Letter to the Editor
X-ray accretion signatures in the close CTTS binary V4046 Sagittarii
Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany e-mail: firstname.lastname@example.org
2 Arizona State University, School of Earth and Space Exploration, Tempe, AZ, 85287-1404, USA
Accepted: 26 September 2006
We present Chandra HETGS observations of the classical T Tauri star (CTTS) V4046 Sgr. The He-like triplets of , , and are clearly detected. Similar to the CTTS TW Hya and BP Tau, the forbidden lines of and are weak compared to the intercombination line, indicating high plasma densities in the X-ray emitting regions. The triplet, however, is within the low-density limit, in agreement with the predictions of the accretion funnel infall model with an additional stellar corona. V4046 Sgr is the first close binary exhibiting these features. Together with previous high-resolution X-ray data on TW Hya and BP Tau, and in contrast to T Tau, now three out of four CTTS show evidence of accretion funnels.
Key words: X-rays: stars / stars: individual: V4046 Sagittarii / stars: pre-main sequence / stars: coronae / stars: activity
© ESO, 2006