Keck/NIRC2 Imaging of the Warped, Asymmetric Debris Disk around HD 32297
Abstract
We present Keck/NIRC2 Ks -band high-contrast coronagraphic imaging of the luminous debris disk around the nearby, young A star HD 32297 resolved at a projected separation of r = 0".3-2".5 (≈35-280 AU). The disk is highly warped to the north and exhibits a complex, "wavy" surface brightness (SB) profile interior to r ≈ 110 AU, where the peaks/plateaus in the profiles are shifted between the NE and SW disk lobes. The SW side of the disk is 50%-100% brighter at r = 35-80 AU, and the location of its peak brightness roughly coincides with the disk's millimeter (mm) emission peak. Spectral energy distribution modeling suggests that HD 32297 has at least two dust populations that may originate from two separate belts, likely at different locations, possibly at distances coinciding with the SB peaks. A disk model for a single dust belt including a phase function with two components and a 5-10 AU pericenter offset explains the disk's warped structure and reproduces some of the SB profile's shape (e.g., the overall "wavy" profile, the SB peak/plateau shifts) but more poorly reproduces the disk's brightness asymmetry and the profile at wider separations (r > 110 AU). Although there may be alternate explanations, agreement between the SW disk brightness peak and disk's peak mm emission is consistent with an overdensity of very small, sub-blowout-sized dust and large, 0.1-1 mm sized grains at ≈45 AU tracing the same parent population of planetesimals. New near-IR and submillimeter observations may be able to clarify whether even more complex grain scattering properties or dynamical sculpting by an unseen planet are required to explain HD 32297's disk structure.
Additional Information
© 2012 American Astronomical Society. Received 2012 May 5; accepted 2012 July 17; published 2012 August 31. We thank Richard Walters and Gregory Wirth for valuable help in setting up these observations, which were conducted remotely from the California Institute of Technology, and to Randy Campbell for indispensable NIRC2 support in helping the observer (T.C.) conduct his observations efficiently. Karl Stapelfeldt, Scott Kenyon, and Margaret Moerchen provided very useful discussions and the anonymous referee provided helpful comments. T.C. is supported by a NASA Postdoctoral Fellowship. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. We acknowledge the significant cultural role and reverence that the Mauna Kea summit has always had within the indigenous Hawaiian community. We are grateful to be able to conduct observations from this mountain. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.Attached Files
Published - 0004-637X_757_1_28.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:97a000b56d23265bbbb7f33eb858d39a
|
1.5 MB | Preview Download |
Additional details
- Eprint ID
- 35215
- Resolver ID
- CaltechAUTHORS:20121031-140234956
- NASA Postdoctoral Fellowship
- W. M. Keck Foundation
- NASA/JPL/Caltech
- Created
-
2012-10-31Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)