Silicate Emission in the TW Hydrae Association

Abstract

The TW Hydrae Association is the nearest young stellar association. Among its members are HD 98800, HR 4796A, and TW Hydrae itself, the nearest known classical T Tauri star. We have observed these three stars spectroscopically between 3 and 13 microns. In TW Hya the spectrum shows a silicate emission feature that is similar to many other young stars with protostellar disks. The 11.2 micron feature indicative of significant amounts of crystalline olivine is not as strong as in some young stars and solar system comets. In HR 4796A, the thermal emission in the silicate feature is very weak, suggesting little in the way of (small silicate) grains near the star. The silicate band of HD 98800 (observed by us but also reported by Sylvester and Skinner (1996)) is intermediate in strength between TW Hya and HR 4796.

22 pages, 11 figures, LaTeX2e and AAS LaTeX macros v5.0. Accepted for publication in AJ

References in corpus (5)

• Discovery of seven T Tauri stars and a brown dwarf candidate in the nearby TW Hydrae Association
• NICMOS Imaging of the HR 4796A Circumstellar Disk
• Silicate Emission in T Tauri Stars: Evidence for Disk Atmospheres?
• A Single Circumbinary Disk in the HD 98800 Quadruple System
• NICMOS Narrow-band Infrared Photometry of TW Hya Association Stars

Cited by in corpus (19)

• Evidence for a developing gap in a 10 Myr old protoplanetary disk
• The Truncated Disk of CoKu Tau/4
• The FUV spectrum of TW Hya. I. Observations of H${}_2$ Fluorescence
• An Inner Hole in the Disk around TW Hydrae Resolved in 7 Millimeter Dust Emission
• Infrared Views of the TW Hya Disk
• A New Probe of the Planet-Forming Region in T Tauri Disks
• High spatial resolution mid-infrared observations of the low-mass young star TW Hya
• C2D Spitzer-IRS spectra of disks around T Tauri stars. IV. Crystalline silicates
• The state of protoplanetary material 10 Myr after stellar formation: circumstellar disks in the TW Hydrae association
• 8--13 um spectroscopy of YSOs: Evolution of the silicate feature
• Detection of crystalline silicates around the T Tauri star Hen 3-600A
• Spatially Resolving the Inner Disk of TW Hya
• The Formation and Evolution of Planetary Systems (FEPS): Discovery of an Unusual Debris System Associated with HD 12039
• Modeling the Infrared Emission from the HR 4796A Disk
• X-ray Diagnostics of Grain Depletion in Matter Accreting onto T Tauri Stars
• Radial Distribution of Dust Grains Around HR 4796A
• 3 - 14 Micron Spectroscopy of Comets C/2002 O4 (Honig), C/2002 V1 (NEAT), C/2002 X5 (Kudo-Fujikawa), C/2002 Y1 (Juels-Holvorcem), 69P/Taylor, and the Relationships among Grain Temperature, Silicate Band Strength and Structure among Comet Families
• Time-Variable Accretion in the TW Hya Star/Disk System
• New Spatially Resolved Mid-IR Observations of the Transitional Disk TW Hya and Tentative Evidence for a Self-Luminous Companion