X-shooter observations of low-mass stars in the η Chamaeleontis association^⋆

¹ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
e-mail: rugel@mpia.de
² INAF–Osservatorio Astrofisico di Arcetri, L.go E. Fermi 5, 50125 Firenze, Italy
³ Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Haidian Qu, 100871 Beijing, PR China

Received: 22 November 2016
Accepted: 7 September 2017

Abstract

The nearby η Chamaeleontis association is a collection of 4–10 Myr old stars with a disk fraction of 35–45%. In this study, the broad wavelength coverage of VLT/X-shooter is used to measure the stellar and mass accretion properties of 15 low-mass stars in the η Chamaeleontis association. For each star, the observed spectrum is fitted with a non-accreting stellar template and an accretion spectrum obtained from assuming a plane-parallel hydrogen slab. Five of the eight stars with an IR disk excess show excess UV emission, indicating ongoing accretion. The accretion rates measured here are similar to those obtained from previous measurements of excess UV emission, but tend to be higher than past measurements from Hα modeling. The mass accretion rates are consistent with those of other young star forming regions.