Context : Star formation in the solar neighborhood is mainly traced by young stars in open clusters , associations and in the field , which can be identified , e.g. , by their X-ray emission .
The determination of stellar parameters for the optical counterparts of X-ray sources is crucial for a full characterization of these stars .

Aims : This work extends the spectroscopic study of the RasTyc sample , obtained by the cross-correlation of the TYCHO and ROSAT All-Sky Survey catalogs , to stars fainter than V = 9.5 mag and it is aimed to the identification of sparse populations of young stars in the solar neighborhood .

Methods : We acquired 625 high-resolution spectra for 443 presumabily young stars with four different instruments in the Northern hemisphere .
The radial and rotational velocity ( v \sin i ) of our targets are measured by means of the cross-correlation technique , which is also helpful to discover single-lined ( SB1 ) , double-lined spectroscopic binaries ( SB2 ) , and multiple systems .
We use the code ROTFIT for performing an MK spectral classification and for determining the atmospheric parameters ( T _ { eff } , \log g , [ Fe/H ] ) and v \sin i of the single stars and SB1 systems .
For these objects , the spectral subtraction of slowly rotating templates is used to measure the equivalent widths of the H \alpha and Li i 6708 Å lines , which enables us to derive their chromospheric activity level and lithium abundance .
We make use of Gaia DR1 parallaxes and proper motions for locating the targets in the HR diagram and for computing the space velocity components of the youngest objects .

Results : We find a remarkable fraction ( at least 35 % ) of binaries and multiple systems .
On the basis of the lithium abundance , the sample of single stars and SB1 systems appears to be mostly ( \sim 60 % ) composed of stars younger than the members of the UMa cluster .
The remaining sources are in the age range between the UMa and Hyades clusters ( \sim 20 % ) or older ( \sim 20 % ) .
In total , we identify 42 very young ( PMS-like ) stars , which lie above or very close to the Pleiades upper envelope of the lithium abundance .
A significant fraction ( \sim 12 % ) of evolved stars ( giants and subgiants ) is also present in our sample .
Some of them ( \sim 36 % ) are also lithium rich ( A ( Li ) > 1.4 ) .

Conclusions :