STABLE AND UNSTABLE REGIMES OF MASS ACCRETION ONTO RW AUR A
Por:
Takami, Michihiro, Wei, Yu-Jie, Chou, Mei-Yin, Karr, Jennifer L., Beck, Tracy L., Manset, Nadine, Chen, Wen-Ping, Kurosawa, Ryuichi, Fukagawa, Misato, White, Marc, Galvan-Madrid, Roberto, Liu, Hauyu Baobab, Pyo, Tae-Soo, Donati, Jean-Francois
Publicada:
1 abr 2016
Resumen:
We present monitoring observations of the active T Tauri star RW Aur,
from 2010 October to 2015 January, using optical high-resolution (R >=
10,000) spectroscopy with Canada-France-Hawaii Telescope/ESPaDOnS.
Optical photometry in the literature shows bright, stable fluxes over
most of this period, with lower fluxes (by 2-3 mag) in 2010 and 2014. In
the bright period our spectra show clear photospheric absorption,
complicated variation in the Ca II lambda 8542 emission profile shapes,
and a large variation in redshifted absorption in the O I lambda 7772
and 8446. and He I lambda 5876. lines, suggesting unstable mass
accretion during this period. In contrast, these line profiles are
relatively uniform during the faint periods, suggesting stable mass
accretion. During the faint periods, the photospheric absorption lines
are absent or marginal, and the averaged Li I profile shows redshifted
absorption due to an inflow. We discuss (1) occultation by circumstellar
material or a companion and (2) changes in the activity of mass
accretion to explain the above results, together with near-infrared and
X-ray observations from 2011 to 2015. Neither scenario can simply
explain all the observed trends, and more theoretical work is needed to
further investigate their feasibilities.
Filiaciones:
Takami, Michihiro:
Acad Sinica, Inst Astron & Astrophys, 11F Astron Math Bldg,1,Sec 4,Roosevelt Rd, Taipei 10617, Taiwan
Wei, Yu-Jie:
Acad Sinica, Inst Astron & Astrophys, 11F Astron Math Bldg,1,Sec 4,Roosevelt Rd, Taipei 10617, Taiwan
Chou, Mei-Yin:
Acad Sinica, Inst Astron & Astrophys, 11F Astron Math Bldg,1,Sec 4,Roosevelt Rd, Taipei 10617, Taiwan
Karr, Jennifer L.:
Acad Sinica, Inst Astron & Astrophys, 11F Astron Math Bldg,1,Sec 4,Roosevelt Rd, Taipei 10617, Taiwan
Beck, Tracy L.:
Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA
Manset, Nadine:
Canada France Hawaii Telescope Corp, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743 USA
Chen, Wen-Ping:
Natl Cent Univ, Inst Astron, Chungli 320, Taiwan
Kurosawa, Ryuichi:
Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany
Fukagawa, Misato:
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
White, Marc:
Australian Natl Univ, Res Sch Astron & Astrophys, Cotter Rd, Weston, ACT 2611, Australia
Galvan-Madrid, Roberto:
UNAM, Ctr Radioastron & Astrofis, Apdo Postal 3-72 Xangari, Morelia 58089, Michoacan, Mexico
Liu, Hauyu Baobab:
Acad Sinica, Inst Astron & Astrophys, 11F Astron Math Bldg,1,Sec 4,Roosevelt Rd, Taipei 10617, Taiwan
European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany
Pyo, Tae-Soo:
Subaru Telescope, 650 N Aohoku Pl, Hilo, HI 96720 USA
Donati, Jean-Francois:
UPS Toulouse, CNRS, INSU, IRAP,UMR 5277, F-31400 Toulouse, France
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