Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-11-21
Astron.J.131:1574-1607,2006
Astronomy and Astrophysics
Astrophysics
To be published in the March 2006 issue of the Astronomical Journal. Paper consists of 40 pages with 10 figures. Complete set
Scientific paper
10.1086/499808
We present near and mid-infrared photometry obtained with the Spitzer Space Telescope of 300 known members of the IC348 cluster. We merge this photometry with existing ground-based optical and near-infrared photometry in order to construct optical-infrared spectral energy distributions (SEDs) for all the cluster members and present a complete atlas of these SEDs. We employ these observations to both investigate the frequency and nature of the circumstellar disk population in the cluster. The observations are sufficiently sensitive to enable the first detailed measurement of the disk frequency for very low mass stars at the peak of the stellar IMF. Using measurements of infrared excess between 3.6 and 8 microns we find the total frequency of disk-bearing stars in the cluster to be 50 +/- 6%. However, only 30 +/- 4% of the member stars are surrounded by optically thick, primordial disks, while the remaining disk-bearing stars are surrounded by what appear to be optically thin,anemic disks. The disk fraction appears to be a function of spectral type and stellar mass. The disk longevity and thus conditions for planet formation appear to be most favorable for stars which are of comparable mass to the sun. The optically thick disks around later type (> M4) stars appear to be less flared than the disks around earlier type stars. This may indicate a greater degree of dust settling and a more advanced evolutionary state for the late M disk population. Finally we find that the presence of an optically thick dust disk is correlated with gaseous accretion as measured by the strength of Halpha emission. These results suggest that it is more likely for dust disks to persist in the absence of active gaseous accretion than for active accretion to persist in the absence of dusty disks.
Allen Lew
Fazio Giacomo
Hartmann Lee
Lada Charles J.
Luhman Kevin L.
No associations
LandOfFree
Observations of IC348: The Disk Population at 2-3 Million Years does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Observations of IC348: The Disk Population at 2-3 Million Years, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observations of IC348: The Disk Population at 2-3 Million Years will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-383602