Geysers in the Lagoon: new Herbig-Haro objects in M8

Abstract

Aims: We search for direct evidence of ongoing star formation by accretion in the Lagoon Nebula (M8), using optical wide-field narrow-band imaging obtained at La Silla Observatory. Methods: We examine [SII] and Halpha images for line-emission features that could be interpreted as signatures of outflow activity of the exciting sources. Results: We discover five new Herbig-Haro objects, study in detail their morphology and attempt to identify their potential driving sources among the population of T Tauri stars and embedded sources in the surroundings. Conclusions: The results reported here conclusively demonstrate the existence of very young stars going through the accreting phase in the M8 region.