干旱区生态环境知识资源中心

We present spectre-imaging observations of DG Tau at 0.5’’ resolution obtained with OASIS in [O I]lambda 6300, H alpha, [N II]lambda 6583, and [S II]lambda lambda 6716,6731. The fast jet core appears wiggling and surrounded by a slower moving flow or cavity. Line ratios are compared with available predictions for heating mechanisms in T Tauri jets (shocks, ambipolar diffusion, turbulent mixing-layers). Shocks with speeds 50-100 km s(-1) increasing with how velocity, and preshock densities 10(5)-10(3) cm(-3) decreasing away from the star, are best able to reproduce the high level of excitation for velocities > 100 km s(-1).