Mapping Accretion In Intermediate Mass Stars

In earlier type Herbig Ae/Be stars the accretion mechanisms are not yet well understood because their magnetic fields are too weak to sustain magnetospheric accretion. These are the first steps in my study of time variability of accretion-related lines in young intermediate-mass stars, using the STAR-MELT code, combined with long- and short-cadence spectroscopic data. The targets chosen for study are promising sources as they have well-known protoplanetary discs, and evidence of extinction by circumstellar material. Emission and absorption lines with broad and narrow components, including metallic ones, are detected in these stars in a similar way to what is found in their lower-mass counterparts, and the STAR- MELT Python code assists in quantifying any variability found. By measuring the variability in velocity and relative intensity for different lines we aim to trace the structure of accretion columns and distinguish between different accretion mechanisms as they evolve over time.