New Herbig-Haro objects and pre-main-sequence stars in the star formation region NGC-7129

Abstract

We present CCD images of the central part of the star forming region NGC 7129 as well as spectra of moderate spectral and high spatial resolution of some nebular objects and stars. The images show many reflection filaments which seem to trace the edges of the molecular cavity associated with the pre-main-sequence star LkHalpha234. Three new T Tauri-like stars and five new Herbig-Haro (HH) objects have been identified in the region. One of the new young stars probably illuminates an elongated reflection filament. One of the HH objects presents a highly collimated structure and an abrupt and unusually large bending of almost-equal-to 90-degrees. The object emanates from the Halpha-emission line star HL 14. Our spectra indicate that this star is likely to be a T Tauri-like star. Large and systematic variations of the radial velocity, electron density, excitation degree and velocity dispersion exist in the object. The data favor the idea that the object is a jet-like outflow which encounters an obstacle - density enhancement or pressure gradient - in the cloud and deflects. The obstacle could be related to the walls of the molecular cavity associated with LkH alpha234 or to the energetic wind from this star.