Mid-infrared spectroscopy of disks around classical T Tauri stars

被引:103
作者
Forrest, WJ [1 ]
Sargent, B
Furlan, E
D'Alessio, P
Calvet, N
Hartmann, L
Uchida, KI
Green, JD
Watson, DM
Chen, CH
Kemper, F
Keller, LD
Sloan, GC
Herter, TL
Brandl, BR
Houck, JR
Barry, DJ
Hall, P
Morris, PW
Najita, J
Myers, PC
机构
[1] Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA
[2] Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA
[3] Univ Nacl Autonoma Mexico, Ctr Radioastron & Astrofis, Morelia 58089, Michoacan, Mexico
[4] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[5] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
[6] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA
[7] Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA
[8] Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands
[9] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA
[10] Natl Opt Astron Observ, Tucson, AZ 85719 USA
关键词
circumstellar matter; infrared : stars; planetary systems : protoplanetary disks; stars : individual (CoKu Tauri/4); stars : pre-main-sequence; stars : variables : other;
D O I
10.1086/423138
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the first Spitzer Space Telescope Infrared Spectrograph observations of the disks around classical T Tauri stars: spectra in the 5.2-30 mum range of six stars. The spectra are dominated by emission features from amorphous silicate dust, and a continuous component from 5 to 8 mum that in most cases comprises an excess above the photosphere throughout our spectral range. There is considerable variation in the silicate feature/continuum ratio, which implies variations of inclination, disk flaring, and stellar mass accretion rate. In most of our stars, structure in the silicate feature suggests the presence of a crystalline component. In one, CoKu Tau/4, no excess above the photosphere appears at wavelengths shortward of the silicate features, similar to 10 Myr old TW Hya, Hen 3-600, and HR 4796A. This indicates the optically thick inner disk is largely absent. The silicate emission features with peaks at 9.7 and 18 mum indicate small dust grains are present. The extremely low 10-20 mum color temperature of the dust excess, 135 K, indicates these grains are located more than 10 AU from the star. These features are suggestive of gravitational influence by planets or close stellar companions and grain growth in the region within 10 AU of the star, somewhat surprising for a star this young (1 Myr).
引用
收藏
页码:443 / 447
页数:5
相关论文
共 33 条
[1]   SPECTRAL EVOLUTION OF YOUNG STELLAR OBJECTS [J].
ADAMS, FC ;
LADA, CJ ;
SHU, FH .
ASTROPHYSICAL JOURNAL, 1987, 312 (02) :788-806
[2]   ISOCAM-CVF spectroscopy of the circumstellar environment of young stellar objects [J].
Alexander, RD ;
Casali, MM ;
André, P ;
Persi, P ;
Eiroa, C .
ASTRONOMY & ASTROPHYSICS, 2003, 401 (02) :613-624
[3]   Processing of silicate dust grains in Herbig Ae/Be systems [J].
Bouwman, J ;
Meeus, G ;
de Koter, A ;
Hony, S ;
Dominik, C ;
Waters, LBFM .
ASTRONOMY & ASTROPHYSICS, 2001, 375 (03) :950-962
[4]  
CALVET N, 1992, REV MEX ASTRON ASTR, V24, P27
[5]   Spectral energy distributions of T Tauri stars with passive circumstellar disks [J].
Chiang, EI ;
Goldreich, P .
ASTROPHYSICAL JOURNAL, 1997, 490 (01) :368-376
[6]   OBSERVATIONAL STUDIES OF PRE-MAIN-SEQUENCE EVOLUTION [J].
COHEN, M ;
KUHI, LV .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1979, 41 (04) :743-843
[7]   SPECTROPHOTOMETRY AT 10 MICRONS OF T-TAURI STARS [J].
COHEN, M ;
WITTEBORN, FC .
ASTROPHYSICAL JOURNAL, 1985, 294 (01) :345-356
[8]   Accretion disks around young objects. I. The detailed vertical structure [J].
D'Alessio, P ;
Canto, J ;
Calvet, N ;
Lizano, S .
ASTROPHYSICAL JOURNAL, 1998, 500 (01) :411-427
[9]   Accretion disks around young objects.: II.: Tests of well-mixed models with ISM dust [J].
D'Alessio, P ;
Calvet, N ;
Hartmann, L ;
Lizano, S ;
Cantó, J .
ASTROPHYSICAL JOURNAL, 1999, 527 (02) :893-909
[10]   Accretion disks around young objects. III. Grain growth [J].
D'Alessio, P ;
Calvet, N ;
Hartmann, L .
ASTROPHYSICAL JOURNAL, 2001, 553 (01) :321-334