Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Adaptive Optics Imaging of the AU Microscopii Circumstellar Disk:
  Evidence for Dynamical Evolution   We present an H-band image of the light scattered from circumstellar dust
around the nearby (10 pc) young M star AU Microscopii (AU Mic, GJ 803, HD
197481), obtained with the Keck adaptive optics system. We resolve the disk
both vertically and radially, tracing it over 17-60 AU from the star. Our AU
Mic observations thus offer the possibility to probe at high spatial resolution
(0.04" or 0.4 AU per resolution element) for morphological signatures of the
debris disk on Solar-System scales. Various sub-structures (dust clumps and
gaps) in the AU Mic disk may point to the existence of orbiting planets. No
planets are seen in our H-band image down to a limiting mass of 1 M_Jup at >20
AU, although the existence of smaller planets can not be excluded from the
current data. Modeling of the disk surface brightness distribution at H-band
and R-band, in conjunction with the optical to sub-millimeter spectral energy
distribution, allows us to constrain the disk geometry and the dust grain
properties. We confirm the nearly edge-on orientation of the disk inferred from
previous observations, and deduce an inner clearing radius <=10 AU. We find
evidence for a lack of small grains in the inner (<60 AU) disk, either as a
result of primordial disk evolution, or because of destruction by
Poynting-Robertson and/or corpuscular drag. A change in the power-law index of
the surface brightness profile is observed near 33 AU, similar to a feature
known in the profile of the beta Pic circumstellar debris disk. By comparing
the time scales for inter-particle collisions and Poynting-Robertson drag
between the two systems, we argue that the breaks are linked to one of these
two processes.

36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs