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D.R. Ardila, D.A. Golimowski (Johns Hopkins University), J.E. Krist (STScI / JPL), M. Clampin (NASA Goddard Space Flight Center), J.P. Williams (University of Hawaii), J.P. Blakeslee, H.C. Ford (Johns Hopkins University), G.F. Hartig (STScI), G.D. Illingworth (University of California, Santa Cruz)
We present resolved scattered-light images of the debris disk around HD 107146, a G2 star 28.5 pc from the Sun. We observed it with the HST/ACS coronagraph, using the F606W (broad V) and F814W (broad I) filters. Outside 2", the disk looks featureless except for a northeast-southwest brightness asymmetry that we attribute to forward scattering. The disk has scattered-light fractional luminosities of (LSca/L*)F606W=6.8 ±0.8 10-5 and (LSca/L*)F814W=10 ±1 10-5 and it is detected up to 6.5'' away from the star. To map the surface density of the disk, we deproject it by 25 ±5 degrees, divide by the dust scattering phase (gF606W = 0.3 ±0.1, gF814W = 0.2 ±0.1) and correct for the geometric dilution of starlight. Within the errors, the surface density appears to be a broad (85 AU) ring with most of the opacity concentrated at 130 AU. The ratio of the relative luminosity in F814W to that in F606W has the constant value of 1.3±.3, with the error dominated by uncertainties in the value of g in each filter. The colors and the derived values of g are consistent with the presence of dust particles as small as the radiation pressure limit. The dust generated by the creation of a small planet or the scattering and circularization of a large one, are possible scenarios that may explain the shape of the surface density profile.
ACS was developed under NASA contract NAS 5-32865, and this research has been supported by NASA grant NAG5-7697. We are grateful for an equipment grant from Sun Microsystems, Inc. The Space Telescope Science Institute is operated by AURA, Inc., under NASA contract NAS5-26555.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.