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arXiv · 1103.5770

Disk Evolution in OB Associations - Deep Spitzer/IRAC Observations of IC 1795

Veronica Roccatagliata·Jeroen Bouwman·Thomas Henning·Mario Gennaro·Eric Feigelson·Jinyoung Serena Kim·Aurora Sicilia-Aguilar·Warrick A. Lawson
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Abstract

We present a deep Spitzer/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/ACIS 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 Msun. 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 - 5 Myr. 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 Msun have a disk fraction of ~20%, while lower mass objects (2-0.8 Msun) have a disk fraction of ~50%. This implies that disks around massive stars have a shorter dissipation timescale.

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Veronica Roccatagliata, Jeroen Bouwman, Thomas Henning, Mario Gennaro, Eric Feigelson, Jinyoung Serena Kim, Aurora Sicilia-Aguilar, Warrick A. Lawson. 2011-03-29. Disk Evolution in OB Associations - Deep Spitzer/IRAC Observations of IC 1795. https://doi.org/10.1088/0004-637x%2F733%2F2%2F113

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