Planet Formation in AB Aurigae: Imaging of the Inner Gaseous Spirals Observed inside the Dust Cavity

Journal Article · Mon May 01 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA6AF7· OSTI ID:22663653

Tang, Ya-Wen; Gu, Pin-Gao; Ho, Paul T. P. ^[1]; Guilloteau, Stephane; Dutrey, Anne; Chapillon, Edwige; Folco, Emmanuel di ^[2]; Muto, Takayuki ^[3]; Shen, Bo-Ting ^[4]; Inutsuka, Shu-ichiro ^[5]; Momose, Munetake ^[6]; Pietu, Vincent ^[7]; Fukagawa, Misato ^[8]; Corder, Stuartt ^[9]; Ohashi, Nagayoshi ^[10]; Hashimoto, Jun ^[11]

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1. Academia Sinica, Institute of Astronomy and Astrophysics, Taipei, Taiwan (China)
2. Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, alle Geoffroy Saint-Hilaire, F-33615 Pessac (France)
3. Department of Physics, National Taiwan University, Taiwan (China)
4. Division of Liberal Arts, Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan)
5. Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
6. College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan)
7. IRAM, 300 rue de la Piscine, Domaine Universitaire, F-38406 Saint-Martin-d’Hères (France)
8. Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)
9. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
10. Subaru Telescope, National Astronomical Observatory of Japan, 650 North Aohoku Place, Hilo, HI 96720 (United States)
11. Astrobiology Center of NINS 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan)

We report the results of ALMA observations of a protoplanetary disk surrounding the Herbig Ae star AB Aurigae. We obtained high-resolution (0.″1; 14 au) images in {sup 12}CO J = 2 − 1 emission and in the dust continuum at the wavelength of 1.3 mm. The continuum emission is detected at the center and at the ring with a radius ( r ) of ∼120 au. The CO emission is dominated by two prominent spirals within the dust ring. These spirals are trailing and appear to be about 4 times brighter than their surrounding medium. Their kinematics is consistent with Keplerian rotation at an inclination of 23°. The apparent two-arm-spiral pattern is best explained by tidal disturbances created by an unseen companion located at r of 60–80 au, with dust confined in the pressure bumps created outside this companion orbit. An additional companion at r of 30 au, coinciding with the peak CO brightness and a large pitch angle of the spiral, would help to explain the overall emptiness of the cavity. Alternative mechanisms to excite the spirals are discussed. The origin of the large pitch angle detected here remains puzzling.

• OSTI ID: 22663653
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 840; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BIOMEDICAL RADIOGRAPHY
BRIGHTNESS
CARBON 12
CARBON MONOXIDE
DISTURBANCES
DUSTS
EMISSION
ORBITS
PLANETS
PROTOPLANETS
RESOLUTION
ROTATION
STARS
WAVELENGTHS