A MAGELLAN MIKE AND SPITZER MIPS STUDY OF 1.5-1.0 M{sub sun} STARS IN SCORPIUS-CENTAURUS
- Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)
- Department of Physics and Astronomy, University of Rochester, 500 Wilson Blvd., Rochester, NY 14627 (United States)
- Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
We obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 {mu}m and 70 {mu}m 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 {approx} 50,000 visual spectra at 3500-10500 A 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 {mu}m F+G-type disk fractions of 9/27 (33% {+-} 11%), 21/67 (31% {+-} 7%), and 25/71 (35% {+-} 7%) for Upper Scorpius ({approx}10 Myr), Upper Centaurus Lupus ({approx}15 Myr), and Lower Centaurus Crux ({approx}17 Myr), 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{sub IR}/L{sub *} = 10{sup -5} to 10{sup -2} and grain temperatures ranging from T{sub gr} = 40-300 K. We searched for an increase in 24 {mu}m excess at an age of 15-20 Myr, consistent with the onset of debris production predicted by coagulation N-body simulations of outer planetary systems. We found such an increase around 1.5 M{sub sun} stars but discovered a decrease in the 24 {mu}m excess around 1.0 M{sub sun} stars. We additionally discovered that the 24 {mu}m excess around 1.0 M{sub sun} stars is larger than predicted by self-stirred models. Finally, we found a weak anti-correlation between fractional infrared luminosity (L{sub IR}/L{sub *}) and chromospheric activity (R'{sub HK}), that may be the result of differences in stellar properties, such as mass, luminosity, and/or winds.
- OSTI ID:
- 21584896
- Journal Information:
- Astrophysical Journal, Vol. 738, Issue 2; Other Information: DOI: 10.1088/0004-637X/738/2/122; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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