Possible Time Correlation between Jet Ejection and Mass Accretion for RW Aur A*
M. Takami, Tracy L. Beck, P. C. Schneider, Hans Moritz Günther, Marc White, K. N. Grankin, Jennifer L. Karr, Youichi Ohyama, Deirdre Coffey, Hauyu Baobab Liu, Roberto Galván-Madrid, Chun‐Fan Liu, Misato Fukagawa, N. Manset, Wen-Ping Chen, Tae‐Soo Pyo, Hsien Shang, T. P. Ray, Masaaki Otsuka, Mei-Yin Chou
Abstract
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 μ m 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 Å and O I 7772 Å 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 yr with an irregular interval of 2–6 yr. The timescale 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 (Δ V < −1) 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 astronomical units of the star, and therefore possible ongoing planet formation at these radii.