Ardila, D. R. and Golimowski, D. A. and Krist, J. E. and Clampin, M. and Ford, H. C. and Illingworth, G. D. (2007) Hubble space telescope advanced camera for surveys coronagraphic observations of the dust surrounding HD 100546. Astrophysical Journal, 665 (1). pp. 512-534. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20090407-140011086
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We present HST ACS coronagraphic observations of HD 100546, a B9.5 star, 103 pc away from the Sun, taken in the F435W, F606W, and F814W bands. Scattered light is detected up to 14" from the star. The observations are consistent with the presence of an extended flattened nebula with the same inclination as the inner disk. The well-known "spiral arms" are clearly observed and trail the rotating disk material. Weaker arms never before reported are also seen. The interarm space becomes brighter, but the structures become more neutral in color at longer wavelengths, which is not consistent with models that assume that they are due to the effects of a warped disk. Along the major disk axis, the colors of the scattered light relative to the star are Δ(F435W - F606W) ≈ 0.0-0.2 mag and Δ(F435W - F814W) ≈ 0.5-1 mag. To explain these colors, we explore the role of asymmetric scattering, reddening, and large minimum sizes on ISM-like grains. We conclude that each of these hypotheses by itself cannot explain the colors. The disk colors are similar to those derived for Kuiper Belt objects, suggesting that the same processes responsible for their colors may be at work here. We argue that we are observing only the geometrically thick, optically thin envelope of the disk, while the optically thick disk responsible for the far-IR emission is undetected. The observed spiral arms are then structures on this envelope. The colors indicate that the extended nebulosity is not a remnant of the infalling envelope but reprocessed disk material.
|Additional Information:||© 2007 American Astronomical Society. Print publication: Issue 1 (2007 August 10) Received 2006 July 7, accepted for publication 2007 April 11. The authors wish to thank Mario Van den Ancker and Dejan Vinković for their willingness to provide guidance regarding our interpretations of their work. Richard White was kind enough to provide us with the results of his PSF simulations in advance of publication, as well as extensive guidance on the use of the Lucy-Richardson algorithm. Dale Cruikshank was kind enough to illuminate the intricacies of KBO colors for us. Karl Stapefeldt provided advice in frequent discussions on the astrophysics of HD100546. ACS was developed under NASA contract NAS5-32865, 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. We are also grateful to K. Anderson, J.McCann, S. Busching, A. Framarini, and T. Allen for their invaluable contributions to the ACS project at JHU. This research has made use of the Catalog of Resolved Circumstellar Disks, NASA’s Astrophysics Data System Bibliographic Services, and the SIMBAD and Vizier databases, operated at CDS, Strasbourg, France.|
|Subject Keywords:||circumstellar matter; planetary systems: protoplanetary disks; stars: imaging; stars: individual (HD 100546); stars: pre-main sequence|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||15 Jul 2009 23:40|
|Last Modified:||26 Dec 2012 10:56|
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