TY - JOUR
T1 - The Spitzer c2d survey of weak-line T Tauri stars. III. The transition from primordial disks to debris disks
AU - Wahhaj, Zahed
AU - Cieza, Lucas
AU - Koerner, David W.
AU - Stapelfeldt, Karl R.
AU - Padgett, Deborah L.
AU - Case, April
AU - Keller, James R.
AU - Merín, Bruno
AU - Evans, Neal J.
AU - Harvey, Paul
AU - Sargent, Anneila
AU - Van Dishoeck, Ewine F.
AU - Allen, Lori
AU - Blake, Geoff
AU - Brooke, Tim
AU - Chapman, Nicholas
AU - Mundy, Lee
AU - Myers, Philip C.
PY - 2010/12/1
Y1 - 2010/12/1
N2 - We present 3.6 to 70 μm Spitzer photometry of 154 weak-line T Tauri stars (WTTSs) in the Chamaeleon, Lupus, Ophiuchus, and Taurus star formation regions, all of which are within 200 pc of the Sun. For a comparative study, we also include 33 classical T Tauri stars which are located in the same star-forming regions. Spitzer sensitivities allow us to robustly detect the photosphere in the IRAC bands (3.6 to 8 μm) and the 24 μm MIPS band. In the 70 μm MIPS band, we are able to detect dust emission brighter than roughly 40 times the photosphere. These observations represent the most sensitive WTTSs survey in the mid-to far-infrared to date and reveal the frequency of outer disks (r = 3-50 AU) around WTTSs. The 70 μm photometry for half the c2d WTTSs sample (the on-cloud objects), which were not included in the earlier papers in this series, those of Padgett et al. and Cieza et al., are presented here for the first time. We find a disk frequency of 19% for on-cloud WTTSs, but just 5% for off-cloud WTTSs, similar to the value reported in the earlier works. WTTSs exhibit spectral energy distributions that are quite diverse, spanning the range from optically thick to optically thin disks. Most disks become more tenuous than Ldisk/L* = 2 × 10 -3 in 2 Myr and more tenuous than Ldisk/L * = 5 × 10-4 in 4 Myr.
AB - We present 3.6 to 70 μm Spitzer photometry of 154 weak-line T Tauri stars (WTTSs) in the Chamaeleon, Lupus, Ophiuchus, and Taurus star formation regions, all of which are within 200 pc of the Sun. For a comparative study, we also include 33 classical T Tauri stars which are located in the same star-forming regions. Spitzer sensitivities allow us to robustly detect the photosphere in the IRAC bands (3.6 to 8 μm) and the 24 μm MIPS band. In the 70 μm MIPS band, we are able to detect dust emission brighter than roughly 40 times the photosphere. These observations represent the most sensitive WTTSs survey in the mid-to far-infrared to date and reveal the frequency of outer disks (r = 3-50 AU) around WTTSs. The 70 μm photometry for half the c2d WTTSs sample (the on-cloud objects), which were not included in the earlier papers in this series, those of Padgett et al. and Cieza et al., are presented here for the first time. We find a disk frequency of 19% for on-cloud WTTSs, but just 5% for off-cloud WTTSs, similar to the value reported in the earlier works. WTTSs exhibit spectral energy distributions that are quite diverse, spanning the range from optically thick to optically thin disks. Most disks become more tenuous than Ldisk/L* = 2 × 10 -3 in 2 Myr and more tenuous than Ldisk/L * = 5 × 10-4 in 4 Myr.
KW - Infrared: stars
KW - Planetary systems
KW - Protoplanetary disks
KW - Stars: pre-main sequence
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U2 - 10.1088/0004-637X/724/2/835
DO - 10.1088/0004-637X/724/2/835
M3 - Article
AN - SCOPUS:78650081923
VL - 724
SP - 835
EP - 854
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
ER -