ScoCen debris disks Around F- and G-type stars

We found such an increase around 1.5M_{sun}_ stars but discovered a decrease in the 24 micron excess around 1.0M_{sun}_ stars. We additionally discovered that the 24 micron excess around 1.0M_{sun}_ stars is larger than predicted by self-stirred models. Finally, we found a weak anti-correlation between fractional infrared luminosity (L_IR/L_*) and chromospheric activity (R'_HK), that may be the result of differences in stellar HK properties, such as mass, luminosity, and/or winds.

We obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 micron and 70 micron observations of 182 nearby, Hipparcos F- and G-type common proper motion single and binary systems in the nearest OB association, Scorpius-Centaurus. We also obtained Magellan/MIKE R~50,000 visual spectra at 3500-10500{AA} for 181 candidate ScoCen stars in single and binary systems. Combining our MIPS observations with those of other ScoCen stars in the literature, we estimate 24 micron F+G-type disk fractions of 9/27 (33%+/-11%), 21/67 (31%+/-7%), and 25/71 (35%+/-7%) for Upper Scorpius (~10Myr), Upper Centaurus Lupus (~15Myr), and Lower Centaurus Crux (~17Myr), respectively.

We confirm previous IRAS and MIPS excess detections and present new discoveries of 41 protoplanetary and debris disk systems, with fractional infrared luminosities ranging from L_IR/L_* = 10^-5^ to 10^-2^ and grain temperatures ranging from T_gr_=40-300K. We searched for an increase in 24 micron excess at an age of 15-20Myr, consistent with the onset of debris production predicted by coagulation N-body simulations of outer planetary systems.

We found such an increase around 1.5M_{sun}_ stars but discovered a decrease in the 24 micron excess around 1.0M_{sun}_ stars. We additionally discovered that the 24 micron excess around 1.0M_{sun}_ stars is larger than predicted by self-stirred models.