STABLE and UNSTABLE REGIMES of MASS ACCRETION onto RW AUR A

Michihiro Takami, Yu Jie Wei, Mei Yin Chou, Jennifer L. Karr, Tracy L. Beck, Nadine Manset, Wen Ping Chen, Ryuichi Kurosawa, Misato Fukagawa, Marc White, Roberto Galván-Madrid, Hauyu Baobab Liu, Tae Soo Pyo, Jean Francois Donati

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

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 λ8542 emission profile shapes, and a large variation in redshifted absorption in the O i λλ7772 and 8446 and He i λ5876 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.

Original languageEnglish
Article number139
JournalAstrophysical Journal
Volume820
Issue number2
DOIs
StatePublished - 1 Apr 2016

Keywords

  • accretion, accretion disks
  • line: profiles
  • stars: individual (RW Aur A)
  • stars: pre-main sequence

Fingerprint

Dive into the research topics of 'STABLE and UNSTABLE REGIMES of MASS ACCRETION onto RW AUR A'. Together they form a unique fingerprint.

Cite this