Spitzer Infrared Spectrograph survey of young stars in the Chamaeleon I star-forming region

Abstract

We present 5 to 36 micron mid-infrared spectra of 82 young stars in the ~2 Myr old Chamaeleon I star-forming region, obtained with the Spitzer Infrared Spectrograph (IRS). We have classified these objects into various evolutionary classes based on their spectral energy distributions and the spectral features seen in the IRS spectra. We have analyzed the mid-IR spectra of Class II objects in Chamaeleon I in detail, in order to study the vertical and radial structure of the protoplanetary disks surrounding these stars. We find evidence for substantial dust settling in most protoplanetary disks in Chamaeleon I. We have identified several disks with altered radial structures in Chamaeleon I, among them transitional disk candidates which have holes or gaps in their disks. Analysis of the silicate emission features in the IRS spectra of Class II objects in Chamaeleon I shows that the dust grains in these disks have undergone significant processing (grain growth and crystallization). However, disks with radial holes/gaps appear to have relatively unprocessed grains. We further find the crystalline dust content in the inner (< 1-2 AU) and the intermediate (< 10 AU) regions of the protoplanetary disks to be tightly correlated. We also investigate the effects of accretion and stellar multiplicity on the disk structure and dust properties. Finally, we compare the observed properties of protoplanetary disks in Cha I with those in slightly younger Taurus and Ophiuchus regions and discuss the effects of disk evolution in the first 1-2 Myr.

arXiv comment80 pages, 32 Figures, Accepted for publication in the Astrophysical Journal Supplement Series

References in corpus (64)

• Disk Frequencies and Lifetimes in Young Clusters
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• The Infrared Spectrograph on the Spitzer Space Telescope
• Interpreting Spectral Energy Distributions from Young Stellar Objects. II. Fitting observed SEDs using a large grid of pre-computed models
• Dust coagulation in protoplanetary disks: a rapid depletion of small grains
• Very Low Mass Stars and Brown Dwarfs in Taurus-Auriga
• ISO spectroscopy of circumstellar dust in 14 Herbig Ae/Be systems: towards an understanding of dust processing
• Spitzer Space Telescope study of disks in the young $\sigma$ Orionis cluster
• Observations of IC348: The Disk Population at 2-3 Million Years
• The SMART Data Analysis Package for the Infrared Spectrograph on the Spitzer Space Telescope
• The effect of dust settling on the appearance of protoplanetary disks
• The Disk Population of the Taurus Star-Forming Region
• Effects of Dust Growth and Settling in T Tauri Disks
• A Survey and Analysis of Spitzer Infrared Spectrograph Spectra of T Tauri Stars in Taurus
• A 10 micron spectroscopic survey of Herbig Ae star disks: grain growth and crystallization
• The Stellar Population of the Chamaeleon I Star-Forming Region
• On the Diversity of the Taurus Transitional Disks: UX Tau A & Lk Ca 15
• Unveiling the Structure of Pre-Transitional Disks
• C2D Spitzer-IRS spectra of disks around T Tauri stars: I. Silicate emission and grain growth
• The Truncated Disk of CoKu Tau/4
• A Spitzer view of protoplanetary disks in the gamma Velorum cluster
• Unveiling the Inner Disk Structure of T Tauri Stars
• Dust dynamics during protoplanetary disc clearing
• A Census of the Chamaeleon I Star-Forming Region
• The Onset of Planet Formation in Brown Dwarf Disks
• Demographics of Transition Objects
• The Disk Around CoKu Tau/4: Circumbinary, not Transitional
• The Disk Population of the Chamaeleon I Star-Forming Region
• The Mid-Infrared Extinction Law in the Ophiuchus, Perseus, and Serpens Molecular Clouds
• The Last Gasp of Gas Giant Planet Formation: A Spitzer Study of the 5 Myr-old Cluster NGC 2362
• Cold Disks: Spitzer Spectroscopy of Disks around Young Stars with Large Gaps
• A Spitzer Census of Transitional Protoplanetary Disks with AU-Scale Inner Holes
• Observational $5-20\mu$m Interstellar Extinction Curves Toward Star-Forming Regions Derived from Spitzer IRS Spectra
• Disk Evolution in the three Nearby Star-Forming Regions of Taurus, Chamaeleon, and Ophiuchus
• Constraints on a planetary origin for the gap in GM Aurigae's protoplanetary disc
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• Inside-Out Evacuation of Transitional Protoplanetary Disks by the Magneto-Rotational Instability
• On the Planet and the Disk of CoKuTau/4
• Probing the Dust and Gas in the Transitional Disk of CS Cha with Spitzer
• Characterizing the nature of embedded young stellar objects through silicate, ice and millimeter observations
• Spitzer IRS Spectra and Envelope Models of Class I Protostars in Taurus
• Evidence for grain growth in T Tauri disks
• Pre-main sequence spectroscopic binaries suitable for VLTI observations
• Dust Processing and Grain Growth in Protoplanetary Disks in the Taurus-Auriga Star-Forming Region
• C2D Spitzer-IRS spectra of disks around T Tauri stars. IV. Crystalline silicates
• The First Discovery of a Wide Binary Brown Dwarf
• The Role of Mass and Environment in Multiple Star Formation: A 2MASS Survey of Wide Multiplicity in Three Young Associations
• The Eta Chamaeleontis Cluster: Origin in the Sco-Cen OB Association
• Confirmation of a gapped primordial disk around LkCa 15
• A Multiplicity Census of Young Stars in Chamaeleon I
• Evolution of Young Brown Dwarf Disks in the Mid-Infrared
• Medium-separation binaries do not affect the first steps of planet formation
• Dust Processing in Disks around T Tauri Stars
• A Near-Infrared Multiplicity Survey of Class I/Flat-Spectrum Systems in Six Nearby Molecular Clouds
• A Spitzer Survey of Protoplanetary Disk Dust in the Young Serpens Cloud: How do Dust Characteristics Evolve with Time?
• Mid-IR spectroscopy of T Tauri stars in Chamealeon I: evidence for processed dust at the earliest stages
• Multiplicity Among Young Brown Dwarfs and Very Low Mass Stars
• Dense and warm molecular gas in the envelopes and outflows of southern low-mass protostars
• The transition disc frequency in M stars
• Wall emission in circumbinary disks: the case of CoKu Tau/4
• Mid-Infrared Observations of Class I/Flat-Spectrum Systems in Six Nearby Molecular Clouds
• Discovery of a New Companion and Evidence of a Circumprimary Disk: Adaptive Optics Imaging of the Young Multiple System VW Cha
• ASTE Submillimeter Observations of a Young Stellar Object Condensation in Cederblad 110
• A sub-AU outwardly truncated accretion disk around a classical T Tauri star

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