Browsing by Author "Carpenter, John M."

Now showing 1 - 4 of 4
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    Are debris disks and massive planets correlated?
    (IOP Publishing, 2007) Moro-Martin, Amaya; Carpenter, John M.; Meyer, Michael R.; Hillenbrand, Lynne A.; Malhotra, Renu; Hollenbach, David; Najita, Joan; Henning, Thomas; Kim, Jinyoung S.; Bouwman, Jeroen; Silverstone, Murray D.; Hines, Dean C.; Wolf, Sebastian; Pascucci, Ilaria; Mamajek, Eric E.; Lunine, Jonathan; Princeton University; California Institute of Technology; University of Arizona; National Aeronautics & Space Administration (NASA); NASA Ames Research Center; National Optical Astronomy Observatory; Max Planck Society; Harvard University; Smithsonian Astrophysical Observatory; Smithsonian Institution; University of Alabama Tuscaloosa
    Using data from the Spitzer Space Telescope Legacy Science Program Formation and Evolution of Planetary Systems (FEPS), we have searched for debris disks around nine FGK stars (2-10 Gyr), known from radial velocity ( RV) studies to have one or more massive planets. Only one of the sources, HD 38529, has excess emission above the stellar photosphere; at 70 mu m the signal-to-noise ratio in the excess is 4.7, while at lambda < 30 mu m there is no evidence of excess. The remaining sources show no excesses at any Spitzer wavelengths. Applying survival tests to the FEPS sample and the results for the FGK survey recently published in Bryden et al., we do not find a significant correlation between the frequency and properties of debris disks and the presence of close-in planets. We discuss possible reasons for the lack of a correlation.
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    THE FORMATION AND EVOLUTION OF PLANETARY SYSTEMS: DESCRIPTION OF THE SPITZER LEGACY SCIENCE DATABASE
    (IOP Publishing, 2008-12) Carpenter, John M.; Bouwman, Jeroen; Silverstone, Murray D.; Kim, Jinyoung Serena; Stauffer, John; Cohen, Martin; Hines, Dean C.; Meyer, Michael R.; Crockett, Nathan; California Institute of Technology; Max Planck Society; Eureka Scientific; University of Arizona; University of California System; University of California Berkeley; University of Michigan System; University of Michigan; University of Alabama Tuscaloosa
    We present the science database produced by the Formation and Evolution of Planetary Systems (FEPS) Spitzer Legacy program. Data reduction and validation procedures for the IRAC, MIPS, and IRS instruments are described in detail. We also derive stellar properties for the FEPS sample from available broadband photometry and spectral types, and present an algorithm to normalize Kurucz synthetic spectra to optical and near-infrared photometry. The final FEPS data products include IRAC and MIPS photometry for each star in the FEPS sample and calibrated IRS spectra.
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    FORMATION AND EVOLUTION OF PLANETARY SYSTEMS: PROPERTIES OF DEBRIS DUST AROUND SOLAR-TYPE STARS
    (IOP Publishing, 2009-03-05) Carpenter, John M.; Bouwman, Jeroen; Mamajek, Eric E.; Meyer, Michael R.; Hillenbrand, Lynne A.; Backman, Dana E.; Henning, Thomas; Hines, Dean C.; Hollenbach, David; Kim, Jinyoung Serena; Moro-Martin, Amaya; Pascucci, Ilaria; Silverstone, Murray D.; Stauffer, John R.; Wolf, Sebastian; California Institute of Technology; Max Planck Society; University of Arizona; Princeton University; Eureka Scientific; University of Alabama Tuscaloosa
    We present Spitzer photometric (IRAC and MIPS) and spectroscopic (IRS low resolution) observations for 314 stars in the Formation and Evolution of Planetary Systems Legacy program. These data are used to investigate the properties and evolution of circumstellar dust around solar-type stars spanning ages from approximately 3 Myr-3 Gyr. We identify 46 sources that exhibit excess infrared emission above the stellar photosphere at 24 mu m, and 21 sources with excesses at 70 mu m. Five sources with an infrared excess have characteristics of optically thick primordial disks, while the remaining sources have properties akin to debris systems. The fraction of systems exhibiting a 24 mu m excess greater than 10.2% above the photosphere is 15% for ages < 300 Myr and declines to 2.7% for older ages. The upper envelope to the 70 mu m fractional luminosity appears to decline over a similar age range. The characteristic temperature of the debris inferred from the IRS spectra range between 60 and 180 K, with evidence for the presence of cooler dust to account for the strength of the 70 mu m excess emission. No strong correlation is found between dust temperature and stellar age. Comparison of the observational data with disk models containing a power-law distribution of silicate grains suggests that the typical inner-disk radius is greater than or similar to 10 AU. Although the interpretation is not unique, the lack of excess emission shortward of 16 mu m and the relatively flat distribution of the 24 mu m excess for ages less than or similar to 300 Myr is consistent with steady-state collisional models.
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    The moth: an unusual circumstellar structure associated with HD 61005
    (IOP Publishing, 2007-11-21) Hines, Dean C.; Schneider, Glenn; Hollenbach, David; Mamajek, Eric E.; Hillenbrand, Lynne A.; Metchev, Stanimir A.; Meyer, Michael R.; Carpenter, John M.; Moro-Martin, Amaya; Silverstone, Murray D.; Kim, Jinyoung Serena; Henning, Thomas; Bouwman, Jeroen; Wolf, Sebastian; University of Arizona; National Aeronautics & Space Administration (NASA); NASA Ames Research Center; Harvard University; Smithsonian Astrophysical Observatory; Smithsonian Institution; California Institute of Technology; University of California System; University of California Los Angeles; Princeton University; Eureka Scientific; Max Planck Society; University of Alabama Tuscaloosa
    We present the discovery of an unusual spatially resolved circumstellar structure associated with the approximate to 90 Myr, nearby, G dwarf star HD 61005. Observations from the FEPS Spitzer Legacy Science survey reveal thermal emission in excess of expected stellar photospheric levels. Follow-up 0.1 '' resolution HST NICMOS coronagraphic images reveal scattered starlight <= 7 '' (similar to 240 AU) from the occulted star (1.1 mu m flux density = 18 +/- 3.3 mJy; and 0.77%+/- 0.16% starlight). The extremely high near-IR scattering fraction and IR excess luminosity f=L-IR/L-* approximate to 2x10(-3) suggests scattering particle sizes of order a <= 1.1 mu m/2 pi similar to 0.2 mu m comparable to the blowout size (a approximate to 0.3 mu m) due to radiation a pressure from the star. Dust-scattered starlight is traced inward to an instrumental limit of similar to 10 AU. The structure exhibits a strong asymmetry about its morphological major axis but is mirror-symmetric about its minor axis.