Stellar kinematics in blue compact galaxies

In a programme of observations of local luminous blue compact galaxies (BCGs), we are investigating kinematics by using tracers of both stars and ionized gas. Here we summarise our program and present new data on the local Lyman break galaxy analogue Haro 11. From spatially-resolved spectroscopy around the near-infrared Ca II triplet, we find that its stars and ionized gas have similar velocity fields. Our programme so far indicates however that emission line velocities can differ locally by a few tens of km/s from the Ca II values. Comparing our data to simple stellar population models, we assess which stellar population the Ca II triplet traces and its potential beyond the local universe.

💡 Research Summary

This paper presents a systematic study of the kinematics of both stars and ionised gas in local luminous blue compact galaxies (BCGs), with a focus on the nearby Lyman‑break galaxy analogue Haro 11 (distance ≈ 88 Mpc). The authors aim to compare the dynamical behaviour of the stellar component, traced by the near‑infrared Ca II triplet (λ 8498, 8542, 8662 Å), with that of the ionised gas, traced by