Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Kinematics of Ionized Gas at 0.01 AU of TW Hya   We report two-dimensional spectroastrometry of Br gamma emission of TW Hya to
study the kinematics of the ionized gas in the star-disk interface region. The
spectroastrometry with the integral field spectrograph SINFONI at the Very
Large Telescope is sensitive to the positional offset of the line emission down
to the physical scale of the stellar diameter (~0.01 AU). The centroid of Br
gamma emission is displaced to the north with respect to the central star at
the blue side of the emission line, and to the south at the red side. The major
axis of the centroid motion is P.A.= -20 degrees, which is nearly equal to the
major axis of the protoplanetary disk projected on the sky, previously reported
by CO sub millimeter spectroscopy (P.A.= -27 degrees) The line-of-sight motion
of the Br gamma emission, in which the northern side of the disk is approaching
toward us, is also consistent with the direction of the disk rotation known
from the CO observation. The agreement implies that the kinematics of Br gamma
emission is accounted for by the ionized gas in the inner edge of the disk. A
simple modeling of the astrometry, however, indicates that the accretion inflow
similarly well reproduces the centroid displacements of Br gamma, but only if
the position angles of the centroid motion and the projected disk ellipse is a
chance coincidence. No clear evidence of disk wind is found.

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The categories of this paper are: nucl-th
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: hep-th
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The categories of this paper are: math-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ph