A Spectroscopic Survey of the Youngest Field Stars in the Solar Neighborhood. II. The optically faint sample

摘要: Star formation in the solar neighborhood is mainly traced by young stars open clusters, associations and field, which can be identified their X-ray emission. The determination of stellar parameters for counterparts sources crucial study. This work extends spectroscopic study RasTyc sample, based on TYCHO RASS catalogs, to fainter than V=9.5 mag. We acquired 625 high-resolution spectra 443 targets with four different instruments Northern hemisphere. radial rotational velocity (vsini) our are measured means cross-correlation technique, also helpful discover binaries multiple systems. use code ROTFIT determining atmospheric vsini single SB1 For these objects, we equivalent widths H$\alpha$ LiI-6708\AA\ lines, enables us derive chromospheric activity level lithium abundance. make Gaia DR1 parallaxes proper motions locating HR diagram computing space components youngest objects. find a remarkable fraction (>35%) Our sample mostly (60%) composed younger members UMa cluster. identify 42 very stars, lie above or close Pleiades upper envelope A significant (12%) giants/subgiants present sample. Some them rich (A(Li)>1.4).