KINEMATICS OF IONIZED GAS AT 0.01 AU OF TW Hya

Journal Article · Tue Mar 20 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/748/1/6· OSTI ID:22016201

Goto, M; Linz, H; Henning, Th ^[1]; Carmona, A ^[2]; Stecklum, B ^[3]; Meeus, G ^[4]; Usuda, T ^[5]

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1. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
2. ISDC, Ch. d'Ecogia 16, CH-1290 Versoix (Switzerland)
3. Thueringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg (Germany)
4. Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam (Germany)
5. Subaru Telescope, 650 North A'ohoku Place, Hilo, HI 96720 (United States)

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 ({approx}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 Degree-Sign , which is nearly equal to the major axis of the protoplanetary disk projected on the sky, previously reported by CO submillimeter spectroscopy (P.A. = -27 Degree-Sign ). 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 are a chance coincidence. No clear evidence of disk wind is found.

• OSTI ID: 22016201
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 748; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
CARBON MONOXIDE
COMPUTERIZED SIMULATION
PHOTON EMISSION
PROTOPLANETS
ROTATION
SPECTROSCOPY
STAR EVOLUTION
STARS
STELLAR WINDS
TELESCOPES
TWO-DIMENSIONAL CALCULATIONS