Possible Time Correlation Between Jet Ejection and Mass Accretion for RW Aur A
Abstract
For the active T-Taur star RW Aur A we have performed long-term (~10 yr) monitoring observations of (1) jet imaging in the [Fe II] 1.644-micron emission line using Gemini-NIFS and VLT-SINFONI; (2) optical high-resolution spectroscopy using CFHT-ESPaDOnS; and (3) V-band photometry using the CrAO 1.25-m telescope and AAVSO. The latter two observations confirm the correlation of time variabilities between (A) the Ca II 8542 A and O I 7772 A line profiles associated with magnetospheric accretion, and (B) optical continuum fluxes. The jet images and their proper motions show that four knot ejections occurred at the star over the past ~15 years with an irregular interval of 2-6 years. The time scale and irregularity of these intervals are similar to those of the dimming events seen in the optical photometry data. Our observations show a possible link between remarkable (Delta_V < -1 mag.) photometric rises and jet knot ejections. Observations over another few years may confirm or reject this trend. If confirmed, this would imply that the location of the jet launching region is very close to the star (r <<0.1 au) as predicted by some jet launching models. Such a conclusion would be crucial for understanding disk evolution within a few au of the star, and therefore possible ongoing planet formation at these radii.
Cite
@article{arxiv.2007.15848,
title = {Possible Time Correlation Between Jet Ejection and Mass Accretion for RW Aur A},
author = {Michihiro Takami and Tracy L. Beck and P. Christian Schneider and Hans Moritz Guenther and Marc White and Konstantin Grankin and Jennifer L. Karr and Youichi Ohyama and Deirdre Coffey and Hauyu Baobab Liu and Roberto Galvan-Madrid and Chun-Fan Liu and Misato Fukagawa and Nadine Manset and Wen-Ping Chen and Tae-Soo Pyo and Hsien Shang and Thomas P. Ray and Masaaki Otsuka and Mei-Yin Chou},
journal= {arXiv preprint arXiv:2007.15848},
year = {2020}
}
Comments
14 pages, 5 figures, Accepted by Astrophysical Journal