Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Speckle-masking imaging polarimetry of Eta Carinae: evidence for an
  equatorial disk   With our new speckle imaging polarimeter we have obtained first polarimetric
images with sub-arcsecond resolution of the Luminous Blue Variable eta Carinae
in the Halpha line. The polarization patterns at the 3'' scale match well
earlier conventional imaging photometry and can be interpreted as Mie
scattering. In centered long-exposure images we detected in polarized light a
bar in the NE part of the equatorial plane of eta Carinae. High-resolution
0.11'' polarimetric speckle reconstructions reveal a compact structure
elongated in the same direction which is consistent, in degree and position
angle of the polarisation, with the presence of a circumstellar, equatorial
disk. The degree of polarization of the previously discovered speckle objects
and the Halpha arm is relatively low (~10%) and thus may indicate a position
within the equatorial plane. We also discovered a highly polarized (20%-40%)
bipolar structure along the major axis of the Homunculus nebula which can be
traced down to the sub-arcsecond scale. This is probably the inner part of a
bipolar outflow into the Homunculus.

10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg