DETECTION OF STRONG MILLIMETER EMISSION FROM THE CIRCUMSTELLAR DUST DISK AROUND V1094 SCO: COLD AND MASSIVE DISK AROUND A T TAURI STAR IN A QUIESCENT ACCRETION PHASE?

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/726/1/45· OSTI ID:21567696

Tsukagoshi, Takashi; Kohno, Kotaro ^[1]; Saito, Masao ^[2]; Kitamura, Yoshimi; Ikeda, Norio; Kamegai, Kazuhisa ^[3]; Momose, Munetake ^[4]; Shimajiri, Yoshito; Ezawa, Hajime; Kawabe, Ryohei ^[5]; Hiramatsu, Masaaki ^[6]; Wilson, Grant; Yun, Min S; Scott, Kimberly; Perera, Thushara ^[7]; Austermann, Jason ^[8]; Hughes, David; Aretxaga, Itziar ^[9]; Mauskopf, Philip ^[10]

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1. Institute of Astronomy, Faculty of Science, University of Tokyo, Osawa 2-21-1, Mitaka, Tokyo 181-0015 (Japan)
2. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)
3. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yoshinodai 3-1-1, Sagamihara, Kanagawa 229-8510 (Japan)
4. Institute of Astrophysics and Planetary Sciences, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan)
5. Nobeyama Radio Observatory, Nobeyama 462-2, Minamimaki, Minamisaku, Nagano 384-1305 (Japan)
6. Academia Sinica Institute for Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China)
7. Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)
8. Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States)
9. Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro 1, Tonantzintla, Puebla (Mexico)
10. Department of Physics and Astronomy, Cardiff University, Cardiff CF24 3YB, Wales (United Kingdom)

We present the discovery of a cold massive dust disk around the T Tauri star V1094 Sco in the Lupus molecular cloud from the 1.1 mm continuum observations with AzTEC on ASTE. A compact (r{approx}< 320 AU) continuum emission coincides with the stellar position having a flux density of 272 mJy, which is the largest among T Tauri stars in Lupus. We also present the detection of molecular gas associated with the star in the five-point observations in {sup 12}CO J = 3-2 and {sup 13}CO J = 3-2. Since our {sup 12}CO and {sup 13}CO observations did not show any signature of a large-scale outflow or a massive envelope, the compact dust emission is likely to come from a disk around the star. The observed spectral energy distribution (SED) of V1094 Sco shows no distinct turnover from near-infrared to millimeter wavelengths, can be well described by a flattened disk for the dust component, and no clear dip feature around 10 {mu}m suggestive of the absence of an inner hole in the disk. We fit a simple power-law disk model to the observed SED. The estimated disk mass ranges from 0.03 M{sub sun} to {approx}>0.12 M{sub sun}, which is one or two orders of magnitude larger than the median disk mass of T Tauri stars in Taurus. The resultant temperature is lower than that of a flared disk with well-mixed dust in hydrostatic equilibrium and is probably attributed to the flattened disk geometry for the dust which the central star cannot illuminate efficiently. From these results, together with the fact that there is no signature of an inner hole in the SED, we suggest that the dust grains in the disk around V1094 Sco sank into the midplane with grain growth by coalescence and are in the evolutional stage just prior to or at the formation of planetesimals.

• OSTI ID: 21567696
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 726; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BINARY STARS
CLOUDS
DETECTION
DUSTS
EMISSION
ENERGY SPECTRA
ERUPTIVE VARIABLE STARS
EVOLUTION
GRAIN GROWTH
SPECTRA
STAR EVOLUTION
STARS
T TAURI STARS
VARIABLE STARS