TY - JOUR
T1 - Disk evolution in ob associations
T2 - Deep Spitzer/IRAC observations of IC 1795
AU - Roccatagliata, Veronica
AU - Bouwman, Jeroen
AU - Henning, Thomas
AU - Gennaro, Mario
AU - Feigelson, Eric
AU - Kim, Jinyoung Serena
AU - Sicilia-Aguilar, Aurora
AU - Lawson, Warrick A.
PY - 2011/6/1
Y1 - 2011/6/1
N2 - We present a deep Spitzer/Infrared Array Camera (IRAC) survey of the OB association IC 1795 carried out to investigate the evolution of protoplanetary disks in regions of massive star formation. Combining Spitzer/IRAC data with Chandra/Advanced CCD Imaging Spectrometer observations, we find 289 cluster members. An additional 340 sources with an infrared excess, but without X-ray counterpart, are classified as cluster member candidates. Both surveys are complete down to stellar masses of about 1 M⊙. We present pre-main-sequence isochrones computed for the first time in the Spitzer/IRAC colors. The age of the cluster, determined via the location of the Class III sources in the [3.6]-[4.5]/[3.6] color-magnitude diagram, is in the range of 3-5Myr. As theoretically expected, we do not find any systematic variation in the spatial distribution of disks within 0.6 pc of either O-type star in the association. However, the disk fraction in IC 1795 does depend on the stellar mass: sources with masses >2 M⊙ have a disk fraction of ∼ 20%, while lower mass objects (2-0.8 M⊙) have a disk fraction of ∼ 50%. This implies that disks around massive stars have a shorter dissipation timescale.
AB - We present a deep Spitzer/Infrared Array Camera (IRAC) survey of the OB association IC 1795 carried out to investigate the evolution of protoplanetary disks in regions of massive star formation. Combining Spitzer/IRAC data with Chandra/Advanced CCD Imaging Spectrometer observations, we find 289 cluster members. An additional 340 sources with an infrared excess, but without X-ray counterpart, are classified as cluster member candidates. Both surveys are complete down to stellar masses of about 1 M⊙. We present pre-main-sequence isochrones computed for the first time in the Spitzer/IRAC colors. The age of the cluster, determined via the location of the Class III sources in the [3.6]-[4.5]/[3.6] color-magnitude diagram, is in the range of 3-5Myr. As theoretically expected, we do not find any systematic variation in the spatial distribution of disks within 0.6 pc of either O-type star in the association. However, the disk fraction in IC 1795 does depend on the stellar mass: sources with masses >2 M⊙ have a disk fraction of ∼ 20%, while lower mass objects (2-0.8 M⊙) have a disk fraction of ∼ 50%. This implies that disks around massive stars have a shorter dissipation timescale.
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U2 - 10.1088/0004-637X/733/2/113
DO - 10.1088/0004-637X/733/2/113
M3 - Article
AN - SCOPUS:79956348916
SN - 0004-637X
VL - 733
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 113
ER -