stars and brown dwarfs in Upper Scorpius
• Mid-infrared observations of young stellar objects in the vicinity of sigma Orionis
• Mid-IR observations of circumstellar disks -- Part III: A mixed sample of PMS stars and Vega-type objects
• Spitzer Spectroscopy of the Circumprimary Disk in the Binary Brown Dwarf 2MASS J04414489+2301513
• Accretion Burst Crystallizes Silicates in a Planet-Forming Disk
• The Curious Case of Glass I: High Ionization and Variability of Different Types