Carbon-rich stars of population II , such as CH stars , can provide direct information on the role of low to intermediate-mass stars of the halo on the early Galactic evolution .
Thus an accurate knowledge of CH stellar population is a critical requirement for building up scenarios for early Galactic chemical evolution .
In the present work we report on several CH stars identified in a sample of Faint High Latitude Carbon stars from Hamburg survey and discuss their medium resolution spectra covering a wavelength range 4000 - 6800 Å .
Estimation of the depths of bands ( 1,0 ) ^ { 12 } C ^ { 12 } C { \lambda } 4737 and ( 1,0 ) ^ { 12 } C ^ { 13 } C { \lambda } 4744 in these stars indicate isotopic ratio ^ { 12 } C/ ^ { 13 } C { \sim } 3 , except for a few exceptions ; these ratios are consistent with existing theories of CH stars evolution .
The stars of Hamburg survey , a total of 403 objects were reported to be carbon star candidates with strong C _ { 2 } and CN molecular bands .
In the first phase of observation , we have acquired spectra of ninety one objects .
Inspection of the objects spectra show fifty one objects with C _ { 2 } molecular bands in their spectra of which thirteen stars have low flux below about 4300 Å .
Twenty five objects show weak or moderate CH and CN bands , twelve objects show weak but detectable CH bands in their spectra and there are three objects which do not show any molecular bands due to C _ { 2 } , CN or CH in their spectra .
Objects with C _ { 2 } molecular bands and with good signals bluewards of 4300 Å which show prominent CH bands in their spectra are potential candidate CH stars .
Thirty five such candidates are found in the present sample of ninty one objects observed so far .
The set of CH stars identified could be the targets of subsequent observation at high resolution for a detail and comprehensive analysis for understanding their role in early Galactic chemical evolution .